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NEW EDITION, 1895

A TREATISE

PHYSIOLOGY AND HYGIENE

FOR EDUCATIONAL INSTITUTIONS
AND GENERAL READERS

jhtllg Ellustratrti

JOSEPH C. HUTCHISON, M.D., LL.D.

EX-PRESIDENT OF THE NEW YORK PATHOLOGICAL SOCIETY, EX VICE-PRESIDENT OF

THE NEW YORK ACADEMY OF MEDICINE, SURGEON TO THE BROOKLYN

CITY HOSPITAL, LATE PRESIDENT OF THE MEDICAL SOCIETY

OF THE STATE OF NEW YORK, ETC., ETC.

NEW YORK

MAYNARD, MERRILL, & CO.

43, 45, and 47 East Tenth Street

1895

J Anon'

SEP 2 4 1946

A COMPLETE COURSE

IN

PHYSIOLOGY AND HYGIENE.

BY

JOSEPH C. HUTCHISON, M.D., LL.D.,

Ex-President of the New York Pathological Society; late Vice-President of the

New York Academy of Medicine ; late Surgeon to the Brooklyn

City Hospital ; late President of the Medical Society

of the State of New 1 'ork.

NEW SERIES.

Our Wonderful Bodies and How to Take Care of Them. First Book.
128 pages.

Our Wonderful Bodies and How to Take Care of Them. Second Book.
222 pages.

Physiology and Hygiene. A Work for High Schools and Academies.
371 pages, i2mo, Cloth.

Each book in the course complies with the laws requiring instruction in the
physiological effects of alcohol and narcotics.

CoPVRtGHl 1895, BY MAYNARD, MERRILL, & Co.

Press Ot W'ALBIUDUE & COMPANY,

17-27 Vandewater Street,
New York.

TO MY WIFE

WHOSE SYMPATHY HAS, FOR MORE THAN TWENTY YEARS>
LIGHTENED THE CARES INCIDENT TO

AN ACTIVE PROFESSIONAL LIFE

THIS HUMBLE VOLUME

IS AFFECTIONATELY INSCRIBED.

PUBLISHERS' NOTE

Revised Edition, 1895

The sales of this work have in the last few years become so large that
it has been found necessary to make new electrotype plates. The pub-
lishers have taken advantage of this to have the book carefully examined
with a view to discovering whether or no it conformed in every respect
to the latest advances in knowledge of the subject. Very few changes
in the text have been found necessary, and these few are of such a minor
character as not in any way to prevent the use of the new and old
editions in the same class.

The main changes to be noted in this edition are as follows : Topical
Outlines have been added at the end of chapters, which it is believed will
be of great value to pupils and teachers. In some of them additional
information has been given, which it has not been thought best to include
in the text, but which may be found useful for the teacher in his class
work.

Such slight changes have been made in the text as were necessary to
meet the requirements of the laws of the several states with respect to
the influence of alcohol and narcotics. The book will be found to comply
fully with all such laws and with the intelligent temperance sentiment of
the country.

A chapter on emergencies has also been added, which, it is hoped, will
give the book a permanent value in the home and be of service to the
many "first aid to the injured" classes that are being formed in all parts
of the country.

A number of new illustrations have been scattered through the book.
The only other change of any prominence is in the experiments, which in
the former edition have been in the appendix, but are now transferred to
the body of the book as footnotes, where they will be more accessible as
an aid to the teacher in more interestingly presenting the subject to the
class. All the experiments, as well as the anatomical demonstrations,
are simple, and the teacher will have no difficulty in reproducing them.
Should there be failure at first, a little patience and a few trials will soon
be followed by success. All complex dissections on recently killed
animals, as well as all vivisections upon frogs, etc., have purposely been
omitted, not only because they are unnecessary in teaching the rudiments
of anatomy and physiology, but also because they would create disgust
and abhortfencte in the majority of pupils.
4

PREFACE

This work is designed to present the leading facts and
principles of human physiology and hygiene in clear and
concise language, so that pupils in schools and colleges, and
readers not familiar with the subjects, may readily compre-
hend them. Anatomy, or a description of the structure of
an organ, is of course necessary to the understanding of its
physiology, or its uses. Enough of the former study has,
therefore, been introduced to enable the pupil to enter intel-
ligently upon the latter.

Familiar language, as far as practicable, has been em-
ployed, rather than that of a technical character. With a
view, however, to supply what might seem to some a defi-
ciency in this regard, a Pronouncing Glossary has been added,
which will enable the inquirer to understand the meaning
of many scientific terms not in common use.

In the preparation of the work the writer has carefully
examined all the best material at his command, and freely
used it; the special object being to have it abreast of the
present knowledge on the subjects treated, as far as that is
possible in a work so elementary as this. The discussion of
disputed points has been avoided, it being manifestly inap-
propriate in a work of this kind.

The aim of a text-book on physiology for schools and col-
leges should be to present in the simplest and clearest pos-
sible manner the well-established facts of the subject to be
taught, so that the students may obtain an intelligent idea of
the workings and uses of the human body. It should be
5

6 PREFACE

scientific enough to be clear and logical, and to appeal to
reason, not a mere compilation of facts to be learned by rote.
To make it preparatory to a higher course in physiology
would be manifestly a mistake, for it would necessitate a
much more scientific plan of arrangement, and the introduc-
tion of an' amount of material which would be confusing.
The teaching of anatomy and physiology in schools should be
considered chiefly as an aid in teaching hygiene, so that the
student may learn how to live a healthful life.

The writer desires to acknowledge his indebtedness to R. M.
Wyckoff, M.D., for valuable aid in the preparation of the
manuscript for the press; and to R. Cresson Stiles, M.D., a
skillful microscopist and physician, for the chapter " On the
Use of the Microscope in the Study of Physiology."

CONTENTS

CHAPTER I

THE FRAMEWORK OF THE BODY

The Bones — Their Form and Composition — The Properties of Bone
— The Skeleton — The Joints — The Spinal Column — The
Growth of Bone — The Bepair of Bone — Changes in the Skele-
ton— Erect Position

CHAPTER II

THE MUSCLES

The Muscles — Flexion and Extension — The Tendons — Contrac-
tion— Physical Strength — Necessity for Exercise — Its Effects-
Forms of Exercise — Walking — Riding — Gymnastics — Ojnn-
air Exercise — Excessive Exercise — Sleep — Recreation ... 33

CHAPTER III

THE INTEGUMENT, OR SKIN

The Integument — Its Structure— The Nails and Hair — The Com-
plexion— The Sebaceous (Hands — The Perspiratory Glands —
Perspiration and its Uses — Importance of Bathing — Different
Kinds of Baths — Manner of Bathing — The Benefit of the Sun
— Importance of Warm Clothing — Poisonous Cosmetics ... 54

CHAPTER IV

THE CHEMISTRY OF FOOD

The Source of Food — Inorganic Substances — Water — Salt —
Lime — Iron — Organic Substances — Albumen, Fibrin, and
Caseine — The Fats or Oils— The Sugars, Starch, and Gum —
Stimulating Substances — Necessity of a Regulated Diet ... 73

CONTENTS
CHAPTER V

FOOD AND DRINK

PAGE

Necessity for Food — Waste and Bepair — Hunger and Thirst —
Amount of Food — Benovation of the Body — Mixed Diet — Milk

— Eggs — Meat — Cooking — Vegetable Food — Bread — The
Fotato — Fruits — Purity of Water — Action of Water upon Lead

— Coffee, Tea, and Chocolate — Effects of Alcohol 89

CHAPTER VI

DIGESTION

The Principal Processes of Nutrition — The General Plan of Di-
gestion— Mastication — The Teeth — Preservation of the Teeth

— Insalivation — The Stomach and the Gastric Juice — The Move-
ments of the Stomach — Gastric Digestion — The Intestines — The
Bile and Pancreatic Juice — Intestinal Digestion — Absorption by
Means of Blood-vessels and Lacteals — The Lymphatic or Absorb-
ent System — The Lymph — Conditions which affect Digestion —
The Quality, Quantity, and Temperature of the Food — The Influ-
ence of Exercise and Sleep — The Kidneys — The Spleen — Effect

of Alcohol upon Digestion, the Liver, and Kidneys 115

CHAPTER VII

THE CIRCULATION

The Blood — Its Plasma and Corpuscles — Coagulation of the Blood

— The Uses of the Blood — Transfusion — Change of Color —
The Organs of the Circulation — The Heart, Arteries, and Veins

— The Cavities and Valves of the Heart — Its Vital Energy —

— Passage of the Blood through the Heart — The Frequency and
Activity of its Movements— The Pulse— The Sphygmograph —
The Capillary Blood-vessels — The Bate of the Circulation — As-
similation — Injuries to the Blood-vessels — Effects of Alcohol
upon the Heart — As a Fat- Producer 145

CHAPTER VIII

RESPIRATION

The Objects of Bespiration — The Lungs— The Air Passages —
The Movements of Bespiration — Expiration and Inspiration —
The Frequency of Bespiration — Capacity of the Lungs— The*'

CONTEXTS

Air we Breathe — Changes in the Air from Respiration — Changes
in the Blood — Interchange of Gases in the Lungs — Comparison
between Arterial aud Venous Blood — Respiratory Labor— Im-
purities of the Air — Dust — Carbonic Acid — ■ Effects of Impure
Air — Nature1 s Provision for Purifying the Air — Ventilation —
Animal Heat 177

CHAPTER IX

THE NERVOUS SYSTEM

Animal and Vegetative Functions — Sensation, Motion, and Volition

— The Structure of the Nervous System — The White and Gray
Substances — The Brain — Its Convolutions — The Cerebellum

— The Spinal Cord and its System of Nerves — The Anterior
and Posterior Roots — The Sympathetic System of Nerves — The
Properties of Nervous Tissue — Excitability of Nervous Tissues —
The Functions of the Spinal Nerves and Cord — The Direction

of the Fibres of the Cord — Reflex Activity and its Uses — The
Functions of the Medulla Oblongata and the Cranial Ganglia —
The Reflex Action of the Brain — Effects of Alcohol, Tobacco,
Snuff, Narcotics, Opium, Chloral, Hasheesh, Chloroform . . . 207

CHAPTER X

THE SPECIAL SENSES

The Production of Sensations — Variety of Sensations — General
Sensibility — Pain and its Function — Special Sensation, Touch,
Taste, Smell, Sight, and Hearing — The Hand, the Organ of
Touch — The Sense of Touch — Delicacy of Touch — Sensation
of Temperature and Weight — The Tongue, the Organ of Taste

— The Nerves of Taste — The Sense of Taste, and. its Relations
with the other Senses — The Influence of Education on th> Taste

— The Nasal Cavities, or the Organs of Smell— The Olfactory
Nerve — The Uses of the Sense of Smell — The Sense of Sight —
Light — The Optic Nerve — The Eyeball and its < 'overings— The
Function of the Iris — The Sclerotic, Choroid, and Retina— The
Tears and their Function — The Movements of the Eyeball —
The Function of Accommodation— The Sense of Hearing and
Sound — The Ear, or the Organ of Hearing — The External,

f Middle, and Internal Ear 251

10 CONTENTS

CHAPTER XI

THE VOICE

PAGE

Voice and Speech — The Larynx, or the Organ of the Voice — The
Vocal Cords — The Laryngoscope — The Production of the Voice

— The Use of the Tongue — The Different Varieties of Voice —
The Change of Voice — Its Compass — Purity of Tone — Ven-
triloquy 308

CHAPTER XII

THE USE OF THE MICROSCOPE IN THE STUDY OF PHYSIOLOGY

The Law of Tissues — Necessity of the Microscopi — Different Kinds
of Microscopes — Additional Apparatus — Prelim in ary Studies —
The Study of Human Tissues — Tissues of the Inferior Animals

— Incentives to Study 320

CHAPTER XIII

FIRST HELP IN ACCIDENTS

Shock — Fainting — Vertigo — Hemorrhage — Fractures and Dislo-
cations— Sprains— Bums and Scalds — Danger from Illumi-
nating Gas and Kerosene — Frost-Bites — Sunstroke — Fits or
Convulsions — Drowning — Poisons and their Antidotes . . . 329

APPENDIX

Care of the Sick-room 343

Disinfection 34">

Home and Health 347

On Going into the Country 349

Exercises for Home Gymnastics 351

Glossary 354

Index , 365

LIST OF ILLUSTRATIONS

FIG.

Frontispiece

Viscera in Position p.U;k

1. Section of bone 19

2. The skeleton 20

3. Structure of bone, magnified 21

4. Section of bone, parallel to surface 21

5. Ribs in natural and healthy state 22

6. Ribs showing effects of tight lacing 22

7. The ligaments of the wrist 24

8. Cells of cartilage 24

!). Elbow-joint 25

10. Spinal column 20

11. The muscles 32

12. .Muscular tissue, magnified 33

13. Biceps muscle of the arm 34

14. Muscles and tendons of the hand 35

15. Lower portion of the leg 30

16. View of knee-joint 37

17. The chest weight 46

18. Root and transverse section of hair, magnified .... 50

19. Magnified hair and section of skin 58

20. Magnified view of sweat-gland and duct .... 59

21. Granules of potato starch 84

22. Section of the trunk 110

23. Section of a tooth 117

24. Section of the jaws 118

2">. Section of the jaws — right side 119

20. Structure of a salivary gland 121

27. Head of a horse, showing salivary gland, etc 122

28. Section of chest and abdomen 126

29. Alimentary canal 127

30. Thelacteals 134

31. Intestinal villi, magnified 135

32. The kidneys and bladder 138

38; Blood corpuscles, highlj magnified 140

34. Blood corpuscles of man and lower animals, magnified . . 147

11

12 LIST OF ILLUSTRATIOXS

PAGE

35. Circulation of the blood, ■»

36. External view of the heart, J

37. Section of the heart 155

38. Valves of heart with walls relaxed 156

39. Valves of heart during contraction of ventricles . . . 156

40. Left section of the heart, \ n .

41. Right section of the heart, J "^

42. Form of the pulse 162

43. Vein with valves open 163

44. Vein with valves closed 163

45. Web of frog's foot, magnified . 165

46. Margin of frog's web 165

47. Organs of the chest 178

48. Larynx, trachea, and bronchial tubes 179

49. Diagram and section of the air-cells 179

50. Section of the lungs 180

51. Section of mouth and throat 181

52. Ciliated cells 182

53. Ventilation by window 199

54. Cerebro-spinal system 210

55. Upper surface of the cerebrum 211

56. Vertical section of the brain 212

57. Lower surface of the brain 213

58. Brain and spinal cord 215

59. Section of spinal cord 216

60. Illustrating the functions of the spinal nerves .... 221

61. An experiment with sense of touch ..... 260

62. Section of nasal cavity 269

63. Front view of the eye 276

64. Vertical section of the eye, magnified 279

65. Front section of eyeball 281

66. Diagram of blind point of the eye 283

67. The retinal image 286

68. The different shapes of the globe of the eye .... 288

69. The function of accommodation 290

70. The ear and its different parts 294

71. Showing the internal mechanism of the ear, magnified . . 296

72. Section of the right ear 298

73. Section of the larynx and trachea 311

74. A vii'W of the vocal curds by means of the laryngoscope . . 312

75. The'different positions of the vocal cords 313

76. Double convex and plano-convex lenses 321

77. Simple microscope 322

78. Compound microscope 323

INTRODUCTION

The Human Body is the abode of an immortal spirit, and is
the most complete and perfect specimen of the Creator's handi-
work. To examine its structure, to ascertain the uses and
modes of action of its various parts, how to protect it from
injury, and maintain it in a healthy condition, is the design
of this work.

The departments of knowledge which are concerned in these
investigations, are the science of Human Physiology and the
art of Hygiene.

Physiology treats of the vital actions and uses of the
various parts of living bodies, whether vegetable or animal.
Each living thing, therefore, has a Physiology. "We have a
Vegetable Physiology, which relates to plants; and an Animal
Physiology, relating to the animal kingdom. The latter is
also divided into Comparative Physiology, which treats of
the inferior races of animals, and Human Physiology, which
teaches the uses of the various parts of the human body.

Hygiene, or the art of preserving health, is the practical
use of Physiology. It teaches us how to cultivate our bodily
and mental powers, so as to increase our streugth, and to fit
us for a higher enjoyment of life. It also shows us how to
prevent some of the accidents which may befall the body, and
how to avoid disease. It is proper that we should understand
the construction and power of our bodies ; but it is our duty,
13

14 INTRODUCTION

as rational beings, to know the laws by which health and
strength may be maintained and disease warded off.

There are various means by which we gain important infor-
mation respecting the Physiology of man. Plants aid us in
understanding the minute structure of the human body, its
circulation, and absorption. From inferior animals we learn
much in respect to the workings of the different organs, as
we call those parts of the system which have a particular
duty to perform. In one of them, as in the foot of the frog,
we can study the circulation of the blood; in another, we
can study the action of the brain.

By vivisection, or the laying bare of some organ of a living
animal, we are able to investigate certain vital processes
which are too deeply hidden in the human body to be studied
directly. This is not necessarily a cruel procedure, as we
can, by the use of anaesthetics, so blunt the sensibility of
the animal under operation, that he need not suffer while the
experiment is being performed. There are other means by
which we gather our information. There are occasionally
men, who, from some accident, present certain parts, natu-
rally out of view, in exposed positions. In these cases, our
knowledge is of much greater value than when obtained from
creatures lower in the scale of being than man.

We are greatly aided, also, by the use of various instru-
ments of modern invention. Chief among these is the micro-
scope, which is, as we shall learn hereafter, an arrangement
and combination of lenses in such a way as greatly to magnify
the objects we wish to examine.

We have much to say of Life, or vital activity, in the course
of our study of Physiology ; but the most that we know of it
is seen in its results. What Life is, or where its precise posi-
tion is, we are not able to determine. We discover one thing,

INTRODUCTION 15

however, that all the parts of the body are united together
with wonderful sympathy, so that one part cannot be injured
and other parts not suffer damage. It is further evident that
.all organs are not equally important in carrying on the work
of Life; for some may temporarily suspend their action, with-
out serious results to the system, while others must never
cease from acting. Yet there is nothing superfluous or with-
out aim in our frames, and no part or organ can suffer harm
without actual loss to the general bodily health. On this
point Science and Holy Writ strictly agree.

PHYSIOLOGY AND HYGIENE

CHAPTER I

THE FRAMEWORK OF THE BODY

The Bones — Their Form and Composition — The Properties of Bone
— The Skeleton — The, Joints— The Spinal Column — The Growth
of Bone — The Repair of Bone — Changes in the Skeleton — Erect
Posture

1. The Bones. — The framework which sustains the human
body is composed of the Bones. The superstructure consists
of the various organs on which the processes of life depend.
These organs are soft and delicately formed, and, if unprotected,
would, in most cases, rapidly be destroyed when subjected to
violence, however slight. The bones, having great strength
and power of resistance, afford the protection required. (Bead
Note 1.)

1. Self-Knowledge. — " It has been said with truth that the human
mind, which can survey the heavens and calculate the motion and density
of the stars, finds itself confounded when, returning from these distant
journeyings, it enters its own dwelling-place — the body. Man's own
organization is still among those mysteries of nature which he is least
able to penetrate, in spite of his incessant efforts to lift the veil which
hides it. In all ages he has sought to knoic himself. In all times he has
studied the relations between his own existence and that of the world,
and those universal influences which, though evident to him, are nearly
all inexplicable in their action upon living beings." — Le Pileur on the
Human Body.

1. The framework of the body? The superstructure? Softness and delicacy of the
organs ? How protected ?

B 17

IS THE FRAMEWORK OF THE BODY

2. The more delicate the organ, the more completely does
Nature shield it. For example : the brain, which is soft in
structure, is enclosed on all sides by a spherical box of bone ;
the eye, though it must be near the surface of the body to
command an extensive view, is sheltered from injury within
a deep recess of bone ; the lungs, requiring freedom of motion
as well as protection, are surrounded by a large "chest" of
bone and muscle. The bones serve other useful purposes. They
give permanence of form to the body, by holding the softer
parts in their proper places. They assist in movement, by
affording points of attachment to those organs which have
power of motion — the muscles.

3. The Form and Composition of the Bones. — The shape and
size of the bones vary greatly in different parts of the body,
but generally they are arranged in pairs, one for each side of
the bod}-. They are composed of both mineral and animal
substances, united in the proportion of two parts of the former
to one of the latter; and we may separate each of these sub-
stances from the other for examination. First, if we expose a
bone to the action of fire, the animal substance is driven off, or
" burned out." We now find that, though the shape of the
bone is perfectly retained. Avhat is left is no longer tough, and
does not sustain weight as before. Again, we may remove the
mineral portion, which is a form of lime, by placing a bone in
a dilute acid. The lime will be dissolved out, and the shape
of the bone remain as before; but now its firmness has dis-
appeared, and it may be bent without breaking. {Bead Xote 2.)

4. If, for any reason, either of these ingredients is dispro-
portionate in the bone during life, the body is in danger. The
mineral substance is useful in giving rigidity of form, while

2. Experiment. — To demonstrate the presence of the mineral mat-
ter in bone, obtain a sheep's rib, clean it thoroughly and macerate it
for three or four days in dilute muriatic acid (one part acid to eight of

2. The more delicate the organ ? Example in relation to the brain ? The eye ? The
lungs? The services performed by the bones?

8. Their shape and size 1 Of what composed ? Possibility of being separated ? Effect
of fire* Of dilate acid ?

Rciency of Ingredient i Usefulness of the lime? Of the animal sub-
Bffect of their anion ': Condition, in youth? Old age?

THE FRAMEWORK OF THE BODY

!'.♦

the animal substance insures toughness and elasticity, so that
by their union we are able to withstand greater shocks and
heavier falls than would be possible with either alone. In
youth, the period of greatest activity, the animal portion is
in excess; a bone then does not break so readily, but, when
broken, unites with great rapidity and strength. On the other
hand, the bones of old persons are more easily broken, and in
some cases fail to unite. The mineral matter being then in
excess, indicates that the period of active exertion is drawing
to a close. (Bead Note 3.)

5. The Structure of the Bones. — If we examine one of the
long bones, which has been sawed through lengthwise, we

Fig. 1. — Section- of Bone. — A, Longitudinal. B, Trans-
verse Section of Bone

observe that it is admirably fashioned for affording lightness
as well as strength (Fig. 1). Its exterior is hard and resisting.
but it is porous at the broad extremities, while through the

water), when the bone will become perfectly soft and pliable. The speci-
men may be preserved in alcohol indefinitely.

3. Some Properties of Bone. — "The power of bone to resist decay is
remarkable. Fossil bones deposited in the ground long before the ap-
pearance of man upon the earth have been found by Cuvier, exhibiting a
considerable portion of cartilage. The jaw of the Cambridge Mastodon
contained over forty per cent, of animal matter — enough to make a
good glue — ami others about the same. From this we see that a nutri-
tious BOup might lie made from the bones of animals that lived before tin
creation of man. The teeth resemble bone in their structure, but resist
decay longer ; they are brought up by deep-sea dredging, when all other
parts of the animal have wasted away. The bones differ at different ages,

5. In what respect admirably fashioned? Its formation? Microscopic examination?
The inference ? " Line of beauty ?"

20

THE FRAMEWORK OF THE BODY

Fig. 2. —The Skeleton

THE FRAMEWORK OF THE BODY

21

central portion there is a cavity or canal which contains an
oily substance, called marrow. If a thin section of bone be

Vv* "

->• i ,-%

Wm

#&

i v *« >

Sfe

Fie. 8.— Stro

TIKE OF BoNI

1 i$m

mm w -

jm

Fig. 4. — Section parallel to the Surface from
the Shaft of the Femir. — Magnified 100
Diameters. — a, Haversian canals; b, c, lacuna1

examined under the micro-
scope, we discover that it is
pierced by numerous fine
tubes (Fig. 3), about which
layers of bone-substance
are arranged. So that, al-
though a bone be as hard as
stone externally, it is by no
means as heavy, by reason
of its light interior texture.
Another element of power
is found in the curved out-
line of the bones. The curved line is said to be "the line of
beauty," as it certainly is the line of strength, and is uniformly

and under different social conditions In the disease called 'rickets,1
quite common among the ill-fed children of the poor in Europe, but some-'
what rare in America, there is an inadequate deposit of the mineral
substance, rendering the bones so flexible that they may be bent almost
like wax. In females and weak nun the bones are light and thin, while
in a powerful frame they are dense and heavy. Exercise is as necessary to
the strength of bone as to the strength of muscle; if a limb be disused.
from paralysis or long sickness, the bones lose in weight and strength as
well as the soft parts. Bone is said to be twice as strong as oak. and. to
crush a cubic inch of it, a pressure equal to 5000 pounds is requisite."

22

THE FRAMEWORK OF THE BODY

present in the bones whose position exposes them to accident.
{Bead Note 4.)

6. The Skeleton. — The number of bones in the human body
exceeds two hundred, and when joined together in their proper
places, they form what is termed the Skeleton (Fig. 2). It
embraces three important cavities. The first of these, sur-
mounting the frame, is a box of bone, called the skull; below
this, is a bony case, or " chest ; " and lower down is a bony
basin, called the ■pelvis. The two latter compose the trunk.

Fig. 5. — Ribs in a Natural and
Healthy State

■Ribs showing the Effects
of Tight Lacing

The trunk and skull are maintained in their proper relations
by the " spinal column." Branching from the trunk are two

4. Experiment. — Obtain one of the long bones of the sheep or calf,
scrape it thoroughly clean, but do not detach the cartilage covering the
ends. Saw it through crosswise in the middle ; then saw the upper half
through lengthwise. (See Fig. 1.)

The transverse section shows the compact, hard outer layer, enclosing
the soft pulp or marrow.

The longitudinal section shows, at its upper end, the layer of cartilage,
its thickness and intimate connection with the bone ; the outer layer of
bone here is thinnest and gradually increases toward the middle of the
shaft, where it is thickest; the central canal, containing the marrow,
becomes smaller as it approaches the head of the bone, where it is lost in
the dense network of bony structure. The latter is best demonstrated by
holding the cut surface for a while under a faucet, so as to wash away the
blood, etc., contained in the meshes. It will now be seen that these

6. Number of bones? Skeleton:- The skull ? Chest? The trunk ? The trunk and
skull, how maintained ? What of the arms ? Legs ?

THE FRAMEWORK OF THE BODY 23

sets of lin;bs : the arms, which are attached to the chest by
means of the "collar-bone" and "shoulder-blade;" and the
legs, directly joined to the lower part of the trunk. !

7. The cavities, three of which we have mentioned, art-
designed for the lodgment and protection of the more delicate
and perishable parts of the system. Thus, the skull, tog
with the bones of the face, shelters the brain and the organs
of four senses — sight, hearing, smell, and taste. The chest
contains the heart, lungs, and great blood-vessels, while the
lower part of the trunk sustains the liver, stomach, and other
organs.

8. The Joints. — The point of union of two or more bones
forms a joint or articulation, the connection being made in
various ways according to the kind and amount of motion
desired. The movable joints are connected by strong fibrous
bands, called ligaments. These ligaments are of a silvery
whiteness, and very unyielding; so much so, that when sudden
violence is brought to bear in the vicinity of a joint, the bone
to which a ligament is attached may be broken, while the
ligament itself remains uninjured. When this connecting
material of the joints is strained or lacerated by an accident, a
" sprain " is the consequence. An injury of this sort may be.

meshes are composed of delicate, but strong, bony partitions, and
arranged in such angles to the outer wall and to themselves as will sup-
port the greatest weight.

5. Two Forms of Skeleton among Animals. — "The solid basis on
which all the soft organs of the body rest is the skeleton. In the human
body the skeleton is composed of a number of bones, each of which has a
distinct name. In the animal kingdom there are two distinct forma of
.skeletons ; the one which is found chiefly in the lower animals is outside,
and covers the soft parts, and is called an exo-skeleton. Examples of
this kind of skeleton are seen in crabs, lobsters, insects, and the shells
of mollusca, as oysters, mussels, and whelks. The shells of these animals
are mostly composed of carbonate of lime. Fishes possess an internal
skeleton ; and all the classes of animals above them, as reptiles, birds, and
mammals, possess internal or endo-skeletons*" — Lankester's Manual of
Health.

7. Design of the cavities f Give the examples.

8. Joint <>r articulation :- Movable Joints, how compacted ! The ligaments of the mov-
able joints ? What is a sprain J Consequence ofa serious sprain I

24

THE FRAMEWORK OF THE BODY

and frequently is, quite as serious as the breaking of a bone.
{Bead Note 6.)

9. The ligament, then, secures firmness to the joint ; it must
also have flexibility and smoothness of motion. This is ac-
complished by a beautiful mechanism, the perfection of which

— The Ligaments

is only feebly imitated by the most ingenious contrivance of
man. The ends of the bones are covered by a thin layer of
cartilage, which, being smooth and elastic, renders all the

6. How Joints may be Injured. — " All the joints are liable to disloca-
tion—that is, being 'put out' of their place. Owing to the shallowness
of the cavity at the shoulder, this joint is frequently dislocated ; and this
sometimes happens with the thigh, but not so often, as the cup in which
the femur moves is much deeper. Joints which have been dislocated
should at once be ' set ; ' but now that you have seen how liable you are
to accident, I hope you will be careful not to indulge in too violent or
rough exercise, by which you might not only dislocate the joints, and so
in time weaken them, but might also break the bones, and perhaps become
crippled for life. Many children have the habit of pulling their fingers
so as to make them ' crack.' This is exceedingly wrong, for it is to a
certain extent pulling the joints out of their sockets, and this may so
loosen the parts as to cause permanent injury." — Davidson's " Our
Bodies."

'.». Office "I' t lie ligament? Wli.it must it have'
m- no via '/

ilished ? Describe it.

THE FRAMEWORK OF THE BODY

25

movements of the joint very easy. In addition to this, there
is an arrangement introduced for ''lubricating" the joint, by
means of a delicate sac containing fluid. This fluid is con-
stantly supplied in small quantities, but only so fast as it is
used up in exercise. In appearance, it is not unlike the white
of an egg, and hence its name synovia, or egg-like.

10. Thus, we observe that two very different substances
enter into the composition of a joint. The ligament, very un-

Fig. 9. — Elbow-Joint. A. Bone of the arm ; B, C, Bones of the fore-arm

yielding, affords strength, while the cartilage, elastic and moist,
gives ease and smoothness of motion. The amount of motion
provided for varies greatly in different joints. In some there
is none at all, as in the skull, where one bone is dove-tailed
into another by what are termed sutures. Others have a hinge-
like motion, such as those of the elbow, wrist, ankle, and knee :
the most complete of these being the elbow-joint (Fig. 9).
Belonging to another class, the ball-and-socket joint, is that at
the shoulder, possessing a freedom of motion greater than any
other in the body.

11. The Spinal Column. — The spinal column is often spoken

10. \\\u\\ do «,. observe :>> regards tin- composition of a joint ? The ligament and carti-
lage} What varies J Example of the skull? Other examples f The ball- and-eocket joint?

11. What is the spinal colnmn ? W hat does it connect and form? Joints of the verti-
bne? Amount of motion ? Result?

26 THE FRAMEWORK OF THE BODY

of as the ••hack-hone." as if it were a single bone, while, in
reality, it is composed of a chain of twenty-six small hones,
called vertebra. The spinal column is a wonderful piece of
mechanism. It not only connects the important cavities of the
body, as has already been shown, but
also, itself forms a canal, which contains
the spinal cord. The joints of the ver-
tebrae are remarkable for the thick layers
(il cartilage which separate the adjacent
surfaces of bone. The amount of motion
between any two of these bones is not
great; but those little movements, taken
together, admit of very considerable flexi-
bility, in several directions, without en-
dangering the supporting power of the
column.

12. The abundant supply of inter-
vertebral cartilage has another impor-
tant use, namely, it adds greatly to the
elasticity of the frame. It is due, in
part, to this elastic material, and in part
to the frequent curves of the spine, that
the brain and other delicate organs are
not more frequently injured by the shock
of sudden falls or missteps. During the
day, the constant pressure upon these
joints, while the body is erect, dimin-
ishes the thickness of the cartilages ; so
that a person is not so tall in the even-
ing as in the morning. The effects of
this compression pass away when the
body is in a reclining posture. (Head
Vote 7. )

7. Some Causes of Curvature of the Spine. — " Much as horse-riding
is valued on account of the healthful character of its exercise, yet an over-
indulgenci \<\ young ladies — owing to the oblique position in which the

12. Elasticity of the frame ! Protection of the brain from shocks ? Tallness of p<
Effects "i r< dining !

THE FRAMEWORK OF THE BODY 27

13. The Growth of Bone. — Bone, like all the other tissues of
the body, is constantly undergoing change, old material being
withdrawn, to make room for a fresh supply. This change
has been shown conclusively by experiments. If an animal he
fed with madder — a red coloring matter — for a day or two,
the bones soon become tinged; then, if the madder he discon-
tinued for a few days, the original color returns. If. however,
this material he alternately given and withheld, at short inter-
vals, the hone will be marked by a succession of red and white
rings. In very young animals, all the bones become colored
in a single day ; in older ones, a longer time is required. The
process of waste and repair, therefore, is constantly taking
place in this hard substance, and with astonishing rapidity.

14. The Repair of Bone. — Xature*s provision for uniting
broken bones is very complete. At first, blood is poured out

female form rests in the side-saddle — will cause the spine to become
curved.'1 To avoid this, it is important for young ladies to ride occasion-
ally on the opposite side of the horse. Another frequent cause of curva-
ture of the spine is the use of the sewing-machine, especially among needy
seamstresses, whose bread frequently depends on the almost unceasing
labor of their hands and feet, while sitting in a constrained position.
Soon after croquet became a favorite amusement among the fashionable
young ladies of England, it was noticed that the bent position assumed
during the time the mallet is used, caused a certain deformity, to which
was given the name of the "croquet curvature." The use of high heels
on boots and shoes of children, by throwing the weight of the body too far
forward, on the front of the foot, and destroying the natural poise of the
body, arts an important part in causing the spine to become crooked.
By many this crooked position is considered to be largely a school-room
disease, for the reason that children often are compelled to sit. and write
or study, in a bent posture ; but there must be other causes for it. since it
has been found that it is almost exclusively a female deformity. Over
eighty-four per cent, of the cases is stated by one writer to be among
girls. But inasmuch as the majority of these cases begin during the
years of schooling — from the auvs of six to fourteen — great attention
should be paid to the position of the body during school hours, and ample
opportunity should be offered, by a regular system of gymnastics, to
counteract all the evil influences of the school-room posture. — Heather-
Bigg "it Deformities (in part).

18, Change in bone? Etfflmpte animal and madder. Rapidity of change i lorl

Waste and repair ?

14. How is a broken bone united ? What becomes of the blood caused bj the injury!
What takes its [Mace ? How Ion;.' <.!"<.•.- it usually take for a broken bone to unite !

28 THE FRAMEWORK OF THE BODY

around the ends of the bone, as a result of the injury. This is
gradually absorbed, and gives place to a watery fluid, which,
thickening from day to day, acquires, at the end of about two
weeks, the consistency of jelly. This continues to harden, by
the deposit of new bone-substance, until, usually at the end of
five or six weeks, the broken bone may be said to be united.
It is, however, still fragile, and must be used carefully a
few weeks longer. The process of hardening continues, but
months must pass before the union can be said to be complete.
(Bead Note 8.)

15. Changes in the Skeleton. — Man does not reach his full
height until he is about twenty-five years old; and even after
that age, the bones continue to increase in strength and hard-
ness. Before that age they are comparatively soft and flexible,
by reason of the gelatin they contain. This is especially true
in childhood ; and it is fortunate that it is so, since that con-
dition is much more favorable to the steady and rapid growth
of the bones than if they contained more of the lime, as is the
case in old age, when there is no occasion for change in the
size or shape of the skeleton. The skull, however, is said to
increase slightly in size, even in advanced life, in those persons
in whom the brain is continually employed in thought or study.

8. The Management of a Broken Limb. — ••Fractures are usually
met with when the person is dressed. Therefore, unless there is bleeding,
or something to call for immediate exposure and examination of the
damaged part, do not be in a hurry to remove the clothes. If the arm be
hurt, extemporize a sling from a neck-handkerchief or some other article
of dress, and support the arm from elbow to wrist, tying the ends of the
handkerchief in a knot over the coat-collar behind, if the thigh or leg
be in pain, fasten the injured limb to its fellow by a cravat bandage or
two, and take care that they lie side by side, and on the same level ; or
fasten outside the clothes some temporary support — a piece or two of
straighl stick, with a bandage — and then remove the sufferer quietly and
carefully to some house near at hand. If medical aid be available, send
for it without any delay ; and be careful, if in the country, and so at some
distance from the doctor's house, to forward a clear statement as to the
apparent nature of the accident, which limb is hurt, and where and how

15. When does a roan gel his growth? What changes then take jilace ? What difference
In the b mes "f :i child and those of :i man ! What exception in case of the ^k. u 11 f Benefit
in flexibility of bones J Cau r knock-knees? Bow legs?

THE FRAMEWORK OF THE BODY 29

However, this very flexibility of the bones, in early life, which
favors their steady growth and prevents their breaking easily,
is sometimes the source of serious deformity. A young child
may be allowed to stand and walk too early, and, as a conse-
quence, the lower limbs become permanently bent inward, in
the distortion called "knock-knees," or outward, as in "bow-
legs." For the same reason, a bent position of the spinal
column, permitted to exist habitually in childhood, may result
in a life-long deformity.

16. The Erect Posture. — Youth is, in a great measure, the
forming as well as the growing period of the frame. Bad
habits of posture, early formed, become fixed in later life, and
their results — as seen in contracted chests and round shoulders
— are with difficulty remedied. Eight habits, on the other
hand, tend to produce an erectness of posture which is favor-
able, not alone to strength and health, but also to grace and
ease. The following directions should be learned and prac-
ticed : hold the head erect with the chin somewhat near the
neck; expand the chest in front; throw the shoulders back,
keeping them of the same height on both sides ; maintain the
natural curves of the spine, as shown in the last figure. Man
alone, of all the animals, has the power to stand and move in
the erect posture.

it happened. Let this statement, too, be in writing, if possible. It may
well happen, however, that skilled assistance cannot be had, and in this
case the patient should be undressed quietly and cautiously. It will be
far better to slit up the dress on the arm or leg with a pair of scissors than
to pull it off ; but however the covering of the injury may be managed, it
must be done very slowly and gently, and the limb should be supported
so as to prevent jarring and shaking to the damaged part. It must be
carefully kept, too, in a right direction, for otherwise some sharp splinter
of bone may penetrate the hitherto unwounded skin." — First Help in
Accidents and Sickness.

16. What is the forming period? Effects of bad habits of posture? Directions for
correct posture ?

30

THE FRAMEWORK OF THE BODY

TOPICAL OUTLINE

1. BONES are composed of mineral substance (lime) two parts, and animal

substance (gelatin) one part. They are hard on the surface, and light
and porous in the interior.
Uses. a. Framework for the body.

b. Protection for delicate organs.

2. LIGAMENTS. StroDg fibrous bands.

Use. a. Bind bones together.

3. CARTILAGE.

Kinds, a. Temporary, — converted into bone in adults.

b. Permanent, — not converted into bone.
Uses. a. Forms strong yet flexible frameworks.

b. Acts as buffers in deadening shocks and blows.

c. Deepens the sockets of joints; example, the hip-joint.

d. Covers the articulating surfaces of bones, thus reducing

friction.

r Immovable Sutures,— Skull.

f Gliding joints, — ankle and wrist.

4. JOINTS. < i Ball-and-socket joints, — shoulder and

j Perfect . . ' hip.
I Movable ..J j Hinge joints, — elbow and knee.

I Pivot joints, — joint of atlas and axis.
I Imperfect Vertebra; joints.

QUESTIONS FOR TOPICAL REVIEW

PAGE

What useful purposes do the bones serve ? 17, 18

State what you can of the composition of the bones 18, 19

Of the usefulness of lime in the bones 18

( )f the usefulness of animal substance in the hones 19

State what you can of the structure of the bones 19, 21

Of the strength belonging to the bones 21, 22

Wlrtt is meanl by the human skeleton? 22

Give a description of its construction 22. 23

What is meant by a joint in the human frame? 23

State what you can of the movable joints 23, 24, 25

What office is performed by the ligaments of the joints? 24, 25

What by the cartilage at the joints? 24, 25

What movable joints are there? 25, 26

Describe the construction of the spinal column 26

What properties and powers 'Iocs the spinal column possess? 26

When is a person taller than at other times? 26

Give the reason for this 26

What can you state of the growth of bone? 27

Describe the process by which a broken hone is repaired? 27, 28

When does man reach his full height ? 28

What changes in the bones then take place? 28

Name an exception to the general rule 28

state the advantage and disadvantage in flexibility of bones 29

What directions are given for the correct position ? 29

THE FRAMEWORK OF THE BODY

31

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32

THE MUSCLES

Fig. 11. —The .Muscles

CHAPTER II

THE MUSCLES

The Muscles — Flexion and Extension — The Tendons — Contraction —
Physical Strength — Necessity for Exercise — Its Effects — Forms of
Exercise — Walking — Biding — Gymnastics — Open-air Exercise —
Effects of Exercise — Excessive Exercise — Sleep — Recreation

1. The Muscles. — The great mass of the body external to
the skeleton is composed of the flesh, or Muscles, which largely
determines its outline and weight. The muscles are the organs
of motion. Their number is about four hundred, and to each
of them is assigned a separate and distinct office. They have
all been studied, one by one, and a name given to each, by the
anatomist. Each is attached to bones which it is designed to
move. A few are circular in form, and enclose cavities, the
size of which they diminish by contraction.

2. If we examine a piece of flesh, we observe that it is soft,
and of a deep red color. Its structure appears to be composed
of layers and bundles of
small fibres. Let us fur-
ther examine these fibres
under the microscope.
We discover that these
in turn are made up of
still finer fibres, or fibrit
Ice, as shown in Fig. 12.
The fibres are beauti-
fully marked by parallel
wavy lines, about ten
thousand to an inch,

Fig. 12. — Mtjsoulab Tubus

6, Btrlped muscular fibre? ; c, The same i

highly magnified

1. What are the muscles? Their number? The design of most of them ? Of a few?

2. The structure of flesh? Its color, etc. ? The composition of the fibres ? How marked ?

C 33

34 TEE MUSCLES

which give the fibre its name of the striped muscular fibre.
All of the voluntary muscles present this appearance.

3. Flexion and Extension. — The muscles are, for the most
part, so arranged in pairs, or corresponding sets, that when
motion is produced in one direction by one set, there is, oppo-
site to it, another muscle, or group of muscles, which brings
the limb back to its place. When they act alternately, a to-
and-fro movement results. When a joint is bent, the motion
is called flexion; and when it is made straight again, it is
called extension. When both sets act equally, and at the same

Fig. 13. — Eaising the Forearm. A, Biceps muscle

moment, no motion is produced, but the body or limb is main-
tained in a fixed position: this occurs when we stand erect.
The muscles which produce extension are more powerful than
those opposite to them.

4. The muscles are also distinguished as the voluntary and
involuntary muscles, according as they are, or are not, under
the control of the will. The heart is an example of the invol-
untary variety. We cannot change its action in the least by
an effort of the will. When we sleep, ami the will ceases to
act, the heart continues to beat without cessation. The volun-
tary muscles, on the other hand, are such as are used only
when we wish or will to use them — as the muscles of the hand
or arm (Figs. 13 and 14). (Bead Note 1.)

8. Arrangement of the muscles? Their action? Flexion and extension? Action of
the muscles when we stand erect?

4. Kinds of muscles ? The voluntary ? Involuntary? The heart? Give the example.
The hand ? Arm ?

THE ill'SCLES

35

5. The Tendons. — Tendons, or sinews, are the extremities

of muscles, and are firmly fastened upon the bone. They are

W

Fig. 14 shows the muscles and tendons of the hand ; A showing the palm, B the back of the
hand. These numerous muscles and tendons form a very complicated piece of mechan-
ism, and help to give to the hand its marvellous dexterity and flexibility

very strong, and of a silvery whiteness. They may be felt just
beneath the skin, in certain parts of the body, when the muscles

1. The Perfection of the Human Hand. — "Gordy counts thirty-four
distinct movements of the hand, and if we include the combinations of
these different movements, we shall reach a much higher number. Prop-
erly speaking, the hand belongs to man alone, and its form does not per-
mit us to consider it an organ of locomotion, as is the case -with certain
animals most closely resembling man. Nothing gives a more complete
idea of the perfection of the mechanism of the hand than the execution of
instrumental music. Examine an artist while he plays the violin. His
fingers rest upon the strings so as to leave them exactly of the length
necessary for the tones they are to give. The half of a millimetre, more
or less, greatly changes the accuracy of the note ; and a chord a milli-
metre out of place produces a note which even the unpractised ear can
recognize as false. But the fingers fall upon the strings at precisely the
point required. They run over them, succeeding each other with ^iddy
rapidity, following every imaginable combination, and yet the hand gliding

5. What are the tendons or sinews ? Their strength ? Color ? Location ? Tendon of
Achilles ? The fable ? Muscles of the

36

THE MUSCLES

are being used, as at the bend of the elbow or knee. The
largest tendon of the body is that which is inserted into
the heel, called the tendon of Achilles, after the hero of the
Grecian poet, the fable relating that it was at this point that
he received his death-wound, no other part of his body being
vulnerable. (Fig. 15.) The muscles in
the front part of the thigh unite to form
a single and very powerful tendon, and
enclose a small bone called the knee-pan,
which, acting like a pulley, greatly in-
■%M creases their power, and at the same
time protects the front of the knee-joint
(Fig. 16).

6. Muscular Contraction. — The muscles,
when acted upon by the appropriate stim-
ulus, contract, or so change their shape,
that their extremities are brought nearer
together. The bending of the arm, or of
a finger, is effected in this manner, by the
will ; but the will is not the only means
of producing this effect. Electricity, a
sharp blow over a muscle, and other stim-
LowEuPoRTto/oFTHELEG uli, also cause it. Contraction does not
always cease with life. In man, after
death from cholera, automatic movements of hands and feet
have been observed, lasting not less than an hour. In certain

over the instrument incessantly changes its position. Sometimes a single
finger produces an isolated note ; sometimes two or three act simultane-
ously to produce a concord ; while a fourth, striking a string with increas-
ing rapidity, produces a trill which rivals the nightingale. Add to all
these the modifications necessary to swell the sound or let it die away —
all, in a word, that constitutes musical expression, and it will he admitted
that this mechanism is allied to the wonderful, and that it surpasses the
most perfect productions of human art." A further idea of the rapidity
of the hand's movements is given in the playing of a skilful pianist, whose
hands, oftenest occupied together, produce on an average six to eight
notes at a time, or ahout 640 notes in a minute in medium time, and 960
notes in extremely quick time. — The Wonders of the Human Body.

6. Contraction of the muscles ? Bending of the i
matic movements ? In cold-blooded animals f

or finger? Other agencies 1 Auto-

THE MUSCLES

■AT

cold-blooded animals, as the turtle, contraction has boon known
to take place for several days after the head has been cut off.

7. The property which, in muscle, enables these movements
to take place is called contractility. If we grasp a muscle while
in exercise (for example, the large muscle in the front of the
arm), we notice the alternate swelling and decrease of the
muscle, as we move the forearm to and fro. It was at one
time supposed that the muscle actually increased in volume
during contraction. This, however, is not the case; for the

Fig. 16. —View of Knee-Joint. A, Thigh-bone; B, Knee-pan: C, D, Leg-bones

muscle, while gaining in thickness, loses in length in the same
proportion ; and thus the volume remains the same in action
and at rest.

8. Contraction is not the permanent, or normal state of a
muscle. It cannot long remain contracted, but after a time it
wearies, and is obliged to relax. After a short rest, it can then
again contract. It is for this reason that the heart can boat
all through life, night and day, by having, as wo shall here-
after see, a brief interval of rest between successive contrac-

T. Contractility? Give the illustration. What was supposed ? What is the case ?
8. What further in relation to contraction ? Weariness of a muscle! Ik-ating of the
heart 1 Standing and walking ?

38 THE MUSCLES

tions. For the same reason, it is more fatiguing to stand for
any great length of time in one position, than to be walking
for the same period.

9. Relative Strength of Animals. — The amount of muscular
power which different animals can exert, has been tested by
experiment. By determining the number of pounds which an
animal can drag upon a level surface, and afterward comparing
that with its own weight, we can judge of its muscidar force.
It is found that man is able to drag a little less than his own
weight. A draught-horse can exert a force equal to about
two-thirds of his weight. The horse, therefore, though much
heavier than man, is relatively not so powerful.

10. Insects are remarkable for their power of carrying
objects larger and heavier than themselves. Many of them
can drag ten, and even twenty times their weight. Some of
the beetles have been known to move bodies more than forty
times their own weight. So far, therefore, from it being a fact
that animals have strength in proportion to their weight and
bulk, the reverse of that statement seems to be the law.

11. Physical Strength. — The difference in strength, as seen
in different individuals, is not due to any original difference in
their muscles. Nature gives essentially the same kind and
amount of muscles to every healthy person, and the power of
one, or the weakness of another, arises, in great part, from the
manner in which these organs are used or disused.

12. Many authors complain of the physical degeneracy oi
men at the present day, as compared with past generations.
There is room for doubt as to the correctness of this statement.
( Jertain experiments have recently been made with the metallic
armor worn seven hundred years ago, by which it is found that
any man, of ordinary height and muscular development, can
carry the armor and wield the weapons of an age supposed to

'.i. Muscular power of animals? How tested? Man's power? Horse's? The com-
parisoD ?

10. Power of insects? Beetles? Give the conclusion.

11. Difference in strength of individuals? How caused?

omplaint in relation to degeneracy? How true? How determined by armor?
The fair supposition ?

THE MUSCLES 39

be greatly our superior in strength. When we consider that in
those days only very strong men could endure the hardships of
soldier-life, it is fair to suppose that our age has not so greatly
degenerated in respect to physical strength.

13. Importance of Exercise. — Action is the law of the living
body. Every organ demands use to preserve it in full vigor,
and to obtain from it its best services. The value of that
training of the mind, which we call education, is everywhere
recognized. The child is early put to school, and for many
years continues to study, in order that his brain, which is the
great centre of mental power, may act healthfully and power-
fully. It is important that the muscles, also, should receive
their education by exercise. This is true, not only in respect
to children, but also of adults whose occupation confines them
within doors, and requires chiefly brain-work.

14. Persons who are engaged in manual labor in the open
air obtain all the exercise necessary for bodily health in their
regular business : their need is more likely to be a discipline
or exercise of the mind. A perfect business of life, therefore,
would be one which would combine both physical and mental
labor in their proper proportions. If such a business were
possible for all the human race, life would thereby be vastly
prolonged. Such, in fact, is to a large extent the occupation
pertaining to one period of life — childhood. One part of the
time is given to study, and another to muscular education by
means of games and sports. The restlessness and playfulness
of children is not only natural but beneficial.

15. The Effects of Exercise. — Exercise consists in a well-
regulated use of the voluntary muscular system. The effects,
however, are not limited to the parts used. Other organs,
which are not under the control of the will, are indirectly
influenced by it. The heart beats more rapidly, the skin acts
more freely, the temperature rises, the brain is invigorated,

13. Action ? Use of organs ? Training of the mind ? The child's brain ? Education
of the body ?

14. Work in the open air ? A perfect business ? The consequence of universal perfect
business ? Occupation of children ?

15. In what does exercise consist ? Effects of it ?

40 THE MUSCLES

and the appetite and power of digestion are increased. An
increased exhalation from the lungs and skin purifies the cur-
rent of the circulation, and the body as a whole thrives under
its influence. (Bead Note 2.)

16. The first effects of exercise, however, are upon the
muscles themselves ; for by use they become rounded out and
firm, and increase in power. If we examine a muscle thus
improved by exercise, we find that its fibres have become
larger and more closely blended together, that its color is of a
darker red, and that the supply of blood-vessels has increased.
Without exercise the muscle appears thin, flabby, and pale.
On the other hand, excessive exercise, without sufficient relax-
ation, produces in the muscle a condition not very different
from that which follows disuse. The muscle is worn out
faster than nature builds it up, and it becomes flabby, pale,
and weak.

17. Violent exercise is not beneficial ; and spasmodic efforts
to increase the muscular strength are not calculated to secure
such a result. Strength is the result of a gradual growth, and
is most surely acquired if the exercise be carried to a point
short of fatigue, and after an adequate interval of rest. To
gain the most beneficial results, the exercise should be at regu-

2. Health in Athletic Exercise. — " Health is perpetual youth — that
is, a state of positive health. Merely negative health, the mere keeping
out of the hospital for a number of years, is not health. Health is to feel
the body a luxury, as every vigorous child does ; as the bird does when
it shouts and quivers through the air, not flying for the sake of the goal,
but for the sake of flight ; as the dog docs when he scours madly across
the meadows, or plunges into the muddy blissfulness of the stream ; but
neither bird, nor dog, nor child enjoys his cup of physical happiness —
let the dull or the worldly say what they will — with a felicity so cordial
as tin- educated palate of conscious manhood. To ' feel one's life in every
limb,' this is the secret bliss of which all forms of athletic exercise are
merely varying disguises ; and it is absurd to say that we cannot possess
this when character is mature, but only when it is half developed. As
the flower is better than the bud, so should the fruit be better than the
flower."

16. General effect upon the muscles ? Special effect ? Effects of inaction ? Of excessive
exercise ?

17. Of violent and spasmodic efforts ? Strength, how attained ? Give the particulars.

THE MUSCLES 41

lar hours and during a regular period, the activity and the time
varying with the strength of the individual, and carefully
measured by it. {Bead Note 3.)

18. Different Modes of Exercise. — There are very few who
have not the power to walk. There is required for it no
expensive apparatus, nor does it demand a period of prelimi-
nary training. Walking may be called the universal exercise.
With certain foreign nations, the English especially, it is a
very popular exercise, and is practised habitually by almost
every class of society ; by the wealthy who have carriages, as
well as by those who have none ; by women as well as by men.

19. Running, leaping, and certain other more rapid and
violent movements are the forms of exercise that are most
enjoyed in childhood. For the child, they are not too severe,
but they may be so prolonged as to become injurious. Instances
have been recorded where sudden death has resulted after
violent playing, from overtaxing the heart: for example, we
have the case of a young girl who, while skipping the rope,

3. The Ill-effects of Over-exertion. — "It should be recollected that
the action of the muscles has limits, as well as that of every other organ
of the body. The muscles and the heart may be taxed too severely, and
permanent derangements may be produced by overtaxing the human
body. The ancient gymnasts among the Greeks are said to have become
prematurely old, and the clowns (or acrobats) and athletes of our own
days suffer from the severe strain put upon their muscular systems.'' The
effects of boat-racing in England have been thus described by Dr. Skey,
an eminent surgeon: "The men look utterly exhausted. Their white
and sunken features and pallid lips show serious congestion of the heart
and lungs, and the air of weakness and lassitude makes it a marvel how
such great exertion should have been so nobly undergone. We have
repeatedly seen the after ill-effects — spitting of blood, congested lungs,
and weakness of the heart from over-distension." "Persons should
neither walk, run, leap, or play at any game, to the extent of producing
permanent or painful exhaustion. All exercise should be attended with
pleasurable feelings ; and when pain is produced by proper exercise, those
who suffer should rather seek medical advice than persevere in exercise."
— Lankester'1 s Manual of Health.

18. What may walking be called f What farther i> said of walking I

19. What is said of running, and other like movements ? What, as related to childhood f
What instances arc alluded to I Example i

42 THE MUSCLES

and endeavoring to excel her playmates by jumping the great-
est number of times, fell dead from rupture of the heart.

20. Carriage-riding is particularly well suited to invalids
and persons advanced in life. Horseback exercise brings into
use a greater number of muscles than any other one exercise,
and with it there is an exhilaration of feeling which refreshes
the mind at the same time. It is one of the manliest of exer-
cises, but not less suitable for women than for men. To be
skilful in riding, it should be begun in youth.

21. For those who live near streams or bodies of water,
there are the delightful recreations of boating, swimming, and
skating. Certain of these exercises have a practical importance
aside from and above their use in increasing the physical vigor.
This is especially true of boating and swimming, since they are
often the means of saving life. Practice in these exercises
also teaches self-reliance, courage, and presence of mind.
Persons who have become proficient in these vigorous exercises
are generally the ones who, in times of danger, are the quickest
to act and the most certain to do so with judgment.

22. Physical Culture. — That form of exercise which interests
and excites the mind, will yield the best results ; but to some
persons no kind of exertion whatever is, at first, agreeable.
They should, nevertheless, make a trial of some exercise, in
the expectation that, as they become proficient in it, it will
become more pleasant. In exercise, as many sets of muscles
should be employed as possible, open-air exercise being the
best. Parlor gymnastics and the discipline of the gymnasium
are desirable, but they should not be the sole reliance for
physical culture. No in-door exercise, however excellent in
itself, can fill the place of hearty and vigorous activity in the
open air. (Read Note 4. )

4. Exercise should be Pleasurable. — "The world seldom attaches
much value to things which are plain and easily understood. The dervish
in the Eastern allegory, well aware of this weakness, knew that it would
be in vain to recommend the sultan, for the cure of his disease, simply to

20. Carriage-riding f Horseback-riding?

21. Boating, swimming, and skating?

22. What kind of exercise yields the best results ? What advice is given

THE MUSCLES 43

23. Excessive Exercises. — If neglect of exercise is injurious,
so also is the excess of it. Violent exertions do harm ; they
often cause undue strain, and even lasting injury to some part
of the body. For this reason the spirit of rivalry which leads
to tests of endurance and feats of strength should be dis-
couraged. Those trials of the muscles, especially, which are
supposed to demand "training," should not be encouraged.
Training, it is true, can produce a remarkable muscular develop-
ment, so that nearly every muscle of the limbs is as large and
corded as the arm of a blacksmith; but it is too often at the
expense of some internal, vital organ. Large muscles are not
a certain index of good health. It was well known by the
ancients that athletes of their day were short-lived, notwith-
standing the perfection of the physical training then employed.
When a person overtasks the heart, or, in other words, "gets
out of breath," he .should regard it as a signal to take rest. It
is well known that both horses and men, after having been
brought into - condition " for competitive trials, soon lose the
advantages of their training after the occasion for it has
passed.

24. Gymnastic Exercises for Schools and Colleges. — In the
.system of education among the ancients, physical culture pre-
dominated. In ancient Greece, physical exercises in schools
were prescribed and regulated by law, and hence these schools
were called gymnasia. At the present time, on the contrary,
this culture is almost wholly unknown, as a part of the course
of education, in our schools, and but to a limited extent in

take exercise. lie knew that mankind in general required to be cheated,
galled, cajoled, even into doing that which is to benefil themselves. He
• lid not, therefore, tell the sultan, who consulted him, to take exercise, but

he said to him : • Here is a ball, which I have stuffed with certain rare,
cnstly, and precious medicinal herbs. Your highness musl take this bat,

and with it heat about tins ball until you perspire very freely. You must
do this every day.' His highness did so, and in a short time the exercise
of playing at bat and ball with the dervish cured his malady." — First Help.

23. Physical culture among the ancients J In Greece! In bcI 1> ami colleges at tin.'

• the body ami mind ?
■J4. Tin' result of gymnastics in our colleges and other institutions of learning?

44 THE MUSCLES

colleges. In a few of our schools, however, physical exercises
have been introduced, with manifest advantage to the students,
and they form a part of the regular curriculum of exercises, —
as much so as the recitations in geography, grammar, or Greek.
The good effect of the experiments, as shown in improved
scholarship as well as increased bodily vigor, in the institutions
where the plan has been tried, will, it is hoped, lead to its
universal adoption. We should then hear less frequently of
parents being obliged to withdraw their children from school,
because they become exhausted or, perchance, have lost their
health from intense and protracted mental application.

25. Were gymnastics more common in our educational insti-
tutions, we should not so often witness the sad spectacle of
young men and women leaving our colleges and seminaries,
with finished educations it may be, but with constitutions so
impaired that the life which should be devoted to the accom-
plishment of noble purposes must be spent in search of health.
Spinal curvatures, which, according to the experience of phy-
sicians, are now extremely frequent, especially among women,
would give place to the steady gait and erect carriage which
God designed his human creatures should maintain. {Bead
Notes 5 and 6.)

5. Health and Strength are not always Identical. — " Health and
strength are not synonymous terms. A person may have great strength
in his limbs, or in certain muscles about the body, but really not have
good health. It is altogether a mistaken idea to suppose that physical
exercises have for their sole object the attainment of strength. There
are other tissues and organs in the human system besides the muscular ;
and the healthy action of the lungs and the stomach is far more important
than great strength in the arms, legs, or the back. It is here, in this
general exercise of all the muscles and parts of the body, that a well-
regulated system of gymnastics has its great excellence. It aims to pro-
duce just that development of the human system upon which good health
is permanently based, described by a distinguished writer as follows : —
' Health is the uniform and regular performance of all the functions of
the body, arising from the harmonious action of all its parts,' — a physical
condition implying that all are sound, well-fitting, and well-matched.
Some minds do not look far enough into life to see this distinction, or to
value it if seen ; they fix their eyes longingly upon strength — upon strength

25. Were gymnastics more common f To what are spinal curvatures due ?

THE MUSCLES 45

26. All the exercises necessary for the proper development
of the body may be obtained from the use of a few simple con-
trivances, that every one can have at home at little cost — less
by far than that of useless toys. Many of these may be made
available in the parlor or chamber, though all exercises are far
more useful in the open air. A small portion of the day thus
spent will afford agreeable recreation, as well as useful exer-
cise. The Indian club, the wand, the ring, and the light
wooden dumb-bell are among the articles devised to assisl in
the smooth performance of class drill. Pleasant music timed
to the movements of the drill is a further aid, just as martial
music by a good band is a great help to soldiers on the march.

27. Home Gymnastics. — This is perhaps a better name than
parlor gymnastics for those exercises which may be practised
by individuals at home. Apparatus of various forms, and
generally simple in construction, has been devised, and may be
had at small cost. It can be set up in almost any room in the
house. In some of these appliances cords or bands of rubber
and pulleys are used; in others, simply weights with cords

now, and seemingly care not for the power to work long, to work well,
to work successfully hereafter, which is health.'1'' — Dr. Nathan Mien on
Physical Culture.

6. On Recreation. ■ — " Our whole method of amusements, especially for
the young, should be reformed. Gas-light should yield to daylight, night
vapors in heated and close rooms should give way to fresh air under the
open heavens, and our young people should be brought up to work and
play under the ministry of that great solar force which is the most benign
and god-like agent known to men. Ardent spirits and tobacco should be
given up. and in their stead genial exercise of riding, gymnastics, and
the dance, with music and all beautiful arts, should be employed to stir
the languid powers and soothe the troubled affections. The old Greeks
taught music and gymnastics as parts of education, and Plato, in uiging
the importance of these, still maintains that the soul is superior to the
body, and religion is the crown of all true culture. Why may not Chris-
tian people take as broad a position on higher ground, and with a generous
and genial culture associate a faith that is no dreamy sentiment or ideal
abstraction, but the best power of man and the supreme grace of God."
— Rev. Dr. Osgood on " The Skeleton in Modern Society."

26. Proper exerrise at home? How obtained at home ? What as to regularity J
-'7. What kind of apparatus is recommended for home gymnastics ? Why ? Describe
advantages of the "chest weight."

46

THE MUSCLES

and pulleys, without elastic material. The latter kind is
better, inasmuch as the movement is even and the action of
the muscle steady, while with
rubber bands the farther they are
stretched the greater is the exer-
tion. No apparatus yet invented
answers its purpose so well as the
"chest weight" (see Fig. 17). By
its use all the prominent muscles
of the body are easily exercised.
Xo instruction is necessary and
the space occupied is easily
spared. A person is obliged only
to grasp the handles and then
follow the simple directions given
to bring into action whatever
muscles or groups of muscles he
wishes to exercise. The weight
can be changed to suit the
strength of the one exercising.
Illustrations showing a few of
the positions and movements that are recommended with one
of the chest weights, are given in the Appendix, page 304.

28. In addition to the movements mentioned many others
might be employed, varying with the particular muscles or
parts that require to be exercised. Combinations of cords and
pulleys suitable for particular cases can be made, and the
resistance of the weights adjusted to the needs of the Aveakly
and the young, as well as to the most robust, These exercises
are by no means limited to those who are in health and who
resort to them as a relaxation from long study or sedentary
occupations. Persons who are not strong, who cannot take
advantage of school drill, or who are convalescing from sick-
aay, under suitable conditions, be especially benefited by
them. Not all the movements should be tried at first, but, on
the contrary, there should be a careful selection of two or
three thai seem to be best suited to the needs of the patient.

THE MUSCLES 47

These exercises must also be undertaken gradually and in-
creased in proportion to the ability of each individual. There
should be some degree of uniformity as to the time of day
as well as to the form and duration of the gymnastic effort
engaged in. Kemember always to stop short of the point
where manifest fatigue begins to be felt, regardless of the
shortness or the length of the time. The keynote to beneficial
home exercise is to put into use as many muscles as is proper
and safe, without bringing about a feeling of exhaustion. If
exhaustion is produced, the exercise passes into violence, and
as we have formerly learned, violence is harmful. It must be
remembered that these movements not only develop the parts
named, but each movement exercises many other muscles at
the same time. In Figs. 9 and 10 (App.) always take a deep
breath before each motion. Then the pressure of the filled
lungs, together with the action of the muscles, will more
quickly widen and deepen the thorax.

29. Rest. — We cannot always be active: after labor Ave
must rest. We obtain this rest partly by suspending all exer-
tion, as in sleep, and partly by a change of employment. It
is said that Alfred the Great recommended that each day
should be divided in the following manner : " Eight hours for
work, eight hours for recreation, and eight hours for sleep."
This division of time is as good as any that could now be
made, if it be borne in mind that, when the work is physical,
the time of recreation should be devoted to the improvement
of the mind; and when mental, we should then recreate by
means of physical exercise.

30. During sleep, all voluntary activity ceases, the rapidity
of the circulation and breathing diminishes, and the tempera-
ture of the body falls one or two degrees. In consequence, the
body needs wanner coverings than during the hours of wake-
fulness. During sleep, the body seems wholly at rest, and the
mind is also inactive, if we except those involuntary mental

29. Need of repose? How do we obtain rest? Alfred the Great} The eight hour

division of time?

80. Cessation of voluntary activity ? Temperature of the body ? Consequence? Body
and mind during sleep ? Nutrition ? Describe it. Consequence of insufficient sleep I

48 THE MUSCLES

wanderings which we call dreams. Nevertheless a very active
and important physical process is going on. Nutrition, or the
nourishing of the tissues, now takes place. While the body is
in action, the process of pulling down predominates, but in
sleep, that of building up takes place more actively. In this
way we are refreshed each night, and prepared for the work
and pleasures of another day. If sleep is insufficient, the
effects are seen in the lassitude and weakness which follow.
Wakefulness is very frequently the forerunner of insanity,
especially among those who perform excessive mental labor.

31. All persons do not require the same amount of sleep, but
the average of men need from seven to nine hours. There are
well-authenticated cases where individuals have remained with-
out sleep for many days without apparent injury. Frederick
the Great required oidy five hours of sleep daily, and Bonaparte
could pass days with only a few hours of rest. But this long-
continued absence of sleep is attended with danger. After
loss of sleep for a long period, in some instances, stupor has
('(.me on so profoundly, that there has been no awaking.

32. There are instances related of sailors falling asleep on
the gun-deck of their ships while in action. On the retreat
from Moscow, the French soldiers would fall asleep on the
march, and coidd only be aroused by the cry, " The Cossacks
are coming ! " Tortured persons are said to have slept upon
the rack in the intervals of their torture. In early life, wrhile
engaged in a laborious country practice, the writer not unfre-
quently slept soundly on horseback. These instances, and
others, show the imperative demand which nature makes for
rest in sleep.

33. Alcohol and Strength. — Alcohol, a substance to be fully
described in our subsequent chapter on Food and Drink, merits
consideration at tins point by reason of the mistaken views
held by many as to its beneficial effects upon the muscles,

81. Amount of Bleep for different persons? Cases? Frederick the Great ? Bonaparte?
Instances of long deprivation of sleep?

:;■_'. Instances of sailors? French soldiers ? During torture ?
83. The former use of grog.

THE MUSCLES 49

when they are put into vigorous use, and especially into daily
manual labor. It is well known that for generations it was
thought to be essential to every army and navy of the civilized
world that "grog"' — which contains alcohol — should be regu-
larly issued to the hard-worked soldier and sailor, especially
when they were in the actual service of war. To the slaves,
also, on many plantations, during the days of slavery in this
country, a daily ration of rum was given out in the busy
seasons, in the belief that thus better results, in regard to the
amount of muscular labor, were secured. So, too, in nearly
every walk of life where hard muscular labor was demanded,
a similar belief and practice commonly prevailed, and some
form of alcohol was resorted to as a trusty servant whenever
any great or unusual amount of labor was to be called forth.

34. How Alcohol affects the Muscles. — The scientific progress
of recent years, however, has put the question in a different
light, and it is now the commonly received view of scientific
men that the benefits to labor derived from alcohol were ap-
parent and not real. Alcohol adds nothing to our bodily
energy; it may spur up the muscles to a temporary and extra-
ordinary exertion, but it does not strengthen the muscles any
more than does the whip or the spur, that is applied to a hard-
laboring horse to make him go faster, add to his strength.

35. Experiments have been made with instruments con-
structed for the purpose, and the results carefully recorded,
and these show that a less degree of muscular power is pos-
sessed by the same person when he is under the influence of
alcohol than when he has not taken it (see foot-note on p. 241).
This is no secret to men who go into training to bring about
the best possible development of their muscular strength; men
who intend to engage in contests, such as boat-racing, foot-
racing, and a great variety of other athletic sports, are taught
to abstain entirely from all forms of drink that contain alcohol
if they would bring their powers to the highest point. The
endurance of severe and prolonged bodily labor is not favored

34. Present belief as to Its use!

85. What experiments have been tried! Training of athletes ? What experience of
soldieTe '.'

50 THE MUSCLES

by the use of alcohol. The test recently made upon the British
troops during the war in the Soudan, showed that the exhaust-
ing work, privation, and the burning heat of the desert can be
better endured by those who have not, than by those who have
the ration of grog. The time is coming when this ration will
be a thing of the past, and that, too, for good scientific reasons.

36. Abnormal Movements due to Alcohol. — The amount of
disturbance in the muscular system that is produced by alcohol
varies greatly under different circumstances. It may be very
great or very slight according as a great or small dose of liquor
is taken. The tongue, the organ of speech, is a muscle that
early betrays the presence of drink. This is the cause of what
is called the " thick " speech of the drunken man, whose words
are not correctly uttered but are dropped, cut short or run
together in an unusual and oftentimes unintelligible manner.
" Seeing double " is another muscular disturbance observed in
drunkenness. At a certain stage of the drunken fit every
single object appears to the victim to be double. In this case
the muscles that move the eyeballs are at fault; they are
temporarily deranged, so that the two eyeballs cease to move
harmoniously and are no longer brought to bear upon the
objects before them, as in health, and the images of two objects
are reported to the brain, while in reality there is only one.
Then, too, objects that are at rest appear to be in motion,
because the eyeballs are affected by an unsteady, rolling
motion. This is one reason why, at a certain stage, the
drunken man who tries to walk abroad, begins to stagger from
side to side over the sidewalk, to stumble and perhaps to fall,
and sober men appear to him to stagger and be drunk. The
muscles of his limbs also, in their turn, becoming weakened,
or not being properly controlled, may refuse to sustain the for-
lorn pedestrian, and he may be seen clinging for support to
some friendly lamp-post, or, later on, sinking powerless into
the gutter.

86. Does alcohol derange the muscles ? What effect upon the tongue ? The eyes and
limbs?

THE MUSCLES

m.

VOLUNTARY MUSCLE.
(Striated or Striped.)

INVOLUNTARY MUSCLE.
(Non-striated or Unstriped.)

MUSCLES OF THE
HEART.

TOPICAL OUTLINE

Under the control of the will.

Composed of bundles of fibres.

These bundles composed oi smaller bundles
( fasciculi) , visible to the unaided eye, and
surrounded by sheaths.

Fasciculi composed of Jibres. Average diame-
ter about .-,,'„, in.

Fibres made op of minute fibrillx {fibrils).

Fibrillar composed of disc-like bodies, and are
consequently striated transv( rsely.

Not iimler the control of the will.

Found chiefly in the muscular walls of the

'mil run! organs and vessels.
Fibres composed of elongated cells with

pointed ends, not marked transversely.
Involuntary, yet striped or striated.
Striated longitudinally as well as trans-

vt rsely.
Fibres composed of oblong and branched cells.

TABLE OF THE PRINCIPAL MUSCLES
(See Figure 11, Page 32)

The Head

Oc-cip'i-to— fron-ta'lis, moves the scalp and eyehrows.

Or-bic-u-la'ris pal'pe-brae, closes the eye.

Le-va'tor pal'pe-brae, opens the eye.

The Recti muscles (four in number) move the eyeball.

Tem'po-ral, { raise the lower •

Mas-se ter, )

The Neck
Pla-tys'ma My-oi'des, j moyfl ^ head fonvanR
Ster no Mas toid, )

Sca-le'ni muscles move the neck from side to side.

The Trunk

Pec-to-ra'lis, moves the arm forwards.

La-tis'si-mus dor'si, moves the arm backwards.

Tra-pe'zi-us, \

Ser-ra'tus mag'nus, > move shoulder-blade.

Rhom-boi-de'us, '

In-ter-cos'tals, move the ribs in respiration.

External Oblique, j m(m ^ trunfe forw!m,s

Internal Oblique, 1

E-rec'tor spi'nae, move the trunk backwards.

THE MUSCLES

The Upper Limb

Del'toid, raises the arm.
Teres ma'jor, lowers the arm.

fub-scaP-u-laris-' rotate the arm.
Spi-na tus, )

Biceps, bends forearm.

Tri'ceps, straightens forearm.

Pro-na'tor, J rQtate forearm>

Su-pi-na tor, )

Flex'or car'pi ra-di-a'lis, i

Flexor car'pi ul-na'ris, I move the hand>

Ex-tensor car'pi ra-di-a'lis,

Ex-tensor car'pi ul-na'ris, J

More than thirty muscles take part in moving the fingers.

The Lower Limb
Il-i'a-cus,

Pso'as mag'nus, | moye ^ mh forwards#
Pec-tin-e us,
Ad-duc'tor, J

Glu-te^us, j move the thi h backwards;
Pyr-i-form is, )

Sar-to ri-us (from Sar'tor, a tailor), crosses one thigh over the other.
Rec'tus, / move the j forwards.
Vas tus, )

Bi ceps, j th j backwards.

Grac'i-hs, ) °

Tib-i-a'lis,

Per-o-ne'us m0Te the foot.

Gas-troc-ne mi-us, j
So-le'us, J

Twenty muscles take part in moving the toes.

QUESTIONS FOR TOPICAL REVIEW

PAGE

1. What can you state of the number and division of the muscles? 33

2. Describe the structure of the muscles 33, 34

3. Their arrangement in pairs and consequent action 34

4. What is the difference between the motion called flexion and that

called extension ? 34

5. Describe their action, and state which are the more powerful 34

(>. AYhat is the difference between voluntary and involuntary muscles? 34

7. Illustrate the difference between t lie two 34

8. State all you can of the tendons or sinews 35, 30

'.). What is meant by contraction of the muscles? 3b"

10. In how many and what ways may contraction be effected? 36

11. What is stated of after-death contraction? 3(), 37

12. Why cannot a muscle in life continue contracted a long time? 37

13. How then can the constant beating of the heart be explained? 37, 38

14. How does the strength of a man compare with that of a horse? 38

1"). What can you state in regard to the relative strength of animals ?. . 38

THE MISCLES 53

PAS!

It;. What, in relation to physical strength? as

17. What, in relation to physical degeneracy '.' 38, 39

18. AN'hat , in relation to the importance of exercise? 39

19. What is the effecl of exercise apon the heart, skin, and appetite? 39, 1"

20. How dues exercise affect the current of the body's circulation .'.... 40

21. How does judicious exercise affect the muscles '.' 40

•_'•_'. "What is stated of violent and spasmodic exercise '.' 40

23. Of the exercise of walking? 41

'_'4. Of running, leaping, and other modes of exercise? 41, 42

25. ( >! physical culture, in connection with out-door exercises? 42

•J*;. What are the result- of excessive exercise? 43

27. I >f the importance of gymnastics in our schools and colleges? 43, u

2-S. ( if the importance of rest from labor or exercise? 47

29. What processes take place during sleep? 48

:'<*). What aboul the amount of sleep required? 48

31. What effects follow insufficient sleep? 48

32. Illustrate nature's demand for sleep 48

CHAPTER III

THE INTEGUMENT, OR SKIN

The Integument — Its Structure — The Xails and Hair — The Complex-
ion— The Sebaceous Glands — The Perspiratory Glands — Perspiration
and Its Uses — Importance of Bathing — Different Kinds of Baths —
Manner of Bathing — The Benefits of the Sun — Importance of Warm
Clothing — Poisonous Cosmetics

1. The Skin. — The skin is the outer covering of the body.
The parts directly beneath it are very sensitive, and without
its protection life would be an agony, as is shown whenever by
accident the skin is broken or torn off, the bared surface being
very tender, and sensitive even to exposure to the air. Nature
has provided the body with a garment that is soft, pliable,
close-fitting, and very thin ; and yet sufficiently strong to ena-
ble us to come in contact with the objects that surround us,
without inconvenience or suffering.

2. The Structure of the Skin. — When examined under the
microscope, the skin is found to be made up of two layers —
the outer and the inner. The inner one is called the cutis, or
true skin ; the outer one is the epidermis, or scarf-skin. The
latter is also known as the cuticle. These two layers are closely
united, but they may be separated from each other. This sepa-
ration takes place Avhenever, from a burn or other cause, a
blister is formed ; a watery fluid is poured out between the
two layers, and lifts the epidermis from the true skin. Of the
two layers, the cuticle is the thinner in most parts of the body,
and has the appearance of a whitish membrane. It is tough

1. What is the skin ? Parte directly beneath ? What Is shown ?
•_'. Microscopic examination ? What is the cutis? The cuticle? Their union? How
separated ? What further is said of the cuticle i

54

THE INTEGUMENT, OR SKIX 55

and elastic, is without feeling, and does not bleed when cut.
Examine it more closely, and we observe that it is composed
of minute flat cells, closely compacted, and arranged layer upon
layer.

3. The outer layer, the epidermis, is constantly being worn
out, and falls from the body in the form of very fine scales.
It is, also, continually forming anew on the surface of the inner
layer. Its thickness varies in different parts of the body.*
Where exposed to use, it is thick and horn-like, as may be seen
on the soles of the feet, or on the palms of the hands of those
who are accustomed to perform much manual labor. This is
an admirable provision for the increased protection of the
sensitive parts below the skin against all ordinary exposure.
Even the liabilities of these parts to injury are thus kindly
provided for by " the Hand that made us." {Bead Note l.)

4. The cutis, or true skin, lies beneath the epidermis, and is
its origin and support. It is firm, elastic, very sensitive, and

* Like all other parts of the body, the scarf-skin is constantly being
worn out ; it dries, shrivels, and falls from the body in the form of fine
flakes, or scales. In the scalp, these scales form the "dandruff." As
fast as it wears away it is renewed from beneath. This seemingly simple
process is very important, for by it a uniform thickness is secured to the
covering of the body. If it were otherwise, this covering would grow
thicker as it grew older, like the bark of a tree, until it became unwieldy;
it would prevent perspiration also, and this, as we shall see, would be
fatal to life. The growth of the true skin is provided for in the blood-
vessels which abound in it.

1. The Renewal of the Cuticle. — The skin is not a permanent sheath,
but is, as it were, always wearing out and rubbing off, and new skin is
always rising up from underneath. A snake leaves off his whole skin at
once, as we leave off a suit of clothes or a dress, and sometimes we may
find his whole cast-off covering turned inside out, just as he crept out of
it. In man, generally, we do not notice the dead particles of the skin as
it wears off ; but where the cuticle is pretty thick, as on the soles of the
feet, we can see it peel off in little rolls whenever we wash the feet in hot
water. After scarlet fever, too, sometimes the dead skin comes off in
great flakes, and from the hands almost like the fingers of a glove.
— Bemers.

8. Wearing out of the cuticle t What then J Variety In thickness of cuticle ? now
accounted for?

4. Location and oflice of the cutis? What further is said of it J Papilltef Touch?

56

THE INTEGUMENT, OR SKIX

is freely supplied with blood-vessels. Hence, a needle entering
it not only produces pain, but draws blood. It is closely
connected with the tissues below it, but may be separated by
means of a sharp instrument. The surface of the cutis is not
smooth, but covered here and there' with minute elevations,
called papilhe. These are arranged in rows, or ridges, such as
those which mark the palm and thumb ; their number is about
80 to the square line (a line being one-twelfth of an inch).
These papilhe contain blood-vessels and nerves also, and are
largely concerned in the sense of touch; hence they are

abundant where the touch is
a most delicate, as at the ends

of the fingers.

5. The Nails and Hair. —
These are modified forms of
the cuticle. The nail grows
from a fold of the cuticle at
the root, and from the under
surface. As fast as it is
formed, it is constantly being
pushed outward.* The rapidity
of its growth can be ascer-
tained by filing a slight groove
on its surface, and noticing
,e root of a hair highly mag™.,:,, how the space between it and

1, 2, 3. The skin forming the hair-sac. 4. So- the root of the nail increases,
baceous glands. 5. The hair-sac , , « « ••

m the course of a few weeks.

When the nail is removed by
an accident, it will be replaced by a new one, if the root be not
injured. (Xotes 2 and 6.)

* The practice of biting the nails should be avoided not only because
of the ugly shape which is produced, but because it impairs the sense of
touch in the ends of the fingers. In paring the nails, let them remain long
enough to nearly cover the pulp of the finger. Avoid scraping either sur-
face of the nail ; do not injure the '• quirk."

2. The Life of the Cells of the Body.— " The life of the body is long

Fig. IS

5. What are the nails and hair * The growth of the nail ? The rapidity of its growth ?
Accident to the nail f

THE INTEGUMENT, OR SKIN 57

6. The hairs are produced in a similar manner; the skin
forming depressions, or hair-sacs, from the bottom of which
they grow and are nourished (Fig. 18;. They are found, of
greater or less length, on almost all parts of the surface, except
the palms of the hands and soles of the feet. On certain pints
of the body, they grow to great length; on other pints they
are so short, that they do not rise beyond the hair-sac from
which they grow.

7. The bulb, or root, from which the hair arises, is lodged
in a small pouch, or depression of the skin. The shaft is the
part which grows out beyond the level of the skin. Its growth
is altogether in one direction, in length alone. The outer part
of the hair is quite firm, while its interior is softer, and supplies
the nutriment by which it grows. The hair is more glossy in
health than at other times.

8. The nail serves as a protection to the end of the finger,
and also enables us to grasp more firmly, and to pick up small
objects. The hair, too, is a protection to the parts it covers.
On the head, it shields the brain from extremes of heat and
cold, and moderates the force of blows upon the scalp. On
the body, it is useful in affording a more extensive surface for
carrying off the perspiration.

under fortunate circumstances ; that of our cells is short. We all know
that the surface of the body is covered by layers of cells. The super-
ficial layers are in loose connection ; they are cells in old age. The fric-
tion of our clothing daily removes an immense number of them. A
cleanly person who uses sponge and towel energetically every day rubs off
a still greater quantity.

■• We swallow ; our tongue acts in speaking ; drink and food pass this
way. Now, the mucous membrane of the mouth is covered with layers
of cells. Here, also, many thousand senile cells are rubbed off daily.
And so on through the entire digestive tract. An immense number of
cells — these living corner-stones of the body — is thus lost daily.

"To show the duration of life in one kind of cell, let us turn to the
human nail. The latter, growing from a furrow of the skin, is made up
of skin-cells. In the depth of the furrow, youth prevails ; at the upper
margin — which we trim — old age. Berthold proved that a nail-cell

0. How arc the bain produced J Difference in their length?

7. Root of the hair 1 Shaft 1 Firmness and softness of the hair ?

8. Office of the nail? Ofthehair? Give the illustrations.

58

THE INTEGUMENT, OR SKIN

9. Complexion. — In the deeper cells of the cuticle lies a
pigment, or coloring-matter, consisting of minute colored grains.
On this pigment complexion depends ; and its presence, in less
or greater amount, occasions the difference of hue that exists
between the light and the dark races of men, and between the
blonde and the brunette of the white races. Freckles are due
to an irregular increase of this coloring matter.

10. The sun has a powerful influence over the development
of this pigment, as is shown by the swarthy hue of those of
the white race who have colonized in tropical climates. It is

also well illustrated by the fact,
that among the Jews who have
settled in northern Europe,
there are many who are fair-
complexioned, while those re-
siding in India are as dark as
the Hindoos around them.

11. An Albino is a person
who may be said to have no
complexion ; that is, there is
an entire absence of coloring

JjifaMwiM5* --- -- matter from the skin, hair, and

| iris of the eye. This condition

exists from birth, and more

Hair and Section frequently occurs among the

or Skin H.ghly Magnified dark mce&> and ^ h()t climates?

although it has been observed in almost every race and clime.

12. Sebaceous Glands. — In all parts of the surface where
the hairs grow, are to be found the sebaceous, or oil-producing

l>^k^JI

Fig. 19. — Showing

lives four months in summer and five in winter. A person dying in his
80th year, lias changed his nail 200 times, at least — and the nail appeared
such an inanimate, unvarying thing ! No other cells, we believe, have a
life nearly so long as that of the nail." — Compendium of Histology by
Heinrich Frey.

9. On what does the complexion depend ? Light and dark root s ? Freckles ?

10. Influence of the sun? How Illustrated J Jews?

11. Wliai Is an Albino? Where are Albinos found ?

12. What are sebaceous glands? llow do they act? Sebaceous glands of the face ?
How do they act f

THE INTEGUMENT, OR SKTX 59

glands. These glands are little rounded sacs, usually connected
with the hair-bulbs; and upon these bulbs they empty their
product of oil, which acts as a natural dressing for the hair
(Fig. 18). A portion of the sebaceous matter passes out upon
the surface, and prevents the cuticle from becoming- dry and
hard. The glands situated upon the face and forehead open
directly upon the skin. In these, the sebaceous matter is
liable to collect, and become too hard to flow off naturally.

13. These glands on the face and forehead f recpiently appear
on the faces of the young as small, black points, which are
incorrectly called "worms." It is true, that
occasionally living animalcules are found in
this thickened sebaceous matter, but they can
only be detected by the aid of the micro-
scope. This sebaceous matter acts not only
to keep the skin flexible, and furnish for
the hair an oily dressing, but it especially
serves to protect the skin and hair from the
acridity arising from the perspiration.

14. The Perspiratory Glands. — The chief
product of the skin's action is the perspira-
tion. For the formation of this, there are
furnished countless numbers of little sweat-
glands in the true skin. They consist of fine
tubes, with globe-like coils at their deeper
extremity. Their mouths or openings may

J l ° J Fig. 20. — Magnified

be seen with an ordinary magnify ing-glass, v«w o» a mum-

upon the fine ridges which mark the fingers, gjj^ W1TH ™

These tubes, if uncoiled, measure about one- a, the gland Burronnded

tenth of an inch in length. In diameter gS^SiST'S.

they are about one three-hundredth of an dermis; e, its continu-
, , atioo through

inch, and upon parts ot the body there are mucosum, and <z,
not far from three thousand of these glands ^f3hthc «W"^
to the square inch. Their whole number in
the body is, therefore, very great ; and it is computed, if they

13. Black points, called worms ? Animalcules ! Service performed by sebaceous matter ?

14. Perspiration? sweat glands ? Of what do they consist ? Dimension of the tubes ?

60 THE INTEGUMENT, OR SKIN

were all united, end to end, their combined measurement would
exceed three miles.

15. The Sensible and Insensible Perspiration. — The pores of
the skin are constantly exhaling a watery fluid; but, under
ordinary circumstances, there is no moisture apparent upon
the surface, for it evaporates as rapidly as it is formed. This
is called insensible perspiration. Under the influence of heat
or exercise, however, this fluid is formed more abundantly,
and appears on the surface in minute, colorless drops. It is
then termed sensible perspiration.

16. AVater is the chief component of this fluid, there being
about ninety-eight parts of water to two parts of solid matter.
The quantity escaping from the body varies greatly, according
to the temperature of the air, the occupation of the individual,
and other circumstances. The average daily amount of per-
spiration in the adult is not far from two pints, or more than
nine grains each minute.

17. The Uses of the Perspiration. — Besides liberating from
the blood this large amount of water, with the worn-out matter
it contains, the perspiration serves to regulate the temperature
of the body. That is to say, as evaporation always diminishes
temperature, so the perspiration, as it passes off in the form
of fine vapor, cools the surface. Accordingly, in hot weather
this function is much more active, and the cooling influence
increases in proportion. When the air is already charged with
moisture, and does not readily receive the vapor of the body,
the heat of the atmosphere apparently increases, and the
discomfort therefrom is relatively greater.

18. The importance of perspiration is shown by the effects
that often follow its temporary interruption, namely, headache,
fever, and the other symptoms that accompany "taking cold."
When the perspiration is completely checked, the consequences

15. What i< Bensible perspiration i Insensible perspiration ?

16. Components of perspiration ? Upon what does perspiration depend ? Amount of
perspiration daily i

17. What does perspiration set free from the blood? What other service does perspira-
tion perforin? Explain the process.

1?. Effect of interruption of excretion ? What experiments are mentioned ?

THE INTEGUMENT, OR SHIN 61

are very serious. Experiments have been performed upon
certain smaller animals, as rabbits, to ascertain the result of
closing the pores of the skin. When they are covered by a
coating of varnish impervious to water and gases, death ensues
in from six to twelve hours — the attendant symptoms resem-
bling those of suffocation. {Bead Note 3.)

19. It is related that, at the coronation of one of the Popes,
about three hundred years ago, a little boy was chosen to act
the part of an angel ; and, in order that his appearance might
be as gorgeous as possible, he was covered from head to foot
with a coating of gold-foil. He was soon taken sick, and
although every known means were employed for his recovery,
except the removal of his fatal golden covering, he died in a
few hours.*

3. On Taking Cold. — •• Of all the things to which humanity is liable,
there is none which recurs more frequently, and whose consequences are
more troublesome and often dangerous, than ' taking cold* Some persons
have quite a faculty for taking cold,' while others do so but rarely. And
yet the one does not argue delicacy of constitution, or the other strength.
The body of man has a constant and agreeable temperature in health, the
variation being slight. In fact, any great variation is incompatible with
health, and constitutes disease. Clothes, by preventing the radiation
away of heat from the surface, retain it, and so the feeling of cold is not
so great — that is, the surface does not become so cold. Clothes are non-
conductors of heat when dry ; but let them be saturated with water, and
unless the loss of heat be met by increased production, there is a lowering
of the body temperature — • taking cold.' Thus, if exertion be continued,
and more heat is produced to meet the loss until a change of dry clothing
is procurable, no injury results. But let the wet clothes be worn without
a corresponding heat production, as when children sit down in school in
their wet clothes, or the shop-boy stands in his moist garments; then
there is a rapid loss of heat, a lowering of the body temperature, and a
cold i.s ' caught.' So is a cold caught by wet feet, when the heat is radi-
ated away from the feet; if exercise be continued the cold is not experi-
enced. A damp bed gives cold because the moist bedclothes conduct
away the heat, and the body temperature is lowered." — Fothergill on the
Mainti nance of Health.

* A clogged action of the skin is disastrous in many diseases, but
especially those attended by an eruption, or "breaking out."' One of
these — small-pox — isexceedini,r fatal among the American Indians, whole
tribes having been swept away by it. And this is explained by the fact

19. Givo the Story iu relatiou to the buy covered with gold-foil.

62 THE INTEGUMENT, OR SKIN

20. The Importance of Bathing. — From these considerations,
it is evident that health must greatly depend upon keeping the
skin clean. "He who keeps the skin ruddy and soft, shuts
many gates against disease." For as the watery portion of the
perspiration evaporates, the solid matter is left behind. There,
also, remain the scales of the worn-out cuticle, and the excess
of sebaceous matter. In order to secure the natural action of
the skin, these impurities require to be removed by the fre-
quent application of water. {Bead Note 4.)

21. In warm climates, and during hot weather, bathing is
especially necessary. For a person in good health, a daily
cold bath is advisable. To this should be added occasionally
a warm bath, with soap, water alone not being sufficient to
remove impurities of a greasy nature. Soap facilitates this,
by forming with such substances a chemical mixture, which is
taken up by water, and by it removed from the body. {Bead
Note 5.)

that they habitually close their pores by covering their bodies with bears'
grease, as a protection against the cold, and with earthy paints as a means
of decoration.

4. Bathing. — " When the civilization of Egypt, Greece, and Rome
faded, the world passed through dark ages of mental and physical bar-
barism. For a thousand years there was not a man or woman in Europe
that ever took a bath, if the historian of those times, Michelet, is to be
believed. No wonder that there came the wondrous epidemics of the
middle ages, which cut off one-fourth of the population of Europe — the
spotted plague, the black death, sweating sickness, and the terrible mental
epidemics which followed in their train — the dancing mania, the mewing
mania, and the biting mania. Not only their persons, but their houses
were uncleanly, even in the classes that were well-to-do. Filth, instead
of being abhorred, was almost sanctified."— Lyon Flayfair.

5. An Imaginary Conversation on Baths and Bathing. — "I have
often amused myself, by fancying one question which an old Roman
emperor would ask, were he to rise from his grave and visit the sights of
London under the guidance of some minister of state. The august shade
would, doubtless, admire our railroads and bridges, our cathedrals and
our public parks, and much more of which we need not be ashamed.
lint after a while, I think, he would look round, whether in London, or
in most of our great cities, inquiringly and in vain, for one class of build-

20. Give the quotation. Perspiration?

21. Ablution in warm climates ? What advice is given ?

THE INTEGUMENT, OR SKIN 63

22. There is a maxim by the chemist Liebig, to the effect,
that the civilization of a nation is high, in proportion to the
amount of soap that it consumes ; and that it is low, in propor-
tion to its use of perfumes. In some degree, we may apply
the same test to the refinement of an individual. The soap
removes impurity; the perfume covers, while retaining it.
(Bead Notes 6 and 7.)

tngs, which in his empire were wont to be most conspicuous and splendid.
'And where,' he would ask, 'are your public baths?' And if the min-
ister of state who was his guide should answer — ' O great Caesar. I really
do not know. I believe there are some somewhere in some out-of-the-way
place ; and I think there have been some meetings lately, and an amateur
concert, for restoring, by private subscriptions, some baths and wash-
houses which had fallen to decay. And there may "be two or three more
about the metropolis ; for parishes have power to establish such places, if
they think fit, and choose to pay for them out of the rates : ' — Then. I
think, the august shade might well make answer— • We used to call you,
in old Rome, northern barbarians. It seems that you have not lost all
your barbarian habits. Are you aware that, in every city in the Roman
empire, there were, as a matter of course, public baths open, not only to
the poorest freeman, but to the slave, usually for the payment of the
smallest current coin, and often gratuitously ? Are you aware that in
Rome itself, millionaire after millionaire, emperor after emperor, built
baths, and yet more baths ; and connected with them gymnasia for exer-
cise, libraries, and porticoes, wherein the people might have shade and
shelter, and rest ? Are you aware that these baths were of the most
magnificent architecture, decorated with marbles, paintings, sculptures,
fountains, what not? And yet I had heard, in Hades down below, that
you prided yourselves here on the study of the learned languages.'" —
Rev. Charles Kingsley on the Air-mothers.

6. Care of the Skin and Nails. — " Much ignorance prevails amongst
the public as to the use of soap and water. Those who have very sensitive
skins should use soft water, for the face at all events, and the best water,
if it can be had, is rain-water with the cold taken off it. Nor is it every
kind of soap which is tolerated by such persons ; probably the safest at taps
are, not those which are said to contain, but those which really do contain,
a large portion of glycerin.

liThe culture of the nails, which when perfect constitute so great a
beauty, is of much importance : bul the tendency is to injure them by too
much attention. The scissors should never be used, except to pare the
free edges when they have become ragged or too long, and the folds of
scarf skin which overlap the roots should not. as a rule, be touched. The
upper surfaces of the nails should on no account be touched with the knife,

88. Liebig's maxim? What further is added ?

64 THE INTEGUMENT, OR SKIN

23. The Different Kinds of Baths. — All persons are not alike
able to use the cold bath. When the health is vigorous, a
prompt reaction and glow upon the surface will show that it is
beneficial. Where this pleasurable feeling is not experienced,
but rather a chill and sense of weakness follows, we are warned
that the system will not, with impunity, endure cold bathing.
Most persons experience the best results when the water is
about the temperature of the body — " blood-heat."

24. It should also be borne in mind, that the warm or hot
bath cannot be continued so long, or repeated so frequently, as
the cold, on account of the enervating effect of unusual heat so
applied to the body. For persons who are not in robust health,
one warm bath each week is sufficient. Such persons should
be carefid to avoid every extreme in reference to bathing,
clothing, and whatever greatly affects the action of the skin.

25. Sea-bathing is even more invigorating than fresh-water
bathing. Those who cannot endure the fresh water, are often
benefited by the salt-water baths. This may be accounted for,
in part, by the stimulant action upon the surface, of the saline
particles of the sea-water ; but the exciting scenes and circum-
stances of sea-bathing also exert an important influence. The
open-air exercise, the rolling surf, the genial weather, and
usually the cheerful company, add to its intrinsic benefits.
(Bead Note 8.)

as it is so often done, the nail brush being amply sufficient to keep them
clean, without impairing their smooth and polished surfaces." — People's
Magazine.

7. On Scents. — " They are the only resource of rude and dirty times
against offensive emanations from decaying animal and vegetable sub-
Btances, from undrained and untidy dwellings, from unclean clothes, from
ill-washed skins, and from ill-used stomachs. The scented handkerchief,
in these circumstances, takes the place of the sponge and the bath ; the
pastile hides the want of ventilation ; the otto of roses seems to render
the scavenger unnecessary ; and a sprinkling of musk sets all other smells
and stinks at defiance." — Johnston.

8. The Proper Use of Sea-bathing. — " The length of time during
which a person should remain in the water necessarily varies according to

23. What i< said about cold bathing ?

24. What is said about warm bathing ?

25. What is said about sea-bathing?

THE INTEGUMENT, OR SKIN 65

26. Time and Manner of Bathing. — A person in sound health
may take a bath at almost any time, except directly after a full
meal. The most appropriate time is about three hours after a
meal, the noon-hour being probably the best. For the cold
bath, taken rapidly, no time is better than immediately after
rising. Those beginning the use of cold baths should first try
them at 70° Fahrenheit, and gradually use those of a lower
temperature. From five to twenty minutes may be considered
the proper limit of time to remain in a bath ; but a sensation
of chilliness is a signal to withdraw instantly, whether at
home, or at the sea-side. Two sea-baths may be taken daily ;
one of any other kind is sufficient.

27. The body should be warm, rather than cold, when step-
ping into the bath ; and after it, the skin should be thoroughly
dried with a coarse towel. It is best to continue friction until
there is a sensation of warmth or " glow " throughout the entire
surface. This reaction is the test of the good effects of the
bath. If reaction is still incomplete, a short walk may be
taken, especially in the sunshine. It is very congenial, how-

the age, sex, and constitutional strength of the bather. Due regard should
also be had to the state of the weather and season of the year.

" In the case of children, five, gradually extended to ten minutes ; of
women, ten to fifteen minutes ; and of men, a quarter of an hour or more,
is a fair average period. There are some people, doubtless, to whom
these periods will appear insufficient, ami who insist on remaining so long
in the water that their skin becomes cold and blue, their teeth begin to
chatter, and a condition of general exhaustion comes on ; people, in short,
who have the ' most ' for their money, like the countryman who grumbled
at having been conveyed thirty miles in about half-an-hour by an express
train, on the score that the length of time occupied in the journey was
not proportionate to the fare that he had paid. On entering the water,
the bather should immerse the whole of the body two or three times, so
as to get the action of the shock from the cold water distributed over its
entire surface. There should be no hesitancy, no dabbling about with
the feet, but a good plunge at once into the next wave that washes in.
Upon coming out of the water the bather should dry the body with good
rough towels, dress quickly, and take a brisk walk for a short distance.
If there be any Eeeling of exhaustion or nervous depression, a little food
or drink should be taken."

26. What is said as to the time and manner of bathing 1

27. Condition of the body when bathing i Direction, after bathing t

C6 THE INTEGUMENT, OR SKTN

ever, both to health, and comfort, to rest for a short time
directly after bathing, or to take some light refreshment.
This is better than severe exercise or a full meal.

28. Bathing among the Ancients. — The Eomans and other
nations of antiquity made great use of the vapor-bath as a
means of preserving the health, but more particularly as a
luxury. Their method was not unlike that employed in some
parts of Europe at the present day. The public baths of Borne
and other cities are among the grandest and most interesting
monuments of ancient luxury and splendor ; and from their
ruins have been recovered some of the most beautiful works
of art.

29. The Thermae, as the baths of Rome were called, were of
great extent, built very substantially, and ornamented at vast
expense. They were practically free to all, the cost of a bath
having been less than a cent. It is related that some persons
bathed seven times a day. After the bath their bodies were
anointed with perfumed oil. If the weather was fine, they
passed directly from the Thermae into the gymnasium, and
engaged in some gentle exercise previous to taking the midday
meal. Between two and three in the afternoon was the favor-
ite hour for this ancient luxury. Swimming was a favorite
exercise, and a knowledge of it was regarded as necessary to
every educated man. Their common expression, when speak-
ing of an ignorant person, was, "He can neither read nor
swim."

30. The Sun-Bath. — Some also were accustomed daily to
anoint themselves, and lie or walk in apartments arranged for
the purpose, with naked bodies exposed to the direct rays of
the sun. There is an interesting allusion to this practice, in a
letter of the younger Pliny to the historian Tacitus, describing
the destruction of Pompeii by an eruption of Vesuvius. " My
uncle " (Pliny the elder) " was at that time in command of the
fleet at Misenum. On the 24th of August, about one in the
afternoon, my mother desired him to notice a cloud which

28. Bathing among the ancients ? Baths of Rome?

29. After the bath ? Swimming among the ancients ?
80. The sun-bath? The story of Pliny I

THE INTEGUMENT, OR SKIN 07

seemed of unusual shape and dimensions. He had just returned
from taking the benefit ofthesun,&ad altera fold bath, and a slight
repast, had retired to his study."' Then follows a description
of the destruction of Pompeii, and the death of the elder Pliny.

31. We may judge somewhat of the benefits of the sun. by
observing the unnatural and undeveloped condition of plants
and animals which are deprived of light. Plants become
blanched and tender ; the fish of subterranean lakes, where the
lighl of day never enters, are undersized, and have no eves;
tadpoles kept in the dark do not develop into frogs ; men
growing up in mines are sallow, pale, and deformed. Besides
the well-known effect of solar light in tanning the skin, it also
makes it thicker and better able to resist exposure ; though
the complexion may be thereby injured, the health gained
more than compensates for the loss of beauty. "To make
good the loss of the lily, where the sun has cast his ray, he
seldom fails to plant the rose." {Bead Notes 9 and 10.)

32. Clothing.* — In reference to clothing, we are far more
apt, in our changeful climate, to use too little than too much.

9. Light Influences Growth and Health. — "I have several times
taken two potatoes which were as nearly as possible alike, and placed
one under a bell-glass through which the light could pass, and the other
under a similar cover rendered opaque by several coats of black paint.
Sprouting went on unchecked under the translucent glass, while it was
always notably retarded and sometimes prevented in the potato under the
dark glass. Milne Edwards, a distinguished French physiologist, per-
formed a series of experiments which showed that tadpoles when deprived
of light did not develop into the frog. I have several times repeated his
experiments, and always with confirmatory results. On one occasion 1
prevented for one hundred and twenty-five days the development of a
tadpole, by confining it in a vessel to which the rays of light had no
access. On placing it in a receptacle open to the light, the process of
transformation was at once begun, and was completed in fifteen days.
The practical application Of these and similar observations is this, that
care should be taken both in health and disease to insure a sufficient
amount of sunlight to the inmates of houses, and that it is impossible to
rear well-formed, strong, and robust children unless attention is paid to
this requirement." — Hammond on the Influence of Light.

* Man is the only animal that requires clothing; and as he advances

81. Benefit of the sun? Effect upon plants ? Skin?

'62. Direction about clothing? Exposing limbs of children? Clothing, night and day?

68 THE INTEGUMENT, OR SKIN

An aphorism of Boerhaave, worth remembering, if not of
adopting, is, "We should put off our winter clothing on mid-
summer's day, and put it on again the day after." He also
says, " Only fools and beggars suffer from the cold ; the latter
not being able to get sufficient clothes, the others not having
the sense to wear them." The practice of exposing the limbs
and necks of young children, for the alleged purpose of " hard-
ening" them, is quite hazardous. It is not to be denied that
some seem to be made tough by the process. But it is so only
with the rugged children; the delicate ones will invariably
suffer under this fanciful treatment. As the skin is constantly
acting, by night as well as by day, it is conducive both to
cleanliness and comfort to entirely change the clothing on
retiring for the night. The day-clothing should be aired dur-
ing the night, and the bedding should be aired in the morning,
for the same reason. (Bead Notes 11 and 12.)

from barbarism to civilization, more and more attention is paid to dress
as a means of protection against cold. As a rule, more harm arises from
using too little clothing than too much, especially in a changeful climate
like our own.

~^I0*. Light in the Sick-room. — "It is the unqualified result of all my
experience with the sick, that second only to their need of fresh air is
their need of light ; that, after a close room, what hurts them most is a
dark room ; and that it is not only light, but direct sunlight they want.
You had better carry your patient about after the sun, according to the
aspect of the rooms, if circumstances permit, than let him linger in a
room when the sun is off. People think that the effect is upon the spirits
only. This is by no means the case. Who has not observed the purify-
ing effect of light, and especially of direct sunlight, upon the air of a
room ? Here is an observation within everybody's experience. Go into
a room where the shutters are always shut (in a sick-room or a bed-room
there should never be shutters shut), and though the room be uninhabited
— though the air has never been polluted by the breathing of human
beings, you will observe a close, musty smell of corrupt air — of air
unpurified by the effect of the sun's rays. The mustiness of dark rooms
and corners, indeed, is proverbial. The cheerfulness of a room — the
usefulness of light in treating disease — is all-important. It is a curious
thing to observe how almost all patients lie with their faces turned to the
li-dit, exactly as plants always make their way toward the light." —
Florence Nightingale's Notes on Nursing.

11. Underclothing and Bedding. — All clothing worn during the day
should be removed at night. A practice prevails in tropical countries of
shaking thoroughly every article of apparel just before it is placed on the

THE INTEGUMENT, OR SKIN 69

33. Poisonous Cosmetics. — The extensive use of cosmetics for
the complexion is a fertile source of disease. The majority of
these preparations contain certain poisonous mineral substances,
chiefly lead. The skin rapidly absorbs the fine particles of
lead, and the system experiences the same evil effects that are
observed among the operatives in lead works and painters,
namely, "painters' colic," and paralysis of the hands, called
" wrist-drop."

body. The motive which prompts this comes from the fear lest a centi-
pede or other lively and virulent specimen of natural history has hid itself
somewhere within the folds of the garment. Even without the danger of
wearing one's shirt in conjunction with such an intruder, it is an excellent
practice to shake it and every other article of clothing thoroughly before
putting them on. The garments worn next to the skin should be changed
before they become saturated with the secretions of the sebaceous glands.
This can be accomplished by renewing them twice a week, though the
majority of people only change them once in that period. Combe recom-
mends to wear two sets of flannels, each being worn and aired by turns,
on alternate days ; he likewise praises a practice common in Italy,
namely, instead of beds being made up in the morning the moment they
are vacated, and while still saturated with the nocturnal exhalations, the
bed-clothes are thrown over the backs of chairs, the mattresses shaken
up, and the window thrown open for the greater part of the day. This
practice, so consonant with reason, imparts a freshness which is peculiarly
grateful and conducive to sleep. Florence Nightingale, who never fails
to speak plainly, says : " Feverishness is generally supposed to be a
symptom of fever ; in nine cases out of ten it is a symptom of bedding.
A real patient should have two beds, remaining only twelve hours in
each ; on no account to carry his sheets with him.1' — Draper (in Part).

12. Rules as to Clothing. — Protection against Cold. — For equal
thicknesses, wool is much superior to either cotton or linen, and should
be worn for all underclothing. In cases of extreme cold, besides wool,
leather or waterproof clothing is useful. Cotton and linen are nearly
equal.

Protection against Heat. — Texture has nothing to do with protection
from the direct solar rays ; this depends entirely on color. White is the
best color ; then gray, yellow, pink, blue, black. In hot countries, there-
fore, white or light-gray clothing should be chosen. In the shade the
effect of color is not marked. The thickness and the conducting power
of the material are the conditions (especially the former) which influ-
ence heat.

The body should not only be so protected by its covering as to be kept
from rain and damp, but the clothing must be so ventilated that the

Cosmetics '? Painters' colic f

70 THE INTEGUMENT, OR SKIN

34. Certain hair-dyes also contain lead, together with other
noxious and filthy ingredients. These do not work as great
harm as the cosmetics, since they are purposely kept away
from the skin; but they rob the hair of its vitality. Eye-
washes, too, are made from solutions of lead, and many an eye
has been ruined by their use. They deposit a white metallic
scale on the surface of the eye, which, when in front, perma-
nently blurs the sight.

emanations from the skin shall not accumulate. The wearing of the
unventilated beaver hat, or fur cap, is a ready method of suppressing
the natural growth of the hair, and of causing the retention of that effete
epithelial scale commonly called scurf, or dandruff. The wearing of
tightly fitting waterproof coats cannot be habitually practiced without
danger to the wearer ; the very painful and troublesome ailment, rheuma-
tism, lias in many persons been produced by this manner of locking in
the excretions of the surface. — Dr. B. W. Bichardson.

THE INTEGUMENT. nil SKIN

71

Epidermis .

Rete
Mucosum

SKIN

Glands

Nails

Hairs

Sweat

Sebaceous

Ducts

Secretion

PERSPIRA-
TION

TOPICAL OUTLINE

Composed of flattened scales.

Horny and transparent.

Impermeable to fluids.

No nerves or blood-vessels.

Simply protective.

Surface continually removed by friction.

Softer and less transparent.

Contains pigment cells.

Gives colour to the skin.

Fibres of connective and elastic tissues.

Numerous blood-vessels and nerves.

Drawn up into papillae.

Fat-cells in deeper portion.

Situated deep in the dermis.
Consist of coiled tubes.
Surrounded by capillary net-
works.

Nearly straight

through dermis.
Twisted in epi-
dermis.
Open at the sur-
face (pores).
Secrete the perspiration.
Connected with hairs.
Secrete an oily fluid.

Discharged into the

follicles.
Lubricates the hair
and skin.
Thick, horny plates of epidermis.

f Only where adherent to skin.
Growth . . < Above, below, and behind at the

[ root.
Pushed forward by growth behind.

{Interior medullary portion or
pith.
Outer cortical or fibrous portion.
j Bulb-like at lower extremity.
Koot • ' * I Imbedded in follicle.
Pushed outward by growth at the base.
(Hands — sebaceous (see above).
| Muscles — tend to erect the hair by their con-
i traction,
f Water,
f Composition \ Salts — especially common salt.

[ Little carbonic acid gas in solution.
f Average about two pounds a day.
Quantity ■ ■ ■ \ Greater in summer than in "winter.
t Greater during activity.
| Removal of waste matter.

Uses -I Tends to reduce the temperature of the body

[ by its evaporation.

THE INTEGUMENT, OR SKIN

QUESTIONS FOR TOPICAL REVIEW

PAGE

1. What are the characteristics of the skin, and what office does it

perform ? 54

2. What can you state of the structure of the skin ? 54

3. Describe the cuticle and tell its use 54, 55

4. Describe the cutis or true skin and tell its use 55, 56

5. What can you state of the nature and growth of the nail ? 56

6. Explain growth of the hair ? 57

7. Of the nature and growth of the hair ? 57

8. Of the offices performed by the nails and hair ? 57

9. What is an Albino ? 56

10. How is the difference in complexion in different persons accounted

for? , 58

11. How is the presence of freckles accounted f or ? 58

12. How does Nature provide a dressing for the hair? 58, 59

13. What is the composition of perspiration ? 60

14. What other service do the sebaceous glands perform ? 59

15. State what you can of the perspiratory glands and their number?. . 59, 60

16. What is the difference between sensible and insensible perspiration? 60

17. State the uses and importance of perspiration ? 60, 61

18. What impurities gather naturally on the skin ? 62

19. What are the effects of stopping perspiratory action ? 60, 61

20. Repeat what is said of the importance of bathing ? 62, 63

21. Different kinds of baths for different individuals? 64

22. When should we indulge in cold, warm, and sea-bathing? 65

23. What is the effect in each case ? 65

24. What directions are given as to the time and manner for bathing?. 6.">, 66

25. What is related of bathing among the ancients? 66

26. Directions after the bath ? 66

27. What is related to show the antiquity of sun-bathing ? 66, 67

28. What are the effects of sun-bathing ? 67, 68

29. What directions are given in relation to clothing the body? 67, 68

30. What can you state of poisonous cosmetics ? 69, 70

31. Of hair-dyes and eye-washes ? 70

CHAPTER IV

THE CHEMISTRY OF FOOD

The Source of Food — Inorganic Substances — Water — Salt — Lime —
Iron— Organic Substances — Albumen, Fibrin, and Caseine — The
Fats or Oils — The Sugars, Starch, and Gum — Stimulating Substances
— Necessity of a Regulated Diet

1. The Source of Food. — The term food includes all those
substances, whether liquid or solid, which are necessary for
the nourishment of the body. The original source of all food
is the earth, which the poet has fitly styled the " Mother of all
living." In her bosom, and in the atmosphere about her, are
contained all the elements on which life depends. But man
is unable to obtain nourishment directly from such crude
chemical forms as he finds in the inorganic world. They
must, with a few exceptions, be prepared for his use, by being
transformed into new and higher combinations, more closely
resembling the tissues of his own body.

2. This transformation is effected, first, by the vegetable
world. But all plants are not alike useful to man, while some
are absolutely hurtful. Accordingly, he must learn to discrimi-
nate between that which is poisonous and that which is life-
supporting. Again, all parts of the same plant or tree are not
alike beneficial : in some, the fruit; in others, the leaves; and
in others, the seeds only are sufficiently refined for his use.
These he must learn to select ; he must also learn the proper
modes of preparing each kind for his table, whether by cooking
or other processes. (Read Note 1.)

1. The Circle of Organic Life. — "Man, as an animal, is chemically an
oxidizing agent, reducing again to primitive forms the principles built up

1. The term food ? Source of food f Need of preparing food f

2. Usefulness and hurtfulneSB of plants? What then must man do? Parts of the same
plant or tree f

73

74 THE CHEMISTRY OF FOOD

3. Again, certain forms of the vegetable creation which are
unfit, in their crude state, for man's food, and which he rejects,
are chosen as food by some of the lower animals, and are, by
them, made ready for his use. Thus the bee takes the clover,
that man cannot eat, and from it collects honey. The cattle
eat the husks of corn and the dried grass, that are by far too
coarse for man, and in their own flesh convert them into tissues
closely resembling his muscular tissue. In this way, by the
aid of the transforming processes of the vegetable and animal
creations, the simple chemical elements of the mineral kingdom
are elaborated into our choice articles of food. (Bead Note 2.)

by the vegetable world, and taken in by him either directly as vegetables,
or indirectly in the shape of the material of other animals. Without
vegetable life animals could not exist, and never could have existed ; side
by side they grow and flourish, indispensable to each other's existence ;
the tree breaking up the exhaled carbonic acid of the animal — the carbon
being stored up in its increasing mass — while the oxygen is returned
again, free and uncombined, to the atmosphere for the respiratory needs
of the animal world. Round and round go the elementary bodies in
ceaseless change of form, nevertheless never more than they were at first
and will be at the last — the atomic material of this planetary sphere
being ever absolutely the same in amount. The material of the bodies of
Saul and his sons, when burnt by the men of Israel after their ignominious
exposure at Bethshan, in consequence of their defeat on Mount Gilboa,
are circulating amongst us still; it served others before them, and has
formed part of thousands since. It is quite within the bounds of chemical
possibility that some of the atoms contained in the fated apple of Eve,
may have lain in the material of the apple which revealed to Newton the
law of gravitation." — Fothergill on the Maintenance of Health.

2. The Food Circle in Nature. — " There are some ultimate elements
in flesh as in flour, the same in animals as in vegetables. The vegetable
draws food from the soil and from the air, and being fully matured, it or
some part of it is eaten by the animal. But in completing the circle, the
vegetable receives and thrives upon the animal itself, in whole or in part,
or the refuse which it daily throws off. The very bones of an animal are
by nature or man made to increase the growth of vegetables and really to
enter into their structure; and being again eaten, animals maybe said
to eat their own bones, and live on their own flesh. Hence there is not
only an unbroken circle in the production of food from different sources,
n the same food may be shown to be produced from itself. Surely
this is an illustration of the fable of the young Phoenix arising from the
ashes of its parent." — Edward Smith on Foods.

8. Certain forms of vegetable creation ? Example of the bee ? Cattle ? The inference ?

THE CHEMISTRY OF FOOD 75

4. Inorganic Substances. — The substances we use as food
are classified as organic and inorganic. By organic sul -

are meant those derived from living forms, such as vegetables
and animals. Inorganic substances are those simpler inani-
mate forms which belong to the mineral kingdom. The former
alone are commonly spoken of as food; but the latter enter
very largely into the constitution of the body, and must there-
fore be present in our food. With the exception of two articles
— ■ water and common salt — these substances enter the >\ stem
only when blended with organic substances.

5. Water. — Water, from a physiological point of view, is
the most important of all the articles of food. It is every-
where found in the body, even in the bones and the teeth. It
has been computed that as large a proportion as two-thirds of
the body is water. The teeth, the densest of the solids in the
human system, contain ten per cent, of water. The muscles,
tendons, and ligaments are more than half water; for it is
found that they lose more than half their weight when dried
with moderate heat. But it is in the fluids of the body that
water is found most abundantly. It gives to them the power
of holding a great variety of substances in solution, and is the
great highway by which new supplies are conveyed to the point
where they are required, and by which old particles of matter,
that have served their uses, are brought to the outlets of the
body to be thus removed from the system. (Bead Notes 3 and 4.)

3. The Only Natural Drink. — "Water is the natural drink of man.
as it is of all organized beings. It enters more largely into his compo-
sition than any otlu-r substance, giving liquidity to the blood, moisture to
all the tissues," ami serving a- the greal solvent of the body; not less
than two-thirds of its weight being of that element. It seems as if all
organic beings were so much "organized water."' "Soft water is more
wholesome than hard, though water moderately hard is not perceptibly
injurious. When very hard, a part of the salts of lime can readily be
precipitated by boiling. As a rule, spring and well-waters, if brought
from deep fountains, are better and more wholesome than running

i. What classification I Defli rganic substances. Inorganic. Organic, how spoken

of? The inorganic J Water and salt J

6. Water in physiology i Where fonnd? Computation? Water in the teeth? Mns-
cl.-s. tendons, ami ligaments .- How ascertained ? Water in the fluids of the bod;
is tin- advantage 1

76 THE CHEMISTRY OF FOOD

6. Man can remain a longer time without solid food than
without water. He may be deprived of the former for ten or
twelve hours without great suffering, but deprivation of water
for the same length of time will produce both severe pain and
great weakness. The food should contain not less than two
parts of water to one of solid nutriment. Water constitutes
the great bulk of all our drinks, and is also a large constituent
of the meats, vegetables, and fruits which come upon the table.
Fruits, especially, contain it in great abundance, and, in their
proper season, furnish most agreeable and refreshing supplies
of the needed fluid.

7. Common Salt. — Salt, or sodium chloride, as an article of
food, is obtained chiefly from the mineral kingdom ; although
plants contain it in small quantities, and it is also found in the
tissues of nearly all animals used as food. In the human body
it is an ingredient of all the solids and fluids. The importance

streams. Well-water, in towns and cities, unless brought from a great
depth, is wholly unfit for drinking and cooking. The immense quantity
of organic matter which permeates every inch of the soil, for many feet in
depth, precludes the possibility of water passing through it without being
corrupted. Kiver water, polluted by sewers, is as disgusting to the senses
as it is destructive to health. The notion that impure water can be
rendered more wholesome by icing it is an erroneous one. Ice-cold
drinks in summer, while the body is heated, are capable of producing
lifetime disease, and even instant death." — J. E. Black on the Ten Laws
of Health.

4. The Sustaining Power of Water. — " Water is the most reliable
and grateful drink for man. Nature has many admixtures in the juices
of fruits, but none so satisfying to excessive thirst as pure water. It will
even prolong life when nutritious food is not taken, as we have a well-
known instance, recorded by Dr. McNaughton, in the transactions of the
Albany Institute of New York for 1836. The case was that of a man
who lived upon water alone for fifty-three days. This he did while labor-
ing under some delusion which impelled him to abstain from all ordinary
nourishment — water alone could he be induced to partake of. His
strength was tolerably well sustained during the first six weeks ; he was
able, in fact, to go out of doors ; and even on the day of his death he was
able to sit up in bed." — Dr. James Knight.

6. Length of time man can do without food or water ? Give the comparison. Bulk of
drinks? Constituent of meats, etc. ? Fruits?

7. Salt, how obtained? Where found? In the human body? Importance of salt?
What else can you state of the value of salt ?

THE CHEMISTR1 OF FOOD 77

of salt to animal life in general, is shown by the greal appetite
for it manifested by domestic animals, and also by the habitual
resort of herds of wild beasts to the "salt-licks" or springs.
In those parts of the world where salt is obtained with diffi-
culty, man places a very high price upon it.

8. Experiments upon domestic animals show that the with-
drawal of salt from their food not only makes their hides
rough and causes the hair to fall out, but also interferes with
the proper digestion of food. If it be withheld persistently,
they become entirely unable to appropriate nourishment, and
die of starvation. (Bead Note 5.)

5. Of Salt.—

"Salt-cellars ever should stand at the head
Of dishes, wheresoe'er a table's spread.
Salt will all poisons expurgate with haste,
And to insipid things impart a taste.
The richest food will be in great default
Of taste, without a pinch of sav'ry salt.
Yet of salt meats, the long-protracted use
Will both our sight and manhood, too, reduce ;
On tables salt should stand both first and last,
Since, in its absence, there is no repast."

— llie Code of the School of Salernum.

"Animals will travel long distances to obtain salt. Men will bar-
ter gold for it ; indeed, among the Gallas and on the coast of Sierra
Leone, brothers will sell their sisters, husbands their wives, and parents
their children for salt. In the district of Accra, on the gold coast of
Africa, a handful of salt is the most valuable thing upon earth after gold,
and will purchase a slave or two. Mungo Park tells us that with the
Mandingoes ami Bambaras the use of salt is such a luxury that to say <>t
a man, 'he flavors his food with salt,' it is to imply that he is rich ; ami
children will suck a piece of rock-salt as if it were sugar. No stronger
mark of respect or affection can be shown in Muscovy, than the sending
of salt from the tables of the rich to their poorer friends. In the book of
Leviticus it is expressly commanded as one of the ordinances of Moses,
that every oblation of meat upon the altar shall be seasoned with salt,
without lacking; and hence it is called the Salt of the Covenant of God.
The Greeks and Romans also used salt in their sacrificial cakes; and it
is still used in the services of the Latin church — the lparva mica,1 or
pinch of salt, being, in the ceremony of baptism, put into the child's
mouth, while the priest says, 'Receive the salt of wisdom, ami may it be

8. Experiments upon animals I

78 THE CHEMISTRY OE EOOD

9. Salt is usually taken into the system in sufficient quantities
in our food. Even the water we drink often has traces of it.
The habitual use of much salt in cooking, or as a seasoning at
the table, is not wise ; and while it may not lead to consump-
tion, as some writers declare, it is a bad habit in itself, and
leads to the desire for other and more injurious condiments.

10. Lime. — This is the mineral substance which we have
spoken of before as entering very largely into the composition
of the bones. It is the important element which gives solidity
and permanence to the framework upon which the body is
built. Calcium tri-phosphate, or "bone-earth," is the chief
ingredient of the bones and teeth, but is found in the carti-
lages and other parts of the body in smaller quantities. {Bead
Note 6.)

a propitiation to thee for eternal life.' Everywhere, and almost always,
indeed, it has been regarded as emblematical of wisdom, wit, and immor-
tality. To taste a man's salt, was to be bound by the rites of hospitality ,
and no oath was more solemn than that which was sworn upon bread and
salt. To sprinkle the meat with salt was to drive away the devil ; ami to
this day, among the superstitious, nothing is more unlucky than to spill
the salt," — Lethehy on Food.

6. Phosphate of Lime and other Inorganic Substances. — "All food
contains certain saline substances. If we burn a portion of the flesh of
any animal, we may drive off the carbon, oxygen, hydrogen, and nitrogen,
and 'ashes' are left. These ashes are the saline and mineral (inorganic)
constituents of the animal. They exist in the blood and tissues, and are
as essential to the life of the animal as those other elements which were
expelled by heat. Like the latter, they are constantly being used up and
carried off from the body, and like them must be replaced by means
of our food. Cooking, especially boiling, t<'nds to dissolve away some of
these suits, ami care should be taken to supply them by means of uncooked
food, as fresh vegetables and fruits; milk also contains them. One of
the most important of these inorganic substances is phosphate of lime,
or 'bone-earth,' as it is called, from the fact that about forty per cent, of
healthy bone is made up of it. When if is deficient, the bones are soft
and are liable to be bent by the actions of the muscles attached to them,
ami a permanent deformity may be the consequence. This form of lime
is contained in wheat, barley, oafs, ami rye, and from these sources the
child' supply of it is derived. These plants require phosphate of lime for

0. s:,it. how tnkcn into the system ? its use in cooking? Consumption ?
m. Lime in the bones 1 Whai does it impart? Chief ingredient of the bones and teeth ?

found?

THE CHEMISTRY OF FOOD 7'.i

11. How does this substance find its way into the body?

Meat, milk, and other articles obtained from the animal king-
dom contain it, and it is abundantly stored away also in the
grains from which our bread is made — in wheat, rye, and
Indian corn. In early life, while the body is growing, the
supplies of this substance should be carefully provided. The
evil effects of the deprivation of it are too often and painfully
evident in the softening of the bones, and in the predisposition
to curvature of the spine — deformities which are most deplor-
able and which continue through life.

12. Iron. — This substance is probably the most abundant
and widely diffused of the metals. It is found in most of
the vegetables, and is a very important component of animal
tissues. It enters into the composition of human blood in
about one part per thousand. Ordinarily, the food conveys to
the system enough iron for its use, but it must sometimes be
introduced separately as a remedy, especially after great loss
of blood, or after some wasting disease. Under its influence
the blood seems to be rapidly restored, and a natural color of
the lips and skin replaces the pallor caused by disease.

13. Other Inorganic Substances. — In addition to the sub-
stances mentioned, the mineral kingdom supplies compounds
of soda, potash, and magnesia, which are essential for the use
of the body. They occur in small quantities in the body, and
enter it in combination with the various articles of diet.

14. Organic Substances. — These substances are derived from
the vegetable and animal creations. They comprise all those

their growth and the perfecting of their grains; hence it is supplied
artificially by the fanner. A diet deficient in substances yielding the
phosphate of lime is injurious t<> man, ami should be avoided, lis
presence in wheat-Hour accounts in part for the fact that our ordinary
loaf of bread makes so good a ' staff of life,' and that it is. and has been,
so widely used as an article of food by the strongest and most vigorous
races of mankind." — Lankester's Manual.

11. How does lime find its way Into the body J Early lift f Effect of its deprivation f

12. Iron, its abundance and diffusion ? Where found? What part of the blood is it !
How supplied to the system J in case of loss of blood or wasting disease}

13. Soda, potash, and magnesia I How do they occur?

14. Organic substances, u hence derh ed F What do they comprise ? Groups '.-

80 THE CHEMISTRY OF FOOD

articles which are commonly spoken of as "food," and which
are essential to sustain the body in life and strength. They
are divided into three groups, namely : the Albuminoid sub-
stances, the Fats, and Sugars.

15. The Albuminoids. — This class includes three important
nutritive substances — (1) Albumen, which gives it its name ;
(2) Fibrin, including gluten; and (3) Caseine. These com-
pounds constitute a large part of the human body, and the
food contains them in proportionally large quantities. Their
importance is so great, and the system so promptly suffers
from their absence, that they have been styled the "nutritious
substances." The properties which they hold in common are,
that they do not crystallize, and have a jelly-like form, except
when heat is applied to them, when they harden, or coagulate.

16. They likewise decompose, or putrefy, under the influence
of warmth and moisture. Hence the decay of all dead animal
tissues. Cold arrests this process. It is well known that
milk, eggs, and the like, " keep " much longer in winter than
at other seasons. The bodies of elephants, caught in the ice
many hundred years ago, are occasionally borne by the icebergs
to the coast of Siberia, completely frozen, but preserved almost
perfectly in form and limb.

17. Albumen exists in milk, meat, the grains, and the juices
of many plants ; but the purest form is obtained from the
white of egg. When we consider that an egg is composed
chiefly of albumen and water — namely, six parts in seven ;
and when we also consider the numerous, diverse, and complex
tissues — the muscles, bones, internal organs, bill, claws, and
feathers — with which the chick is equipped on leaving his
shell, we are impressed with the importance of these apparently
simple constituents of the food and body. (Head Note 7.)

7. Weight and Health. — " The weight of the body is very generally
assumed to be an infallible index or proof of the maintenance of a healthy

15. The Albuminoid class includes what? These compounds constitute what? The
food ? Their importance ? Their properties ?

16. Decomposition? Effect of cold? Illustrations? Elephants?

17. In what substances does albumen exist ? What further is said of the egg ?

THE CHEMISTRY OF FOOD 81

18. Fibrin is derived from meats, and exists in the blood
both of man and the lower animals. Gluten, or vegetable
fibrin, resembles closely true fibrin, and is abundantly furnished
in wheat and other grains from which Hour is commonly made.
Animal fibrin coagulates spontaneously when it is removed
from the body, and thus causes the "clotting" of the blood.

19. Caseine is the curdy ingredient of the milk, and a highly
important food-substance. Its coagulation in milk takes place
not from heat, but by the addition of an acid, and also when
milk becomes sour from exposure to the air. It is commonly
effected, however, by introducing a piece of rennet, a prepara-
tion made from a calf's stomach. The curds, or caseine, may
then be separated from the whey, and made into cheese, by
pressing it sufficiently to drive off the water.

20. The Fats or Oils. — This is the second group of organic
foods. Those which are more solid are called fats; the more
fluid ones are the oils. Oleaginous substances are supplied in
both animal ami vegetable food; but, from whatever source
derived, they are chemically much alike. They are insoluble
in water, and yet they unite readily with the watery fluids of
the body, and are by them conveyed to its various parts for
their nourishment. This is due to their property of " emulsi-
fying: " that is. they are held in suspension, in a finely divided
state, in water. Ordinarily milk is an example of an emulsion.

condition of the body ; and that food which keeps up the weight has been
regarded as satisfactory and nutritious. But this is not always a safe
judgment, owing to the property in water from innutritions food to make
good the loss of weighl caused by the withdrawal of albumen and fat.
The weight may remain the same, while we are 'losing flesh.' Fat.
also, m:i\ ii!> rease in badly nourished people, while the more essential
element of albumen is diminishing ; the fact being that the badly fed are
not always lighter than those who are well nourished. And further, the
feeling of satisfaction after eating is deceptive; the Irish peasant who
consumes ten pounds of potatoes in a day feels quite satisfied, but is in

reality badly nourished by his diet containing three-fourths water."

Prof. V'lit. of Munich.

18. Fibrin, gluten, cl..tti:iir of the bl 1 f

19, Caseine? [ts coagulation ? Effect of rennet? Making of cheese ?

80. What are the fats ? The oils? How supplied? How alike ? Emulsifying? Ex-
ample ? How do we know it ?
F

82 THE CHEMISTRY OF FOOD

We know that it contains fat, for butter is obtained from it ;
and, under the microscope, the minute oil-globules may be
distinctly seen.

21. In our country and climate, and also in colder climates,
fatty articles of food are principally derived from the animal
creation, such as meat or flesh, milk and butter. But most of
the bread-stuffs contain more or less fat or oil — Indian meal
as much as nine parts in a hundred.

22. Among persons living in cold climates, the appetite for
oleaginous food is especially eager ; and they require large
quantities of it to enable them to resist the depressing influ-
ences of cold. Since vegetation is scanty and innutritious, and
the waters of the frozen regions abound in animal life, they
must rely wholly upon a diet derived from the latter source.
The Esquimau consumes daily from ten to fifteen pounds of
meat or blubber, a large proportion of which is fat. The
Laplander will drink train-oil, and regards tallow-candles as a
great delicacy. In hot climates, on the contrary, where flourish
the olive and the palm, this kind of food may be obtained
from vegetable sources in abundant quantities. {Bead Notes
8 and 9.)

8. The Necessity of Fat in the Food of Children. — " Children who
dislike fat cause much anxiety to parents, for they are almost always thin,
and, if not diseased, are not healthy. If care be not taken, they fall into
a scrofulous condition, in which diseased joints, enlarged glands, sore
eyes, and even consumption occur ; and every effort should be made to
overcome this dislike. If attention be given to this matter of diet, there
need be no anxiety about the possibility of increasing the quantity of food
consumed ; whilst the neglect, the dislike, will probably increase until
disease is produced. The chief period of growth — viz., from seven to
sixteen years of age — is the most important in this respect, for a store of
fat in the body is then essential. Those who are inclined to be fat usually
like fat in food, and then it may be desirable to limit its use. Some who
cannot eat it when hot like it when cold, and all should select that kind
which they prefer. Those living in Russia and Lapland devour very
large quantities — as seven pounds daily — and eat it even raw, while
those dwelling in hot countries use very little. It produces more heat
than any other kind of food." — Edward Smith on Health.

21. Whence are fatty articles of food derived ?

22. Appetite of persons in cold climates ? What do they require ? Upon what must
they rely ? Why r The Esquimau ? Laplander ? Olive and palm ?

THE CHEMISTRY OF FOOD 83

23. The Sugars, or the Saccharine Substances. — These con-
stitute the third and last group of the organic substances which
are employed as food. This group embraces, in addition to the
different kinds of Sugar, the varieties of starch and gum, from
whatever source derived. The two substances last named do
not, at first sight, present many points of similarity to sugar ;
but they closely resemble it in respect to their ultimate chem-
ical composition, being made up of the same elements, in nearly
the same proportions. And their office in the system is the
same, since they are all changed into sugar by the processes of
digestion.

24. Sugar is chiefly of vegetable origin, the animal varieties
being obtained from honey and milk. The most noticeable
characteristic of this substance is its agreeable, sweet taste,
which makes it everywhere a favorite article of food. But
this quality of sweetness is not possessed by all the varieties
of sugar in the same degree; that obtained from milk, for
instance, has a comparatively feeble taste, but rather imparts
a gritty feeling to the tongue. The other important properties

9. The Effect of Climate on the Appetite. — "Climate has an impor-
tant influence on the quantity of food demanded by the system ; and
every one has experienced in his own person a considerable difference at
different seasons of the year. Travelers' accounts of the amount of food
consumed by the natives of the frigid zone are almost incredible. They
speak of men eating a hundred pounds of meat in a day ; and a Russian
admiral, Saritcheff, mentions an instance of a man who, in his presence,
ate at a single meal a mess of boiled rice and butter weighing twenty-
eight pounds. Although it is difficult to regard these statements with
entire confidence, the general opinion is undoubtedly well founded that
the appetite is greater in cold than in warm climates. Dr. Hayes, the
Arctic explorer, states, from his own observation, that the daily ration of
the Esquimaux is from twelve to fifteen pounds of meat, about one-third
of which is fat. He once saw an Esquimau consume ten pounds of walrus
flesh and blubber at a single meal, which however lasted several hours,
with the thermometer 60° or 70° below zero. Some members of his own
party manifested a constant craving for fatty substances, and were in the
habit of drinking the contents of the oil-kettle with evident relish." —
Flint's Physiology.

88. Which are the third of the organic groups ? What do they embrace ? Points of
resemblanoe ?

24. Origin of the sugars ? Ordinary sugar ? Beet-root? Maple-sugar? Grape- sugar ?
Cane-sugar ?

84 THE CHEMISTRY OF FOOD

of sugar are, its power to crystallize when evaporated from
watery solutions, such as the juices of many plants; a ten-
dency to ferment, by which process alcohol is produced ; and a
ready solubility in water. This latter quality renders it very
easy of digestion, and more so than any other of the saccharine
group. It is computed that the annual production of sugar, in
all parts of the world, is more than one million of tons. The
kind of sugar that is in ordinary use, in this country, is pre-
pared from the juice of the sugar-cane, which contains eighteen
per cent, of sugar. In Trance it is manufactured from the
beet-root, which holds about nine per cent. ; the maple-tree of
our climate yields a similar sugar. The sweet taste of fruits
is due to the presence of grape-sugar: the white grains seen on
raisins belong to this variety. Cane-sugar is more soluble than
the latter, and has twice the sweetening power. {Bead Note 10.)
25. Starch. — This is the most widely distributed of the
vegetable principles. It is tasteless, inodorous, and does not

crystallize. It consists of mi-
nute rounded granules, which,
under the microscope, reveal
a somewhat uniform structure
(Fig. 21). Starch will not
dissolve in cold water, but in
boiling water the small grains
burst open, and may then be
dissolved and digested.

26. The bread-stuffs —
wheat, corn, and rye flours —
are more than one-half starch.

Fig. 21. — Granules of Potato Starch Rice, which is the " staff of

MAGNIF1ED life" to one-third of the

human family, contains eighty per cent. Unripe fruits have
much starch in them, which renders them indigestible when

10. Why too much Sugar is Injurious. — " Sugar is very wholesome,
and, as I told you, we want some in our diet. But children will often eat

25. Starch, how widely distributed ? Its qualities? Its constituents ? Its solubility ?

26. How much starch in bread-stuffs ? Iu rice f Unripe fruits ? Ripe fruits ?

THE CHEMISTRY OF FOOD 85

eaten uncooked, for the grains of raw starch are but slightly
acted upon within the body. But, under the potent chemistry
of the sun's ray, this crude material is converted into sugar.
Thus are the fruits prepared by the careful hand of Nature, so
so that when ripe they may be freely used without further
preparation.

27. Gum is commonly found in those articles which also con-
tain starch, and has the same chemical composition as the
latter, but is much less nutritious. In the East, gum-arabic
and similar substances are largely employed as food. Persons
who travel by caravan across vast, sandy deserts, find such
substances well adapted to their wants, since they are not
perishable, and are easily packed and carried.

28. Stimulating Substances. — The three classes of food-prin-
ciples already considered — the Albuminoids, the Fats, and the
Sugars — comprise all the more important organic ingredients
of our food. There are, besides, a great variety of coloring
and flavoring matters, that stimulate or increase the appetite
for food by appealing to the eye and taste ; but they are not
nutritious, and are quickly separated from the truly useful
substances, and do not long remain in the body. Among these
may be classed spices, flavors of fruits, tea, coffee, and vege-
table acids.

too much sugar, just as they will eat too little fat. The harm it does them
is — first, it is very apt to spoil the teeth ; second, it takes away the ap-
petite for other food. If you are always eating sweet cakes and sugar-
plums, you will not care for plain, nourishing diet. Now, what is best for
us all is, to have good appetites for wholesome food ; it will do more to
keep us in health all our lives than anything else ; and there is a great
deal in getting the right habit." Candies are frequently adulterated with
plaster-of-paris, chalk, and certain forms of earth, that are indigestible ;
but worse than that, the coloring matters and flavoring extracts that are
used in the bright-tinted and fruity-flavored confectionery are absolute
poisons in many instances, such as arsenic, copper, zinc, lead, prussic and
sulphuric acid." — l'» ru< r's Lessons mi Health (in part).

27. Gum, where found? Its composition I Gum-arabic?

28. The three classes of food-principles? What besides? What is said of them ? Nairn'
the articles uot nutritious.

86 THE CHEMISTRY OF FOOD

29. Necessity of a Regulated Diet. — A great variety of ex-
periments have been tried, in order to test the relative value
of the different nutritive principles. They have been practised
to some extent upon man, but chiefly upon those inferior
animals which require a similar diet to man.

30. By this means it has been demonstrated that — first,
when any one of these substances is eaten exclusively, the
body is imperfectly nourished, and life is shortened. Dogs fed
exclusively upon albumen, fat, or sugar, soon die of star-
vation. Second, a diet long deprived of any one of these
principles is a fertile cause of disease ; for example, on ship-
board, where fresh vegetables are not dealt out for a long
period, scurvy becomes prevalent among the sailors. They are,
however, to a certain extent mutually convertible, and thus
the missing article is indirectly supplied. For instance, sugar
changes to fat in the body ; and hence, as is well known, the
" hands " on a sugar plantation grow fat during the sugar season
by partaking freely of the ripened juices of the cane. {Bead
Note 11.)

31. That is the best diet, therefore, which contains some of
each of these principles, in due proportion; and that is the
worst which excludes the most of them. The cravings and
experience of man had unerringly guided him to a correct
regulation of his diet, long before the chemistry of food was
understood; so that his ordinary meals long ago combined

11. The Effects of a Poor Diet. — "The food of the poor in olden
times was poor and scanty ; so much so, in fact, that their powers of life
were depressed ; and we believe this fact had much to do with the fearful
mortality of the plague throughout Europe during the middle ages. The
lower classes, especially those living in crowded cities, and subsisting on
the scanty and monotonous diet that the historians of the period describe,
were the principal sufferers. From 1296 to 160G, hundreds of thousands
were carried off by the most fearful pestilences the earth has ever known.
Rye in France and oats in England were for generations the almost exclu-
sive diet ; wheat was a luxury, which even the rich might only indulge in
at Christmas. Oats were known in Germany 2,000 years ago, and were
probably the original bread-grain for all Europe." — Dr. J. Knight.

29. What is said of experiments that have been tried ?

30. What has been demonstrated in the first place? Example? Second demonstra-
tion ? Example ? Give the illustration in relation to convertibility.

THE CHEMISTRY OF FOOD

87

these various principles, the necessity and value of which are
now explained. (Bead Notes 12 and 13.)

12. Variety in Diet and in its Preparation Beneficial. — " Every

dietary should contain fresh vegetables. It is further necessary that cer-
tain articles belonging to the same class be varied from day to day. other-
wise the appetite cloys. Beef should alternate with mutton, for example ;
or variety should be secured by different modes of cooking the Bame
article. Indeed, it is not too much to say that the art of cookery is a
matter of national importance, not only because it renders food palatable,
but because the more it is studied and practised the greater is the
economy which may be effected. It is chiefly in this relation, that bever-
ages, condiments, etc., become such valuable dietetic adjuncts." — Wil-
son's Hand-book of Hygiene.

13. Some Experiments as to Food. — " Magendie made numerous
experiments on the inferior animals to test the value of different forms of
nutriment. He showed that a diet exclusively composed of starch and
sugar would not support life. So, too, dogs confined to white bread and
water died with all the symptoms of starvation ; but on the military
brown-bread animals lived pretty well, as this article contains a greater
variety of the alimentary principles. Other experiments have given an
account of geese limited to some one substance. All of them died — the
animal fed upon gum, on the sixteenth day ; that fed with sugar, on the
twenty-first day ; one fed with starch, on the twenty-fourth day ; and one
fed with white of egg, on the twenty-sixth day. In 1769, before these
experiments were performed, Dr. Stark, a young English physiologist,
fell a victim at an early age to ill-judged experiments on himself as to the
effects of different foods. He lived for forty-four days on bread and
water, for twenty-nine days on bread, sugar, and water, and for twenty-
four days on bread, water, and olive oil; until finally, his constitution
became broken, and he died from the effects of his experiments." —
Flint's Physiology.

TOPICAL OUTLINE

FOODS

Nitrogenous

ANIMAL

VEGETABLE

MINERAL

r Albumen — white of egg.

Caseine — milk and cheese.
j Fibrin — blood.

Myosin — muscle.
I Gelatin — bone.

I Non-nitrogenous
f Nitrogenous . .

I Non-nitrogenous

Fats and sugar.
f Gluten — cereal grains.
I Legumen — beans, etc.

Starch — all pa>-t$ of plarits.
j Sugars — all parts of plaJits.
j Gums — all parts of plants.
Oils— fruits.
Water, common salt, calcium carbonate, calcium
phosphate, i te.

THE CHEMISTRY OF FOOD

QUESTIONS FOR TOPICAL REVIEW

PAGE

1. What is understood by the term food ? 73

2. What can you state in relation to the source of food ? 73

3. What discriminations and selections are necessary? 73

4. How can you tell the organic from the inorganic substances'.' 75

5. What relative position does water hold as an article of food 75

G. In what parts of the body is water found ? 75

7. In what articles that we eat is it found ? 7(5

8. If you were required to go without water or solid food for a number

of days, which would you prefer to have, and why '.' 7G

9. What can you state of the importance of salt as an article of food?. 1C, 77

10. How abundant is salt, and how does it find its way into the human

system ? 7(1, 77, 78

11. What can you state of the importance of lime in the body? In

what does it occur ? 78, 7!)

12. What, of the importance of iron ? Til

13. What further is stated of other inorganic substances? 79

14. What in relation to organic substances ? 79, 80

15. What can you state in relation to the albuminoids? 80

16. What, in relation to albumen ? 80

17. What, in relation to caseine ? 81

18. In relation to the fats or oils, and how generally consumed ? 81, 82

19. What do we understand by the sugars or saccharine substances?. . . 83

20. State what you can of sugar — its origin and various qualities 83, M

21. Of starch — its varieties and qualities 84

22. Of the abundance of starch, and its importance as a food-principle. 84, 85
2:!. What is stated in relation to stimulating substances ? 85

24. Of the necessity for regulation in diet? 86

25. What is considered the most healthful diet ? SO, 87

CHAPTER V

FOOD AND DRINK

Necessity for Food — Waste and 7?< ipair — Hunger and Thirst — Amount
of Food — Renovation of the Body — Mixed Diet — Milk — Eggs—

M ■' — Cooking — Vegetable Food — Bread — The Potato — Fruits —
Purity of Water — Action of Water upon Lead — Coffee, T-
Chocolate — Effects of Alcohol

1. Necessity for Food. — Activity is everywhere followed by
waste. The engine uses up coal and water to produce motion,
the stream wears away its bank, the growing corn-blade draws
tribute from the soil. When the human body acts, and it is
always in action during life, some of its particles are worn out
and thrown off. This waste must constantly he repaired, or
the body suffers. In tins fact is seen the necessity for food.
The particles, thus worn out, being henceforth useless, are
removed from the body. Our food and drink are rapidly
transformed into a new supply of living, useful material, to
be in turn used up and replaced by a fresher supply.

2. Waste and Repair. — In this way the healthful body,
though always wasting, is always building up, and does not
greatly change in size, form, or weight. At two periods of
life the processes of waste and repair are not exactly balanced.
In early life the process of building up is more active, and in
consequence the form is plump and the stature increases.
Repair now exceeds waste. On the other hand, when old
age comes on, the wasting process is more active, the flesh
and weight diminish, the skin falls in wrinkles, and the senses
become dull. Only during the prime of life — from about

1. What follows activity J Examples} Necessity for food ?

2. Give the theory iu relation t.. waste and repair.

Ml

90 FOOD AND DRINK

twenty to sixty years of age — is the balance exact between
loss and gain. (Bead Note 1.)

3. Hunger and Thirst. — When the system is deprived of its
supply of solid food during a longer time than usual, nature
gives warning by the sensation of hunger, to repair the losses
that have taken place. This sensation or pain appears to be
located in the stomach, but it is really a distress of the system
at large. Let a sufficient quantity of nourishment be intro-
duced into the system in any other way than by the mouth,
and it will appease hunger just as certainly as when taken in
the usual manner.

4. The feeling of thirst, in like manner, is evidence that
the system is suffering from the want of water. The apparent
seat of the distress of thirst is in the throat; but the injection
of water into the blood-vessels is found to quench thirst, and
by the immersion of the body in water, the skin will absorb
sufficient to satisfy the demands of the system. The length
of time that man can exist without food or drink is estimated
to be about seven days. If water alone be supplied, life will

1. The Waste of the Body. — "In the physical life of man there is
scarcely such a thing as rest — the numberless organs and tissues which
compose his frame are undergoing perpetual change, and in the exercise
of the function of each some part of it is destroyed. Thus, we cannot
think, feel or move without wasting some proportion, great or small,
according to the energy of the act, of the apparatuses concerned — such
as brain, nerve or muscles. Now this waste-product cannot remain in
its original situation, where it would not only be useless dross, but also
obstructive and injurious. Such old material is being daily removed
from our bodies to the average amount of three or more pounds ; and
that an equal quantity of new shall take its place is the first principle of
alimentation. To express it in commercial language, the income must be
equal to the expenditure ; and in each of us the amount of this exchange
must in a lifetime reach many tons. This tissue-change is so complete,
that not a particle of our present body will be ours a short time hence ;
and we will be, as I have lately seen it phrased, like the knife which,
after having had several new blades, and at least one new handle, was
still the same old knife to its owner. We are, in fact, constantly ' moult-
ing.' " — Mapother,8 Lectures on Public Health.

3. System deprived of food ? Warning? What is the pain ? How proved?

4. Feeling "f thirst i Seat of the pain ? How proved ? Time a person can exist with-
out food ?

FOOD AND DRINK 91

last much longer — there being cases recorded where men have
lived twenty days and over without taking any solid food.
(Bead Note 2.)

5. Quantity of Food. — The quantity of food required varies
greatly, according to the individual and his mode of life. The
young, and others who lead active lives, or who live in the open
air, require more food than the old, the inactive, or the sed-
entary. Those who live in cold regions require more than
the inhabitants of hot climates. Habit, also, has much to do
with the quantity of food required. Some habitually eat and
drink more than they actually need, while a few eat less than
they should.

6. The average daily quantity of food and drink for a
healthy man of active habits is estimated at six pounds. This
amount may be divided in about the following proportions :
the mineral kingdom furnishes three and one-half pounds, in-
cluding water and salt ; the vegetable kingdom, one and one-
half pounds, including bread, vegetables, and fruits; the
animal kingdom, one pound, comprising meat, eggs, butter, and
the like. This quantity is about one twenty-fourth the weight

2. Hunger and Thirst. — " We none of us object to a sharp-set appe-
tite ; that is by no means unpleasant, especially when there is food at
hand ; but if this is not the case, it soon becomes a craving passion — a
strong impelling power. The cravings of hunger have done much for this
world ; ' look where we may, we see it as the motive power which sets
the vast array of human machinery in action.' Hunger is also the incen-
tive which directs our attention to the system's need for food, and if it
be sharp enough the most loathsome substances are greedily devoured.
By it has man, and civilized man, too, been driven to feed upon the
putrid corpse of his comrade. Hunger is one of the great forces in action
in the preservation of the life of the individual ; and the fear of it is one
of the strongest incentives to action. But the pangs of hunger are toler-
able in comparison with the tortures of raging thirst. In fact, so terrible
are the latter that they form one of the crudest tortures which man can
inflict on man ; so cruel a torture, indeed, that it has rarely been used,
except in cases of bitter personal animosity, by others than brutal Eastern
tyrants, or bigots under the influence of religious fanaticism." — Fothi r-
gill on the Maintenance of Health.

5. Amount of food required ? The young- and others ? Those living in hot and cold
climates ? Habits ?

6. Quantity of food daily ? Uow divided ? Compare with the weight of the body.

92

FOOD AND DRINK

of the body, as it is generally computed ; the average weight
of an adult man being placed at 140 pounds. A man, there-
fore, consumes an amount of solid and liquid nutriment every
twenty-four days equal in weight to that of his body, a corre-
sponding amount being excreted, or removed from the system in
the same time. (Bead Notes 3 and 4).

3. A Lifetime Allowance of Food. — "M. Soyer, in his 'Modern
Housewife,' makes a calculation as to how much food an epicure of 70
years of age has consumed. This imaginary epicure, who is supposed to
be a wealthy personage, is placed by him on Primrose Hill at ten years
old and told to look around him at the vast assemblage of animals and
other objects he will in the course of a lifetime send down his throat —
the sight of which is, of course, described as appalling. Among the other
things, he is to devour 30 oxen, 200 sheep, 100 calves, 200 lambs, 50 pigs,
1,200 fowls, 300 turkeys, 263 pigeons, 120 turbot, 140 salmon, 30,000
oysters, 5,745 lbs. of vegetables, 243| lbs. of butter, 24,000 eggs, and 4|
tons of bread, besides fruits, sweetmeats, etc., and 49 hogsheads of wine,
548 gals, of spirits, and about 3,000 gals, of tea and coffee. This is a
mere outline of what we are told is destined to be consumed. To show
there is no exaggeration, Soyer assures us that he has from experience
made up a scale of food for the day for a period of 60 years, and it
amounts to 33| tons of meat, farinaceous food, and vegetables, etc." —
Journal of Chemistry.

4. A Daily Ration for an Adult Man. — " We may arrive at something
like an average daily diet by taking the case of the man in good health,
weighing 154 lbs., and measuring 5 feet 8 inches in height. Simply to
maintain his body, without loss or gain in weight, his ration of food
should not contain less, during 24 hours, than the following proportions
and quantities of the main ingredients ;

THE AVERAGE DAILY DIET FOR AN ADULT

FOOD SUBSTANCES.

PER CENTUM.

WEIGHT.

81.5
3.9

10.G
3.0

.7

lbs. oz.

5 8

4

11

3

grs.
320
110
178
337
325
170

Albuminoids or flesh formers

Phosphates, potash, salts, etc

100.

6 13

128

" Water, it will be remembered, enters into the composition of every
article of food as well as in the liquids we drink. In reality, the weight

FOOD AND DRINK 93

7. Renovation of the Body. — By this process, so far as
weight is concerned, the body might be renewed every twenty-
four days; but these pounds of food are not all real nutriment.
A considerable portion of that which we eat is innutritious,
and though useful in various ways, is not destined to repair
the losses of the system. An opinion has prevailed that the
body is renewed throughout once in seven years; how correcl
this may be, it is not easy to decide, but probably the reno-
vation of the body takes place in a much shorter period.
Some parts are very frequently renewed, the nutritive fluids
changing more or less completely several times during the day.
The muscles, and other parts in frequent exercise, change
often during a year; the bones not so often, and the enamel
of the teeth probably never changes after being once fully
formed. < Bead -Vote 5.)

8. Mixed Diet. — The habits of different nations in respect
to diet exhibit the widest and strangest diversity. The civil-
ized cook their food, while savages often eat it in a raw state.
Some prefer it when fresh ; others allow it to remain until it
has become tainted with decay. Those dwelling in the far

of the dry food we take will exceed that given above ; chiefly for the
reason that they do not come to us pure and unmixed with fibrous
material and gelatine, whose use in nourishing the body is limited and
uncertain." — Kensington Museum Hand-Book on Food.

5. The Renewal of the Body. — "To meet these constant chemical
changes, material is taken in, in the form of food and drink, which is
being constantly assimilated, and so nutrition and repair are conducted.
The rapidity with which these changes are carried on is much greater
than is usually supposed. Paley, in his 'Natural Theology,' states that
seven years arc requisite for the perfect renewal of the body; and this
statement, owing partly to the mysticism associated with the number 7,
is generally accepted and believed. The time really is rather months
than years ; but it is absurd to fix a time which must necessarily vary in
different individuals, being much less in the infant than in the aged, in
the active than the indolent; widely different, too, in various tissues,
from the epithelium lining of the glands of the stomach, renewed several
times in each act of digestion, to the enamel of the tooth, which is proba-
bly never renewed during a lifetime.''

T. How often, then, might the body be renewed? Why is it not? Opinion ? Uow
correct? What farther is stated ':

8. Habits of nations ? Give the different cases.

94 FOOD AND DRINK

north subsist almost wholly on animal food, while those living
in hot climates have bountiful supplies of delicious fruits with
which to satisfy all their bodily wants. One race subsists
upon the banana, another upon the blubber of seals. In
temperate climates, a diet composed partly of vegetable and
partly of animal food is preferred. {Bead Note G.)

9. The important point to consider is, however, not one of
origin, but whether the chemical principles (mentioned in the
last chapter) enter into the composition of the diet. A purely
vegetable diet may be selected which would contain all the
principles necessary to sustain life. It is recorded of Louis
Cornaro, a Venetian noble, that he supported himself comfort-
ably for fifty-eight years on a daily allowance of twelve ounces
of vegetable food, and about a pint of light wine. On the
other hand, the food of John the Baptist, consisting of
"locusts and wild honey," is an example of the sustaining
power of a diet chiefly animal in its origin.

10. In our climate, those who lead active lives crave an
allowance of animal food ; and it has been found by experience
that with it they can accomplish more work and are less sub-
ject to fatigue, than without it. Among nations where an
exclusively vegetable diet is employed, indigestion is a dis-
order especially prevalent. (Bead Note 7.)

6. Different Effects of Animal and Vegetable Food. — "Raw meat
gives fierceness to animals, and would do the same to man. This is so
true that the English, who eat their meat underdone, seem to partake of
this fierceness more or less, as shown in pride, hatred, and contempt of
other nations." — De La Mettrie.

"The carnivora are, in general, stronger, bolder, and more pugnacious
than the herbivora on which they prey ; in like manner, those nations
who live on vegetable food differ in disposition from such as live on
flesh." — Liebuj.

7. A Mixed Diet affords the Best Results. — "The mixed diet to
which the inclination of man in temperate climates seems usually to lead
him, when circumstances allow that inclination to develop itself freely,
appears to be fully conformable to the construction of his dental and
digestive apparatus, as well as to his instinctive cravings. And whilst

9. The point to consider ': Vegetable diet ? Louis Cornaro ? John the Baptist ?
10. What has been found in our climate f Exclusive vegetable diet f

FOOD AND DRINK 95

11. The necessity for occasionally changing or varying the
diet, is seen in the fact that no single article comprises all the
necessary principles of food, and that the continuous use of
any one diet, whether salt or fresh, is followed by defective
nutrition and disease. There is one exception to this rule: in
infancy, milk alone is best calculated to support life ; for then
the digestive powers are incompletely developed, and the food
must be presented in the simplest form possible. It should
also be remembered that too rich diet is injurious, just as truly
as one that is inadequate. When the food of horses is too
nutritious, instinct leads them to gnaw the wood-work of their
mangers.

12. Different Articles of Diet — Milk. — Milk is the earliest
nutriment of the human race, and in the selection and arrange-
ment of its constituents, may be regarded as a model food, no
other single article being capable of sustaining life so long.
Cow's milk holds caseine, one of the albuminoids, about five
parts in one hundred ; a fatty principle, when separated, known
as butter, about four parts ; sugar of milk four parts ; water
and salts eighty-seven parts. The caseine and fatty substance
are far more digestible in milk than after they have been sepa-
rated from it in the form of cheese and butter.

13. Since milk, in itself, is so rich an article of food, the
use of it as a beverage is unwise, unless the quantity of the

on the one hand it may be freely conceded to the advocates of ' vegeta-
rianism, ' that a well-selected vegetable diet is capable of producing, in
the greatest number of individuals, the highest physical development of
which they are capable, it may, on the other hand, be affirmed with
equal certainty, that the substitution of a moderate proportion of animal
flesh is in no way injurious; but, so far as our evidence at present
extends, this seems rather to favor the highest mental development.
And we can scarcely avoid the conclusion that the Creator, by conferring
on a man a remarkable range of choice, intended to qualify him for sub-
sisting on those articles of diet, whether animal or vegetable, which he
finds most suitable to his tastes and wants." — IT. D. Carpenter on the
Principles of Physiology.

11. Necessity for change in diet ? Continuous use of the same diet ? Exception ? Why
Too rich diet ? Horses ?

12. Milk as a model food ? Cow's milk ? The constituents when separated ?

13. Milk as a beverage ! Milk sold in cities ? How to detect the cheat ?

96 FOOD AND DRINK

other articles consumed be reduced at the same time. The
milk sold in cities is apt to be diluted with water. The way
to detect the cheat is by testing the specific gravity of the
article. Good milk is about 1030 ; skimmed milk, 1035 ; but
milk diluted one-fifth is 1021. An instrument called the
lactometer is also used, by which the amount of cream present
is ascertained.

14. Eggs. — The egg is about two-thirds water, the rest is
pure albumen and fat in nearly equal portions. The fat is in
the yolk, and gives it its yellow color. Eggs contain none of
the sugar principles, and should be eaten with bread or vege-
tables that contain them. Soft-boiled eggs are more wholesome
than those which are hard-boiled or fried, as the latter require
longer time to digest.

15. Meats. — The meats, so called, are derived from the
muscular parts of various animals. They are most important
articles of food for adults, inasmuch as they are richly stored
with albuminoid substances and contain more or less fat. Such
food is very nourishing, and easily digested if eaten when
fresh, — veal and pork being exceptions. The flesh of young
animals is more tender and, in general, more digestible than
that of older ones. All meat is more tough immediately after
the killing of the animal, but improves by being kept a certain
length of time.

16. Some persons prefer flesh that has begun to show signs
of decomposition, or is unmistakably putrid. By some, venison
is not considered to have its proper flavor until it is tainted.
In England, people prefer mutton that is in a similar condition,
just as on the continent of Europe many delight in cheese that
is in a state of decomposition. In certain less civilized coun-
tries, flesh is not only eaten uncooked, but in a mouldy, rotten
condition. The use of such food is not always immediately
injurious, but it predisposes to certain diseases, as indigestion
and fevers. {Bead Note 8.)

14. Composition of eggs 1 Yolk? How should eggs be eaten ?' Why ? How boiled 1
Why ?

15. Meats, whence derived ? Why important ? Flesh of young animals 1

16. Preference of persons ? Venison ? Mutton ? Cheese ? Uncooked flesh ?

FOOD AND DRINK 97

17. Cold is one means of preserving meat from decay. In
the markets of northern Russia, the frozen carcasses of animals
stand exposed for sale in the winter air for a considerable time,
and are sawed in pieces, like sticks of wood, as the purchases
are made — such meat, when thawed, being entirely fit for
food. Beef and pork arc preserved by salting down in brine,
and in this condition may be carried on long voyages, or kept
for future use. Salted meat is not as nutritious as fresh, since
the brine absorbs its rich juices and hardens its fibres. Long-
continued use of salt meats, without fresh vegetables, gives
rise to the disease called scurvy, formerly very prevalent on
ship-board and in prisons, but now scarcely known.

18. Cooking. — The preparation of food by the agency of fire
is of almost universal practice, even among the rudest nations.
The object of cooking is to render food more easy of digestion
by softening it, to develop its flavor, and to raise its tempera-
ture more nearly to that of the body. A few articles of flesh-
food are eaten uncooked in civilized lands, the oyster being
an instance. Raw meat is occasionally eaten by invalids
with weak digestive powers, and by men training for athletic
contests.

19. The cooking may be so conducted as to rob the meat of
its tenderness, and of its flavor. The proper method, in order

8. A Summary Concerning Diet. — " The food on which the man who
would be healthy sin mid live, should be selected so as to insure a variety
without excess. Animal food should not be taken oftener than twice
daily. The amount of animal and vegetable food combined should not
exceed 30 ounces in the 24 hours; and for the majority of persons an
average of 24 ounces of mixed .-, . » 1 i » I food, a third only of which should be
animal, is sufficient. All animal foods should be eaten while they are
fresh, and after th.y been have well cooked. The habit of eating under-
done flesh is an almost certain cause of parasitic disease. The amount of
fluid taken, in any form, should not exceed the average of 24 ounces
daily. Water is the only natural beverage." — £>/-. B. W. Bichardson,
The Diseases of Modern Life.

17. Colli as a preserver? Meat in Russia? Beef and pork, how preserved? Salted
meat as food ? Scurvy ?

18. The antiquity of the custom of cooking food ? Object of cooking ? The oyster?
Raw meat as an occasional food ?

10. KtTect of boiling meat? How may the cooking be done? The proper method?
Making of soup?
O

98 FOOD AND DRINK

to preserve or promote these qualities, is to place the meat in
boiling water, which, after a few minutes, should be reduced
in temperature. In this way the intense heat, at first, coagu-
lates the exterior layers of albumen, and imprisons the delicate
juices; after that, moderate heat best softens it throughout.
When soup is to be made an opposite course should be pursued ;
for then the object is to extract the juices and reject the fibre.
Meat, for such purpose, should be cut in small pieces and put
into cold water, which should then be gradually raised to boil-
ing heat. (Bead Note 9.)

20. Eoasting is probably the best method of cooking meat,
especially "joints" or large pieces, as by this process the meat
is cooked in its own juices. Eoasting should begin with intense
heat, and be continued at a moderate temperature, in order
to prevent the drying out of the nutritious juices, as by this
process an outer coating or crust of coagulated albumen is
formed. During this process the meat loses one-fourth of its

9. Cooking Paves the Way for Easy Digestion. — The objects to be
obtained by cooking meat are : 1. To coagulate the albumen and blood
of the tissues, so as to render the meat agreeable to the sight. 2. To
develop flavors, and to make the tissue crisp, as well as tender, and there-
fore more easy of mastication and digestion. 3. To secure a certain
temperature, and thus to be a means of conveying warmth to the system.
4. To kill parasites in the tissues of the meat.

The action of heat should not be continued after these objects are
accomplished, as the meat will thereby be rendered indigestible. If a
piece of meat be placed in water which is briskly boiling, a crust, so to
speak, is formed by the rapid coagulation of the albumen upon and near
the surface ; so that the juice of the meat cannot escape, nor the water
penetrate its interior. If, on the other hand, the meat be put in cold
water, and slowly heated, the meat is left poor and tasteless. Even in
roasting meat the heat must be strongest at first, and it may then be
much reduced. The juice which, as in boiling, flows out, evaporates, in
careful roasting, from the surface of the meat, and gives to it the dark
brown color, the lustre, and the strong aromatic taste of roast meat. All
baked and masted fatty foods are apt to disagree with delicate stomachs :
and it is often remarked that, although bread and butter, boiled puddings,
boiled fish, or boiled poultry can be eaten freely without discomfort, yet
toast and butter, or meat pies and pastry, or fried fish, or roasted fowl
will disagree with the stomach. — Letheby on Food.

20. Eoasting? How should it be done? Give the philosophy of the process. Frying?

FOOD AND DRINK 99

weight, but the loss is almost wholly water, evaporated by the
heat. Too intense or prolonged heat will dry the meat, or
burn it. Frying is the worst possible method, as the heated
fat, by penetrating the meat, or other article placed in it, dries
and hardens it, and thus renders it indigestible.

21. Trichina. — It should be remembered that ham, sausages,
and other forms of pork should never be eaten in a raw or
imperfectly cooked condition. The muscle of the pig is often
infested by a minute animal parasite, or worm, called trichina
spiralis. Tins worm may be introduced alive, in pork food,
into the human body, where it multiplies with great rapidity,
and gives rise to a painful and serious disease. This disease
has been prevalent in Germany, and cases of it occur from
time to time in this country.

22. Fish. — The part of fish that is eaten is the muscle, just
as in the case of the meats and poultry. It closely resembles
flesh in its composition, but is more watery. Some varieties are
very easy of digestion, such as salmon, trout, and cod ; others
are quite indigestible, especially lobsters, clams, and shell-fish
generally. A diet in which fish enters as the chief article, is
ill adapted to strengthen mind or body, while its continued
use is said to be the fertile source of nearly every form of
disease of the skin. Some persons are so constituted that they
can eat no kind of fish without experiencing unpleasant results.

23. Vegetable Food. — The list of vegetable articles of diet
is a very long one, including the grains from which our bread-
stuffs are made, the vegetables from the garden, and the fruits.
All the products of the vegetable kingdom are not alike useful.
Some are positively hurtful; indeed the most virulent poisons,
as strychnia and prussic acid, are obtained from certain vege-
tables. A.gain, of such articles as have been found good for
food, some are mure nourishing than others; some require very
little preparation for use, while others are hard and indigest-

21. What is " Trichina?" Hew guarded against !

'J-.'. What part of fish is eaten ( What does it resemble? Fish as food for digestion J
Fish as a diet?

28. List of vegetable articles? Usefulness of the different vegetables? Strychnia?
What farther is said in relation to the nourishing and other qualities of vegetables -

100 FOOD AND DRINK

ible, and can only be used after undergoing many preparatory
processes. Great care must therefore be exercised, and many
experiments made, before we can arrive at a complete knowl-
edge in reference to these articles of diet. Tea, coffee, and
other substances from which drinks are made are of vegetable
origin.

24. Bread. — Wheat is the principal and most valuable kind
of grain for the service of man. Bread made from wheat-flour
has been in use for many hundreds of years, and on this
account, as well as because of its highly nourishing properties,
has been aptly called " the staff of life." We never become
tired of good bread as an article of daily food. The white
kinds of flour contain more starch and less gluten than the
darker, and are therefore less nutritious. The hard-grain wheat
yields the best flour. In grinding wheat, the chaff or bran is
separated by a process called "bolting." Unbolted flour is
used for making brown or Graham bread. (Bead Note 10.)

25. The form of bread most easily digested is that which
has been "leavened," or rendered porous by the use of yeast,
or by some similar method. Unleavened bread requires much
more mastication. Hot bread is unwholesome, because it is
not firm enough to be thoroughly masticated, but is converted
into a pasty, heavy mass, that is not easily digested.

10. Bread. — "The health and power of a nation, as of an army,
depend greatly on its food. The quality of bread in any nation, com-
munity, or family is a pretty good measure of its civilization. No one
can entirely dispense with it. Good or bad, in some form it must be had.
So it is, and has been from the earliest records of the race, and so it will
doubtless continue. Leavened or fermented bread is as old as the time
of Moses, and its value lias been fully tested. Whatever be the precise
action of the leaven, it transforms the grain by partial decomposition of
its original elements, and leaves as its resultant what all men in all ages
have approved. Is the art of making good, honest, leavened, Bible bread
lost in Massachusetts, as some of our friends declare ? Baker's bread is
almost universally adulterated. Bread hastily made in families is mixed
in a variety of ways, with a variety of chemicals, and is generally imper-

U. Wheat? " Staff of life ? " White flour? Hard-grain wheats ? Bolting? Graham
bread ?

25. Leavened bread ? Unleavened ? Hot bread ?

FOOD AND DRINK 101

26. Wheaten bread contains nearly every principle requisite
for sustaining life, except fat. This is commonly added in
other articles of diet, especially in butter, — "bread and butter,"
consequently, forming an almost perfect article of food. The
following experiment is recorded: "A dog eating ad libitum of
white bread, made of pure wheat, and freely supplied with
water, did not live beyond fifty days. He died at the end of
that time with all the signs of gradual exhaustion." Death
took place, not because there was anything hurtful in the
bread, but because of the absence of one or more of the food
principles.

27. The Potato. — The common or Irish potato is the vege-
table most extensively used in this country and Great Britain.
Among the poorer classes in Ireland it is the main article of
food. While it is not so rich in nutritious substances as many
others, it has some very useful qualities. It keeps well from
season to season, and men do not weary of its continuous use.
It is more than two-thirds water, the rest being chiefly starch,
with a little albumen.

28. The sweet potato differs from the white or common in
containing more water and a small proportion of sugar. The
common potato and the tomato belong to the same botanical
order as the "nightshades," but do not possess their poisonous

fectly cooked. Very often the elements of wheat and fat which the body
demands (a wise and witty clergyman of the last generation used to say,
'bread is the staff of life, but bread and butter is a gold-headed cane')
are furnished in underdone pastry, made from flour and hog's lard. Any
family who will take the pains can have good bread. It involves not
more than ordinary skill and judgment. It is to be found on the con-
tinent of Europe, on all the great lines of travel, and is as common
among the people of France and Germany as it is rare with us. The
materials I'm- an honest, wholesome loaf are simple and not expensive.
The value of time and labor required for kneading the dough are the
only difficulties, and these we would not, undervalue; they are in many
families very serious, and not easily overcome." — Derby on the Food of
Massachusetts.

26. Wheaten bread f Bread and batter ? Experiment on the dog?

2T. State what la said of the Irish potato.

28. Sweet potato? Nightshades? Potatoes when germinating I

102 FOOD AND DRINK

qualities, unless we except potatoes that are in the process of
germination or sprouting, when they are found injurious as
food.

29. Fruits. — These are produced, in this country, in great
abundance, and are remarkable alike for their variety and
delicious flavor; consequently they are consumed in large
quantities, especially during the warmer months. The moder-
ate use of ripe fruits, in their season, is beneficial, because
they offer a pleasant substitute for the more concentrated diet
that is used in cold weather. The amount of solid nutriment
they contain is, however, small. The percentage of water in
cherries is seventy-five, in grapes eighty-one, in apples eighty-
two. Unripe fruits contain starch, which, during the process
of ripening, is converted into sugar. Such fruits are indi-
gestible, and should be avoided; cooking, however, in part
removes the objection to them.

30. Pure "Water. — It is important that the water we drink
and use in the preparation of food should be pure. It should
be clear and colorless, with little or no taste or smell, and free
from any great amount of foreign ingredients. Chemically
pure water does not occur in nature; it is obtained only by
the condensation of steam, carefully conducted, and is not as
agreeable for drinking purposes as the water furnished by
springs and streams. Rain-water is the purest occurring in
nature; but even this contains certain impurities, especially
the portion which falls in the early part of a shower ; for in
its descent from the clouds, the particles floating in the air are
caught by the falling drops.

31. "Water from springs and wells always contains more or
less foreign matter of mineral origin. This imparts to the
drink its pleasant taste — the sparkle, or "life," coming from
the gases absorbed by the water during its passage under-

29. Fruits? Vsa of ripe fruit? Nutriment they contain? Stareh in unripe fruits?
Cooking of unripe fruits ?

80. How should drinking-water be as regards color and smell ': Chemically pure water ?
How obtained ? Agreeableneas of perfectly pun- water ?

81. Spring and well water ? Whence the sparkle, or life ? The water supply of cities ?
Croton water? Bidgewo "1 ?

FOOD AND DRINK 103

ground. The ordinaiy supply of cities is from some pure
stream or pond, conveyed from a distance through pipes, the
limpid fluid containing generally only a small amount of im-
purity. Croton water, the supply of New York City, is very
pure, and contains only four and a half grains to a gallon ; the
Ridgewood water, of Brooklyn, holds even less foreign matter.

32. Drinking-water may contain as large a proportion as
sixty to seventy grains per gallon of impurity, but a much
larger quantity renders it unwholesome. The mineral spring
waters, used popularly as medicines, are highly charged with
mineral substances. Some of them, such as the waters at
Saratoga, contain three hundred grains and more to the gallon.
(Bead Note 11.)

33. Action of Water upon Lead. — The danger of using water
that has been in contact with certain metals is well known.

11. Impure Water Spreads Disease. — "In the year 1867, three
millions of pilgrims, of whom a handful had come from a cholera dis-
trict, assembled at Hurdwar, a few miles from the spot where the Ganges
escapes from the Himalayas. On the 12th of April the three millions
resolved to bathe and drink. ' The bathing-place of the pilgrims was a
space 650 feet long by 30 feet wide, shut off from the rest of the Ganges
by rails. Into this long and narrow inclosure pilgrims from all parts
of the encampment crowded as closely as possible from early morn to
sunset ; the water within this space, during the whole time, was thick
and dirty — partly from the ashes of the dead, brought by surviving
relatives to be deposited in the water of their river god, and partly from
the washing of the clothes and bodies of the bathers. Now, pilgrims at
the bathing ghaut, after entering the stream, dip themselves under the
water three times or more, and then drink of the holy water, whilst
saying their prayer. The drinking of the water is never omitted ; and
when two or more members of a family bathe together, each from his
own hand gives to the other water to drink. On the evening of the next
day, the 13th of April, eight cases of cholera were admitted into one of
the hospitals at Hurdwar. By the loth, the whole of this vast concourse
of pilgrims had dispersed.' carrying the cholera in every direction over
India ; it attacked the British troops along the various routes, it passed
the northern frontier, got into Persia, and so on into Europe, where it
will work its wicked will for some time to come. That is a sample of
the mischief water can do in the way of spreading disease." — London
Medical Press.

82. Impurities in drinking-water ? Mineral springs ?
38. What is stated of the action of water upon lead ?

104 FOOD AND DRINK

Lead is one of the most readily soluble, and probably the most
poisonous of these substances in common use. When pure
water and an untarnished surface of lead come in contact,
the water gradually corrodes the metal, and soon holds an
appreciable quantity of it in solution. When this takes place
the water becomes highly injurious ; the purer the water, and
the more recent the use of the metal, the greater Avill be the
danger. {Read Note 12.)

34. In cities, lead pipes are commonly used to convey water
through the houses ; lead being also used in the construction of
roofs, cisterns, and vessels for keeping water and other liquids.
After articles made of lead have been in use several months,
the danger of lead-poisoning diminishes. An insoluble coating
of the sulphate of lead forms upon the exposed surface, thus
protecting it from further corrosion. It is, however, a wise
precaution, at all times, to reject the water or other fluid that
has been in contact with leaden vessels over night, or for a
number of hours. Allow the water in pipes to run freely
before using.

35. Coffee. — This is an important addition to diet, and, if
moderately used, is beneficial to persons of adult age. As
commonly employed, it consists of an infusion in boiling water
of the roasted and ground berry. The water extracts certain
flavoring and coloring matters, but that which gives it its
peculiar stimulant qualities is the alkaloid caffeine. With most
persons its action is that of a gentle stimulant, without any
injurious reaction. It produces a restful feeling after exhaust-

12. Lead in Drinking-Water. — "The clanger of using lead for pipes
or cisterns is now well known, the case of the late royal family of France,
at Claremont, having made the matter notorious. In this case there was
one-tenth of a grain in the gallon, and one-third of the persons who
drank the water were affected. But even one one-hundredth of a grain
per gallon has produced palsy in those who drank this impurity habitually.
It is remarkable that the Thames water will at one time dissolve lead,
and not at another." — Mapother's Health Lectures.

34. Lead in pipes and other things? Advice? What takes place after the articles of

lead have been used much ? What is wise ?

85. Coffee as an article of diet? Of what does it consist? How does the water affect
the coffee ? The peculiar stimulant ? How does it affect most persons ?

FOOD AXD DRINK 105

ing efforts of mind or body; it tranquillizes, but does no1 dis-
qualify for labor, and hence it is highly esteemed by persons
of literary pursuits.

36. Another property of coffee is, that it diminishes the
waste of the tissues, and consequently permits the performance
of excessive labor upon an economical and inadequate diet.
This has been tested among the miners of Belgium. Their
allowance of solid food was below that found necessary in
prisons and elsewhere; but, with the addition of about four
pints of coffee daily, they were enabled to undergo severe
labor without reducing their muscular strength. The caravans
which traverse the deserts are supported by coffee during long
journeys and lengthened privation of food. Among armies it
is indispensable in supplementing their imperfect rations, and
in relieving the sense of fatigue after great exposure and long
marches. When taken with meals, coffee is also thought to
promote digestion.

37. Tea. — The effects of tea-drinking are very similar to
those of coffee, and are due to a peculiar principle called theine.
This principle is probably the same as that found in coffee —
caffeine — since the chemical composition of both is precisely
alike. Tea, as a beverage, is made from the dried leaves of
the plant by the addition of hot water ; if the tea be boiled,
the oil which gives it its agreeable flavor is driven off with the
steam. There are two kinds of tea — the black and the green ;
the latter is sometimes injurious, producing wakefulness and
other nervous symptoms. The excessive use of either coffee
or tea will cause wakefulness.

38. During Dr. Kane's expedition in the Arctic regions, the
effects of these articles were compared. " After repeated trials,
the men took most kindly to coffee in the morning, and tea in
the evening. The coffee seemed to continue its influence
throughout the day, and they seemed to grow hungry less

36. Another property of coffee '? Miners of Belgium ? The Caravans ? Among armies ?
Taken with meals ?

37. Effects of tea-drinking 1 Peculiar principle ! The tea beverage, how made ? Black
and green tea ! Excessive use of tea or coffee i

38. Experiments made during Kane's expedition ?

106 FOOD AND DRINK

rapidly than after drinking tea, while tea soothed them after a
day's hard labor, ?,_ 3 the better enabled them to sleep. They
both operated upon fatigued men like a charm, and their supe-
riority over alcoholic stimulants was very decided."

39. Chocolate is made from the seeds of the cocoa-tree, a
native of tropical America. Its effects resemble somewhat
those of tea and coffee, but it is very rich in nutriment. Lin-
naeus, the botanist, was so fond of this beverage, that he gave
to the cocoa-tree the name Theobroma — "the Food of the
Gods." Its active principle is theobromin.

40. Alcohol. — The word alcohol is of doubtful origin. It is
commonly supposed to be derived from the Arabic language,
several words in that tongue resembling it in sound, but none
of them or any other in the language have a meaning corre-
sponding with that of the English term.

41. History. — Alcohol was distilled from rice many centu-
ries before that seed was known in Europe. We hear of it in
Bagdad about the year 900. It was known to the Moors of
Spain, through whom the knowledge of its production spread
into Western Europe. The first description of alcohol was
given by a western writer about 1280, who wrote of a " burning
or ardent water " that resulted from the distillation of wine.
It may also have been known to the Eomans, for Pliny, in
the first century, wrote of a strong kind of wine that was in-
flammable — a quality that strongly suggests the knowledge
of a product of distillation.

42. The Alcohols. — There are at least twelve members of
the alcohol family, the oldest of which is common alcohol.
This last is the only one that need be referred to here. Com-
mon Alcohol is sometimes known as spirit of wine, also as
vinic alcohol. It is commonly obtained by the distillation of
grains or of wine. The ardent spirits of commerce (brandy,
whiskey, gin, and rum) contain about one half water, the other

89. State what is said of chocolate.

40. In what language has the word alcohol its origin ?

41. Give its history.

42. How is common alcohol obtained ?

FOOD AND DRINK 107

half alcohol. Alcohol is also found in all the wines and malt
liquors (beer, ale, and porter) in varying proportions. The
juices of ripe, sweet fruits will, at seventy degrees Fahren-
heit, begin spontaneously to "work" or ferment; also wheat
and other starch-grains, when sprouting, will have their starch
changed into sugar, and this, in like manner, will undergo
fermentation — alcohol being one of the results of this action
in both cases. Thus this fermentation, in changing barley,
grapes, and apples, into beer, wine, and cider, respectively,
transforms valuable foods into most seductive poisons.

43. Properties of Alcohol. — Alcohol is a clear, colorless,
volatile, and inflammable liquid of penetrating odor and
burning taste. It is lighter than water. As it cannot be
frozen, it is used in thermometers for taking low or exceedingly
cold temperatures. It is also used in spirit levels. It burns
with a pale, bluish flame, without smoke, and with intense
heat ; hence its use in the spirit-lamp.

*44. Is Alcohol Food? — Some authorities class alcohol among
the food substances. Chemically it is allied to the sugars, but
the effect of alcohol within the body is very unlike that of the
sugars. The latter are nourishing, while the former tends to
impair nutrition. It was on the mistaken theory that alcohol
had sustaining power, that for two hundred years the armies
and navies of certain countries were supplied with rations of
rum or some other alcoholic drink, under the name of "grog."
During recent years, a systematic inquiry has been made to
discover whether the grog-ration was really serviceable or the
reverse. Tests have been tried upon considerable bodies of
men. under military discipline, by withdrawing that ration;
comparisons have been made at home and abroad, in hot cli-
mates and in cold, in active service and at rest. The results
of these observations have, without exception, been favorable to
the non-use of spirits. The proportion of ill-health, the num-
ber of sick days, and the incapacity for work have invariably
been greater among the men to whom the spirit-ration has been

43. What are the properties of alcohol 1

44. What cau you say ol' alcohol as a food i

108 FOOD AND DRINK

issued, the quality of food and other circumstances being made
as nearly equal as possible. Hence the conclusion that not
only is alcohol not a food, but is injurious in itself, and a
detriment to the food taken. Sp(

45. Does Alcohol Relieve Thirst? — One of the most striking
properties of alcohol is its affinity to water. When swallowed,
therefore, its tendency is to deprive the body of water, and to
create thirst rather than to relieve it. It may then be stated
that alcoholic drinks which appear to quench thirst do so by
means of the water that, in greater or less quantities, dilutes
the alcohol they contain. Water, the peerless beverage of
nature, does its work better in proportion as it remains free
from alcohol. To maintain normal action, the delicate organs
of the body require a uniform supply of water. When alcohol
is introduced, it draws the water to itself, and leaves the organs
without their share of proper moisture ; hence, after death from
alcoholism, we find them affected in different degrees, being
drier and harder than is natural.

46. Does Alcohol Enable its Consumers to Resist Extreme
Cold? — If this could be proved to be a fact, some of its
boasted usefulness would receive support. In extreme cold
climates, the inhabitants are enabled to live comfortably by
consuming vast quantities of animal food alone, especially if it
is abundantly oily. Will alcohol act in a similar way or assist
in maintaining heat ? Experience and observation say no.

47. Before the thermometer was applied to the testing of
the body's temperature, it was commonly supposed, by reason
of the sensations of warmth, that alcohol increased bodily heat.
When, however, this new test was applied, it became apparent
that those sensations were deceptive, and that there had been
an actual fall in temperature as the result of imbibing alcohol.
The surface of the stomach is irritated by this powerful agent,
causing the nerves of sensation to convey to the brain the im-
pression that something has entered the stomach which is pro-

45. Does alcohol relieve thirst?

46. Does alcohol enable <<»<■ to resisl cold ?

■47. How is the temperature of the body aftV-ctod ?

FOOD AND DRINK 109

during warmth. This is a delusive impression, as we know,
by pouring a few drops of alcohol on the skin, that the ten-
dency of alcohol is to cool the surface whenever evaporation
can take place.

48. The sensation of warmth of the face and surface of the
body is also deceptive. The flashing of the face, common to
hard drinkers, does not indicate that they have a superabun-
dance of animal heat, the temperature of their bodies being
below normal. The true cause of the flush is a paralysis of
one set of nerves governing the natural action of the hair-like _
vessels that course just below the skin. Nature has provided
these infinitely fine vessels with minute controlling nerves,
whose duty it is to regulate the flow of blood in exposed
positions. Alcohol paralyzes this control; the blood flows at
random, and the terminal vessels are overcharged with blood.
Hence, the high color, which is so remarkable in habitual
drinkers that it amounts to a disfigurement, is Nature's signal
of distress, showing that the circulation is deranged, and the
blood unduly brought into contact with the lower temperature
of the outer air. Alcohol, therefore, is not a producer of heat,
but a promoter of cold, and must be dangerous to any persons
taking it when they are exposed to low temperatures. {Read
Note 13.)

49. The testimony of those who have had experience in
contact with the realms of snow and ice is unanimous against
the cold-resisting property of alcohol. It is recorded of the
men who served in Napoleon's campaign in Russia, under
greal exposure to cold, that death was hastened by the use of
alcohol. The evidence of the Monks of St. Bernard is similar.

13. Dr. Rae's Statement. — "The Arctic explorer, Dr. Rae, states
that lie found entire avoidance of alcohol necessary iii the far North. The
moment a man had .swallowed a drink of spirits, it was certain that his
day's work was nearly at an end. ' It was absolutely necessary that the
rule of total abstinence should be rigidly enforced, if we would accomplish
our day's task. Any use of liquor, as a beverage, when we had work on
hand, in that terrific cold, was out of the question.1 "

4- ' If what is the Unshod face of drinkers the index ?
19. What do travelers iu cold countries say of its use ?

110 FOOD AND DRINK

Numerous Arctic explorers testify that not only is the tem-
porary indulgence liable to result in most serious consequences,
but that strong, able-bodied men in the habit of using alcoholic
drinks are entirely unfitted to resist the cold to which they
must be exposed. The natives and travelers alike rely upon
fresh animal food, especially fatty food, and avoid alcohol as a
danger to life.*

50. Alcohol Destructive to Life. — Instead of being a pro-
moter of life, as the early alchemists who produced it hoped
it would be, alcohol is hostile to life; it is a poison. Plant
life is speedily destroyed when brought into close contact with
it. The lower animals are poisoned by it. When applied
directly to small insects and reptiles, death commonly occurs
in a few seconds or minutes. It is hurtful to the larger ani-
mals, and the more intelligent of them appear to resent its
use instinctively. This is seen when dogs have been forced to
take brandy in small doses for some time. Instead of learn-
ing to like it, they gradually show a greater and greater dis-
like to it.

51. The Proper Use of Alcohol. — Like opium, chloral,
arsenic, and many other poisons, alcohol may be rightly
used, and that is as a medicine. For the relief of sickness
and feebleness of body, or conditions of unusual fatigue,
alcohol can be beneficially used under the advice of a physi-
cian. Like the other poisons, it should be definitely pre-
scribed and the size and number of the doses precisely ordered
by the physician.

52. Errors in the Use of Alcohol. — If this view of the ques-
tion is the correct one, how utterly foolish is the practice of
those who are continually prescribing for themselves doses of
this poisonous substance for any trifling disturbance of their

* "Alcohol is not the warming cordial and invigorating stimulant that
it is reputed to be, but there is a world-full of preconceived opinions in
its favor that must be yiet and overcome before the true view can make
its way. But the truth must prevail at last. Its true place is not along

50. What is the effect of alcohol upon life ?

51. Wli.it is the proper use of alcohol ?

52. What three errors mentioned ?

FOOD AND DRINK 111

health. And how much worse is the practice of taking the
various forms of alcohol when the person so taking them is in
good health and merely indulges in drinking for the purpose
of bringing about a temporary stimulation. And worse than
all the others is the practice of those who not only indulge in
these stimulants themselves, but who ask others to join in
with them under the name of good-fellowship, when none of
them are to be benefited by so doing, but rather all of them
are in danger of being injured by the act.

53. This practice, last referred to, is often mistakenly
spoken of as a sign of generosity, and is ordinarily called
"treating." It is wholly indefensible from a physiological
point of view, being harmful both to body and mind; and
from a social point of view is without its equal for the evil
that it has wrought and is capable of working. The "social
glass " and the " treat at the bar " count a hundred victims to
every other single one that can be traced to any other mistaken
practice of human society. It is in regard to the evils that
flow from this false show of generosity and geniality that the
minds of the young should early be instructed. It is a well-
established fact that, in some people, alcohol has the power to
create a craving for more. Their nervous systems become so
easily poisoned by its use that they must have more, and they
have not the will-power to resist the temptation. This ten-
dency to be so easily poisoned is also hereditary in some fami-
lies, producing drunkards for several generations.

54. Moderation Societies. — " Moderation societies " have been
organized to check the evils of "treating," but they have not
met with success, and it is not to be expected that they will,
for there can be no moderation in the use of this dangerous
drug except in the way mentioned at the beginning of this sec-
tion, namely, as a prescribed medicine. As Dr. Alden has

with the displays of wealth and luxury upon our sideboards, but in the
medicine-chest along with hasheesh, henbane, opium, stramonium, and
so forth, labeled as a Poison ! " — Dr. A. F. Kinne.

63. What is said of treating ? Is alcohol deceptive 1
54. What is said of moderation societies f

112 FOOD AXD DRINK

said, "There is no such thing as a temperate use of spirits.
In any quantity they are an enemy to the human constitution.
Their influence upon the physical organs is unfavorable to
health. They produce weakness, not strength; sickness, not
health ; death, not life."

55. Diminished Use of Alcohol as Medicine. — As a medicine,
alcohol is far less freely used by physicians now than formerly.
The dangers from its use are more generally recognized, and
other remedies have been discovered and brought into use that
are fully as efficient and active, but have not the tendency to
habit-forming that is so peculiar to alcohol and other narcotics.
There are able physicians who refuse to employ any form of
alcohol as stimulant or medicine, in the belief that it can be
safely and happily replaced by other remedies. In London
and some other cities, hospitals have recently been organized
and are now being operated on the basis of total abstinence
from alcoholic treatment. In many parts of England the use
of alcohol has greatly declined in the alms-houses and other
public institutions, in which formerly the amount of stimu-
lants annually consumed was very great.

56. It is well known that alcohol is an ingredient in many
of the "Bitters" and other so-called patent medicines that
have come into popular use through advertisement in the
newspapers. Many persons have been deluded into the use of
these, to them, doubly bitter substances ; for, not only have
they not found the curative results falsely proclaimed in the
papers, but they have been beguiled into habits of drinking
and into a liking for alcohol that the "Bitters" soon fail to
satisfy.

57. Concerning the Purity of Alcoholic Beverages. — It is well
known that many makers and friends of wines and liquors
claim that when these articles are pure they are not injurious,
but that they become hurtful after they leave their place of
manufacture by reason of the impurities that are added to
them by unscrupulous dealers. "Pure and good liquor," they

55. Is alcohol as highly valued in medicine now as formerly ?

56. The effect of Bitters?

57. What do wine-dealers say ? What is the harmful element ?

FOOD AND DRINK 113

say, "does no harm." Is this correct? It cannot be denied
that deadly additions have been, and may be, so made that
these beverages will become more speedily and manifestly
poisonous than they would otherwise be, but the teaching of
modern physiology is this: that so long as the main element
of danger — that same alcohol from which they get their
stimulating and seductive properties — is present, the ques-
tion of purity, or age, or smoothness of taste is one of little
importance. The "unclean thing," as the Bible calls it, is
present in all intoxicants, whether they be old and costly, or
cheap and new and fiery to the taste. {Bead Note 14.)

58. This so-called "purity" is commonly an accompaniment
of high cost, especially as applied to wines, and represents
money or capital that has long been lying idle in order that
the commodities in question may acquire "age" and smooth-
ness to the palate. " Purity" is therefore largely the cry of
the seller, who is anxious to get back his invested capital, with
interest, or perhaps with usury. It should be clearly under-
stood that the best of these drinks, even though obtained from
the vineyards or wine-cellars of princes, are injurious, and that
the word " purity " is, in the light of science, a misnomer when
applied to any beverage that contains alcohol. {Mead Note 15.)

14. Adulteration in Liquors. — " It is not enough that alcoholic drinks
axe dangerous when purely made, but there is an added danger growing
out of the almost universal practice of the manufacturers of these drinks
to tamper with them and adulterate them with other harmful materials.
Not many months ago the city government of Paris caused a testing of
all the wines that were brought into the market during a month ; there
were 1,518 samples of French wine examined, and only G5 found abso-
lutely free from injurious addition — that is, less than 5 per cent, was
really pure." — N. Y. Scientific Times.

15. Adulteration of Wine. — The difficulty in the way of getting pure
wine is nothing new. Pliny, who lived eighteen hundred years ago, wrote
the following complaint : " Let us suppose that we all agree as to what
wine is the best, how shall we get it ? Our very princes do not drink
pure wine ; to such a point has the villainy of the producers and sellers
of wine arrived that we can buy nothing more than the name of a
vintage — from the very wine-vat it is all adulterated — and so, marvellous
to tell, we may say of wine, the poorer, the purer."

68. What is said of parity as a commercial term ?

114 FOOD AND DRINK

QUESTIONS FOR TOPICAL REVIEW

PAGE

1 . How is the necessity for food shown ? 89

2. To what process of waste and repair is the body constantly subjected ? 89, 90

3. How do you account for the sensations of hunger and thirst? 90, 91

4. What further can you state having relation to the subject ? 90

5. What can you state in regard to the quantity of food required for

the support of life ? 91, 92

G. What circumstances change the needs of persons, old and young, as

regards food and drink ? 91

7. What becomes of all the food and drink we consume ? 93

8. What further can you state in relation to the process of renovation

through which the body passes ? 93

9. What can you state of the habit of nations in respect to diet? 93, 94

10. What in relation to the selection of articles for food ? 94

11 . What has been proved as regards animal food ? 94

12. What as respects the necessity for changing or varying the diet?. . . 94, 95

13. Of what importance is milk as an article of food ? 95, 96

14. What are the constituents of milk? 95

15. What can you state of eggs as an article of food ? 96

16. Of the meats, so called, as an article of food ? 96

17. What effect does cold have upon meats ? 97

18. In what other way may beef and pork be preserved ? 97

19. What can you state of salted meat as food, and of its continued use ? 97

20. What change does meat undergo in the cooking ? 97, 99

21. What directions are given for boiling meat ? 98

22. What for roasting, and with what results ? 98, 99

23. What is said about the frying of meats ? 99

24. Give the statement in relation to trichina 99

25. State what is said in relation to fish 99

26. What is stated of the usefulness and other properties of the prod-

ucts of the vegetable kingdom ? 99, 100

27. What further is said of vegetable food ? 99, 100

' 28. Why is bread made of wheat-flour so important as an article of food ? 100

29. State whatever else you can in relation to bread 100, 101

30. Give the statement respecting the potato 101, 102

31. What is stated of fruits, the use of them, their nutritious qualities,

etc. ? 102

32. How general is the existence of perfectly pure water? 102, 103

33. What is stated in relation to drinking water ? 103

34. What effect has the action of water upon lead ? 103, 104

35. What further can you state on the subject ? 104

36. What properties has coffee as an article of diet ? 104, 105

37. In what circumstance has coffee been found peculiarly beneficial. . . 105

38. What comparison is made between coffee, tea, and chocolate? 105, 106

39. How are the wines, and malt, and other alcoholic beverages pro-

duced ? 106, 107

40. What articles are employed in their production? 107

41. What are the properties of alcohol? 107

42. Is alcohol a food ? 107, 108

4:;. What is said of the property of alcohol to relieve thirst ? 108

44. What effect does alcohol have upon the body's temperature? 108, 109

45. What is the cause for flushing of face in drinkers? 109

4ti. What is the testimony of Antic explorers and others? 109, 110

47. What is the effect of alcohol upon plant and animal life ? 110

48. What are the only conditions for use of alcohol ? 110

CHAPTER VI

DIGESTION

The Principal Processes of Nutrition — The General Plan of Digestion
— Mastication — The Teeth — Preservation of the Teeth — Action of
the Saliva — The Stomach and the Gastric Juice — The Movements of
the Stomach — Gastric Digestion — The Intestines — The Bile and
Pancreatic Juice — Intestinal Digestion — Absorption by means of
Blood-vessels and Lacteals — The Lymphatic or Absorbent System —
The Lymph— Conditions which affect Digestion — The Quality, Quan-
tity, and Temperature of the Food — The Influence of Exercise and
Sleep— The Kidneys— The Spleen — Effect of Alchohol on Digestion,
the Liver, and Kidneys

1. Nutrition. — The great design of food is to give nutriment
or nourishment to the body. But this is not accomplished
directly, as the food must first pass through certain preparatory
changes, as follows : (1), Digestion, by which the food is reduced
to a soluble condition ; (2), Absorption, by which, when digested,
it is taken into the blood ; (3), Circulation, which carries the
enriched blood to the various parts of the system; and (4),
Assimilation, by which each tissue selects from the blood the
materials necessary for its support.

2. By these four steps the sustaining power of food is gradu-
ally brought into exercise and the vital machinery kept in
working order, somewhat after the manner of the steam-engine.
To operate the latter, the force imprisoned within the coal
and water is set free and converted into motion by the burning
of the fuel and the vaporization of the water. It will be seen,
however, when we come to study these operations in the human
body, that they are conducted silently and harmoniously, with
marvellous delicacy and completeness, ami without that friction,
and consequent loss of power, which attend the working of the
most perfect machinery of man's invention.

1. Design of food ? How ai mplished f

2. Sustaining power of food? Simile of the engine f Operation in the human body ?

115

116

DIGESTION

3. General Plan of Digestion. — The great change which food
undergoes in digestion is essentially a refining process, re-
ducing articles of diet, which are at first more or less solid,
crude, and coarse, to a liquid and finely comminuted condition,
suitable for absorption into the blood.
The entire process of digestion takes
place in what is called the " alimen-
tary canal," a narrow, crooked tube,
about thirty feet in its entire length.
This canal begins in the mouth, ex-
tends thence downward through the
gullet to the stomach (a receptacle in
which the principal work of digestion
is performed), and thence onward
through the small and large intes-
tines.

4. The stomach and intestines are
situated in the cavity of the abdomen
(Fig. 22, C, and Fig. 28), and occupy
about two-thirds of its space. The
action to which the food is subjected
in these organs is of two kinds —
mechanical and chemical. By the
former it is softened, agitated, and

Fig. 22. -Section of t„e Trunk, Carried Oil ward from Olie puillt to

BHownre the cavities op the another: by the latter it is changed

Chest and Abdomen .

A, Chest C, Abdomen 1U form through the Solvent pOWCl' oi

u, Diaphragm D, Spinal Column the various digestive fluids.

K, Spinal Cord

5. Mastication. — As soon as solid
food is taken into the mouth, it undergoes mastication or
chewing. It is caught between the opposite surfaces of the
teeth, and by them is cut and crushed into very small frag-
ments. In the movements of chewing, the lower jaw plays
the chief part; the upper jaw, having almost no motion, acts

3. Change of food in digestion ? Process of digestion i I (escribe the alimentary canal.

4. Situation of the stomach and intestines '! Action of the food:' Mechanical action ?
Chemical ?

&. describe the process of mastication. How many and what movements ?

DIGESTION

in

simply as a point of resistance, to meet the action of the
runner. These movements of the lower jaw are of three .sorts:
an up-and-down or cutting, a lateral or grinding, ami a to-and-
gnawing motion.

6. The teeth are composed of a bone-like material, and are
held in place by roots running deep into the jaw. The
exposed portion, or ••crown,'' is

protected by a thin layer of
enamel | Fig. 23, a), tin' hardest
substance m the body, and. like
tlim. ;s capable of striking tire
with steel. In the interior of
each tooth is a cavity, contain-
ing blood-vessels and a nerve,
which enter it through a minute
opening at the point of the root
(Fig. 25).

7. There are two sets of
teeth: first, those belonging to
the earlier years of childhood.
called the milk teeth, which
are twenty in number and small.
At six or eight years of age,
when the jaw expands, and
when the growing body requires
a more powerful and numerous
set. the roots of the milk teeth
are absorbed, and the latter are
another i Fig. 24 i. to make room for the permanent set.

8. There are thirty-two teeth in the permanent set, an
equal number in each jaw. Each half-jaw has eight teeth,
similarly shaped and arranged in the same order: thus, two
incisors, one canine, two bicuspids, and three molars. The
front teeth are small, sharp, and chisel-edged, and are well
adapted for cutting purposes; hence their name incisors. The

6. Composition of the teeth) Enamel of the teeth 1 Interior of tei-tht
T. The milk teeth ': The permanent teeth 1
8, 9. Xuuiber of teeth ': How arranged ?

Pig. 28.— Skctiom of a Tooth

.<. Enamel : '». Cavity ; ,-. ,-. Roots ;

./. Body of the Tooth

shed,*" or fall out, one after

118

DIGESTION

canines stand next, one on each side of the jaw ; these receive
their name from their resemblance to the long, pointed tusks
of the dog (Fig. 25).

9. The bicuspids, next in order, are larger and have a
broader crown than the former; while behind them are the
molars, the largest and most powerful of the entire set. These

Fig. 24. — Section of the Jaws
1' 2' 3' 4' 5'. The Milk Teeth; 1" to S": The Germs of the Permanent Set

large back teeth, or " grinders," present a broad, rough surface,
suitable for holding and crusbing the food. The third molar,
or " wisdom tooth," is the last to be cut, and does not appear
until about the twenty-first year. The arrangement of the
teeth is indicated by the following dental formula:

M —3 m

DIGESTION

110

10. It is interesting, at this point, to notice the differenl
forms of teeth in different animals, and observe how admirably
their teeth are suited to the respective kinds of food upon
which they feed. In the carnivora, or flesh-feeders, the teeth
are sharp and pointed, enabling them both to seizu theii prey

Fig. 25. — Section of the J a wb— Eight Side
V, A, N, Veins, Arteries, and Nerves of the Teeth. The root of one tooth in each jaw is
cut vertically to show the cavity and the blood-vessels, etc., within it. 1 to :■>. Perma-
nent Teeth

and tear it in pieces; while the kerbivora, or vegetable-feeders,
have broad, blunt teeth, with rough crowns, suitable for grind-
ing the tough grasses and grains upon which they feed.

H\ Different forms of teeth ? Human teeth? The inference?

120 DIGESTION

Human teeth partake of both forms ; some of them are sharp,
and others are blunt ; they are therefore well adapted for the
mastication of both flesh and vegetables. Hence we infer
that, although man may live exclusively upon either vegetable
or animal food, he should, when possible, choose a diet made
up of both varieties.

11. Preservation of the Teeth. — In order that the teeth shall
remain in a sound and serviceable condition, some care is of
course requisite. In the first place, they require frequent
cleansing; for every time we take food, some particles of it
remain in the mouth, and these, on account of the heat and
moisture present, soon begin to putrefy. This not only ren-
ders the breath very offensive, but promotes decay of the teeth.

12. The saliva, or moisture of the mouth, undergoes a
putrefactive change, and becomes the fertile soil in which a
certain minute fungus has its growth. This fluid, too, if
allowed to dry in the mouth, collects upon the teeth in the
form of an unsightly, yellow concretion, called tartar. To
prevent this formation, and to remove other offensive sub-
stances, the teeth should be frequently cleaned with water,
applied by means of a soft tooth-brush. The prevention of
the tartar fungus is best effected by the use of a weak solution
of carbolic acid. (Bead Note 1.)

1. The Proper Care of the Teeth. — "In the famous history of Don
Quixote, the hero of La Mancha, it is related that at the end of one of
his great battles, wherein he was as usual conquered, he found himself
wounded in the face by a violent blow from a stone, and gi'ieved to find
that with it he had lost one of his teeth. Reflecting awhile on this un-
happy accident, he sagely remarked that to lose a molar was very much
like losing an old friend. And it is an important question, in view of
this bit of wisdom, how to care for the molars, that they may become old
friends. To this end, the cardinal maxim is cleanliness ; and again clean-
liness. One means of cleansing is the natural one — that is, by chewing
food ; for it is well known that if we have a tooth so situated in the jaw
that it is seldom brought into use, that tooth early shows signs of decay.
But more effectual is the artificial means — the brush. Children should
early be taught to use this ; and for them a softer brush should be selected

11. Cleaning of tooth ? Effects of not cleaning ?

12. Effects of the saliva '! Formation of tartar ? How prevented ? How destroyed ',

DIGESTION 121.

13. It should be borne in mind that the enamel, Nature's
protection for the teeth, when once destroyed, is never formed
anew ; and the body of the tooth thus exposed is liable to rapid
decay. On this account, certain articles are to be guarded
against; such as sharply acid substances that corrode the
enamel, and hard substances that break or scratch it — as
gritty tooth-powders, metal tooth-picks, and the shells of hard
nuts. Sudden alterations from heat to cold, when eating or
drinking, also tend to crack the enamel.

14. Action of the Saliva. — "While the morsel of food is cut
and ground by the teeth, it is at the same time intimately
mixed with the saliva, or
fluids of the mouth. This
constitutes the second step
of digestion, and is called
insalivation. The saliva,
the first of the digestive
solvents, is a colorless,
watery, and frothy fluid.
It is secreted (i.e., sepa-
rated from the blood)
partly by the mucous

membrane which lines the

,..,..„, ., Fio. 36.— STBtrcTUBE op a Salivary Gland

mouth, but chiefly by the

salivary glands, of which there are three pairs situated near

the mouth.

than for adults. They should also early be taught to use no metallic
substances, as pins, needles, etc., to remove substances from between the
teeth. The teeth should always be thoroughly cleansed after taking acids
into the mouth — for they are the great enemies to the teeth — and also
after candies and other forms of sugar, for their particles that linger on
the teeth are changed bydecomposition into lactic acid. Occasional ex-
amination of the teeth is prudent, in order that a commencing cavity may
be promptly detected and remedied. Teeth that are decayed beyond
remedy by rilling should be immediately removed." — Lane on the
Hygiene of the Teeth.

18. Destruction of the enamel ': \\«w guarded against f

it. Mixiiiir of food with the saliva? What is the saliva 1 now secreted - The salivary

glands ?

122

DIGESTION

15. These glands consist of clusters of very small pouches,
around which a delicate network of blood-vessels is arranged ;
they empty into the mouth by means of little tubes, or ducts.
The flow from these glands is generally sufficient to maintain
a soft and moist condition of the tongue and mouth ; but when

they are excited by the pres-
ence and taste of food, they
pour forth the saliva more
freely. Even the mere thought
of food will at times cause the
saliva to flow, as when the ap-
>etite is stimulated by the
sight or smell of some savory
article; so that the common
expression is correct that " the
mouth waters " for the favorite

Fig. 27. — The Head of a Horse, showing articles of food. Anxiety and
the large salivary glanch(o), its duet (6), the ~r\pf nrpvenr its flow" qnrl
muscles of mastication (c, tf, «,/, and g) Sliet Pie^ent; lts now> ana

cause " the tongue to cleave to
the roof of the mouth." In the horse, and other animals that
feed upon dry and coarse fodder, and require an abundant
supply of saliva, we find large salivary glands, as well as
powerful muscles of mastication.

16. The mingling of the saliva with the food seems a simple
process, but it is one that plays an important part in digestion.
In the first place, it facilitates the motions of mastication, by
moistening the food and lubricating the various organs of the
mouth. Secondly, it prepares the way for other digestive
acts : by the action of the teeth, the saliva is forced into the
solid food, softens the harder substances, and assists in con-
verting the whole morsel into a semi-solid, pulpy mass, that
can be easily swallowed, and readily acted upon by other
digestive fluids. The saliva, also, by dissolving certain sub-
stances, as sugar and salt, develops the peculiar taste of each ;
whereas, if the tongue be dried and coated, they are taste-

15. The flow of saliva ? The thought of food f Anxiety and grief f Animals fed upon

dry :u)(\ coarse food ':

1G. Importance of the process? The first place '/ The second ? The third ?

DIGESTION 123

less. Hence, if substances are insoluble, they are devoid of
taste.

17. Finally, the saliva has the property of acting chemically
upon the food. As we have before stated (Chap. IV.), starch,
as starch, cannot enter the tissues of the body; but, in order to
become nutriment, must first be changed to grape-sugar. This
change is, in part, effected by the saliva, and takes place almost
instantly, whenever it conies in contact with cooked starch.
This important function is due to an organic ingredient of the
saliva called ptyalin. This substance has been extracted from
the saliva by the chemist, and has been found, by experiment,
to convert into sugar two thousand times its own weight of
starch. (Bead Notes 2 and 3.)

2. The First Step of Digestion. — "The digestive process begins in
the mouth ; among civilized people it begins in the plate, or even before.
Undoubtedly mastication is the natural method of mincing meat, and not
the least of its value lies in the fact that it takes time. A man who is
eating a tough, and therefore not very digestible chop, will be slow in
eating, if he is careful to masticate it well. There will be a long interval
between each mouthful, and the stomach will run no risk of being hastily
loaded.

" Now, a hastily-loaded stomach is as bad almost as, or, rather, is the
same thing as, an overloaded stomach ; and there can be no doubt that
artificial mastication becomes a snare when it leads any one to introduce
a large quantity of finely-minced meat suddenly and rapidly into an
unprepared stomach, especially into the feeble stomach of an invalid,
under the idea that, because the meat is so nicely minced, and so very
tender, it can be no possible burden to that sorely-tried organ. Natural
mastication has, besides, another advantage over the artificial process,
which is perhaps not always recognized. Whenever fond enters the
mouth, it gives rise to what is called a flow of saliva. This saliva is
secreted by certain glands, which pour into the mouth the fluid they
Strain off from the blood, and which are excited or stimulated to action
by the presence of food in the mouth, as well as by other causes. Saliva
rapidly changes starch into sugar, and sugar is pre-eminently a soluble
body, passing with the greatest ease from the alimentary canal into the
blood." — People's Magazine (Lorn

3. Experiment. Saliva. — The chemical action of saliva upon boiled
starch may be demonstrated by the following simple experiments :

1. Prepare a thin solution of boiled starch ; three parts of starch to
one hundred parts of water ; boil for a few minutes.

17. Its final importance ? Starch ! How effected ? Ptyalin ?

124 DIGESTION

18. Importance of Mastication and Insalivation. — Each of
these processes complements the other, and makes the entire
work available; for, by their joint action, they prepare the
food in the best possible manner for further digestive changes.
The study of these preliminary functions will appear the more
important, when we reflect that they are the only ones which
we can regulate by the will. For, as soon as the act of swallow-
ing begins, the food not only passes out of sight, but beyond
control; and the subsequent acts of digestion are consequently
involuntary and unconsciously performed.

19. It is generally known that rapid eating interferes with
digestion. How does this occur ? In the first place, in rapid
eating, the flow of the saliva is insufficient to moisten the solid
parts of the food, so that they remain too hard and dry to be
easily swallowed. This leads to the free and frequent use of
water, or some other beverage, at meals, to " wash down " the
food — a most pernicious practice. For these fluids not only

2. Obtain a fresh quantity of saliva, which is best done by revolving
a small pebble in the mouth, which causes a copious flow. Collect this
in a separate vessel.

3. Demonstrate that no sugar is present in this starch solution.
Obtain from a druggist an ounce or two of " Fehling's solution" (this
is a solution of sulphate of copper and of certain alkalies). Sugar has
the power of changing the sulphate into an oxide of copper which is red-
dish-brown. Of this put half a teaspoonful into a test-tube, add an equal
quantity of the starch solution, and let it come to a boil over an alcohol
lamp. No change in the blue color will be observed.

4. Demonstrate that the saliva does not contain sugar by boiling a
small quantity with an equal quantity of "Fehling's solution," when no
change of the blue color will be observed.

5. Now in a third test-tube mix a quantity of the starch solution with
one-third its volume of fresh saliva, and set aside for five to ten minutes
in a warm place, or a glass of warm water of about 100° V. Then take
of this again a small quantity and add an equal part of " Fehling's solu-
tion," shake the mixture and boil. As soon as the boiling point is
approached, it will be seen that the blue color disappears, being replaced
by a reddish-brown color. This demonstrates the presence of sugar in
the starch solution, produced by the action of the saliva added.

Is Each of the processes ? Why is a knowledge of the digestive functions important ?
How shown '!

19. Rapid eating ? Describe the process and effects.

DIGESTION 125

cannot take the place of the natural digestive juices, but, on
the contrary, dilute and weaken them.

20. Secondly, the saliva being largely the medium of the
sense of taste, the natural flavors of .the food are not devel-
oped, and consequently it appears comparatively insipid.
Hence the desire for highly-seasoned food, and pungent
sauces, that both deprave the taste and over-excite the diges-
tive organs. Rapid eating also permits the entrance of injuri-
ous substances which may escape detection by the taste, and
be unconsciously received into the system. In some instances,
the most acrid and poisonous substances have been swallowed
" by mistake," before the sense of taste could act and demand
their rejection.

21. Thirdly, the food, being imperfectly broken up by the
teeth, is hurried onward to the stomach, to be by it more
thoroughly divided. But the stomach is not at all adapted to
perform the task thus imposed upon it; and the crude masses
of food remain a heavy burden within the stomach, and a
sourer of distress to that organ, retarding the performance
of its proper duty. Hence persons who habitually eat too
rapidly, frequently fall victims to dyspepsia.* Rapid eating
also conduces to overeating. The food is introduced so
rapidly that the system has not time to recognize that its
real wants are met, and hence the appetite continues, although
more nutriment has been swallowed than the system requires,
or can healthfully appropriate.

22. The Stomach. — As soon as each separate portion of food

is masticated and insalivated, it is swallowed; that is, it is
caused to move downward to the stomach, through a narrow
muscular tube about nine inches in length, called the cesopha-
gus, or gullet | Fig. 29). The stomach is the only large expan-

* For the same reason, persons who prematurely lose their teeth suffer
from dyspepsia. Tor them a proper means of relief is the use of artificial
teeth.

20. Loss of taste ? Another effect »f rapid eating ? Mistakes ?

21. Effect i.i' imperfectly-broken food in the Btotnach? Dyspepsia? Overeating?
'.".'. (Juliet ! Describe tin- Btomaoh and its location. Effects of goiwaudizing ?

126

DIGESTION

sion of the digestive canal, and is a most important organ
of digestion. It is a hollow, pear-shaped pouch, having

a capacity of three pints,
in the adult. Its walls
are thin and yielding, and
may become unnaturally
distended, as in the case
of those who subsist on
a bulky j innutritions diet,
and of those who habit-
ually gormandize.

23. The stomach has
also two openings; that
by which food enters,
being situated near the
heart, is called the car-
diac, or heart orifice; the
other is the pylorus, or
'•'gatekeeper,'' which
guards the entrance to the
intestines, and, under ordi-
nary circumstances, per-
mits only such matters to
pass it as have first been
properly acted upon in the
stomach. Coins, buttons, and the like are, however, readily
allowed to pass, because they can be of no use if retained.
The soft and yielding texture of this organ — the stomach —
indicates that it is not designed to crush and break up solid
articles of food.

24. The Gastric Juice. — We have seen how the presence of
food in the mouth excites the salivary glands, quickly causing
the saliva to flow. In the same manner, when food reaches
the stomach, its inner lining, the mucous membrane, is at

Fig. 28. — Section of

A, Heart

B, The Lungs

C, Diaphragm

D, The Liver

ro Abdomen

E, Gall Bladder

F, Stomach

G, Small Intestine
H, Large Intestine

23. Heart orifice ? Gatekeeper ? Coins, etc. ? Indication of the soft and yielding text-
ure of the stomach }

24. What is meant by the gastric juice ?

DIGESTION

127

once excited to activity. At first, its surface, which while

the stomach is empty presents a

pale pink hue, turns to a bright red

color, for the minute blood-vessels

which course through it are filled

with blood. Presently a clear, color-

less, and acid fluid exudes, drop by

drop, from millions of little tubes in

the inner surface of the stomach,

until finally the surface is moistened

in every part, and the fluid begins to

mingle with the food. This fluid is

termed the gastric juice.

25. The gastric juice dissolves cer-
tain articles of food, especially those
belonging to the albuminoid class.
This solvent power is due to its
peculiar ingredient, pepsin ; in diges-
tion, this substance acts like a fer-
ment— that is, it induces changes in
the food simply by its presence, but
does not itself undergo change. The
acidity of the gastric juice, which is
due to hydrochloric acid, is not acci-
dental; for we find that the pepsin
cannot act in an alkaline solution —
that is, one which is not acid or neu-
tral. The quantity of gastric juice
secreted daily is very large, probably
not less than three or four pints at
each meal. Though this fluid is at
once used in the digestion of the

food, it is not lost; since it is soon re-absorbed by the stomach,
together with those parts of the food which it has digested and
holds in solution.

Fig. '29. Ai.imkn'tary Canal — in-
cludlng Gullet, Stomach, Small
and Large Intestines

'.'.">. What Is the office of the gastric juice ? Acidity of the gastric juice ? Quantity of

gastric juice used f What becomes of it '.'

128 DIGESTION

26. Movements of the Stomach. — The inner coating of the
stomach is the mucous membrane, which, as we have seen,
furnishes the gastric juice. Next to this coating lies another,
called the muscular coat, composed of involuntary muscular
fibres, some of which run circularly, and others in a longitudinal
direction. These expand to accommodate the food as it is intro-
duced, and contract as it passes out. In addition, these fibres
are in continual motion while food remains in the stomach,
and they act in such manner that the contents are gently
turned round from side to side, or from one end of it to the
other.

27. By these incessant movements of the stomach, called
the peristaltic movements, the gastric juice comes in contact
with all parts of the food. We are, however, not conscious
that these movements take place, nor have we the power to
control them. When such portions of the food as are suffi-
ciently digested approach the pylorus, it expands to allow them
to pass out, and it closes again to confine the residue for further
preparation.

28. The knowledge of these and other interesting and instruc-
tive facts has been obtained by actual observation ; the work-
ings of the stomach of a living human being have been laid
open to view and examined — the result of a remarkable acci-
dent. Alexis St. Martin, a Canadian voyageur, received a gun-
shot wound which laid open his stomach, and which, in healing,
left a permanent orifice nearly an inch in diameter. Through
this opening the observer could watch the progress of digestion,
and experiment with different articles of food. Since that
occurrence, artificial openings into the stomach of the inferior
animals have been repeatedly made, so that the facts of stomach-
digestion are very well ascertained and verified. (Bead Note 4.)

4. The Digestibility of Solid Foods. — "The accompanying table
shows some of the results obtained from the experiments of Dr. Beaumont

26. Muscular coat of the stomach ? Expansion and contraction of its fibres ? Action
of the fibres J

27. Peristaltic movements ': What is said of our consciousness of and power over these
movements? Describe the movement of the pylorus.

28. How has the knowledge and the workings of the stomach been ascertained? St.
Martin f How else ?

DIGESTION

129

29. Gastric Digestion. — What portions of the food are
digested in the stomach ? It was formerly thought that all
the great changes of digestion were wrought here, but later
investigation has taught us better. We now know that the
first change in digestion takes place in the mouth, by the partial
conversion of starch into sugar. We also know that, of the
three organic food principles (considered in Chap. IV.) two
— the fats and the sugars — are but slightly affected by the
stomach ; but that its action is confined to that third and very
important class from which the flesh is formed, the albuminoids.
A few articles need no preparation before entering the system,
as water, salt, and fruit-sugar. These are rapidly taken up
by the blood-vessels of the stomach, which everywhere underlie
its mucous membrane in an intricate and most delicate network.
In this way the function of absorption begins.

upon the stomach of Alexis St. Martin. It will surprise many to find that
vegetable foods — they are placed in the latter part of the table — require
so long a time for their digestion."

Food.

Time re-
Mode of quired for
Cooking, digestion,
h. m.

Pork roasted 5 15

Cartilage boiled 4 15

Ducks roasted 4 0

Fowls do 4 0

Do boiled 4 0

Beef fried 4 0

Eggs do 3 30

Do hard boiled . .3 30

Cheese 3 30

Oysters stewed 3 30

Mutton roasted 3 15

Do boiled 3 0

Beef roasted 3 0

Do boiled 2 45

Chicken fricasseed . . .2 45

Lamb broiled •_' 80

Pig (suckling) roasted 2 30

Goose do 2 30

Gelatin boiled 2 80

Turkey do 2 25

Eggs roasted 2 15

Cod Fish (cured, dry).... boiled 2 0

Ox Liver broiled i 0

Venison Steak do 130

Food.

Time re-
Mode of quired for
Cooking, digestion

Salmon Trout boiled 1 30

Eggs (whipped) raw 1 30

Tripe (soused) boiled 1 0

Pig's Feet (soused) do 1 0

Cabbage boiled 4 0

Beetroot do 3 45

Turnips do 3 30

Potatoes do 3 30

Wheaten Bread baked 3 30

Carrots boiled 8 15

Indian Corn Bread baked 3 15

Do. Cake do 3 0

Apple-dumpling boiled 3 0

Potatoes baked 2 33

Do roasted 2 30

Parsnips boiled 2 30

Sponge Cake baked 2 30

Beans boiled 2 30

Apples (sour) raw 2 0

Barley boiled 2 0

Tapioca do 2 0

Sago do 1 45

Apples (sweet) raw 1 30

Bice boiled 1 0

29. What was formerly thought? What do we now know? What else
know ? Water, salt, and sugar 1 Absorption ?

I

130 DIGESTION

30. The albuminoid substances are speedily attacked and
digested by the gastric juice. From whatever source they are
derived, vegetable or animal, they are all transformed into the
same digestive product, called peptone. This is very soluble
in water, and is in part absorbed by the blood-vessels of the
stomach. After a longer or shorter time, varying from one to
five hours, according to the individual and the quantity and
quality of his food, the stomach will be found empty. Not
only the unabsorbed digested food, but also those substances
which the stomach could not digest, have passed little by little
through the pylorus, to undergo further action in the intestines.
At the time of its exit the digested food is of a pulpy con-
sistence, and dark color, and is then known as the chyme.
(Bead Notes 5 and 6.)

5. Indigestible Matters. — "Children sometimes swallow coins, but-
tons, etc., and so cause great alarm. There is little real ground for appre-
hension under these circumstances, unless the coins are bronze. If the
latter, there is some cause for fear that copper poisoning will ensue, and
the ready passage of the coin is desirable. This is best effected by meals
of figs or pudding, in which the coins are imbedded, and so passed harm-
lessly. As to bulk, whatever will go into the stomach will pass the
various straits and emerge again." — Fothergill.

6. Experiment. Gastric Juice. — The action of the gastric juice upon
the albuminoids can be readily demonstrated outside of the body. For
this it is necessary to prepare a solution of pepsin and a solution of hydro-
chloric acid. The first of these may be made in one of two ways. The
simplest of these is to obtain some pure pepsin from the druggist, and
dissolve of this thirty grains in four ounces of pure glycerin ; the other,
but more complicated way, is to obtain a pig's stomach, dissect off the
mucous membrane, mince finely and add six ounces of glycerin, set aside
for a week and strain through muslin. The solution of hydrochloric acid
should be of the strength of two parts per thousand, which would be
about two or three drops of the strong acid to four ounces of water.

Demonstrate that neither the solution of pepsin nor the hydrochloric
acid alone have the power to digest albuminoids.
Prepare three test-tubes as follows :

1. Into one put about a teaspoonful of the pepsin solution, and add a
small piece of the white of a hard-boiled egg.

2. Into the second test-tube put a teaspoonful of the dilute hydro-
chloric acid, diid add again a small piece of the white of the egg.

3. The third test-tube fill half with the solution of acid, add half a tea-
spoonful of the pepsin solution, and again a small piece of the egg.

Albuminose? The process ? Chyme?

DIGESTION 131

31. The Intestines. — The intestines are continuous with the
stomach, and consist of a fleshy tube, or canal, twenty-rive feet
in length. The small intestine whose diameter is about one
inch and a half, is twenty feet long, and very winding. The
large intestine is much wider than the former, and five feet
long (Fig. L'9). The general structure of these organs resembles
that of the stomach. Like it. they are provided with a mucous
membrane, or inner lining, whence flow their digestive juices;
and, just outside of this, a muscular coat, which propels the
food onward from one point to another.

32. ^Moreover, both the intestines and stomach are enveloped
in the folds of the same outer tunic or membrane, called the
peritoneum. This is so smooth and so well lubricated, that
the intestines have the utmost freedom of motion within
the abdomen. In the small intestines the work of digestion is
completed, the large intestine receiving from them the indi-
gestible residue of the food, and in time expelling it from the
body.

33. Intestinal Digestion. — As soon as the food passes the
pylorus and begins to accumulate in the upper part of the
intestines, it excites the flow of a new digestive fluid, which
enters through a small tube, or duct, about three inches below
the stomach. It is formed by the union of two distinct fluids
— the bile and the pancreatic juice. The bile is secreted by the
cells of the liver, the largest gland of the body, situated on
the right side and upper part of the abdomen (Fig. 28). The
bile is constantly formed, but it flows most rapidly during
digestion. During the intervals of digestion it is stored in the
gall-bladder, a small membranous bag attached to the under

Now set these three tubes aside in a warm place for a few hours, or
until the following day. when you will be able to demonstrate that in the
first two no change has taken place, while the white of egg in the third
has been entirely dissolved.

31. What are the intestines? The small intestines? The large intestines? Their
Btrnetnre 1

32. Peritoneum? The work of digestion ?

83. The presence of food in the intestines ? Bile ?

132 DIGESTION

side of the liver. This fluid is of a greenish-yellow color,
having a peculiar smell, and a very bitter taste. (Read Note 7.)

34. The pancreatic juice is the product of a gland called the
pancreas, situated behind the stomach. This fluid is colorless,
watery, alkaline, and without odor. Like the digestive juices
previously described, it owes its solvent power to its peculiar
ferments. The most important of these ferments, called pan-
creatin, transforms starch into sugar. Another, trypsin, causes
the solution of undissolved albuminoid substances ; and a third
ferment, which has not received a name, causes a partial acidi-
fication of the fats. By the joint action of these fluids, the
food is prepared for absorption. There results from this action
of the pancreatic juice a white and milky fluid, termed the
chyle, which holds in solution the digestible portions of the
food, and is spread over the extensive absorbent surface of
the small intestines. (Bead Note 8.)

35. The mucous membrane of the intestines, also, secretes
or produces a digestive fluid by means of numerous " follicles,"
or minute glands ; this is called the intestinal juice. From
experiments on the lower animals, it has been ascertained that
this fluid exerts a solvent influence over each of the three
organic food principles, and in this way completes the action
of the fluids previously mentioned, viz. : — of the saliva in
converting starch into sugar, of the gastric juice in digesting
the albuminoids, and of the pancreatic juice and bile in
emulsifying the fats.

7. Experiment. Bile. — The chief function of the bile in the diges-
tion of food is the emulsifying of fats.

If a quantity of oil is shaken up with an equal part of water in a test-
tube, the two will not mix. But if we substitute bile for the water, and
shake thoroughly, we obtain an emulsion which will separate but slowly
and imperfectly.

The bile may be obtained from the gall-bladder of the ox or sheep at
any butcher's or slaughter-house.

8. Experiment. Pancreatic Juice. — To obtain the pancreatic juice,
it will be necessary to extract it from a fresh pancreas, "sweet-bread"

34. The pancreatic juice f The joint action of these fluids 1
86. The mucous membrane ? Experiments on inferior animals f

DIGESTION 1 33

36. Absorption. — With the preparation of the chyle, the
work of digestion is completed ; but it has not yet become a
part of the blood, by means of which it is to reach the dif-
ferent parts of the body. The process by which the licpiefied
food passes out of the alimentary canal into the blood is called
absorption. This is accomplished in two ways; first, by the
blood-vessels. We have seen how the inner membrane of the
stomach is underlaid by a tracery of minute and numerous
vessels, and how some portions of the food are by them
absorbed. The supply of blood-vessels to the intestines is
even greater; particularly to the small intestines, where the
work of absorption is most actively carried on.

37. The absorbing surface of the small intestines, if con-
sidered as a plane surface, amounts to not less than half a
square yard. Besides, the mucous membrane is formed in
folds with an immense number of thread-like prolongations,
called villi, which indefinitely multiply its absorbing capacity.
These villi give the surface the appearance and smoothness of
velvet, and during digestion they dip into the canal, and. by

(which may be bought of any butcher), by means of either water or
glycerin. Mince the pancreas finely ami add sufficient of either of these
liquids to cover it, set aside for a day and strain or filter. The glycerin
extract will keep for a long time ; the watery extract soon spoils.

The pancreatic juice has a digestive action on all the food-stuffs.

Its action upon boiled starch maybe demonstrated by repeating the
experiments detailed under "Saliva," only substituting the extract of the
pancreas for the saliva.

It- action upon albuminoids is shown by adding to a few teaspoonfuls
of the pancreatic extract Borne finely minced meat, or a part of tin-
white of a boiled egg. But as the action of the pancreatic juice can only
proceed in an alkaline medium, it is necessary to be certain of the
alkalinity of the fluid. This is best done by adding about live grains of
carbonate of soda (washing soda) to each ounce of pancreatic extract
Set the test-tube aside in a warm place for a few hours, when the meal
or white of egg will be found entirely dissolved.

Its action upon fats may be shown by shaking up in a test-tube a
quantity of the extract with an equal part of melted lard or oil, when «e
will obtain a very perfect emulsion.

Bow much thus far has been done with the food?
The next process ': Give the first way.

134

DIGESTION

means of their blood-vessels, absorb its fluid, contents, just as
the spongioles which terminate the rootlets of plants imbibe

moisture from the sur-
rounding soil.

38. Secondly, absorption
is also effected by the lac-
teals, a set of vessels pecul-
iar to the small intestines.
These have their begin-
nings in the little villi just
mentioned, side by side
with the blood-vessels.
B These two sets of absorb-
A ents run in different
courses, but their destina-
tion is the same, which is
the right side of the heart.
The lacteals receive their
name from their milky-
white appearance. After a
meal containing a portion
of fat, they are distended
with chyle, which they are
specially adapted to receive; at other times they are hardly
discernible. The lacteals all unite to form one tube, the
thoracic duct, which passes upward through the thorax, or
chest, and empties into a large vein, situated just beneath the
left collar-bone.

39. The Absorbents. — The lacteals belong to a class of ves-
sels known as absorbents, or lymphatics, which exist in nearly
all parts of the body, except the brain and spinal cord. The
fluid which circulates through the lymphatics of the limbs, and
all the organs not concerned in digestion, is called lymph.
This fluid is clear and colorless, like water, and thus differs

Fig. 30. — The Lacteals
A, Small Intestine B, Lacteals
C, Thoracic Duct D, Absorbents

E, Blood-vessel

38. How is absorption effected in another way? Describe it. Name of the lacteals?
i'horacic duct ?

39. The absorbents ? Lymph ? What further of the lymph ?

DIGESTION

135

from the milky chyle which the lacteals carry after digestion :
it consists chiefly of the watery part of the blood, which was
not required by the tissues, and is re-
turned to the blood by the absorbents
or lymphatics. {Bead Note 9.)

40. Circumstances Affecting Digestion.
— What length of time is required for
the digestion of food? From observa-
tions made, in the case of St. Martin,
the Canadian already referred to, it has
been ascertained that, at the end of two
hours after a meal, the stomach is ordi-
narily empty. How much time is needed
to complete the digestion of food, within
the small intestines, is not certain ; but,
from what we have learned respecting
their methods of action, it must be evi-
dent that it largely depends upon the
amount of starch and fat which the
food contains.

Fig. 31. - Two Intestinal
Vill . Magnified 100

DIAilETERS

a, b, and c, lacteals ; d, blood-
vessels

9. Absorption of the Lacteals. — "The force by which the milky fluid
moves upward through the lacteals is very considerable. This has been
proved by the distension of the whole system of vessels, including the
thoracic duct, even to the occurrence of rupture, when that duct has been
tied in an animal a short time before it has been fed. The movement of
the fluid thus, in some measure, resembles absorption by the spongioles
at the extremities of the roots of trees, and the continuous rising of the
sap. The thoracic duct may become diseased, and a serious derange-
ment of nutrition take place. In the case of an unfortunate person,
who was some years ago exhibited as a curiosity under the name of the
1 living skeleton,' was illustrated the slow starvation that may thus be
produced. Although he was able to take food in abundant supply, he
was not nourished by it. Finally he died, and an examination of his
body disclosed the fact that the thoracic duct had been obstructed by
disease, and absorption by the lacteals was prevented. Hard work
directly after a hearty meal is bad practice. Remember the story of the
two hounds. They were both fed alike in the morning ; one of them
was taken out to run on a hunt, the other was tied up at home. When
the master came back from the hunt, both dogs were killed, and their

40. What can you state as to the time required for digestion ?

136 DIGESTION

41. In addition to the preparation which the food undergoes
in cooking, which we have already considered, many circum-
stances affect the duration of digestion; such as the quality,
quantity, and temperature of the food; the condition of the
mind and body; sleep, exercise, and habit. Fresh food,
except new bread and the flesh of animals recently slain, is
more rapidly digested than that which is stale ; and animal
food more rapidly than that from the vegetable kingdom.

42. Food should not be taken in too concentrated a form,
the action of the stomach being favored when it is somewhat
bulky ; but a large quantity in the stomach, especially if there
is much liquid, often retards digestion. If the white of one
egg be given to a dog, it will be digested in an hour, but if the
white of eight eggs be given it will not disappear in four
hours. A wine-glassful of ice-water causes the temperature
of the stomach to fall thirty degrees ; and it requires a half-
hour before it will recover its natural warmth — about a
hundred degrees — at which the operations of digestion are
best conducted. A variety of articles, if not too large in
amount, is more easily disposed of than a meal made of a
single article ; although a single indigestible article may inter-
fere with the reduction of articles that are easily digested.
{Bead Note 10.)

stomachs examined. It was found that the hound that hunted still had
the stomach full of food, while that of the stay-at-home was empty.
When you have a hard piece of work on hand do not eat much ; the
more you eat the weaker you are for the purpose." — Bud-land (in part).
10. Digestibility of Warm Food. — "It is very desirable that all
cooked food should be taken hot. When it is eaten cold it reduces the
temperature of the stomach, and both the nerves and vessels of the
stomach are taxed in order to bring the temperature of the food thus
taken up to that of the human body. Mankind in all ages seems to
have discovered that it is desirable to prevent this tax upon the internal
organs, and have taken their food hot in order to prevent it. It was
death to the Roman slave to bring in his master's water tepid or cold —
so much importance did they attach to hot water as drink. Many of
our own beverages are taken hot even in summer weather ; and it is an

41. Circumstances affecting duration of digestion ? Fresh food ?

4J. Food in concentrated form ? A large quantity of food ? Experiment on the dog '
Ice-water 1 Variety of articles ?

DIGESTION ]:;:

43. Strong emotion, whether of excitement 01 depression,
checks digestion, as do also a bad temper, anxiety, business
cares, and bodily fatigue. The majority of these conditions
make the mouth dry — that is, they restrain the flow of the

saliva ; and without doubt they render the stomach dry also,
by preventing the flow of the gastric juice. And. as a general
rule, we may decide, from a parched and coated tongue, that
the condition of the stomach is not very dissimilar, and that it
is unfit for the performance of digestive labor. This is one of
the points which the physician bears in mind when he examines
the tongue of his patient. (Head Note 11.)

44. The practice of eating at short intervals, or " between
meals," as it is called, has its disadvantage, as well as rapid
eating and overeating, since it robs the stomach of its needed
period of entire rest, and thus overtasks its power. AVith the
exception of infants and the sick, no persons require food more
frequently than once in six hours. Severe exercise, either
directly before or directly after eating, retards digestion; a
period of repose is most favorable to the proper action of the
stomach. The natural inclination to rest after a hearty meal
may be indulged, but it should not be carried to the extent of

economy of the vital powers to take hot meals rather than cold ones. As
a rule, hot food is better than cold, in our climate, except in very hot
weather ; in tropical climates only can food be taken with advantage
when cold, or ice and iced drinks be used with impunity." — Larikester'a
Mn mini of Health.

11. On the Demands of Digestion. — '-The system never does two
things well at the same time. No one can meditate a poem and drive a
saw simultaneously without dividing his force ; he may poetize fairly
and saw poorly ; or he may saw fairly and poetize poorly ; or he may
both saw and poetize indifferently. Brain-work and stomach-work inter-
fere with each other if attempted together. The digestion of a dinner
calls force to the stomach, and temporarily slows the brain : the experi-
ment of trying to digest a hearty supper, and to sleep during the process,
has sometimes cost the careless experimenter his life. The physiological
principle is to do only one thing at a time, if you would do it well." —
Dr. E. H. Clarke: Sex in Education.

43. Strong emotion ? The tongue of the patient t

44. Eating between meals :■ Severe exercise? Sleep after meals ?

138

DIGESTION

sleeping ; since in that state the stomach, as well as the brain
and the muscles, seeks release from labor. (Bead Notes 12 and 13.)
45. The Kidneys. — Besides those already described, the
abdominal cavity contains other important organs, viz., the
kidneys and spleen. The kidneys are two in number, located in
the loins behind the intestines, one
on each side of the spinal column.
They are shaped like a bean, being
about four inches long, two inches
wide, and one inch thick. The func-
tion of the kidneys is to purify the
blood by removing from it a poison-
ous substance called urea and cer-
tain waste products. If their action
is in any way interfered with, blood-
poisoning takes place, on account
of the accumulation of urea, and
effete materials in the system, pro-
ducing coma, which rapidly proves
fatal unless it is relieved. The
watery fluid secreted by the kid-
neys is carried by two tubes, called

Tiik Kidneys and

ureters, to the bladder.

12. Work of Exertion. — "The best time to make great exertion is
about two hours after a meal. It is not a good time before breakfast,
although moderate work may be then performed ; and those who go to
work before breakfast should first take a cup of hot milk, tea, or coffee,
or other simple food. The body is weakest before breakfast.

" Violent or rapid exertion made by children, and also by stout and
aged people, often injures, and sometimes causes disease of the heart,
when the same taken in the ordinary way would do no harm. Rapidly
running upstairs, or to meet a train, sometimes causes death. Hence,
while exercise is of the utmost importance to health, it should be taken
in a regulated and rational manner, and particularly by those who have
passed the period of youth. But disease of the heart, even in youth, may
often be traced to indiscretion in this particular, whether in rowing, run-
ning, or jumping." — Edward Smith on Health.

13. Tight Clothing interferes with Digestion. — " On one wet winter's
day at Florence, some years ago, I had been spending the morning in the

45. What are the kidneys and their functions ?

DIGESTION 139

46. The Spleen. — The spleen is situated on the left side of
the abdomen behind the stomach. It is called the " milt " by
the butcher. It has no duct, and its uses are not positively
known. In malarial fevers, it is sometimes much enlarged,
and the individual is said to have an " ague cake."

47. Effect of Alcohol upon Digestion. — The irritating effects
of alcohol upon the lining of the stomach* are first seen in
deranged digestive action, in loss of appetite, and at a later
stage, in changes in the stomach's structure, principally by a
thickening of the walls of that organ. {Bead Note 14.)

studio of a sculptor of world-wide reputation. We had discussed the
perfections of female beauty, and I felt that I was sitting at the feet of a
thinker, as well as an ' elegans formarum spectator.' In the evening we
met again at a hospitable palazzo, and, under cover of the waltz, from a
quiet corner of observation, we saw hurling by in the flesh, much that we
had been thinking of in the marble and the clay, and our eyes could not
but follow one particular face, famous for the assistance its great natural
beauty received from art. ' Face,' I said, but the mind of Hiram Powers
was penetrating deeper, for he exclaimed, after a short silence : ' That

is all very well, but I want to know where Lady puts her liver ! '

Where, indeed ! for, calculating the circumference of the waist by the
eye, allowing a minimum thickness for the walls of the chest, an area for
the spine, oesophagus, and great blood-vessels, the section of the waist
seemed to admit of no room for anything else. In such a body the liver
must be squeezed down into the abdomen, stick into its hollow neighbors,
and infringe upon all the organs. The organ which suffers most is the
unresisting stomach, which is dragged and pushed out of all form during
the continuance of this packing process." — Dr. T.K. Chambers on the
Indigestions.

* Dyspepsia due to Alcohol.— " Many cases of dyspepsia are due to
alcohol solely and wholly, and no reliance whatever can be placed upon
the word, statement, or assertion under oath of a drunkard; for 'a
drunkard is a liar.' And this holds good of both sexes, all ages, every-
where and ever." — Dr. J. M. Fothergill.

14. Cordials, Bitters, etc. — "In health, alcohol no wise plays a
friendly part in regard to digestion. And it is just here that a mistake
is made by many persons who have been deluded into the use of what
are termed 'cordials' ; these are very strong alcoholic liquors, and they
are supposed by those who use them to be especially appropriate at the
end of a hearty meal. Absinthe, the pet poison of the Parisian, is one of
these falsely-named ' cordial ' substances. These cordials are never less

46. What is the location of the spleen ?

47. How is the digestion affected by alcohol ?

140 DIGESTION

Dr. Beaumont was able to observe the condition of the
stomach of Alexis St. Martin (see paragraph 28, page 128) after
alcoholic excesses. He states that the surface of the organ was
overcharged with blood, at times drops of blood exuding from
it; and that its secretions became thick, unnatural, and slightly
tinged with blood.* It is a fact beyond dispute that other
organs concerned in the act of digestion, particularly the liver,
become diseased by the habitual use of spirituous liquors.
{Bead Note 15.)

48. Effects of Alcohol on the Liver. — When alcohol is taken
into the stomach it is absorbed, and is carried by the portal
vein directly into the liver. The blood in the liver is thus
made more stimulating, and repeated stimulation produces
over-action, which results in impairment or loss of power to
secrete healthy bile. For the same reason, organic changes
take place more frequently in the liver, from the use of alcohol,

welcome than after a substantial meal. So many misleading names have
been given to beverages (Cordials, Bitters, etc.), that many persons have
used them without knowing the evil consequences which follow. It is
made clear by recent proofs that the so-called cordials are the most rapidly
poisonous of all flie spirituous beverages."

* Alcohol and Digestion. — "The effects of alcohol upon digestion vary
greatly according to the quantity imbibed ; it may act as a temporary
check, or in large doses it may completely arrest the digestive act : vomit-
ing is frequently induced — the stomach thus freeing itself from the hurt-
ful intruder. The habitual use of spirits often gives rise to a most dis-
tressing form of dyspepsia."

15. Effect upon the Appetite. — " At a Peace Congress held at Frank-
fort, Germany, the inn-keepers found it necessary to increase the price
of board of the strangers attending the congress, the majority of whom
were teetotalers, for the reason that their appetites required an amount
of solid food in excess of that usually consumed by their own nationality,
who are habitual drinkers of beer containing appreciable amounts of
alcohol.

" By direct contact, alcohol acts upon the stomach and leads to a
destruction of its secreting tubules. Nothing with such certainty impairs
the appetite and the digestive power as the continued use of strong alco-
holic liquids. From the stomach it is absorbed, and with its distribution
through the system it interferes with nutrition and leads to a diseased
state of the liver, kidneys, and other organs." — Pavy.

48. What effect produced on the liver by alcohol?

DIGESTION 141

than in any other organ. It first becomes enlarged, owing to
congestion from obstruction of the circulation and excessive
growth of the connective tissue. One result of this overgrowth
is compression and diminution in size of the cells which secrete
the bile. Another result is a hindrance to the flow of blood
through the liver. The organ is not only diminished in size,
but it becomes hardened and roughened — an appearance which
has given it the name of hob-nailed liver ox drunkard's liver.
This condition not only interferes with the proper formation
of bile, but it obstructs the return of blood from the organs in
the abdomen, and Ave have dropsy as a consequence.

49. The Effects of Alcohol on the Kidneys. — The action of
alcohol on the kidneys is similar to that which takes place in
the liver. The first effect of repeated stimulation by alcohol
is an increase of the natural secretions of the organs, but this
continued over-action, in obedience to a universal law, after-
ward results in a diminished secretion and in injury to the
substance of the kidney. "Granular degeneration," one of
the forms of Bright's disease, takes place. The kidneys are
unable to perform efficiently the duty of removing impurities
from the blood ; urea, and other noxious materials accumulate,
and the whole system is poisoned.

50. The Effect of Tobacco on Digestion. — Very few persons
are able to take up the habit of smoking without first experi-
encing the sickening effect of tobacco upon the stomach. The
use of tobacco has a perverting influence over the salivary
glands, causing the secreted fluid to become so watery as to
deprive it of its property of converting starch into sugar. In
the case of some persons this amounts to a serious impairment
of digestion, and can be relieved only by the abandonment of
the off ending substance.

The habitual use of tobacco has a tendency to leave the
mouth and throat in a condition of unnatural dryness, and this
has the effect of an artificially produced thirst which has, in

4K. How arc the kidneys affected by alcohol?

50. What effect of tobacco on digestion ? Upon the mouth ? What are the " twin
vices" ?

142

DIGESTION

many instances, led to the habit of taking alcoholic liquors.
These two habits do not always co-exist in the same persons,
but the danger that the one will lead up to the other is so
great that they are frequently spoken of as the " twin vices."

The young should appreciate this danger, and should also
remember that the habit of using tobacco is most commonly
established early in life, if at all ; very few persons, compara-
tively, who have passed twenty years of age without forming
the habit, adopt it in their later years.

TOPICAL OUTLINE

THE

CAVITIES OF
THE TRUNK

Thorax or
Chest

Shape

Walls

f Conical, with the diaphragm

1 as its base.

Back — Vertebral column.

Sides - i Ribs-

\ Intercostal muscles.

Front -

Diaphragm

Abdomen

Walls

bternum.
Costal cartilages.
[ Floor — Diaphragm.
A muscular partition, dividing the thorax
from the abdomen. Convex above and
concave below.

f Roof — Diaphragm.
Back — Vertebral column.
Sides and Front — Abdomi-
l nal muscles.

f Solution commenced in the mouth by the

^ i Completed in the intestines by the intestinal

[ juices.
Solution commenced in the stomach by the

gastric fluid.
Continued in the intestines by the pancreatic
fluid, and also (probably) by the intestinal
secretions.
f Fat globules loosened from their nitrogenous
I cell-walls and membranes by the gastric
| fluid.

Digested in the intestiries by the bile and the
I pancreatic fluid.
Mineral salts Dissolved by the various digestive fluids.

From the mucous membrane in all parts of the alimentary
| canal.
Absorption by ! No power of selection —

Blood-vessels ] Every kind of food absorbed if dissolved, or if so finely
divided that it can permeate the walls of the blood capil-
laries.

PROCESS

OF

DIGESTION

Nitrogenous
foods

Fats

DIGESTION

148

LYMPHATIC
SYSTEM

Lacteals

Other
Lymphatics

Glands

Thoracic duct

The lymphatics of the intestines.

Many originate in the villi of the small
intestine.

(During digestion — a milky fluid

Contain | {chyle).

[During fasting — a, watery fluid.

Absorb fatty substances.

Absorb the fluid portion of blood (lymph)
which has exuded through the blood-
vessels.

Also other substances for reorganization.

Engaged in elaborating blood from the
lymph and chyle.

Iu front of backbone, chiefly in thorax.

Receptaculum chyli — lower portion — situ-
ated in the abdomen.

Receives lymph and chyle, and pours them
into the blood system.

QUESTIONS FOR TOPICAL REVIEW

PAGE

What do you understand by nutrition? 115

How is the process of nutrition carried on ? 115

What further can you state on the subject ? 115

Describe the general plan of digestion 116

How is the process of mastication carried on ? 116

State what you can in relation to the formation of the teeth 117, 118

What, in relation to their arrangement ? 117, 118

What, in relation to the process of " shedding " ? 117

In relation to the different forms of teeth in different animals?.. .119, 120

What causes operate to injure or destroy the teeth ? 120

What suggestions and directions are given for the preservation of

the teeth ? 120, 121

What do you understand by insalivation ? 121

How is the process of insalivation carried on? 121, 122

Of what importance is the saliva to the process ? 122, 123

Of what importance are mastication and insalivation? 124

Describe the consequences of rapid eating 124, 125

What becomes of the food directly after it has undergone mastica-
tion and insalivation ? 125

Describe the location and formation of the stomach 125, 126

Describe the process by which the gastric juice is formed 126, 127

What are the properties and uses of the gastric juice ? 127

What are the movements of the stomach, and what their uses? 128

What further can you state on the subject ? 128

What portions of the food are digested in the stomach? 121', 130

What are the first changes of digestion ? 12'.'

What further can you state in relation to the stomach ? 129, 130

Describe the intestines 131

Describe the process of intestinal digestion 131, 132

What do you understand by absorption ? 133

144 DIGESTION

PAGE

29. How is the process of absorption effected ? 133

30. What are the lacteals, arid of what use are they? 134

31. What length of time is required for the digestion of food? 135

32. What circumstances, of food, affect digestion ? 130

33. What circumstances, of emotion, affect digestion ? 137

34. What suggestions and directions are given upon the subject of eat-

ing and drinking ? '. 136, 137

35. Describe the kidneys and their office 138

'>ii. What happens when their action ceases? 138

37. Give the location of the spleen. Has it a duct ? 139

38. How does alcohol affect digestion ? 139, 140

39. Give the experiment on St. Martin 140

40. State the effects of alcohol upon the liver 140, 141

41. State the effects upon the kidneys 141

CHAPTER VII

THE CIRCULATION

The Blood — Its Plasma and Corpuscles — Coagulation of the Blood —
The Uses of the Blood — Transfusion — Change of Color — The Organs
of the Circulation — The Heart, Arteries, and Veins — The Cavities
'i in! Valves of the Heart — Its Vital Energy — Passage of the Blood
through the Heart— The frequency and Activity of its Movements —
Tlie Pulse— The Spygmograph — The Capillary Blood-vessels — The
Bate of the Circulation — Assimilation — Injuries to the Blood-vessels
— Effects of Alcohol on Heart

1. The Blood. — Every living organism of the higher sort,
whither animal or vegetable, requires for the maintenance of
life and activity, a circulatory fluid, by which nutriment is dis-
tributed to all its parts. In plants, this fluid is the sap; in
insects, it is a watery and colorless blood; in reptiles and
fishes, it is red but cold blood ; while in the nobler animals
and man, it is red and warm blood.

2. The blood is the most important, as it is the most abun-
dant, fluid of the body ; and upon its presence, under certain
definite conditions, life depends. On this account it is fre-
quently, and very properly, termed "the vital fluid." The
importance of the blood, as essential to life, was recognized in
the earliest writings. In the narration of the death of the
murdered Abel, it is written, "the voice of his blood crieth
from the ground." In the Mosaic law, proclaimed over thirty
centuries ago, the Israelites were forbidden to eat food that
contained blood, for the reason that "the life of the flesh is in
the blood." With the exception of a few tissues, such as the
hair, the nails, and the cornea of the eye, blood everywhere
pervades the body, as may be proved by puncturing any part

1. What is required by every living organism 1 In plants? Insects'- Reptiles! Man?

2. Importance and abundance of blood? Dependence of lift! A l.»l - Mosaic law?
In what part of the body is blood not found J Quantity of blood in the body f

k 145

146 THE CIRCULATION

with a needle. The total quantity of blood in the body is
estimated at about one-eighth of its weight, or eighteen pounds.

3. The color of the blood, in man and the higher animals,
as is well known, is red ; but it varies from a bright scarlet
to a dark purple, according to the part whence it is taken.
" Blood is thicker than water," as the adage truly states, and
has a glutinous quality. It has a faint odor, resembling that
peculiar to the animal from which it is taken.

4. When examined under the microscope, the blood no
longer appears a simple fluid, and its color is no longer red.
It is then seen to be made up of two distinct parts : first, a
clear, colorless fluid, called the plasma; and, secondly, of a mul-
titude of minute solid bodies, or corpuscles, that float in the
watery plasma. The plasma, or nutritive liquid, is composed
of Avater richly charged with materials derived from the food,
viz., albumen, which gives it smoothness ; fibrin ; certain fats ;
traces of sugar ; and various salts.

5. The Blood Corpuscles. — In man, these remarkable " little
bodies," as the meaning of the word corjntscles signifies, are of

a yellow color, but by their vast
numbers impart a red hue to the
blood. They are very small, hav-
ing a diameter of about -g-g^ of an
inch, and being one-fourth of that
fraction in thickness; so that if
3500 of them were placed in line,
side by side, they would only ex-
tend one inch; or, if piled one
above another, it would take at

Fig. 38. — The Blood Corpuscles, least 14,000 of them to Stand an

HIGHLY MAGN.FIED -^ fog^ AlthOUgll SO Small ill

size they are very regular in form. As seen under the micro-
scope, they are not globular or spherical, but flat, circular, and
disc-like, with central depressions on each side, somewhat like

8. Color of blood ? Its consistence ? Odor ?

4. What is stated of the blood as viewed under the microscope ?

5. State what you can of the little bodies called corpuscles.

T1IF. CIRCULATION 11.

a pearl button that has not been perforated. In freshly -drawn
blood they show a disposition to arrange themselves in little
rolls like coins (Fig. 33).

6. The size and shape of blood corpuscles vary in different
animals. In man they are circular and flat, with a central
depression on both sides, also in all warm-blooded quadrupeds.
except the camel and lama, where they are oval. In birds,
reptiles, and fish, they are oval, but with

raised centre or nucleus. This variation is ©T

often of vital importance in murder trials, ©> ^

where blood-stained weapons or clothing are a b

used as evidence. A microscopical examina-
tion shows us the corpuscles, and we deter-
mine from their shape, whether it was caused
by blood from a warm-blooded quadruped,
from a camel, or from a fowl or fish. But
we cannot affirm that the stain was made by
human blood, and not by that of the dog, ox,
or sheep, because in all of these the corpuscles
are shaped alike, and the size varies but little.

7. The character of the blood of dead, ex- Co
tiint. and even fossil animals, such as the Corpuscles of a frog. <•,

, , , , • t i i , • ■ Those of a shark

mastodon, has been ascertained by obtaining The Ave small ones at
and examining traces of it which had been !he uwer Part of the

° figure, represent thehu-

shut up, perhaps for ages, in the circulatory man corpuscles magni-
canals of bone. A means of detecting blood fied four hundrt'd times
in minute quantities is found in the spectroscope, the same
instrument by which the constitution of the heavenly bodies
has been studied. If a solution containing not more than one
one-thousandth part of a grain of the coloring matter of the
corpuscle be examined, this instrument will detect it,

8. The corpuscles just described are known as the red-blood
corpuscles. Besides these, and floating along in the same
plasma, are the white corpuscles. These are fewer in number.

6. The size and shape of the corpuscles J Why is the fact important ?

7. The character of the Mood of dead animals f Means of detecting such Mood J

8. White corpuscles ? Total number of corpuscles in the body?

148 THE CIRCULATION

but larger and globular in form. They are colorless, and their
motion is less rapid than that of the other variety. The total
number of both varieties of these little bodies in the blood is
enormous. It is calculated that in a cubic inch of that fluid
there are eighty-three millions, and at least five hundred times
that number in the whole body. {Bead Note 1.)

9. Coagulation. — The blood, in its natural condition in the
body, remains perfectly fluid ; but within a few minutes after
its removal from its proper vessels, a change takes place. It
begins to coagulate, or assume a semi-solid consistence. If
allowed to stand, after several hours it separates into two
distinct parts, one of them being a dark red jelly, called
the coagulum, or clot, which is heavy and sinks ; and the
other, a clear, straw-colored liquid, called serum, which covers
the clot. This change is dependent upon the presence in the
blood of fibrin, which possesses the property of solidifying
under certain circumstances, one of them being the separation
of the blood from living tissues. The color of the clot is due to
the entanglement of the corpuscles with the fibrin.

10. In this law of the coagulation of the blood is our safe-
guard against death by hemorrhage, or undue loss of blood. If

1. The Blood. — " You feel quite sure that blood is red, do you not ?
Well, it is no more red than the water of a stream would be if you were
to fill it with little red fishes. Suppose the fishes to be very, very small —
as small as a grain of sand — and closely crowded together through the
whole depth of the stream, the water would look red, would it not?
And this is the way in which the blood looks red : only observe one
thing — a grain of sand is a mountain in comparison with the little red
bodies that float in the blood, which we have likened to little fishes. If
I were to tell you they measured about the 3200th part of an inch in
diameter, you would not be much the wiser ; but if I tell you that in a
single drop of blood, such as might hang on the point of a needle, there
are a million of these bodies, you will perceive that they are both very
minute and very numerous. Not that any one has ever counted them,
as you may suppose, but this is as close an estimate as can be made in
view of what is known of their minute size." — Mace's History of a
Mouthful of Bread.

9. The blood in its natural condition in the body ? Describe the process by which the
coagulation of blood takes place.

10. If coagulation were impossible 1 How is it in fact ?

THE CIRCULATION 149

coagulation were impossible, the slightest injury in drawing
blood would prove fatal. Whereas now, in many cases, bleed-
ing ceases spontaneously, because the blood, as it coagulates,
stops the mouths of the injured blood-vessels. In another class
of cases, where larger vessels are cut or torn, it is ordinarily
sufficient to close them by a temporary pressure ; for in a few
minutes the clot will form and seal them up. In still more
serious cases, where the blood-vessel is of large size, the sur-
geon is obliged to tie a ligature about it, thus preventing the
force of the blood-current from washing away the clots, which,
forming within and around the vessel, close it effectually.

11. It is worthy of remark that this peculiarity is early
implanted in the blood, even before birth, and in advance of
any existing necessity for it — thus anticipating and guarding
against danger. But this is not all. Of most of the inferior
animals, which, as compared with man, are quite helpless, the
blood coagulates more rapidly, and in the case of the birds,
almost instantly. The relative composition of fluid and coagu-
lated blood may be thus represented :

Fluid Blood Coagulated Blood

-Serum-

. Fibrin.

-Corpuscles-

(Read Note 2.)

12. The Uses of the Blood. — The blood is the great pro-
vider and purifier of the body. It both carries new materials
to all the tissues, and removes the worn-out particles of matter.

*2. Experiment. Coagulation of Blood. — The coagulation of blood
can be shown to a class with but little trouble. Obtain from a butcher or
slaughter-house about a pint of fresh blood, have it drawn into a tin can
or pail, and put it immediately into a freezing mixture of ice and salt. If
it be during the winter and freezing, this is not necessary, as freezing
suspends coagulation.

11. What is worthy of remark ? Coagulation of the blood of inferior animals ? Of the
lil' io,l of birds?

12. The blood, as a provider and purifier ? What uses does the blood subserve ? Ex-
periments ? Transfusion ?

150 THE CIRCULATION

This is effected by the plasma. It both conveys oxygen and
removes carbonic acid. This is done through the corpuscles.
Some singular experiments have been tried to illustrate the
life-giving power of the blood. An animal that has bled so
freely as to be at the point of death, is promptly brought back
to life by an operation called transfusion, by which fresh blood
from a living animal is injected into the blood-vessels of his
body. {Bead Note 3.)

13. It is related that a dog, deaf and feeble from age, had
hearing and activity restored to him by the introduction into
his veins of blood taken from a young dog; and, that a horse,
twenty-six years old, having received the blood of four lambs,
acquired new vigor. And further, that a dog, just dead from
an acute disease, was so far revived by transfusion, as to be
able to stand and make a few movements.

14. Transfusion has been practised upon man. At one time,
shortly after Harvey's discovery of the "Circulation of the
Blood," it became quite a fashionable remedy, it being thought

Fill a glass vessel with the blood, and observe the different steps in its
coagulation. In about two to three minutes it becomes viscid, and after
about five to ten minutes it has assumed a jelly-like character, so that the
vessel can be turned over without spilling its contents. Now will be seen
on the surface of the jelly a few drops of fluid, which rapidly multiply,
so that soon a layer of straw-colored fluid is floating on the surface. This
fluid increases, and the clot contracts more and more, until at the end of
about twelve hours, the process is complete, and we have a firmly con-
tracted clot floating in a clear straw-colored fluid. The clot is composed
of the fibrin and corpuscles, and the fluid is the serum, colored by a few
red corpuscles.

3. The Work of the Blood. — "The blood, which is our life, is a
complex fluid. It contains the materials out of which the tissues are
made, and also the debris which results from the destruction of the same
tissues, — the worn-out cells of brain and muscle, — the cast-off clothes
of emotion, thought, and power. It is the common carrier, conveying
unceasingly to every gland and organ, the fibrin and albumen which
repair their constant waste, thus supplying their daily bread. Like the
water flowing through the canals of Venice, that carries health and wealth
to the portals of every house, and filth and disease from every doorway,

13. The case of the deaf and feeble dog ? Horse ? Dead dog f

14. Transfusion, as a fashionable remedy ? What further of transfusion f

THE CIRCULATION 151

possible by it to cure all forms of disease, and even to make
the old young again. But these claims were soon found to be
extravagant, and many unhappy accidents occurred in its prac-
tice; so that being forbidden by government and interdicted
by the Pope, it rapidly fell into disuse. At the present time,
however, it is sometimes resorted to in extreme cases, when
there has been a great and rapid loss of blood ; and there are
upon record several instances where, other means having
failed, life has been restored or prolonged by the operation of
transfusion.

15. This reviving power of the blood seems to reside in the
corpuscles; for transfusion, when performed with the serum
alone, has, in every case, proved fruitless. Now, though so
much depends upon the blood and its corpuscles, it is a mis-
take to suppose that in them alone is the seat of life, or that
they are, in an exclusive manner, alive. All the organs and
parts of the body are mutually dependent one upon the other,
and the complete usefulness of any part results from the har-
monious action of the whole.

16. Change of Color. — The blood undergoes a variety of
changes in its journey through the system. As it visits the
different organs it both gives out and takes up materials. In
one place it is enriched, in another it is impoverished. By
reason of these alterations in its composition, the blood also
changes its color. In one part of the body it is bright red, or
arterial ; in another it is dark blue, or venous. In the former
case it is pure, and fit for the support of the tissues ; in the
latter, it is impure and charged with effete materials. (The
details of the change from dark to bright will be given in the
chapter on Respiration.) (Bead Notes 4, 5, and 6.)

the blood flowing through the canals of our organization carries nutriment
to all tissues, and refuse from them." — Clarke's Sex in Education.

4. On Purifying the Blood. — " By some the blood is regarded as the
source of all diseases, and to ' purify the blood ' is the object of their
treatment. Quacks seize on this notion, and in sublime ignorance of the

15. The seat of the reviving power of the blood ? What further is related 1

16. Changes In the blood ? What further is stated ?

152 THE CIRCULATION

17. Circulation. — The blood is in constant motion during
life. From the heart, as a centre, a current is always setting
toward the different organs ; and from these organs a current
is constantly returning to the heart. In this way a ceaseless
circular movement is kept up, which is called the Circulation
of the Blood. This stream of the vital fluid is confiued to
certain fixed channels — the blood-vessels. Those branching
from the heart are the arteries ; those converging to it are the
veins. The true course of the blood was unknown before the
beginning of the seventeenth century. In 1619 it was dis-
covered by the illustrious William Harvey. Like many other
great discoverers, he suffered persecution and loss, but unlike
some of them, he was so fortunate as to conquer and survive
opposition. He lived long enough to see his discovery uni-
versally accepted, and himself honored as a benefactor of
mankind.

nature of the blood they profess to purify, and of the means by which
their drugs could possibly purify it, make fortunes out of the credulity of
the public. I would warn you against this notion of ; purifying ' the
blood. The blood is not like a river into which anything can be intro-
duced from without. It gets rid of, or destroys, all substances which
intrude — all which do not form part and parcel of its own structure ; or,
failing in that, it ceases to act as living blood." — George Henry L< uoes.

5. By Means of the Blood, Exercise Benefits the Whole Body. —
"The employment of the muscles in exercise not only benefits their
especial structure, but it acts on the whole system. When the muscles
are put in action, the capillary blood-vessels with which they are supplied
become more rapidly charged with blood, and active changes take place,
not only in the muscles, but in all the surrounding tissues. The heart is
thus required to supply more blood, and accordingly beats mure rapidly
in order to supply the demand. A large quantity of blood is sent through
the lungs, and larger supplies of oxygen are taken in and carried to the
various tissues of the body." The oxygen engenders a large amount of
heat, which produces an action on the skin whereby the increase of heat
may be got rid of. By this means the skin is exercised, the perspiration
is poured forth, the surface is caused to glow and is kept in health.
" Not only are these organs benefited by the increased circulation of the
blood, produced by exercise, but wherever the blood is sent, changes of a
healthful character occur. The brain and the rest of the nervous system
are invigorated ; the stomach has its powers of digestion improved ; and

17. Motion of the blood ? What is meant by the circulation of the blood? He
fined ? Discovery made by Harvey 1

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THE CIRCULATION 153

18. The Heart. — The heart is the central engine of the cir-
culation. Tn this wonderful little organ, hardly larger than

a man's fist, resides that sleepless force by which, during the
whole of life, the current of the blood is kept in motion. It
is placed in the middle and front part of the chest, inclining
to the left side. The heart-beat may be felt and heard between
the fifth and sixth ribs, near the breast-bone. The shape of
the heart is conical, with the apex or point downward and in

the liver, pancreas, and other organs perform their functions with more
vigor." — Lankester's Manual of Health.

6. Experiment. The Heart. — To demonstrate the physiological
anatomy of the heart will require some dissecting, and a little more care
and work than the other experiments, but the teacher will be fully
rewarded by the close attention and great interest shown by the pupils.

< Obtain from your butcher a bullock's heart inclosed in the pericardium
or " bag." Instruct him to cut it out carefully and as high up as he can,
so as not to injure it, and so as to leave of the large blood-vessels as much
attached as is possible.

Cut away all the fat surrounding the heart and great blood-vessels ;
cut open the pericardium from apex to base, and partly away from the
latter, so as to give room for exposing the cavities of the heart. The
latter should be opened by two incisions along the septum separating the
right from the left heart. The incision should run from apex to base,
laying open both ventricle and auricle. Cut open all the large vessels
found at the base, into the cavities to which they lead.

Going from without inward observe and explain the different parts as

follows :

1. The Pericardium. — Note its structure and smooth, shining inner
surface. Show how it surrounds the heart, and how it is attached along
the base and great blood-vessels.

2. General Structure of the Heart. — Show the thin-walled auri-
cles ; the difference between the thickness of the walls of the ventricles ;
the difference in structure between the arteries and veins; demonstrate
the two coronary arteries and their accompanying veins.

3. Bight Auricle am> Vehtbicle. — Demonstrate the vense cavse and
their entrance into the auricle; the auriculo-ventricular valves between
the two cavities ; the structure, attachment, and action of the valves ; the
pulmonary artery.

4. Left Auricle and Vektbiclb. — Demonstrate the pulmonary veins
and their entrance into the auricle ; the mitral valve between auricle and
ventricle; the aortic valve, its structure, action, and attachment; the
structure and great strength of the aorta.

is. Office of the heart ? Location <rf the heart ? Its beat? Its shape ? Protection to
the hearty What else la said in relation to the heart?

154 THE CIRCULATION

front. The base, which is upward, is attached so as to hold it
securely in its place, while the apex is freely movable. In
order that loss of power from friction may be obviated, the
heart is enclosed between two layers of serous membrane,
which forms a kind of sac. This membrane, called the peri-
cardium, is as smooth as satin, and itself secretes a fluid in
sufficient quantities to keep it at all times well lubricated.
The lining membrane of the heart, called the endocardium, is
extremely delicate and smooth. {Bead Note 7.)

19. The Cavities of the Heart. — The heart is hollow, and so
partitioned as to contain four chambers or cavities ; two at the
base, known as the auricles, from a fancied resemblance to the
ear of a dog, and two at the apex or point, called ventricles.
An auricle and a ventricle on the same side communicate with
each other, but there is no opening from side to side. It is
customary to regard the heart as a double organ, and to speak
of its division into the right and left heart. For while both
halves act together in point of time, each half sustains an
entirely distinct portion of the labor of the circulation. The
right side always carries the dark or venous blood, and the
left always circulates the bright or arterial blood.

20. If we examine the heart, we at once notice that, though
its various chambers have about the same capacity, the walls
of the ventricles are thicker and stronger than those of the
auricles. This is a wise provision, for it is by the powerful
action of the ventricles that the blood is forced to the most
remote regions of the body. The auricles, on the contrary,
need much less power, for they simply discharge their contents
into the ventricles below. (Figs. 35 and 36.) (See Note 6.)

7. A Poet's Summary of the Circulation : —

" The smooth, soft air with pulse-like waves
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

19. Formation of the heart ? Right and left heart ?

20. Capacity of the chambers of the heart ? What wise provision is mentioned ? The
auricles ?

THE CIRCULATION

155

21. Action of the Heart. — The substance of the heart is of a
deep red color, and its fibres resemble those of the voluntary
muscles by which we move our limbs. But the heart's move-
ments are entirely involuntary. The advantage of this is
evident ; for if it depended
upon us to will each move-
ment, our entire attention
would be thus engaged,
and we would find no time
for study, pleasure, or even
sleep. The action of the
heart consists in alternate
contractions and expan-
sions. During contraction
the Avails come forcibly to-
gether, and thus drive out
the blood. They then ex-
pand and receive a renewed
supply. These movements
are called respectively sys-
tole and diastole. The latter
may be called the heart's
period of repose; and al-
though it lasts only during
two-fifths of a heart-beat, or about a third of a second, yet
during the day it amounts to more than nine hours of total rest.

The ebbing current steals away,
And, red with Nature's flame, they start
From the warm fountains of the heart.
"No rest that throbbing slave may ask,
Forever quivering o'er his task,
While far and wide a crimson jet
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."

—Dr. 0. W. Holmes.

Fig. 37 — Sbctioh of the Heart

A, Right Ventricle E, F, Inlets to the Ventricles

B, Left Ventricle G, Pulmonary Artery

C, Bight Auricle H, Aorta
1>, Left Auricle

21. Substance of the heart? Its fibres I Its movements 1
movements? Action of the heart ? Its period of repose !

The advantage of sue!

156

THE CIRCULATION

22. A remarkable property of the tissue of the heart is its
intense vitality. For while it is more constantly active than
any other organ of the body, it is the last to part with its vital
energy. This is especially interesting in view of the fact that
after life is apparently extinguished, as from drowning, or
poisoning by chloroform, there yet lingers a spark of vitality
in the heart, which, by continued effort, may be fanned into a
flame so as to revivify the whole body. In cold-blooded ani-
mals, this irritability of the heart is especially remarkable.

Fig. 38. — Diagram showing tiie Position Fig. 39. — Diagram showing tiie Position
of the Valves of the Heart while of the Valves of the Heart during
the Walls are relaxed the Contraction of the Ventricles

The heart of a turtle will pulsate, and the blood circulate for a
week after its head has been cut off ; and its heart will throb
regularly many hours after being cut out. The heart of a frog
or serpent, separated entirely from the body, will contract at
the end of ten or twelve hours ; that of an alligator has been
known to beat twenty-eight hours after the death of the
animal.

23. Passage of the Blood through the Heart. — Let us now
trace the course of the blood through the several cavities of

22. Remarkable property of the tissne of the heart ? How shown ? How interesting ?
Tn cold-blooded animals ? Heart of a turtle f Of a frog ? Alligator ?

23. ( uihm' of the blood through the heart ? Course of heart-currents ?

THE CIRCULATION 157

the heart. In the first place, the venous blood, rendered dark
and impure by contact with the changing tissues of the body,
returns to the right heart by the veins. It enters and fills the
right auricle during its expansion ; the auricle then contracts
and fills the right ventricle. Almost instantly, the ventricle
contracts forcibly and hurries the blood along the great artery
of the lungs, to be purified in those organs. Secondly, having
completed the circuit of the lungs, the pure and bright arterial
blood enters the left auricle. This now contracts and fills the
left ventricle, which cavity, in its turn, contracts and sends the
blood forth on its journey again through the system. This
general direction from right to left is the uniform and undevi-
ating course of heart-currents.

24. The mechanism which compels this regularity is as sim-
ple as it is beautiful. Each ventricle has two openings, an
inlet and an outlet, each of which is guarded by strong cur-
tains, or valves. These valves open freely to admit the blood
entering from the right, but close inflexibly against its return.
Thus, when the auricle contracts, the inlet valve opens; but as
soon as the ventricle begins to contract, it closes promptly.
The contents are then, so to speak, cornered, and have but one
avenue of escape — that through the outlet valve into the
arteries beyond. As soon as the ventricle begins to expand
again, this valve shuts tightly and obstructs the passage. The
closing of these valves occasions the two heart-sounds, which
we hear at the front of the chest. (Figs. 38, 39, 40, and 41.)

25. Frequency of the Heart's Action. — The alternation of
contraction and expansion constitutes the heart-beats. These
follow each other not only with great regularity, but with
great rapidity. The average number in an adult man is about
seventy-two in a minute. But the heart is a susceptible
organ, and many circumstances affect its rate of action. Heat,
exercise, and food increase its action ; cold, fasting, and sleep
diminish it. Posture, too, has a curious influence ; for if while

24. Openings of the 7entriclesT How guarded? How do the valves operate? The
oonaequenee ? Heart-sounds 1

25. Heart-beats 1 The heart as a susceptible organ J Heat, exercise, etc. ? Posture ?

158 THE CIRCULATION

sitting the beats of the heart number seventy-one, standing
erect will increase them to eighty-one, and lying down will
lower them to sixty-six. {Bead Note 8.)

26. The modifying influence of mental emotions is very
powerful. Sudden excitement of feeling will cause the heart to
palpitate, or throb violently. Depressing emotions sometimes
temporarily interrupt its movements, and the person faints in
consequence. Extremes of joy, grief, or fear have occasionally
suspended the heart's action entirely, and thus caused death.
The rate of the heart-beat may be naturally above or below
seventy -two. Thus it is stated that the pulse of the savage is
always slower than that of the civilized man. Bonaparte and
Wellington were very much alike in their heart pulsations,
which were less than fifty in the case of each. {Read Note 9.)

8. The Heart is Injured by Over-exertion. — " During exertion, if the
heart is not oppressed, its movements, though rapid and forcible, are reg-
ular and equal. But when it becomes embarrassed, the pulse-beats are
quick, unequal, and at last become irregular, indicating injury to the
organ. All great and sudden efforts are to be carefully avoided ; exces-
sive exercise often produces palpitation, and sometimes enlargement and
valvular disease of the heart." — Huxley.

"No great intellectual thing was ever done by great effort; a great
thing can only be done by a great man, and he does it without effort.
The body's work and the head's work are to be done quietly, and com-
paratively without effort. Neither limbs or brain are ever to be strained
to their utmost ; that is not the way in which the greatest quantity of
work is to be got out of them ; they are never to be worked furiously, but
with tranquillity and constancy. We are to follow the plough from sunrise
to sunset, but not to pull in race-boats at the twilight ; we shall get no
fruit of that kind of work — only disease of the heart." — Buskin.

9. Fainting. — "When the heart suddenly ceases to act, fainting or
swooning is very apt to take place. This takes place for the reason that
the brain feels most speedily the lack of its supply of blood. Many cir-
cumstances may cause a faint — such as a fright, joy, excitement, the
sight of blood, or the breathing of foul air ; or it may be due to disease
of the heart. In some persons, fainting becomes a kind of habit ; they
fall into a fainting tit on very slight agitation. In them the appearances
are much worse than the reality, especially to those who are not familiar
with the ailment. But persons who faint after exhaustion, fatigue, fast-
ing, or anguish, require prompt attention. The ordinary signs are great

26. Mental emotions? Sudden excitement? Excessive joy? The heart-beat rate;
Bonaparte and Wellington ?

SUPERIOR^
VENA CAVA I

'

r

THE CIRCULATION 159

27. Activity of the Heart. — The average number of heart-
beats during a lifetime may be considered as at the rate of
seventy-two per minute, although this estimate is somewhat
low, for during several years of early life the rate is above one
hundred a minute. In one hour, then, the heart pulsates four
thousand times ; in a day, one hundred thousand times ; and
in a year, nearly thirty -eight million times. If we compute
the number during a lifetime — forty years being the present
average longevity of civilized mankind — we obtain as the vast
aggregate, fifteen hundred millions of pulsations. {Bead Note 10.)

pallor, loss of sensation, and trembling of the limbs and loss of power
over the muscles ; the breathing and pulse go on imperfectly or stop.
The first thing to do is to place the head low, thus favoring the supply of
blood to the brain ; the very act of falling is often sufficient to restore
consciousness. Water may be sprinkled on the face, hartshorn held to
the nose, or mustard over the heart. Pure air is a great restorative ;
allow a current of fresh air to flow over the face, and loosen any tight
bands that may confine the chest." — Dr. J. Knight (in part).

10. The Heart a Vital Machine. — " The heart is a machine. It is an
organ constructed of muscular chambers and communicating passages,
and supplied with mechanical contrivances, adapted to guide the stream
of blood passing through it, and to prevent a reflux in the backward
direction. Does Dot this take away wonderfully from the character of
fanciful mystery with which poets and sentimentalists have invested it ?
The heart that we have always heard of as the centre of the affections,
the home of sensibility, the dwelling-place of courage, of faith, of hope,
and all the rest of the virtues, is after all, nothing but an organ to serve
for the impulsion of the blood — a mere force-pump, a machine. Does
not this bring down our ideas, and show that no poetical mystery can
escape the searching investigation of the anatomist ? Not at all.

" For this machine that we carry about with us in our breasts is alive.
There, at its post, at the central point of the circulation, with the soft
lobes of the lungs folded round it like a curtain, it contracts and relaxes,
and relaxes and contracts, with a steady and unremitting industry that
by itself is something worthy of our admiration. No other muscle in the
body can do this. By some incomprehensible vitality of its own, it keeps
up its rhythmical contractions without the aid of our will and even with-
out our knowledge. While you are asleep and while you are awake, from
the first moment of your birth, even from before your birth, up to the
present time, it has never for one moment stopped or flagged in its move-
ments, for if it were to do so death would be the result." — Dr. J. C.
Dalton.

27. Average uuiubei of heart-beats ? In one hour? Year? Lifetime?

160 THE CIRCULATION

28. Again, if we estimate the amount of blood expelled by
each, contraction of the ventricles at four ounces, then the
weight of the blood moved during one minute will amount to
eighteen pounds. In a day it will be about twelve tons ; in a
year, four thousand tons ; and in the course of a lifetime over
one hundred and fifty thousand tons. These large figures
indicate, in some measure, the immense labor necessary to
carry on the interior and vital operations of our bodies. In
this connection, we call to mind the fanciful theories of the
ancients in reference to the uses of the heart. They regarded
it as the abode of the soul and the source of the nobler emo-
tions — bravery, generosity, mercy, and love. The words cour-
age and cordiality are derived from a Latin word signifying
heart. Many other words and phrases, as hearty, heart-felt, to
lea, .1 by heart, and large-hearted, show how tenaciously these
exploded opinions have fastened themselves upon our language.

29. At the present time, the tendency is to ascribe purely
mechanical functions to the heart. This view, like the older
one, is inadequate ; for it expresses only a small part of our
knowledge of this organ. The heart is unlike a simple ma-
chine, because its motive power is not applied from without,
but resides in its own substance. Moreover, it repairs its own
waste, it lubricates its own action, and it modifies its move-
ments according to the varying needs of the system. It is
more than a mere force-pump, just as the stomach is something
more than a crucible, and the eye something more than an
optical instrument. {Bead Note 11.)

30. The Arteries. — The tube-like canals which carry the
blood away from the heart are the arteries. Their walls are

11. The Heart. — " You all know where it is. It is the most wonder-
ful little pump in the world. There is no steam-engine half so clever at
its work, or so strong. There it is, in every one of us, beat, beating — all
day and all night, year after year, never stopping, like a watch ticking ;
only it never needs to be wound up, — God winds it up once for all." —
Author of " Itab and His Friends."

28. Amount of blood expelled? Theories of the ancients?

29. The tendency at the present time ? Why is this view inadequate ?

30. What are the arteries ? Their walls ? Their membrane ?

THE CIRCULATION 161

made of tough, fibrous materials, so that they sustain the mighty
impulse of the heart, and are not ruptured. In common with
the heart, the arteries have a delicately smooth lining mem-
brane. They are also elastic, and thus re-enforce the action
of the heart ; they always remain open when cut across, and
after death are usually found empty.

31. The early anatomists observed this condition, and sup-
posing that it existed during life, came to the conclusion that
these tubes were designed to act as air-vessels — hence the
name artery, from Greek words which signify " containing air."
This circumstance affords us an illustration of the mistaken
notions of the ancients in reference to the internal operations
of the body. Cicero speaks of the arteries as " conveying the
breath to all parts of the body."

32. The arterial system springs from the heart by a single
trunk, like a minute and hollow tree, with numberless branches.
As these branches leave the heart, they divide and subdivide,
continually growing smaller and smaller, until they can no
longer be traced by the naked eye. If, then, we continue the
examination by the aid of a microscope, we see these small
branches sending off still smaller ones, until all the organs of
the body are penetrated by arteries.

33. The Pulse. — With each contraction of the left side of
the heart, the impulse causes a wave-like motion to traverse
the entire arterial system. If the arteries were exposed to
view, we might see successive waves speeding from the heart
to the smallest of the branches. The general course of the ar-
teries is as far as possible from the surface. This arrangement
is certainly wise, as it renders them less liable to injury — the
wounding of an artery being especially dangerous. It also
protects the arteries from external and unequal pressure, by
which the force of the heart would be counteracted and wasted.
Accordingly, we generally find these vessels close to the bones,

81. Early anatomists ? The service of the illustration ?

82. The arterial system ? The branches and sub-branches of the arteries f

33. Successive undulations from the heart? Course of the arteries ? Protection of the
arteries ? General location of the arteries ?

162 THE CIRCULATION

or hiding behind the muscles and within the cavities of the
body.

34. In a few situations, however, the arteries lie near the
surface ; and if we apply the finger to any of these parts, we
shall distinctly feel a throbbing motion taking place in har-
mony with the heart-beat. This is part of the wave-motion
just mentioned, and is known as the pulse. All are familiar
with the pulse at the wrist, in the radial artery ; but it is not
peculiar to that position, for it may be felt in the carotid of
the neck, in the temporal at the temple, and elsewhere, espe-
cially near the joints.

35. Since the heart-beat makes the pulse, whatever affects
the former affects the latter also. Accordingly, the pulse is
a good index of the state of the health, so far as the health
depends upon the action of the heart. It informs the physi-
cian of the condition of the circulation in four particulars —
— its rate, regularity, force, and fullness; and nearly every
disease modifies in some respect the condition of the pulse.

KJVNJv^J

Fig. 4,_'. — The Fukm of the Film:

A very ingenious instrument, known as the sphygmograph, or
pulse-writer, has recently been invented, by the aid of which
the pulse is made to write upon paper its own signature, or
rather to sketch its own profile. This instrument shows with
great accuracy the difference between the pulses of health and
those of disease. In Fig. 42 is traced the form of the pulse in
health, which should be read from left to right. That part of
the trace which is nearly perpendicular coincides with the
contraction of the ventricles, while the wavy portion marks
their dilatation. (Read Note 12.)

12. The Beating of the Pulse. — ' ' According to experiments made in
Paris, the pulse of a lion beats forty times a minute ; that of a tiger,

84. Where do the arteries lie ? If we apply the finger ? Pulse ? Where felt ?
35. The pulse as an index ? Of what does it inform the physician ? Instrument for
recording pulsation ?

Till-: CIRCULATION

L6;

36. The Veins. — The vessels by which the blood returns to
the heart are the veins. At first they are extremely small ;
but uniting together as they advance, they constantly increase

in size, reminding us of the way in which the fine rootlets of
tin' plant join together to form the large roots, or of the rills
and rivulets that flow together to form the large streams and
rivns. In structure, the veins resemble the arteries, but their
walls are comparatively inelastic. They are more numerous,

Fig. 43. — Vein with Valves

OPEN

Fig. 44. — Vein with Valves closed ;
the Stream of Blood passing off
by a Lateral Branch

and communicate with each other freely in their course, by
means of interlacing branches.

37. But the chief point of distinction is in the presence of
the valves in the veins. These are little folds of membrane,

ninety-six times ; of a tapir, forty-four times ; of a horse, forty times ; of
a wolf, forty-five times ; of a fox, forty-three times ; of a bear, thirty-
eight times ; of a monkey, forty-eight times ; of an eagle, one hundred
and sixty times. It was impossible to determine the beatings of the
elephant's pulse. A butterfly, however, it was discovered, experienced
sixty heart pulsations in a minute."

86. What are the veins ? How do they form ? What do they resemble ?

87. Valves In the veins I What are they ? Their position ? Experiment with the cord ?

164 THE CIRCULATION

disposed in such, a way that they open only to receive the
blood flowing toward the heart, and close against a current in
the opposite direction. Their position in the veins on the back
of the hand may be readily observed, if we first obstruct the
return of blood by a cord tied around the forearm or wrist.
In a few moments the veins will appear swollen, and upon
them will be seen certain prominences, about an inch apart.
These latter indicate the location of the valves, or, rather, they
show that the vessels in front of the valves are distended by
the blood, which cannot force a passage back through them.

38. This simple experiment proves that the true direction
of the venous blood is toward the heart. That the color of the
blood is dark will be evident, if we compare the hand thus
bound by a cord with the hand not so bound. It also proves
that the veins lie near the surface, while the arteries are
beneath the muscles, well protected from pressure; and that
free communication exists from one vein to another. If now
we test the temperature of the constricted member by means
of a thermometer, we will find that it is colder than natural,
although the amount of blood is larger than usual. From this
fact we infer, that whatever impedes the venous circulation
tends to diminish vitality; and hence, articles of clothing or
constrained postures, that confine the body or limbs, and hinder
the circulation of the blood, are to be avoided as injurious to
the health.

39. The Capillaries. — A third set of vessels completes the
list of the organs of circulation, namely, the capillary vessels,
so called (from the Latin word capillaris, hair-like), because of
their extreme fineness. They are, however, smaller than any
hair, having a diameter of about 3Jo0 of an inch, and can only
be observed by the use of the microscope. These vessels are
the connecting link between the last of the arteries and the
first of the veins. The existence of these vessels was unknown
to Harvey, and was the one step wanting to complete his great
discovery. The capillaries were not discovered until 1661, a
short time after the invention of the microscope

88. What will be proved by the experiment ? What inference is drawn ?

89. Capillaries? How regarded J Harvey?

THE CIRCULATION

165

40. The circulation of the blood, as seen under the micro-
scope, in the transparent web of a frog's foot, is a beautiful
Bight, possessing more than ordinary interest, from the fact
that something much grander is taking place in our own bodies.
It is like opening a secret page in the history of our own
frames. We there see distinctly the three classes of vessels
with their moving contents ; first, the artery, with its torrent of
blood rushing down from the heart ; secondly, the vein, with
its slow, steady stream flowing in the opposite direction; and

Via. 4"). — Wf.b of a Frog's Foot,
slightly magnified

Fig. 46. — March* of Frog's Web,
magnified thirty diameUrs

between them lies the network of capillaries, so fine that the
corpuscles can pass through only " in single file." The current
of the capillaries has here an uncertain or swaying motion,
hurrying first in one direction, then hesitating, and turning
back in the opposite direction, and sometimes the capillaries
contract so as to be entirely empty. Certain of the tissues are
destitute of capillaries ; such are cartilage, hair, and a few
others on the exterior of the body. In all other structures,
networks of these vessels are spread out in countless numbers;
so abundant is the supply, that it is almost impossible to
puncture any part with the point of a needle without lacerat-

40. The circulation of the blood in the web of a frog's foot !
is the existence of I lie tissues f

Describe it. Uow general

166 THE CIRCULATION

ing tens, or even hundreds of these vessels. (Head Notes 13
and 14.)

41. The capillaries are elastic, and may so expand as to pro-
duce an effect visible to the naked eye. If a grain of sand, or
some other foreign particle, lodge in the eye, it will become
irritated, and in a short time the white of the eye will be
"blood-shot." This appearance is due to an increase in the
size of these vessels. A blush is another example of this, but
the excitement comes through the nervous system, and the
cause is some transient emotion, either of pleasure or pain.
Another example is sometimes seen in purplish faces of men

13. Course of the Blood in the Capillaries. — " The phenomena of
the capillary circulation are only observable with the aid of the micro-
scope. It was not granted to the discoverer of the circulation to see the
blood moving through the capillaries, aud he never knew the exact mode
of communication between the arteries and veins. After it was pretty
generally acknowledged that the blood did pass from the arteries to the
veins, it was disputed whether it passed in an intermediate system of ves-
sels, or became diffused in the substance of the tissues, like a river flow-
ing between numberless little islands, to be collected by the venous
radicles and conveyed to the heart. Accurate microscopic investigations
have now demonstrated the existence, and given us a clear idea of the
anatomy, of the intermediate vessels. In 1661 the celebrated anatomist
Malpighi first saw the movement of the blood in the capillaries, in the
lungs of a frog. This spectacle has ever since been the delight of the
physiologist. We see the great arterial rivers, in which the blood flows
with wonderful rapidity, branching and subdividing, until the blood is
brought to the superb network of fine capillaries, where the corpuscles
dart along one by one, the fluid then being collected by the veins, and
carried in great currents to the heart." — Flint.

14. Experiment. Circulation. — The circulation of the blood can be
fairly well illustrated by the aid of a " Davidson " syringe, some rubber
tubing, and a piece of glass tubing.

The bulb of the syringe represents the heart, the elastic tubing the
arteries, and the fine glass tubing the capillaries.

Attach the rubber tubing to the smallest nozzle of the syringe (the
tubing should be highly elastic, the black kind is the best ; it should be
about one-fourth inch diameter), place the other end of the syringe in a
vessel filled with water.

Upon compressing the bulb of the syringe, the water will be seen to
issue from the tubing in jets corresponding with the compressions of the
bulb, but a little retarded ; placing the finger on the tubing but little

41. Elasticity of the capillaries ? Grain of sand in the eye ? Blush f Other cases f

THE CIRCULATION 167

addicted to drinking brandy ; in them the condition is a con-
gestion of the capillary circulation, and is permanent, the ves-
sels having lost their power of elastic contraction.

42. Rapidity of the Circulation. — That the blood moves with
great rapidity is evident from the almost instant effects of cer-
tain poisons, as prussic acid, which act through the blood.
Experiments upon the horse, dog, and other inferior animals,
have been made to measure its velocity. If a substance which

expansion will be felt. Now into the rubber tube insert the glass tube,
which should be about two feet long and be drawn out to a fine point.
Compressing again the bulb of the syringe, the water will be seen to issue
from the glass point in a continuous stream, and not in an interrupted
one, as from the rubber end.

The explanation of this is as follows : During each compression of the
bulb, the water expands the rubber tubing because its outflow is con-
siderably lessened by the resistance of the unyielding glass tube and its
much-narrowed end, and during the interval of two compressions, during
which the bulb fills again, the rubber tubing contracts upon its contents
and slowly expels it. If now the compressions of the bulb are so timed
that the rubber tubing is kept stretched, the flow from the glass-end will
be continuous. The finger on the tubing will now feel each stroke of the
syringe in the decided expansion of the rubber.

Applied to the circulation of the blood, this experiment shows the
following :

The power of the hand together with the bulb of the syringe represent
the heart, which, with each contraction, sends its contents forth into the
arteries. These are well represented by the elastic tubing, as they, in
reality, are nothing more than that. During the systole of the heart
(the compression of the bulb), they are distended to their full capacity ;
during the diastole of the heart (represented by the passive filling of the
bulb), they contract upon their contents and send it forward toward the
capillaries and veins. The latter are represented by the glass tubing,
from which we have seen the water issue in a continuous stream. In the
capillaries and veins the blood flows in a continuous stream, due to the
fact that the force of the heart's action is gradually lost in expanding
the arteries, and is felt less and less the farther they are removed from
the heart ; the arteries becoming smaller and smaller, the intermittency
of the flow is lost when the capillaries are reached.

The expansion which the finger feels when placed upon the rubber
tubing represents the pulse, which is the maximum distension of the
artery at that point.

42. Show what time is required for a given portion of blood to travel once around the
body.

168 THE CIRCULATION

is capable of a distinct chemical reaction (as potassium ferro-
cyanide, or barium nitrate) be introduced into a vein on one
side of a horse, and at the end of twenty or thirty-two seconds
blood be taken from a distant vein on the other side, its
presence may be detected. In man, the blood moves with
greater speed, and the circuit is completed in twenty-four
seconds.

43. What length of time is required for all the blood of the
body to make a complete round of the circulation ? This
question cannot be answered with absolute accuracy, since the
amount of the blood is subject to continual variations. But,
if we assume this to be one-eighth of the weight of the body —
about eighteen pounds — it will be sufficiently correct for our
purpose. Now to complete the circuit, this blood must pass
once through the left ventricle, the capacity of which is two
ounces. Accordingly, we find that, under ordinary circum-
stances, all the blood makes one complete rotation every two
minutes — passing successively through the heart, the capil-
laries of the lungs, the arteries, the capillaries of the extremi-
ties, and through the veins.

44. Assimilation. — The crowning act of the circulation —
the furnishing of supplies to the different parts of the body —
is effected by means of the capillaries. The organs have been
wasted by use ; the blood has been enriched by the products
of digestion. Here, within the meshes of the capillary net-
work, the needy tissues and the needed nutriment are brought
together. By some mysterious chemistry, each tissue selects
and withdraws from the blood the materials it requires, and
converts them into a substance like itself. This conversion
of lifeless food into living tissue is called assimilation. The
process probably takes place at all times, but the period espe-
cially favorable for it is during sleep. Then the circulation is
slower, and more regular, and most of the functions are at
rest. The body is then like some trusty ship, which, after a
long voyage, is "hauled up for repairs." (Bead Note 15.)

43. Time required for all the blood to circulate completely around ?

44. What is meant by assimilation ? What can you say of its use, etc. ? Time ?

THE CIRCULATION 1G9

45. Injuries to the Blood-vessels. — It is important for us to
be able to discriminate between an artery and a vein, in the
case of a wound, and if we remember the physiology of the
circulation we may readily do so. For, as we have already
seen, hemorrhage from an artery is much more dangerous than
that from a vein. The latter tends to cease spontaneously
after a short time. The arterial blood flows away from the
heart with considerable force, in jets, and its color is bright
scarlet. The venous blood flows toward the heart from that
side of the wound furthest from the heart, its stream being
continuous and sluggish; its color is dark. In an injury to
an artery, pressure should be made between the heart and the
wound, while, in the case of a vein that persistently bleeds, it
should be made upon the vessel beyond its point of injury.

46. Effects of Alcohol upon the Heart. — The first symptoms
after a moderate dose of alcohol is an increase of the heart's
action, a flushing of the face, a sensation of warmth within, a
general glow without, and some other appearances of increased
vitality. The action has been that of a spur or goad. It has
caused strength to be expended instead of increasing it, and, in
fact, costs the system whatever amount of force is necessary
to expel it ; so that there is a loss of strength, and not a gain.

15. Assimilation in Repair. — " Most animals have the power to
repair, to a greater or less extent, the mutilations they undergo. In
man, if the skin is torn off, a new skin heals over the injury, and a broken
bone is caused to re-unite by the deposit of bone tissue between the frag-
ments. But among the lower animals this power is carried to a high
degree. The tail of a lizard, if cut off, will quickly form anew, although
of a complex structure ; and spiders and crabs are able to develop new
claws upon the stumps of broken ones. Observations made on salaman-
ders, or water-lizards, show the still more remarkable fact that the eye
and a part of the head may be entirely restored. Certain kinds of earth-
worms can reproduce a large portion of their bodies, and any fragment of
the hydra is able to restore itself, and become a complete creature after its
kind. Assimilation is especially active in early years, while the body is
growing; for this reason, among others, the perfect health of children
requires that they shall give a greater number of hours to sleep — deep,
regular, and undisturbed sleep — than is needed in later life." — Milne
Edwards.

45. What is stated of the injuries to the blood-vessels ?

46. How does alcohol affect the heart's action ?

170 THE CIRCULATION

47. The late Dr. Parkes made a careful study of the amount
of strain put upon the heart by alcohol. He found that it
increased both the number and force of the heart's pulsations.
The period of rest between the beats is reduced, and, conse-
quently, the heart's nutrition must be interfered with. He
estimates, in one set of experiments, that the extra work of
the heart, induced by alcohol, was equivalent to the lifting of
15.8 tons one foot daily ; and during two days, 24 tons in excess
of the regular work. Another experimenter states that he has
known a single glass of liquor to cause 8000 extra heart-beats,
equivalent to the unnecessary lifting of 9 tons the distance of
one foot. Estimated in another way, this amount of over-tax
of the heart is equal to that which takes place, during one day,
in a person having a fever that raises the pulse six to nine
beats above the rate of health.

48. Alcohol as a Fat Producer. — Alcohol is said to diminish
waste, and to make those " fleshy " who use it. This may well
be the case in those — and the proportion is not small — who
are rendered sluggish and sleepy by it. The fat which they
acquire is the fat of inaction. If we may judge of the true
influence of alcohol by experiments on the lower animals, that
are compelled to take it pure, we will not grant it any fattening
power.

49. There is a certain " fatty degeneration " in man — the
result of alcohol drinking — that is very disastrous, namely, a
deposit of fat in the muscles of the body. This is destructive
or weakening to muscular power, and when it evinces itself in
the heart, it creates a change that is to be dreaded as sapping
the strength of the one particular organ that should be strong
in drinkers. It attacks them at a vital spot. The blood also
undergoes a fatty change which greatly impairs its work of
nourishing the body.

50. Exhaustion Due to Alcohol. — The heart does not become
habituated to the poison nor become tolerant of it. On the

47. Give Dr. Parkes' experiment.

4s. How does alcohol make one fleshy ?

49. What results? What change in the blood due to alcohol ?

50. Does the heart tolerate alcohol ? Do users of it know the effects ?

THE CIRCULATION 111

contrary, it is set moving, with this abnormal activity, with
each renewal of the dose. This form of exertion is not exer-
cise, it is overwork; it is not strengthening, it is exhausting.
Very few persons who habitually use alcoholic stimulants are
aAvare of the enormous strain that is imposed upon the heart,
although to those who studiously consider the matter the
wonder is that this organ is not more rapidly worn out than it
is. If it were not for the fact that the heart is made of the
strongest muscular tissue in the body, it would of necessity
fail from overstrain long before it does.

51. The condition of the heart, mentioned in the last section,
is known to physicians as "fatty heart," and in part explains
why it is that drunkards are so little able to withstand the
attack of those diseases which are attended by fever. It is a
well-known fact that they are among the first to succumb to
cholera and other epidemic diseases. Sunstroke is another
disorder peculiarly frequent in that class of persons; and to
indicate that fact some physicians apply the term " drink-
stroke " to that disease.

52. Action of Tobacco on the Heart. — Tobacco both quickens
and enfeebles the heart. In some of those who habitually use
it, it gives rise to a throbbing or heaving sensation in the
region of the heart, an exaggerated kind of palpitation; at
times, this is so tumultuous that the patient fears lest his last
hour has come. In other cases, there is a weak and irregular
heart-beat, caused by tobacco poisoning. This is not so alarm-
ing to the patient as the condition just mentioned, but is no
Less dangerous and much less easily cured. It is apt to injure
a man's capacity for business affairs, being repressive of health-
ful energy and exertion.

51. Can they withstand fever?

52. What two noticeable ett'ects from tobacco ?

172

THE CIRCTLATIOX

TOPICAL OUTLINE

C Right Cavity
[ Left Cavity

Right Auricle

Right Ventricle

CAVITIES OF
THE HEART

Left Auricle

Left Ventricle

BLOOD-
VESSELS

Capillaries

I Veins

I. Vessels

i Right auricle , Between these the tri-
l Right ventricle I cuspid valve.
( Left auricle i Between these the bicus-
I Left ventricle ( pid or mitral valve.
! Thin irregular walls.

r Vena cava superior — from tipper

i Vessels I partSl

I Vena cava inferior — from lower

{ parts.

Thick walls.

Papillary muscles.

Chordae tendinem.

Three cusps — form the tricuspid valve.

I Right pulmonary
J artery — to right i Semilunar
lung. I valves just

Left pulmonary j below june-
I artery — to left | tion.
I lung. j

i Thin irregular walls.

I Right pulmonary vein — from

I Vessels I right lung-

I Left pulmonary vein — from left

I lung.

Very thick walls.

Papillary muscles.

Chorclse tendinese.

I Two cusps — form the bicuspid or mitral

valve.

Vessel — The aorta — to all parts.

Semilunar valves at its origin.

Coronary arteries commence just outside

the semilunar valves.

Take blood from the heart.
f 1. Outer areolar.

~ J 2. Middle muscular and elastic

— thick.
I 3. Inner epithelial.

Assist in propelling blood by their elastic
L recoil.

f Connect small arteries with small veins.
J Arranged like networks.
] Very thin trails.
I Diameter about so'ob inch.
f Convey blood to the heart.
| Coats — same as in arteries, but less muscu-
j lar and elastic tissue.

Generally provided with valves — like the
I semilunars.

THE CIRCULATION

173

ACTION OF
THE HEART

Auricular
Contraction

Ventricular

Contraction

Beating

In Arteries

CIRCULATION In Capillaries

In Veins

Simultaneous.

Blood forced into ventricles.

Force not sufficient to cause regurgitation

into the veins.
Valves between the auricles and ventricles

closed.
Chordae tendineas tightly stretched.
Semilunars forced open.
I Blood forced into the great arteries.
| Apex of heart tilted forward against the
front wall of the chest.
From 60 (old age) to 120 (young child) per
I minute.

(Dull sound — closure of tricuspid and mitral
valves, and contraction of ventricles (?).
Sharp sound — sudden closure of semilu-
nars.
L Followed by a pause.

f In jerks (pulsations).

{Very rapid.
Elastic recoil tends to produce a continuous
stream in the smaller arteries.
f Very slow and uniform.
-i Great resistance offered by the capillary
[ walls.

Much faster than in capillaries.
j Not so rapid as in arteries.

Steady flow.

[ Valves prevent backward flow.

COURSE OF
THE BLOOD

Right auricle.

Right ventricle.

Pulmonary arteries.

Lungs (capillary system).

Pulmonary veins.

Left auricle.

Left ventricle.

Aorta.

Capillary networks in all parts.

Vena- cava-.

Right auricle.

Pulmonary Circulation.

Systemic Circulation.

174

THE CIRCULATION

COMPOSITION
OF THE
BLOOD

CLOTTED
BLOOD

BLOOD . . .

Corpuscles

Serum .

") Fibrin .
I Corpuscles

Arterial .

Venous

Temperature
l Quantity .

The liquid of the blood.
f Water.

Dissolved albumen.
j Mineral salts.
I The elements of fibrin.

Discs, round, with concave

I Contains

Red

White

Diameter, s^ro inch.

Thickness, rjioo inch.

Yellowish, when viewed singly.

Have a tendency to ail here and
form piles when the blood is
drawn.

Hemoglobin, the oxygen car-
rier.

Shape constantly varying.

Diameter, ^W inch.

Transparent, jelly-like.
{ One to every 300 red.

f Water.

j Dissolved mineral salts.

I Dissolved albumen.

Formed during I
coagulation . y Clot — floats in the serum.

Red and white. J

f Bright red.

-j Red in oxygen.

I Usually contained in arteries.

( Dark purple.

I Usually found in veins.

I r . j Less oxygen than arterial blood.

| 0ontams "| More carbonic acid gas.

Converted into arterial blood by absorp-
[ tion of oxygen.

99 F.

One-tenth the weight of the body.

THE CIRCULATION 17 5

TABLE OF THE PRINCIPAL ARTERIES
(See Plate opposite Page 145)

The Head

Internal Ca-rot'id, j g , , braiQ

Ver'te-bral, J ll *

Oph-thal'mic, supplies the eye.

External Ca-rot'id fLin'gual, supplies the tongue.

• ™ < Fa ci-al, Bupphes the lower part of the face.

' (.Tem'po-ral, supplies the upper part of the head and face.

The Trunk

The A-or'ta, arising from the heart, is the main arterial trunk.

Cor'o-na-ry, supplies the walls of the heart.

Bron'chi-al, supplies the lungs.

In-ter-cos'tals, supply the walls of the chest.

Gas'tric, supplies the stomach.

He-pat'ic, supplies the liver.

Splen'ic, supplies the spleen.

Re'nal, supplies the kidney.

Mes-en-ter'ics, supply the bowels.

Spi'nal, supplies the spinal cord.

The Upper Limb

Branches of the Ax-il-la'ry, supply the shoulder.
" " Bra'chi-al, supply the arm.

it •< Ra'di-al )

M ,, TT , ' [supply the forearm and ringers.

The Lower Limb

Branches of the Fem'o-ral, supply the hip and thigh.
" " Pop-li-te'al, ]

" " Tib'i-al, > supply the leg and foot.

iiDi-ai, h
Per-o-ne'al, J

QUESTIONS FOR TOPICAL REVIEW

PAGE

1. In what organisms is the so-called circulatory fluid found ? 145

2. How is it designated in the different organisms ? 14."i

3. What can you state of the importance of blood to the body? 145

4. Of its great abundance, color, and composition '.' 145, 14ti

5. Describe the corpuscles of the human blood 14i>, 147

G. What is said of them in comparison with those of the lower animals '.' 147

7. Of the importance of sometimes detecting human from other blood '.' 147

8. What means have we of detecting blood in spots or stains? 147

y. What is meant by coagulation of the blood ? 148

176 THE CIRCULATION

PAGK

10. What wisdom is there in the law of the blood's coagulation? 148, 149

11. How is this wisdom made manifest ? 149

12. In what cases is the aid of the surgeon required ? 149

13. What are the two great uses of the blood ? 149, 150

14. Through what mediums is the blood provided with new material and

relieved of the old material ? 150

15. What do you understand by the operation called transfusion ? 150

16. What cases of transfusion are reported of the lower animals? 150

17. What can you state of transfusion as practised upon man ? 150, 151

18. What further can you say on the subject ? 151

19. What changes take place in the color of the blood in its journey

through the system ? 151

20. State all you can in relation to the circulation of the blood 152

21. All, in relation to the size, shape, and location of the heart 153, 154

22. How is the loss of power in the heart-movements obviated ? 154

23. Give a description of the formation of the heart 154

24. What can you state of the ventricles and auricles of the heart?. . . . 154

25. Describe the action of the heart 155

26. What special vitality does the tissue of the heart possess? 156

27. State all you can on the subject 156

28. Describe the course of the blood through the cavities of the heart. 156, 157

29. Describe the mechanism that regulates the heart-currents 157

30. How do you account for the two heart-sounds at the front of the

chest? 157

31. State what you can of the frequency of the heart's action 157, 158

32. Of the activity of the heart 159, 160

33. What do you understand by the arteries ? 160, 161

34. State what you can of the arteries and the arterial system 161

35. What do you understand by the pulse? 161, 162

36. In what part of the body may the pulse be felt? 162

37. What further can you state of the pulse ? 162

38. What are the veins ? 163

39. Where do they exist, and how are they formed ? 163

40. Describe the valves of the veins and their uses 16.°., 164

41. Now give a full description of the construction of the veins 163, 164

42. What further can you state of the veins ? 164

43. What do you understand by the capillaries ? 164

44. What service do the capillaries perform? 165, 166

45. What can you state of the rapidity of the blood's circulation ? 167, 168

46. Of the process known as assimilation ? 168

47. Of injuries to the blood-vessels ? 169

48. What is the effect of alcohol upon the heart ? 169, 170

49. What is said of alcohol as a fat-producer ? 170

CHAPTER VIII

RESPIRATION

The Objects of Respiration — The Lungs — The Air-passages — The
Movements of Respiration— Expiration and Inspiration— The Fre-
quency of Respiration — ( 'opacity of the Lungs — The Air we Breathe
— Changes in the Air from Inspiration — ('linages in the Blood —
Interchange of Gases in the Lungs — Comparison between Arterial
and Venous Blond — Respiratory Labor — Impurities of the Air —
Dust — Carbonic Acid — Effects of In pure Air — Nature's Provision
for Purifying the Air — Ventilation — Animal Heat — Spontaneous
Combustion

1. The Object of Respiration. — In one set of capillaries, or
hair-like vessels, the blood is impoverished in order to support
the different members and organs of the body. In another
capillary system the blood is refreshed and again made fit to
sustain life. The former belongs to the greater or systemic cir-
culation ; the latter to the lesser or pulmonary, so called from
pulmo, the lungs, in which organs it is situated. The blood, as
sent from the right side of the heart to the lungs, is venous,
dark, impure, and of a nature hurtful to the tissues. But,
when the blood returns from the lungs to the left side of the
heart, it has become arterial, bright, pure, and no longer injuri-
ous. This marvellous purifying change is effected by means
of the very familiar act of respiration, or breathing.

2. The Lungs. — The lungs are the special organs of respi-
ration. There are two of them, one on each side of the chest,
which cavity they, with the heart, almost wholly fill. The
lun^-substance is soft, elastic, and sponge-like. Under pres-
sure of the finger, it crepitates, or crackles, and floats when

1. Difference between the two sits of capillaries ? Change effected by respiration or
breathing i

'2. What are the lungs? How many lungs are there? Lung-substance? Its proper-
ties? The pleura I

M 177

178

RESPIRATION

thrown into water ; these properties being due to the presence
of air in the minute air-cells of the lungs. To facilitate the
movements necessary to these organs, each of them is provided
with a double covering of an exceedingly smooth and delicate
membrane, called the pleura. One layer of the pleura is

Fig. 47. — Oi

A, Lungs

B, Heart

of the Chest

D, Pulmonary Artery

E, Trachea

attached to the walls of the chest, and the other to the lungs ;
and they glide, one upon the other, with utmost freedom.
Like the membrane which envelops the heart, the pleura
secretes its own lubricating fluid, in quantities sufficient to
keep it always moist.

3. The Air-Passages. — The lungs communicate with the
external air by means of certain air-tubes, the longest of
which — the trachea, or windpipe — runs along the front of

Communication of the lungs with the external air? Bronchial tubes?

RESPIRATION

179

the neck (Fig. 47, E, and 48). Within the chest this tube is
divided into two branches, one entering each lung; these in
turn give rise to numerous branches, or bronchial tubes, as
they are called, which gradually diminish in size until they
are about one twenty-fifth of an inch in diameter. Each of
these terminates in a cluster of little pouches, or " air-cells,"
having very thin walls, and covered with a capillary network,
the most intricate in the body (Fig. 49).

4. These tubes are somewhat flexible, sufficiently so to bend
when the parts in which they are situated move ; but they are

;. 4^. -Larynx, Trachea, and
Beoni hial TniF.s

Diagram and Section of
mi: Air-cells

greatly strengthened by bands or rings of cartilage which keep
the passages always open; otherwise there would be a con-
st;mi Ly-reciirring tendency to collapse after every breath. The
lung-substance essentially consists of these bronchial tubes
and terminal air-cells, with the blood-vessels ramifying about
them (Fig. 50). At the top of the trachea is the larynx, a
sort of box of cartilage, across which are stretched the vocal

4. Office of the bronchial tabes ! What further can you state of them ?

180

RESPIRATION

cords. Here the voice is produced chiefly by the passage of the
respired air over these cords, causing them to vibrate (Fig. 51).

5. Over the opening of the larynx is found the epiglottis,
which fits like the lid of a box at the entrance to the lungs,
and closes during the act of swallowing, so that food and
drink shall pass backward to the oesophagus, or gullet (Fig.
51). Occasionally it does not close in time, and some sub-
stance intrudes within the larynx, when we at once discover,
by a choking sensation, that " something has gone the wrong

way." and. by coughing, we attempt to expel the unwelcome
intruder. The epiglottis is one of the many safeguards fur-
nished by nature for our security and comfort, and is planned
and put in place long before these organs are brought into
actual use in breathing and in taking food.

6. The air-passages are lined throughout almost their whole
extent with mucous membrane, which keeps them in a con-

5. The epiglottis ? When it does not close in time, what is the consequence ?

6. Lining of the air-passages ? Ciliated cells ? Their uses ? The three diseases of the
lungs ?

RESPIRATION

181

stantly moist condition. This membrane has cells of a
peculiar kind upon its outer surface. If examined under a
powerful microscope, we may see, even for a considerable time
after their removal from the body, that these cells have minute
hair-like processes in motion, which wave like a field of grain

^

-m.i Hun Hi" Tin: Murm AHD Throat

A. The Tongue

B, The Uvula

(', Vocal Cord
E, Epiglottis
L, Larynx

N, Trachea
I >. GEsophagoa

under the influence of a breeze (Fig. 52). This is a truly
beautiful sight ; and since it is found that these little cilia, as
they are called, always produce currents in one direction —
from within outward — it is probable that they serve a useful
purpose in catching and carrying away from the lungs dust

182 RESPIRATION

and other small particles drawn in with the breath (Fig. 52).
The three diseases which more commonly affect the lungs, as
the result of exposure, are pneumonia, or inflammation of the
lungs, affecting, principally, the air-cells ; bronchitis, an inflam-
mation of the large bronchial tubes; and pleurisy, an inflamma-
tion of the pleura, or outside wrapping of the lungs. Among
the young, an inflammation of the trachea takes place, known
as croup.

7. The Movements of Respiration. — The act of breathing has
two parts — (1), inspiration, or drawing air into the lungs, and
(2), expiration, or driving it out again. In inspiration, the

chest extends in its length, breadth,
and height. The motion outward and
upward can be observed every time
we draw a full breath ; and is caused
by a lifting of the ribs. But the mo-
tion downward is not so apparent, as
it is caused by a muscle within the

Fig. 52.— Ciliated Cells hh.hly body called the diaphragm, This is
the thin partition which separates the

chest from the abdomen, rising like a dome within the chest

(Fig. 22).

8. With every inspiration the diaphragm contracts, and in
so doing, approaches more nearly a level surface, and thus
enlarges the capacity of the chest. Laughing, sobbing, and
sneezing are due to sudden action of the diaphragm. On the
proper acting of this muscle depends our power to breathe
deeply; and like other muscles, its strength is increased by
exercise. This gives that endurance, or " long wind," as it is
commonly called, which is possessed in a marked degree by
the mountaineer, the oarsman, and the trained singer. The
habit of taking frequent and deep inspirations, in the erect
position, with the shoulders thrown back, tends greatly to
increase the capacity and power of the organs of respiration.

7. The act of breathing ? Extension of II best by breathing- ?

B. < ontraction of the diaphragm ? Power of the diaphragm ? Effects of extending the
walls of the chest? The habit of taking fre pent and deep inspirations ?

RESPIRATION 183

9. Expiration is a less powerful act than inspiration. The
diaphragm relaxes, and ascends in the form of a dome; the
ribs descend and contract the chest; while the lungs them-
selves, being elastic, assist to drive out the air. The latter
passes out through the same channels by which it entered,
At the end of each expiration there is a period of repose, last-
ing about as long as the period of action.

10. Frequency of Respiration. — It is usually estimated that
we breathe once during every four beats of the heart, or about
eighteen times in a minute. There is, of course, a close rela-
tion between the heart and lungs, and whatever modifies the
pulse, in like manner affects the breathing. "When the action
of the heart is hurried, a larger amount of blood is sent to the
lungs, and, as a consequence, they must act more rapidly.
Occasionally, the heart beats so very forcibly that the lungs
cannot keep pace with it, and then we experience a peculiar
sense of distress from the want of air. This takes place when
we run until we are "out of breath." At the end of every
fifth or sixth breath, the inspiration is generally longer than
usual, the effect being to change more completely the air of
the lungs. (Read Note 1.)

1. Experiment. The Lungs — Respiration. — Obtain from your
butcher a pair of sheep's or calf's lungs ; they should be cut out with
great care, so as not to be injured in any part. Insert the nozzle of a
pair of bellows into the trachea and tie it securely ; then inflate the lungs
fully, and tie the trachea just below the point of the nozzle very securely,
so that no air escapes. Now hang the lungs up to dry. If there is no
hole in any part of them, they will retain the air sufficiently long to allow
the air-cells to dry in this distended state. During the drying the lungs
will shrink somewhat, but that will not interfere with the demonstration
of the specimen. When thoroughly dry, cut through both lungs length-
wise (see Fig. 50, page 180) with a long, sharp knife. You will then obtain
a very interesting and valuable specimen, which will keep for a long time
if protected from dust. It shows the trachea and its structure, bronchi
and their subdivision, and the terminal air-cells.

The presence of carbonic acid gas in the expired air may be demon-
strated by blowing air through some perfectly clear lime water, by means
of a glass tube. Carbonic acid gas produces a chemical change in the
lime contained in the water, transforming it into carbonate of lime, which

9. Expiration? The mechanism of expiration 1
10. Frequency of respiration ! Effect of hurried action of the heart?

184 RESPIRATION

11. Although, as a general rule, the work of respiration goes
on unconsciously and without exertion on our part,, it is, never-
theless, under the control of the will. We can increase or
diminish the frequency of its acts at pleasure, and we can
"hold the breath," or arrest it altogether for a short time.
From twenty to thirty seconds is ordinarily the longest period
in which the breath can be held ; but if we first expel all the
impure air from the lungs, by taking several very deep inspira-
tions, the time may be extended to one and a half or even two
minutes. This should be remembered, and acted upon, before
passing through a burning building, or any place where the air
is very foul. The arrest of the respiration may be still further
prolonged by training and habit. It is said that the pearl-
fishers of India can remain three or four minutes under water
without being compelled to breathe.

12. Capacity of the Lungs. — The lungs are not filled and
emptied by each respiration. For while their full capacity, in
the adult, is three hundred and twenty cubic inches, or more
than a gallon, the ordinary breathing air is only one-sixteenth
part of that volume, or twenty cubic inches — being two-thirds
of a pint. Accordingly, a complete renovation, or rotation, of
the air of the lungs does not take place more frequently than
about once a minute ; and by the gradual introduction of the
external air, its temperature is considerably elevated before it
reaches the delicate capillaries that surround the air-cells. In
tranquil respiration, less than two-thirds of the breathing power
is called into exercise, leaving a reserve capacity of about one
hundred and twenty cubic inches, equivalent to three and one-
half pints. This provision is indispensable to the continua-
tion of life ; otherwise, a slight interference with respiration
— by an ordinary cold, for instance — would suffice to cut

is insoluble in water. After the air has been blown through for a few
minutes, the water becomes turbid, and after a longer time, milky. Upon
standing, this milkiness subsides to the bottom in the form of a fine pow-
der, carbonate of lime.

11. Respiration controlled by the will ? Advantage of the knowledge to us ?

12. Capacity of the lungs '! Time required to renovate the air in the lungs ? In tran-
quil respiration ? Importance of the provision f

RESPIRATION 185

off the necessary air, and the spark of life would be speedily
extinguished.

13. The Air we Breathe. — The earth is enveloped on all
sides by an invisible fluid, called the atmosphere. It forms a
vast ocean of air, forty-five miles deep, encircling and per-
vading all objects on the earth's surface, and is absolutely
essential for the preservation of all vegetable and animal life
— in the sea. as well as on the land and in the air. At the
bottom, or in the lower strata of this ocean of air, we move
and have our being. Perfectly pure water will not support
marine life, for a fish may be drowned in water from which
the air has been exhausted, just as certainly as a mouse, or
any other land animal will perish if held under water for a
short time. The cause is the same in both cases — the animal
is deprived of the requisite amount of air. It is also stated,
that if the water-supply of the plant be deprived of air, its
growth is checked. {Bead Nott 2. |

14. The air is not a simple element, as the ancients sup-
posed, but is formed by the mingling of two gases, known to

2. The Atmosphere. — "It surrounds us on all sides, yet we see it not ;
it presses on us with a load of fifteen pounds to every square inch of sur-
face of our In. dies, or from seventy to (Hie hundred tons on us in all. yet
we do not so much as feel its weight. Softer than the softest down —
more impalpable than the finest gossamer — it leaves the cobweb undis-
turbed, and scarcely stirs the lightest Mower that feeds on the dew it sup-
plies ; yet it bears the fleets of nations on its wings around the world,
ami crushes the most refractory substances beneatb its weight. When in
motion, its force is sufficient to level the mosl stately forests with the
earth; to raise the waters of the ocean into ridges like mountains, and
dash the strongest ships to pieces like toys. It bends the rays of the sun
from their path, to give us the twilight of evening and of dawn; itdis-
",id refracts their various tints, to beautify the approach and
retreat of the orb of day. But for the atmosphere, sunshine would burst
on ib and fail as at once, and at once remove us from midnight darkness
to the blaze of noon. We should have no twilght to soften and beautify
the landscape, no clouds to shade as from the scorching heat ; but the
bald earth, as it revolved on its axis, would turn its tanned and weakene '
front to the full and unmitigated rays of the lord of day.'* — Bttish.

18. The atmosphere ! How high or deep 1 How essential to life J Marino life in per-
fectly pure water and air ?

14. OompoaitioD of the air ': Properties of the two gases f

186 RESPIRATION

the chemist as oxygen and nitrogen, in the proportion of one
part of the former to four parts of the latter. These gases are
very unlike, being almost opposite in their properties : nitrogen
is weak, inert, and cannot support life : while oxygen is power-
ful, and incessantly active, and is the essential element which
gives to the atmosphere its power to support life and com-
bustion. The discovery of this fact was made by the French
chemist, Lavoisier, in 1778.

15. Changes in the Air from Respiration. — Air that has been
once breathed is no longer fit for respiration. An animal con-
fined within it will soon die ; so, also, a lighted candle placed
in it will be at once extinguished. If we collect a quantity of
expired air and analyze it, we shall find that its composition
is not the same as that of the inspired air. When the air
entered the lungs it was rich in oxygen ; now it contains
twenty-five per cent, less of that gas. Its volume, however,
remains nearly the same — its loss being made up by another
and very different gas, which the lungs exhale, called carbonic
acid gas, or, as the chemist terms it, carbon dioxide.

16. The expired air has also gained moisture. This is no-
ticed when we breathe upon a mirror or the window-pane, the
surface being tarnished by the condensation of the watery vapor
given off by the lungs. In cold weather, this causes the fine
cloud which is seen issuing from the nostrils or mouth with each
expiration, and contributes in forming the feathery crystals of
ice which decorate our window-panes on a winter's morning.

17. This watery vapor contains a variable quantity of ani-
mal matter, the exact nature of which is unknown ; but when
collected it speedily putrefies and becomes highly offensive.
From the effects, upon small animals, of confinement in their
own exhalations, having at the same time an abundant supply
of fresh air, it is believed that the organic matters thrown off
Kv the lungs and skin are direct and active poisons ; and that

15. Air once breathed? An animal in it? A candle? Analysis of expired air?
Change in volume ?

16. What else has the expired air gained ? When and where noticed ?

17. Nature of the watery vapor ? Its effects upon animals ?

RESPIRA TION 187

to such emanations from the body, more than to any other
cause, are due the depressing and even fatal results which
follow the crowding of large numbers of persons into places
of limited capacity. {Bead Note 3.)

18. History furnishes many painful instances of the ill
effects of overcrowding. In 1756, of one hundred and forty-
six Englishmen imprisoned in the Black Hole of Calcutta,
only twenty-three, at the end of eight hours, survived. After
the battle of Austerlitz, three hundred prisoners were crowded
into a cavern, where, in a few hours, two-thirds of their num-

3. The Two Breaths. — " Every time you breathe, you breathe two
different breaths : you take in one, you give out another. The compo-
sition of thus*' two breaths is different. Their effects are different. The

breath which has been breathed out must not be breathed in again. To
tell you why it must not would lead me into anatomical details, not quite
in place here as yet ; but this I may say : those who habitually take in
fresh breath will probably grow up large, strong, ruddy, cheerful, active.
clear-headed — tit for their work. Those who habitually take in the
breath which has been breathed out by themselves, or any other living
creature, will certainly grow up — if they grow up at all — small, weak,
pale, nervous, depressed, unlit for work, and tempted continually to
resort to stimulants and become drunkards.

" If you want to see how different the breath breathed out is from the
breath taken in, you have only to try a somewhat cruel experiment, but
one which people -too often try upon themselves, their children, and their
work-people. If you take any small animal with lungs like your own —
a mouse for instance — and force it to breathe no air but what you have
breathed already ; if you put it in a close box, and, while you take in
breath from the outer air, send out your breath through a tube into that
box, the animal will soon faint ; if you go on long with this process, he
will die. * * * * What becomes of this breath which passes from
your lips? Is it merely harmful, merely waste? God forbid ! God has
forbidden that anything should be merely harmful or merely waste in this
so wise and well-made world. The carbonic acid gas which passes from
your lips at every breath is a precious boon to thousands of things of
which you have daily need. For though you must not breathe your
breath again, you may at least eat your breath, if you will allow the sun
to transmute it for you into vegetables; or you may enjoy its fragrance
and its color in the shape of a lily or a rose. When you walk in a sun-
lit garden, every word you speak, every breath you breathe, is feeding
the plants and flowers around." — Rev. Charles Kinysleij on the Two
Breaths.

i>. Give some of the Instances famished by history.

188 RESPIRATION

ber died. On board a steamship, during a stormy night, one
hundred and fifty passengers were confined in a small cabin,
but when morning came, only eighty remained alive.

19. Changes in the Blood from Respiration. — The most strik-
ing change which the blood undergoes by its passage through
the lungs, is the change of color from a dark blue to a bright
red. That this change is dependent upon respiration has been
fully proved by experiment. If the trachea, or windpipe, of a
living animal be so compressed as to exclude the air from the
lungs, the blood in the arteries will gradually grow darker,
until its color is the same as that of the venous blood. When
the pressure is removed, the blood speedily resumes its bright
hue. Again, if an animal breathes an atmosphere containing
more oxygen than atmospheric air, the color changes from
scarlet to vermilion, and becomes even brighter than arterial
blood. This change of color is not of itself a very important
matter, but it indicates a most important change of com-
position. (See Note 4.)

20. The air, as we have seen, by respiration loses oxygen
and gains carbonic acid gas ; the blood, on the contrary, gains
oxygen and loses carbonic acid gas. Oxygen is the food of the
blood corpuscles ; while the articles we eat and drink go more
directly to the plasma of the blood. The air, then, it is plain,

4. Experiment. Changes in the Color of the Blood. — The changes
produced in the blood by the atmosphere are of easy demonstration
before a class. Obtain from a butcher some freshly "whipped" blood,
i.e., blood rapidly stirred with a bundle of twigs while it is being drawn
from the animal. This removes all the fibrin, and the blood no longer
coagulates. Upon standing, this gradually assumes a dark-brown color.

To show that the atmosphere, or rather the oxygen in the atmosphere,
produces the bright red or arterial blood, fill a pint bottle of white glass
about one-third full with this dark blood, and shake it briskly ; it will
very promptly assume a brighter color. The same, or a rather better
result may be obtained by blowing air through the blood by means of a
glass tube inserted into the bottle nearly to the bottom. After having
blown air through for a few minutes, the blood assumes a bright scarlet
color. Upon standing it again gradually grows dark.

19. Change in the blood from blue to red. Upon what does the change depend f Hi;
shown ':

20. What does the air lose and gain by respiration ? What, the blood '! Air as food ?

RESPIRATION 189

is a sort of food, and we should undoubtedly so regard it, if it
were not for the fact that we require it constantly, instead of
taking it at stated intervals, as is the case with our articles
of diet. Again, as the demand of the system for food is
expressed by the sensation of hunger, so the demand for air is
marked by a painful sensation called suffocation.

21. Interchange of Gases in the Lungs. — But the air and the
blood are not in contact, as they are separated from each other
by the walls of the air-cells and of the blood-vessels. How
then do the two gases, oxygen and carbonic acid gas, exchange
places'/ Moist animal membranes have a property which
enables them to transmit gases through their substance,
although they are impervious to liquids. This may be beau-
tifully shown by suspending a bladder containing dark venous
blood in a jar of oxygen. At the end of a few hours the
oxygen will have diminished, the blood will be brighter in
color, and carbonic acid gas will be found in the jar.

22. If this interchange take place outside of the body, it
must take place more perfectly within it, where it is favored
by many additional circumstances. The walls of the vessels
and the air-cells offer no obstacle to this process, which is
known as gaseous diffusion. Both parts of this process of
exchange are equally important. Without oxygen life ceases ;
if cail ionic acid gas is not thrown off, it acts like a poison, pro-
ducing unconsciousness, convulsions, and death.

23. Difference between Arterial and Venous Blood. — The fol-
lowing table presents the essential points of difference in the
appearance and composition of the blood, before and after its
passage through the lungs :

Venous Blood. Arterial Blood.

Color, Dark blue, Scarlet.

Oxygen, 8 per cent., 18 per cent.

Carbonic Acid Gas, 15 to 20 per cent., 6 per cent. , or less.

Water, More, Lr><.

The temperature of the blood varies considerably; but the
arterial stream is generally warmer than the venous. The

21. Moist animal membranes ? How shown with the bladder?
ii. Gaseous diffusion ! [f oxygen be not received ? If carbonic acid be retained?
28. Difference in tin- appearance and composition of the blood? Temperature of the
blood ' The blood while passing through the lungs ? The consequence ?

190 RESPIRATION

blood imparts heat to the air while passing through the lungs,
and consequently the contents of the right side of the heart
have a higher temperature than the contents of the left side.*

24. By means of the spectroscope, we learn that the change
of color in the blood has its seat in the corpuscles ; and that,
according as they retain oxygen, or release it, they present the
spectrum of arterial or of venous blood. There evidently
exists, on the part of these little bodies, an affinity for this gas,
and hence they have been called " carriers of oxygen." It was
long ago thought that blue blood was peculiar to persons of
princely or royal descent, and boastful allusions to the " sang
azure" of kings and nobles are often met with. Physiology,
however, informs us that blue blood flows in the veins of all —
the low as well as the high — and that so far from being a
mark of purity, it really indicates waste and decay.

25. Amount of Respiratory Labor. — During ordinary calm
respiration, we breathe eighteen times in a minute ; and twenty
cubic inches of air pass in and out of the lungs with every
breath. This is equivalent to the use of three hundred and
sixty cubic inches, or more than ten pints of air each minute.
From this we calculate that the quantity of air which hourly
traverses the lungs is 'about thirteen cubic feet, or seventy-
eight gallons; and daily, not less than three hundred cubic
feet, an amount nearly equal to the contents of sixty barrels.

26. Of this large volume of air five per cent, is absorbed in
its transit through the lungs. The loss thus sustained is almost
wholly of oxygen, and amounts to fifteen cubic feet daily. The
quantity of carbonic acid gas exhaled by the lungs during the
day is somewhat less, being twelve cubic feet. Under the in-

*" Bernard has succeeded in establishing the following facts with
regard to the temperature (of the blood) in various parts of the circu-
latory system in dogs and sheep : 1. The blood is wanner in the right
than in the left cavities of the heart. 2. It is warmer in the arteries than
in the veins, with a few exceptions." — Physiology of Man, Flint.

24. What do we learn by means of the spectroscope ? " Carriers of oxygen " ? Blue
blood in the system f

25. The amount of air that passes in and out of the lungs ?

26. Air absorbed in its transit through the lungs ? The loss y Carbonic acid exhaled ?
ttt'ect of excitement or exertion y What estimate t

RESPIRATION I'll

fluence of excitement or exertion, the breathing becomes more
frequent and more profound; and then the internal respiratory
work increases proportionately, and may even be double that
of the above estimate. It has been estimated that in drawing
a full breath, a man exerts a muscular force ecpial to raising
two hundred pounds placed upon the chest.

27. Impurities of the Air. — The oxygen in the atmosphere
is of such prime importance, and its proportion is so nicely
adjusted to the wants of man, that any gas or volatile substance
which supplants it must be regarded as a hurtful impurity.
All gases, however, are not alike injurious. Some, if inhaled,
are necessarily fatal ; arsenurelied hydrogen being one of these,
a single bubble of which destroyed the life of its discoverer,
Gehlen. Others are not directly dangerous, but because they
take the place of oxygen, and exclude it from the lungs, they
do harm, and become dangerous. To this latter class belongs
carbonic acid gas.

28. Most of the actively poisonous gases have a pungent or
offensive odor ; and, as may be inferred, most repugnant odors
indicate the presence of substances unlit for respiration.
Accordingly, as we cannot see or taste these impurities, the
sense of smell is our principal safeguard against them. In this
we recognize the forethought which has stationed this sense,
like a sentinel, at the proper entrance of the air-passages, to
give us warning of approaching harm. Take, as an example,
the ordinary illuminating gas of cities, from which so many
accidents happen. How many more deaths would it cause it.
when a leak occurs, we were not able to discover the escape of
the gas by means of its disagreeable odor. (Head Notes 5 and 0.)

5. Cleanliness the Sum Total of Hygiene. — ■• Disinfectants have
the power of destroying the cause, and of arresting the spread of most

epidemics and contagions diseases, but cleanliness is the best preventive
of disease. Whenever practicable, the abundant use of water is better
than disinfection. ' Let no one ever depend upon disinfectants, fumiga-
tions, and the like, for purifying the air. The offensive thing, not its
smell, must be removed.' " — Ho re nee Nightingale, Notes on Nursing
(in part).

•2~. Importance of the oxygon in the atmosphere I Injurious character ofgasec I
28, Pungency of gases 1 The inference ? Our safeguard 1

192 RESPIRATION

29. Organic matters exist in increased measure in the ex-
pired breath of sick persons, and impart to it, at times, a
putrid odor. This is especially true in diseases which, like
typhus and scarlet fever, are referable to a blood poison. In
such cases the breath is one of the means by which nature
seeks to expel the offending material from the system. Hence,
those who visit or nurse fever-sick persons should obey the
oft-repeated direction, "not to take the breath of the sick."
At such times, if ever, fresh air is demanded, not alone for the
sick, but also for those who take care of them. (See Care of
Siek-Room, Appendix.)

30. Dust in the Air. — Attention has lately been directed to
the dust, or haze, that marks the ray of sunshine across a
shaded room. Just as, many years ago, it was discovered that
myriads of animalcules were found in the water we drank, so
now the microscope reveals " the gay motes that dance along a
sunbeam " to contain multitudes of animal and vegetable forms
of a very low grade — the germs of fermentation and decay,
and the probable sources of disease.

31. It is found that the best filter by which to separate this
floating dust from the air is cotton wool, although a handker-
chief will imperfectly answer the same purpose. In a lecture

6. The True Prevention of Epidemics. — " It was in England that
solution of the great problem of hygiene was first attempted. ' Pre-
ventive Medicine,' it is there called. Palmerston told a deputation which
waited on him in order to ask him to order a fast on the approach of the
second epidemic of cholera, to cleanse their sewers, and diligently visit
the dwellings of the poor. And he did not confine himself to good advice,
but, with his usual energy, he laid his hand on sanitary legislation, and
purified the air of London and the large manufacturing towns. The
result of the sanitary measures carried out was a reduction of tin- mor-
tality of London from 2G to 23 per 1,000, and in some of the towns to 17
per 1,000 — a low death-rate previously only equalled in the Isle of
Wight. More than four thousand lives have been preserved yearly in
London ; and, assuming that the mortality among the sick is 1 in 20, this
number represents a diminution in yearly sickness to the extent of eighty
thousand." — Dr. Joseph Seegen in the Vienna Medical Weekly.

29. The air of rooms in which fever-Sick persons are confined ?

30. Animalcules in the water ? Dust in the air ?

31. The hest air filter ? The remarks of Prof. Tyndall ?

RESPIRA TION 193

on this subject by Prof. Tyndall, he remarks that, "by breath-
ing through a cotton wool respirator, the noxious air of the
sick-room is restored to practical purity. Thus filtered, attend-
ants may breathe the air unharmed. In all probability, the
protection of the lungs will be the protection of the whole
system. For it is exceedingly probable that the germs which
lodge in the air-passages are those which sow epidemic disease
in the body. If this be so, then disease can certainly be
warded off by filters of cotton wool. By this means, so far as
the germs are concerned, the air of the highest Alps may be
brought into the chamber of the invalid."

32. Carbonic Acid Gas in the Air. — We have already spoken
of this gas as an exhalation from the lungs, and a source of
impurity ; but it exists naturally in the atmosphere in the pro-
portion of one-half part per thousand. In volcanic regions it
is poured forth in enormous quantities from fissures in the
earth's surface. Being heavier than air, it sometimes settles
into caves and hollows in the surface. It is stated that in the
island of Java, there is a place called the " Valley of Poison,"
where the ground is covered with the bones of birds, tigers,
and other wild animals, which were suffocated by carbonic acid
gas while passing over it. The Lake A vermis, the fabled
entrance to the infernal regions, was, as its name implies, bird-
less, because the birds, while flying over it, were poisoned by
the gas, and fell dead into its waters. In mines, carbonic acid
gas forms the dreaded choke-damp, while carburetted hydrogen
is the fire-damp.

33. In the open air, men seldom suffer from carbonic acid
gas, for, as we shall see presently, nature provides for its rapid
distribution, and even turns it to a good use. But its ill effects
are painfully evident in our homes, schools, and churches,
where it is liable to collect as the waste product of respiration,
and of that combustion which is necessary for lighting and
warming our homes. A man exhales, during repose, no1 Less
than one-half cubic foot of carbonic acid gas per hour. A single

3:2. Carbonic acid in volcanic regions ? In Java f At Lake A vermis ? In mines?
33. In the open air ? Amount of carbonic acid exhaled by a man ? A gas-burner? A
room tire ? From furnaces ?

194 RESPIRATION

gas-burner liberates five cubic feet in the same time, therefore
spoiling about as much air as ten men. A fire burning in a
grate or stove emits some impure gases, and at the same time
abstracts from the air as much oxygen as twelve men would
consume in the same period, thus increasing the relative
amount of carbonic acid gas in the air. From furnaces, as
ordinarily constructed, this and other gases are constantly
leaking and poisoning the air of tightly-closed apartments.

34. Effects of Impure Air. — Carbonic acid gas, in its pure
form, is irrespirable, causing rapid death by suffocation. Air
containing forty parts per thousand of this gas (the composition
of the expired breath) extinguishes a lighted candle, and is
fatal to birds ; when containing one hundred parts, it no longer
yields oxygen to man and other warm-blooded animals, and is,
of course, speedily fatal to them. In smaller quantities, this
gas causes headache, labored respiration, palpitation, uncon-
sciousness, and convulsions.

35. In crowded and badly ventilated apartments, the air is
breathed over until it contains from six to ten times the natural
amount of carbonic acid gas. This contaminated air causes
dullness, drowsiness, and faintness, because the dark, impure
blood circulates through the brain, oppressing that organ, and
causing it to act like a blunted tool. This is a condition not
uncommon in our schools, churches, and court-rooms — the
places of all others where it is desirable that the mind should
be alert and free to act; but, unhappily, an unseen physio-
logical cause is at work, dispensing weariness and stupor over
pupils, audience, and juries. (Bead Notes 7 and 8.)

7. The Grounl-Atmosphere and its Relations to Dwellings. — "The
soil, which naturally contains wholesome air, and gives facility to its every
movement, is not less permeable by poisonous gases, which are often found
to pervade and issue from it. It is easy to find illustrations of the fact
that people are poisoned through the ground, since it is almost a daily
occurrence. Here is one, related by an eminent authority, von Petten-
kofer: — 'In a residence at Augsburg, apparently endowed with every
qualification for health and comfort, several priests lived together. On a

34. Effects of Inhaling carbonic acid alone? In small quantities ?

35. Effects of the air in crowded and badly-ventilated rooms t

RESPIRATION 195

36. Another unmistakable result of living in and breathing
foul air is found in certain diseases of the lungs, especially
consumption. For many years the barracks of the British
army were constructed without any regard to ventilation; and
during those years the statistics showed that consumption was
the cause of a very large proportion of deaths. At last the
government began to improve the condition of the buildings,

certain morning, one of these, net the leasl zealous and prompt in the

performance of his duties, was missed from his usual post at the matin
service. His colleagues hurried back to their common dwelling in search
of the missing priest, and found him lying prostrate and insensible upon
the floor of his bed-chamber. A doctor was immediately called in, and
at the first sight of his patient, declared him to be suffering from an attack
of typhus fever. Tin' Sisters of Charity, upon whom devolved the duty
of nursing him. and these clerical associates who were active in their
sympathy and prompt to visit him and give assistance, were, a few hours
after, attacked in the same way. The doctor did not hesitate in his
diagnosis, and pronounced the additional cases also typhus fever. A
general alarm prevailed in the city, and many called at the house of the
priest, who was greatly beloved. Among others was an old woman, who
discovered a strong smell of gas, and believing this to he the cause of the
sickness, obtained permission to remove the priest to her own house. The
priest had no sooner breathed the fresh air than he began to revive, and
during the very first evening of his removal to the new abode he became
so much better as to make an importunate demand for food. He soon
got entirely well. The old woman, thus confirmed in her gas theory, and
eager to save the remaining patients, who had continued to increase in
number in the priests' house, now had an interview with the manager
of the gas-works which supplied the town, and prevailed upon him to
investigate the condition of the gas-pipes in the vicinity of the priests'
residence. This was done, and a leak from which the gas was escaping
into the ground was found anil stopped. The air of the house was per-
ceived at once to improve, and with it the health of the patients that were
not removed ; these finallj completely recovered from what the doctor even
was compelled to admit was not typhus fever, bat poisoning by gas.'" —
The Book of Health.

8. Pure Air and Good Morals. — "Cleanliness and self-respect go to-
gether, and it is no paradox to affirm that you tend to purify men's
thoughts and feelings when you purify the air they breathe. * * * *
With a low average of popular health yon will have a low average of
national morality, and probably also of national intellect. Drunkenness
and vice of other kinds will flourish in such a soil, and you cannot get
healthy brains to grow on unhealthy bodies." — Lord Derby,

86. A cause of consumption J How waa the tact illustrated ?

196 RESPIRATION

giving larger space and air-supply ; and as a consequence,
the mortality from consumption has diminished more than
one-third.

37. The lower animals confined in the impure atmosphere
of menageries, contract the same diseases as man. Those
brought from a tropical climate, and requiring to be closely
housed, generally die of consumption. In the Zoological
Gardens of Paris, this disease affected nearly all monkeys,
until care was taken to introduce fresh air by ventilation, and
then it almost wholly disappeared. The tendency of certain
occupations to shorten life is well known, disease being occa-
sioned by the fumes and dust which arise from the materials
employed, in addition to the bad air of the workshop ol-
factory, where many hours are passed daily. {Bead Note 9.)

38. The following table shows the comparative amount of
carbonic acid gas in the air under different conditions, and the
effects sometimes produced :

PROPORTION OF CARBONIC ACID GAS. In 1000 parts of Air.

Air of country 4

Air of city 5

In hospital, well ventilated 6

In school, church, etc., fairly ventilated . . . 1.2 to 2.5
In court-house, factory, etc. without ventilation 4. to 40.

In bed-room, before being aired 4.5

In bed-room, after being aired 1.5

Constantly breathed, causing ill health .... 2.
Occasionally breathed, causing discomfort ... 3.
Occasionally breathed, causing distress . ... 10.

Expired air 40.

Air no longer yielding oxygen 100.

9. Consumption is Lung Starvation. — " The practice of allowing the
lungs only improper food, in the form of vitiated air, is one of the most
prevalent habits of civilized life, and diseases of the lungs are its greatest
bane and greatest dread. More persons die by consumption than by any
other single disease. If there be added to those the large number that
perish every year by inflammation of the lungs and bronchial tubes, disease
and premature death may be well said to have in these organs their chief

37. How, in the case of the lower animals ? Tendency of certain occupations ?

38. Give the fact as set forth in the table.

RESPIRATION 197

39. Nature's Provision for Purifying the Air. — We have seen
ili.ii carbonic acid gas is heavier than air, and irrespirable.
Why, then, docs it not sink upon and overwhelm mankind
with a silent, invisible wave of death '.' Among the gases
there is a more potenl force than gravity, which forever pre-
vents such a tragedy. It is known as the diffusive power of
gases. It acts according to a definite law. and with a cesisl
less energy compelling these gases, when in contact, to mingle
until they arc thoroughly diffused. The added influence of
the winds is useful, by insuring more rapid changes in the air,
air in motion being perfectly wholesome. The rains also wash
the ail'.

citadel. The leading cause of all this is. undoubtedly, the poor quality

of tin- food mi which the lungs arc nurtured. The very best physicians,
when their attenti m is directed to the subject, admit the full force of
this conclusion, and that it lias not received the attention it deserves.
Professor Hartshorne remarks mi this point, that -the influence of
impure air in promoting consumption has probably heretofore been
underrated.' 'The vitiated air of the European barrack system for
soldiers,' says Professor Parkes, 'is the only way in which the great
prevalence of consumption in European armies can be accounted for.*
This is the conclusion to which the Sanitary Commissioners for the army
came, in their celebrated report: -A great amount of phthisis (con-
sumption) has prevailed in the most varied stations of the army and in
the most beautiful climates — in Gibraltar, Malta. Ionia, Jamaica. Trini-
dad. Bermuda, etc. — in all of which places the only common condition
was the vitiated atmosphere which our barrack system everywhere pro-
duced. Ami. as if lo clinch the argument, there has been of late years a.
most decided decline in phthisis in these stations, while the only circum-
stance which has notably changed in the time has been the condition of
the air.' A very eminent authority, the late Dr. Marshall Hall, of Eng-
land, said, in reference to pure air in the treatment of consumption. -If
I were seriously ill of consumption. I would live out doors day and
night, except in rainy weather, or midwinter; then I would sleep in
an unplastered log house. Physic has no nutriment, gaspings for air
cannot cure you, monkey capers in a gymnasium cannot cure you. and
stimulants cannot cure you. What consumptives want is pure air, not
physic — pure air. not medicated air — plenty of meat and bread.' Let
it lie remembered, in this connection, that every hygienic or health-pro-
moting measure which tends to .aire a disease is much more efficacious in

preventing it." — Black's Ten /.</"-.-; of Health.

89. What ran you state of the diffusive power of gases? The added influence of the
winds?

198 RESPIRATION

40. We have seen that the whole animal creation is con-
stantly taking oxygen from the atmosphere, and as constantly
adding to it vast volumes of gas, that is prejudicial to the
normal performance of animal respiration. How, then, does
the air retain, unchanged, its life-giving properties ? The
uniform purity of the air is secured by means of the vegetable
creation. Carbonic acid gas is the food of the plant, and
oxygen is its waste product. The leaves are its lungs, and
under the stimulus of sunlight a vegetable respiration is set in
motion, the effects of which are just the reverse of that of
animals. Thus nature purifies the air, and at the same time
builds up beautiful and useful worlds — the life of each growing
out of the decay of the other. (Bead Note 10.)

41. In the sea, as in the air, the same circle of changes is
observed. Marine animals consume oxygen and give off car-
bonic acid gas, while marine plants consume carbonic acid gas,

10. Plants and the Air. — " Though the air is dependent for the renewal
of its oxygen on the action of the green leaves of plants, it must not be
forgotten that it is only in the presence and under the stimulus of light
that these organisms decompose carbonic acid gas. All plants, irrespec-
tive of their kind or nature, absorb oxygen and exhale carbonic acid gas
in the dark. The quantity of noxious gas thus eliminated is, however,
exceedingly small when compared with the oxygen thrown out during the
day. Aside from the highly deleterious action that plants may exert on
the atmosphere of a sleeping-room, by increasing the proportion of car-
bonic acid gas during the night, there is another and more important
objection to be urged against their presence in such apartments. Like
animals, they exhale peculiar volatile organic principles, which in many
instances render the air unfit for the purposes of respiration. Even in
the days of Andronicus this fact was recognized, for he says, in speaking
of Arabia Felix, that ' by reason of myrrh, frankincense, and hot spices
there growing, the air was so obnoxious to their brains, that the very
inhabitants at some times cannot avoid its influence.' What the influence
on the brains of the inhabitants may have been docs not at present interest
us ; we have only quoted the statement to show that long ago the emana-
tions from plants were regarded as having an influence on the condition
of the air ; and, in view of our present ign< trance, it w< tuld be wise to banish
them from our sleeping apartments, at least until we are better informed
regarding their true properties." — Draper on Poisoned Air.

40. How is the constant parity of the sir secured * Explain the process.

41. What process occurs in the Ben ': How is the fact illustrated ?

RESPIRATION

199

and liberate oxygen. Taking advantage of this fact, we may
so arrange aquaria with fishes and sea-plants, in their proper
combinations, that each may supply the needs of the other,
and the water may seldom require to be renewed. This affords
us, on a small scale, an illustration of the grand circle of
changes taking place in the air about us, and also of the har-
monious dependence of the two great kingdoms of nature.

42. Ventilation. — Since the external atmosphere, as pro-
vided by nature, is always pure, and since the air in our
dwellings and other buildings is almost always impure, it
becomes imperative that there should be a free communication
from the one to the other. This we aim to accomplish by venti-
lation. As our houses are ordinarily constructed, the theory of
ventilation, " to make the internal as pure as the external air,"
is seldom carried out. Doors, windows, and flues, the natural
means of replenishing the air, are too often closed, almost
hermetically, against
the precious element.
Special means, or spe-
cial attention, must
therefore be used to se-
cure even a fair supply
of fresh air. This is
still more true of those
places of public resort,
where large numbers
of persons are crowded
together. (See House-
Drainage, Appendix.)

43. If there are two
openings in a room, one
as a vent for foul air,
and the other an inlet
for atmospheric air, and
if the openings be large

!':*!:*!

L^.

z.

^mmm^i^mm

Tha. 58. — Showing manner of ventilating by Inserting
Btrlp of wood beneath lower sash of window

43. Character of the external air ? < >f the air in our dwellings ? What beoomes impera-
tive ? Imperfect ventilation of onr dwellings !

43. What hints are given for the ventilation of our dwellings T

200 respira tion

in proportion to the number of air consumers, the principal
object will be attained. Thus, a door and window, each open-
ing into the outer air, will ordinarily ventilate a small apart-
ment ; or a window alone will answer, if it be open both above
and below, and the open space at each end be not less than one
inch for each occupant of the room, when the window is about
a yard wide. The direction of the current is generally from
below upward, since the foul, heated air tends to rise ; but this
is not essential. * Its rate need not be rapid ; a " draught,"
or perceptible current, is never necessary to good ventilation.
The temperature of the air admitted may be warm or cold. It
is thought by many that if the air is cold, it is pure ; but this
is an error, since cold air will receive and retain the same
impurities as warm air.

44. Shall we open our bed-rooms to the night air ? Florence
Nightingale says, in effect, that night air is the only air we
can then breathe. "The choice is between pure air without
and impure air within. Most people prefer the latter — an
unaccountable choice. An open window, most nights in the
year, can hurt no one. In great cities, night air is the best
and purest to be had in twenty-four hours. I could better
understand, in towns, shutting the windows during the day
than during the night." {Bead Note 11.)

* When the window is of the common sash kind, a good supply of
fresh air may be obtained without a current, by placing a strip of board
about four inches wide under the lower sash (Fig. 53). The window is
thus closed against rain and snow, but allows of a supply of fresh air to
enter between the sashes. If still more ventilation is needed to keep the
air of the room sweet, the same arrangement may be made at the top of
the window.

11. Pure Air in our Homes during Cold Weather. — "Fresh air is the
great natural disinfectant, antiseptic, and purifier, and not to be com-
pared for a moment with any of artificial contrivance. There is plenty of
it in the world ; yet, disguise the fact as we may, there is no getting over
the unwelcome truth, that to provide it in abundance in our climate is
expensive, since during seven months in the year it must be artificially
warmed, in order that our homes may be comfortable. To take in air at
the average winter temperature of 28°, raise it to 68°, and discharge it

44. State what Florence Nightingale says about inhaling night air.

BE8PIRATI0N 201

45. Animal Heat. — Intimately connected with respiration is
the production of animal heat, or the power of maintaining the
temperature of the body above that of the medium in which
the creature moves; thus, the bird is wanner than the air. and
the fish than the water. This elevation of temperature is the
result of the various chemical changes which are constantly
taking place in the system. Although common to all animals,
in a greater or less degree, heat is not peculiar to them, since
plants also generate it, especially at the time of sprouting and
flowering. If a thermometer be placed in a cluster of geranium
flowers, it will indicate a temperature several degrees above
that of the surrounding air.

46. Among animals great differences are noticed in this
respect, but the degree of heat produced is always proportional
to the activity of respiration and the amount of oxygen con-
sumed. Accordingly, the birds, whose habits are extremely
active, and whose breathing capacity is the greatest, have uni-
formly the highest temperature. Sluggish animals, on the
contrary, as frogs, lizards, and snakes, have little need for
oxygen, and have incompletely developed lungs; these animals
are cold to the touch — that is, they have relatively a lower
temperature than man, and their positive temperature is but
little above that of the external air. Accordingly, zoologists
have so arranged the animal kingdom that warmMooded ani-
mals, including man, the birds, and the quadrupeds, are classi-
fied together; while the cold-blooded animals, such as the hsii.
tortoise, frog, and all that have no vertebral column, are classed
by themselves.

again from our houses even once in an hour, is a process which cannot lie
accomplished without paying roundly ; yet on no other condition can we
reasonably expect health and long life. The best way is to freely admit
that it is expensive, but worth the money it costs. If Benjamin Franklin
thought that 'a penny saved is a penny earned.' he is equally sure that
•health is wealth.' " — George Derby <>*< <!<<■ Prevention of Disease.

4.".. Warmth of the bird Bfl compared with thai of the air? Of the flab ami the water?
II. at in animals and plants? Sow Illustrated with the thermometer?

46. Amount of heat In animals, how apportioned ? A- regards the birds * Frogs, and
other sluggish animals ? Arrangement made by zoologists (

202 RESPIRATION

47. The temperature of the human body is about 100° Fah-
renheit, and remains about the same through winter and sum-
mer— in the tropics as well as in the frozen regions of the
north. It may change temporarily within the range of about
twelve degrees ; but any considerable, or long-continued eleva-
tion or diminution of the bodily heat is certain to result dis-
astrously.

48. Man is able to adapt himself to all extremes of climate ;
and, in fact, by means of clothing, shelter, and food, is able to
create for himself an artificial climate wherever he chooses to
reside. The power to resist cold consists chiefly in prevent-
ing the heat which is generated by the vital processes of
the body from being lost by radiation. Warm clothing, such
as we wear in winter, has, in reality, the same temperature as
that which is worn in summer ; but, by reason of being thick
and porous, it is a bad conductor of heat, and thus prevents the
escape of that produced by the body. If woollen fabrics were
intrinsically warm, no one would wrap a piece of flannel, or
blanket, around a block of ice to prevent its melting in sum-
mer.

49. The faculty of generating heat explains how it is that
we are enabled to resist the effects of cold ; but how does the
1 )ody withstand a temperature higher than its own ? Men have
been know to remain several minutes in an atmosphere heated
above the boiling-point of water, and yet the temperature of
their own bodies was not greatly increased. Those who labor
in foundries and glass-works are habitually subjected to very
high degrees of temperature, but they do not suffer in health
more than those engaged in many other occupations.

50. The regulation of the temperature of the body is effected
by means of perspiration, and by its evaporation. So long as
the skin acts freely, and the air freely absorbs the moisture,
the heat of the body does not increase, for whenever evapora-

47. State what is said respecting the temperature of the human body.

48. Ability of man to adapt himself to different climates ? In what does the power to
resist cold consist '! What is said about warm clothing ?

49. Men in an atmosphere above the boiling-point ''. In foundries and glass-works?
60. The regulation of the temperature of 'h" '■•'•. five the explanation.

RESPIRATION 203

tion takes place, it is attended with the abstraction of heal —
that is, the part becomes relatively colder. This may be
by moistening seme part of the surface with cologne, ether, or
other volatile liquid, and then causing it to evaporate rapidly
by fanning. The principle that evaporation produces cold has
been ingeniously and practically employed, in the manufacture
of ice by means of freezing machines.

51. Spontaneous Combustion — Alcohol the Indirect Cause. —
Is ir possible that the temperature of the living body can be so

increased that its tissues will burn spontaneously '.' From time
to time eases have been reported in which, by some mysterious
means, considerable portions of the human body have been
consumed, apparently by fire — the victim being found dead, or
incapable of explaining the occurrence. Hence, the theory has
been current that, under certain conditions, the tissues of the
body might become self-ignited : and the fact that this so-called
spontaneous combustion has ordinarily taken place in those who
had been addicted to the use of alcoholic drinks, has given a
color of probability to the opinion. It has been supposed that
the flesh of these unfortunate persons. becoming saturated with
alcohol thus taken into the system, took fire upon being ex
posed to a flame, as of a lighted candle, or. indeed, without any
external cause. But, whether this be possible or not. one thing
is certain — this strange kind of combustion has never been
actually witnessed by any one competent to give a satisfactory
account of it.

52. The results that have been observed may be satisfacto
rily explained by the accidental ignition of the clothes, or other
articles near the body, and by the supposition that the indi
vidua! was at the time too much stupefied by intoxication to
notice the source of danger and provide for his safety. The
highest temperature that has been observed in the body —
about 111'3 Fahrenheit — is too low to ignite the vapor of alco-
hol; much less will it cause the burning of animal tissues. It
is undoubtedly true that when the tissues are tilled with alco-

61. State what is said of spontaneous combustion.
69. How is the theory refuted '/

204 BESPIRATIOX

hoi, combustion will more easily take place than when the body
is in a normal state ; but, under any condition, the combustion
of the body requires a higher degree of heat than can be gener-
ated by the body itself, or the mere proximity of a lighted
candle, or any cause, of similar character.

53. The Effect of Alcohol upon Respiration. — Whenever wine,
or any other form of alcoholic drink, is taken into the stomach,
it is quite rapidly absorbed into the blood-current, and in a few
minutes it imparts to the breath a peculiar, offensive odor.
This is due to the vapor of alcohol that, little by little, is ex-
pelled from the body, along with the carbonic acid gas exhaled
through the lungs. If the quantity of drink taken has been con-
siderable, this disagreeable odor may continue a day or more.

This condition is evidence that an unnatural labor has been
thrown upon the lungs ; namely, it is an effort on the part of
the general system to get rid of a poison that is hurtful to every
organ by which it is retained. While this exhalation of alco-
holic vapor continues, the respiratory act is impaired, for not
only can less carbonic acid gas be thrown off, but there is also
a diminished inhalation of oxygen.

54. Respiratory Diseases among the Intemperate. — The struc-
ture of the respiratory organs is such that they are relatively
tolerant of the presence of alcohol in the body.

Wheezy breathing and hoarseness of voice are noticeable
among inebriates ; but this class does not suffer greatly from
severe attacks of lung diseases that can be said to be directly
due to the liquor they drink. Indirectly, however, they suffer
greatly, as a class, from those diseases, because they incur ex-
posures of every imaginable variety, while under the intoxicant
influence of this powerful drug, which can, according as it is
taken in less or greater quantity, deprive a person of his sober
self-management or bring him down to utter loss of conscious-
ness. It is in this way that the users of alcohol fall a prey,
especially in the winter season, to attacks of pneumonia, or
lung fever, and other serious disease of the respiratory organs.

53. Does alcohol appear in the breath ? Does it interfere with respiration}

54. What respiratory disca: es among the Intemperate ?

RESPIRATION

205

TOPICAL OUTLINE

TRACHEA

LARYNX

LUNGS

INSPIRATION

EXPIRATION

Rings

Bronchial
tubes

I Cartilaginous rings.
Structure . . . Fibrous tissue.

Lined with ciliated epithelium.
I C-shaped.

Complete in front. Incomplete behind.
: Connected by fibrous tissue.
I Right and left.
I In structure similar to trachea.

Rings of cartilage very imperfect.
; Cartilage disappears in smallest tubes,
[ which terminate in groups of air-cells.

Thyroid cartilage j pwge.
f Two rings ... Incomplete behind.

1 Cricoid cartilage — A complete ring.

i. Contains . . . J Vocal cords-

I Epiglottis — Closes the glottis.

f Right Three lobes.

| Left Two lobes.

Air-vessels — Bronchial tubes and cells.
I Vessels . . .' . J f Pulmonary arteries.

[Blood-vessels j Capillaries.

i Pulmonary veins.

External intercostals contract.
Raise the ribs.
Make the chest under.
Diaphragm depressed.
Chest made deeper.
Lungs expand with the chest.

Air rushes in through the trachea, filling the enlarged lungs.
| Elastic walls of the thorax recoil.
Elastic lungs recoil.
Internal intercostals con- "
tract.
Ribs depressed.
Chest becomes narrower.
Diaphragm raised.
| Chest made shallower.

Abdominal muscles contract.
I Abdominal organs press on
under side of diaphragm.
Air forced out through the trachea.

r Chest enlarged

Chest made
smaller

Forced
expiration.

206 RESPIRATION

QUESTIONS FOR TOPICAL REVIEW

PAGE

1. What is the object of respiration ? 177

2. What are the special organs of respiration ? 177

3. In what organs does a change in the blood take place ? 177

4. What is the nature of the change ? 177

5. Where are the lungs situated, and what is the character of the sub-

stance of which they are composed ? 177, 178

6. Describe the facilities provided for the lung movements 178

7. Describe the trachea, or windpipe 178-181

8. Describe the bronchial tubes, and their uses 178, 179

9. What can you state in relation to the epiglottis ? 180

1(). What are the cilia, and what use do they probably serve ? 181

11. How may the lungs be affected by not being properly protected? 182

12. Describe the movements necessary to the act of perfect respiration. 182, 183

13. What is the diaphragm, and what is its office ? 182, 183

14. How may the organs of respiration be so improved as to increase their

capacity and power ? 182

15. What is stated in relation to the frequency of respiration? 183

16. To what extent may the act of respiration be subjected to our wills?. 184

17. What may be said to be the capacity of the lungs ? 184

18. How long does it take every particle of air in the lungs to he expelled

and new air to take its place ? 184

19. What would be the consequences, if the entire capacity of the lungs

were constantly used ? 184, 185

20. What would be the consequences to a fish put into water from which

the air had been completely exhausted ? Why ? 185

21. What is the air, and what are its parts ? 185, 18(5

22. What is the character of the air that has been just breathed ? 180

23. Why is it that such air is not fit for respiration ? 180-188

24. What are the effects, as recorded in notable cases of confinement in

places the air of which has been breathed " over and over "?.. . 187, 188

25. What can you state of changes in the blood from respiration ? 1S8

20. What of the air as an article of food ? 188, 189

27. What on the subject of interchange of gases in the lungs ? 189

28. Explain the difference between arterial and venous blood 189, 190

29. Explain, if you can, the cause of the difference 190

30. State what you can in relation to blue blood 190

31. In relation to the amount of labor exerted in respiration 190, 191

32. In relation to the deleterious properties of different gases 191

33. In relation to the dust that floats in the air 192

34. What are the properties of carbonic acid gas .' 193, 194

35. In what places is carbonic acid gas commonly found ? 194

36. Describe the effects of carbonic acid gas 194

37. What are the general effects of breathing any impure atmos-

phere ? 194-196

38. What are Nature's provisions for purifying the air? 197-199

39. What hints and directions are given on the subject of ventilation ? 199, 200

40. How does the temperature of the body compare with the medium in

which it lives ? 201

41. How is temperature of the body regulated and sustained ? 202, 203

42. State what you can on the subject of spontaneous combustion 203

CHAPTER IX

THE NERVOUS SYSTEM

Animal and Vegetative Functions — Sensation, Motion, and Volition —
The Structure of the Nervous System— The White and Gray Sub-
stances— The Brain — Its Convolutions — The Cerebellum — The
Spinal Cord and its Systeyn of Nerves — The Anterior and Posterior
Boots — The Sympathetic System of Nerves — The Properties of Ner-
vous Tissue — Excitability of Nervous Tissues — The Functions of the
Spinal Nerves and Cord — The Direction of the Fibres of the Cord —
Beftex Activity , and its Uses — Tlxe Functions of the Medulla Oblon-
gata and the Cranial Ganglia — The Befiex Action of the Brain —
Effects of Alcohol, Tobacco, Snuff, Narcotics, Opium, Chloral, Hash-
eesh, Chloroform

1. Animal Functions. — The vital processes which Ave have
been considering in the three previous chapters — of digestion,
circulation, and respiration — belong to the class of functions
known as vegetative functions. That is, they are common* to
vegetables as well as animals; for the plant, like the animal,
can originate nothing, not even the smallest particle of matter ;
and yet it grows, blossoms, and bears fruit, by reason of obtain-
ing and digesting the nutriment which the air and soil provide.
The plant has its circulatory fluid and channels, by which the
nutriment is distributed to all its parts. It has, also, a curious
apparatus in its foliage, by which it abstracts from the air
those gaseous elements so necessary to its support; and thus it.
accomplishes vegetable respiration. These vegetative functions
have their beginning and end within the organism of the plant;
and their object is the preservation of the plant itself, as well
as of the entire species.

1. What processes are known as the vegetative function?? Why so called? What
properties and functions does the plant possess ? Their object ?
207

208 THE NERVOUS SYSTEM

2. The animal, in addition to these vegetative functions, has
another set of powers, by the use of which he becomes con-
scious of a world external to himself, and brings himself into
active relations with it. By means of the vegetative processes,
his life and species are maintained ; while, by means of certain
animal functions, he feels, acts, and thinks. These functions,
among which are sensation, motion, and volition, not only dis-
tinguish the animal from the plant, but, in proportion to their
development, elevate one creature above another ; and it is by
virtue of his pre-eminent endowment, in these respects, that
man holds his position at the head of the animal creation.

3. Among animals whose structure is very simple — the
hydra, or fresh-water polyp, being an example — no special
organs are empowered to perform separate functions, but every
part is endowed alike ; so that, if the animal be cut into pieces,
each portion has all the properties of the entire original ; and,
if the circumstances be favorable, each of the pieces will soon
become a complete hydra. As we approach man, in the scale
of beings, we find that the organs multiply, and the functions
become more complete. The function of motion, the instru-
ments of which — the muscles and bones — have been con-
sidered in former chapters, and all the other animal functions
of man, depend upon the set of organs known as the nervous
system.

4. The Nervous System. — The intimate structure of this
system differs from any tissue which we have before examined.
It is composed of a soft, pulpy substance, which early in life is
almost fluid, but which gradually solidifies with the growth of
the body. 'When examined under the microscope, it is found
to be composed of two distinct elements: (1) the white sub-
stance, composing the larger proportion of the nervous organs
of the body, which is formed of delicate cylindrical filaments,

2. What second set of powers has the animal ? What functions are mentioned ? The
advantage they give ?

3. Animals whose structure is simple? As we approach man? Dependence of the
animal functions of man J

4. The nervous tissues, of what composed ? When examined by the aid of the micro-
scope ? The white substance ? The gray substance ?

THE NERVOUS SYSTEM 209

diameter, termed the nerve-fibres;
and (2) the gray substance, composed of grayish-red, or ashen-
colored cells, of various sizes, generally possessing one or more
off-shoots, which are continuous with the nerve-fibres just men-
tioned.

5. The gray, cellular substance constitutes the larger por-
tion of those important masses which bear the name of nervous
centres and ganglia (from ganglion, a knot), in which all the
nerve-fibres unite. These white nerve-fibres are found com-
bined together in long and dense cords, called nerves (from
neuron, a cord), which serve to connect the nervous centres
with each other, and to place them in communication with all
the other parts of the body which have sensibility or power of
motion. That part of the nervous system which is concerned
in the animal functions comprises the brain, the spinal
cord, and the nerves winch are derived therefrom; these are,
together, called the cerebrospinal system (Fig. 54); while that
other set of organs, which presides over and regulates the vege-
tative functions, is called the sympathetic system of nerves.

6. The Brain. — The brain is the great volume of nervous
tissue that is lodged within the skull. It is the largest and
most complex of the nervous centres ; its weight, in the adult,
being about fifty ounces, or one-fortieth of that of the whole
body. The shape of the brain is oval, or egg-shaped, with one
extremity larger than the other, which is placed posteriorly in
the skull, to the concavity of which it very closely conforms.
The brain consists chiefly of two parts; the cerebrum, or brain
proper, and the cerebellum, or "little brain." In addition to
these, there are several smaller organs at the base, among which
is the commencement or expansion of the spinal cord, termed
the medulla oblongata, or oblong marrow.

7. The tissue of the brain is soft and easily altered in shape
by pressure; it therefore requires to be placed in a well-pro-

.".. Nervous centres and ganglia? Nerves? What do they servo? Cerebro-sptnal
system ?

i'.. Location of the brain? its weight? its shape? Of what it consists? What organs
at tin- base I

T. The tissue of the brain ? What, therefore, is required ? Blows on the head? Mem-
branes of the brain S Blood sent to the brain f

?10 THE XERVOFS SYSTEM

Fia. 54. — The Uekebko-Si-inal System

THE NERVOUS SYSTEM

211

The brain of man is heavier

tected position, such as is afforded by the skull, or cranium,
which is strong without being cumbrous. In the course of an
ordinary lifetime, this bony box sustains many blows with little
inconvenience; while, if they fell directly upon the brain, they
would at once, and completely, disorganize that structure.
Within the skull, the brain is enveloped by certain mem-
branes, which at once protect it from friction and furnish it
with a supply of nutrient vessels; they are called the arach-
noid, or "spider's web," the dura mater, and the pia mater, or
the "tough" and "delicate coverings." The supply of blood
sent to the brain is very liberal, amounting to one-fifth of all
that the entire body possesses,
than that of any other
animal, except the ele-
phant and whale.

8. The Cerebrum. — /
The brain proper, or
cerebrum, is the largest
of the intracranial or-
gans, and occupies the
entire upper and front
portion of the skull. It
is almost completely bi-
sected by a fissure, or
cleft, running through it
lengthwise, into two equal
parts called hemispheres.
The exterior of these
hemispheres is gray in
color, consisting chiefly
of nerve-cells, arranged
so as to form a layer of
gray matter one-fifth of an inch in thickness, and is abundantly
supplied with blood-vessels. The interior of the brain, how-
ever, is composed almost wholly of white substance, or nerve-
fibres.

-. Size of the brain proper? How divided I The exterior of the hemispheres I The
interior?

[JPPBB SlTBFAOI "K TIIK

A. Longitudinal Fissure

B, The Hemispheres

212

THE NERVOUS SYSTEM

9. The surface of the cerebrum is divided by a considerable
number of winding and irregular furrows, about an inch deep,
into " convolutions," as shown in Fig. 55. Into these furrows
the gray matter of the surface is extended, and, in this manner,
its quantity is vastly increased. The extent of the entire sur-
face of the brain, with the convolutions unfolded, is computed to
be equal to four square feet ; and yet it is easily enclosed within
the narrow limits of the skull. When it is stated that the
gray matter is the true source of nervous power, it becomes
evident that this arrangement has an important bearing on the

A, Left Hemisphere of Cerebrum

B, Corpus Callosum

C, < (ptic Thalamus

SECTION OF THE BRAIN

D, The Pons Varolii

E, Upper extremity of the Spinal Cord

F, The Arbor V it*

mental capacity of the individual. And it is noticed that in
children, before the mind is brought into vigorous use, these
markings or furrows on the surface are comparatively shallow
and indistinct ; the same fact is true of the brain in the less
civilized races of mankind and in the lower animals. It is also
noticeable that among animals, those are the most capable

9. The surface df the cerebrum, how marked ? The gray matter of the surface? Ex-
tent of the entire brain surface '! Source of nervous power ? What further ?

THE NERVOUS SYSTEM 213

of being educated which have the best development of the
cerebrum. {Bead Note 1.)

10. The Cerebellum. — The "little brain" is placed beneath
the posterior part of the cerebrum, and, like the latter, is

- . . . : 01 TUB BBAIH

refer to the jiairs of nerves

divided into hemispheres. Like it, also, the surface of the
cerebellum is composed of gray matter, and its interior is

1. Ihe Brain. — " < >ur brains are seventy-year clocks. The Angel of
Life winds them up once for all, then closes the case, and gives the key
to the Angel of the Resurrection. Tic-tac ! tic-tac ! go the wheels of
thought; our will cannot stop them ; they cannot stop themselves ; sleep
cannot stop them ; madness only makes them go faster ; death alone can
break into tin- case, and, seizing the ever-swinging pendulum, which we
call the heart, silence at last the clicking of the terrible escapement we
have carried so long beneath our wrinkled for. heads. . . . Now, when
a gentleman's brain is ill-regulated or empty, it is, to a great extent, his
own fault, and so it is simple retribution that, while he lies slothfully or
aimlessly dreaming, the fatal habit settles on him like a vampire and
sticks his blood, fanning him all the while with its hot wings into deeper
slumber or idl< r dreams." — Holmes' The Autocrat of the Breakfast-Table.

10. Location of the "little brain ?" How divided} Its surface and interior ? Its sub-
dirisione I lis

214 THE NERVOUS SYSTEM

chiefly white matter. It has, however, no convolutions, but is
subdivided by many parallel ridges, which, sending down gray
matter deeply into the white, central portion, give the latter
a somewhat branched appearance. This peculiar appearance
has been called the arbor vita', or the " tree of life," from the
fact that when a section of the organ is made, it bears some
resemblance to the trunk and branches of a tree (Fig. 56, F).
In size, this cerebellum, or "little brain," is less than one-
eighth of .the cerebrum.

11. From the under surface of the cerebrum, and from the
front margin of the cerebellum, fibres collect together to form
the medulla oblongata (Fig. 57, Ma), which, on issuing from
the skull, enters the spinal column, and then becomes known
as the spinal cord. From the base of the brain, and from the
sides of the medulla originate, also, the cranial nerves, of
which there are twelve pairs. These nerves are round cords
of glistening white appearance, and, like the arteries, generally
lie remote from the surface of the body, and are well protected
from injury.

V2. The Spinal Cord. — The spinal cord, or "marrow," is a
cylindrical mass of soft nervous tissue, which occupies a
chamber, or tunnel, fashioned for it in the spinal column
(Figs. 58 and 59). It is composed of the same substances
as the brain; but the arrangement is exactly reversed — the
white matter encompassing or surrounding the gray matter,
instead of being encompassed by it. The amount of the white
substance is also greatly in excess of the other material. A
vertical fissure partly separates the cord into two lateral halves,
and each half is composed of two separate bundles of fibres,
which are named the anterior and posterior columns.

13. These columns have entirely different uses, and each of
them unites with a different portion of the nerves which have
their origin in the spinal cord. The importance of this part
of the nervous system is apparent from the extreme care taken

11. Medulla oblongata ? Cranial nerves? Their shape and position ';

12. The spinal cord ? Of what composed ? How divided? Bach half?

13. Uses of these columns ? Importance of this part of the nervous system ? How
protected ?

THE XK R 1 'O I B 8 ) B TEM

215

to protect it from external injury. For, while a very slight
disturbance of its structure suffices to disarm it of its power,
yet so staunch is its bony enclos-
ure, that only by very severe inju-
ries is it put in peril. The three
membranes that cover the brain are
continued downward, so as to en-
velope and still further shield this
delicate organism.

14. The Spinal Nerves. — The
spinal nerves, thirty-one pairs in
number, spring from each side of
the cord by two roots, an anterior
and a posterior root, which have the
same functions as the columns bear-
ing similar names. The posterior
root is distinguished by possessing
a ganglion of gray matter, and by a
somewhat larger size. The succes-
sive points of departure, or the off-
shooting of these nerves, occur at
short and nearly regular intervals
along the course of the spinal cord.
Soon after leaving these points, the
anterior and posterior roots unite to
form the trunk of a nerve, which is
distributed, by means of branches,
to the various organs of that part
of the body which this nerve is
designed to serve. The spinal
nerves supply chiefly the muscles
of the trunk and limbs and the
external surface of the body.

15. The tissue composing the FlG> 58

,. , , ,, . ., \. < rr.Ki:r.iM. R. Cerebf.li.i~m,

nerves is entirely of the white Di d simn.w. c.kp

14. The spinal nerves f The posterior root ? The nerves, how arranged ! Their offlc

15. The nerve tissue ? Its character J Coarse of each mrve-iibre?

216

THE NERVOUS SYSTEM

variety, or, in other words, the nerve-fibres ; the same as we
have observed forming a part of the brain. Uut the nerves,
instead of being soft and pulpy, as in the ease of the brain,
are dense in structure, being hardened and strengthened by
means of a fibrous tissue which surrounds each of these deli-
cate fibres, and binds them together in glistening, silvery
bundles. Delicate and minutely fine as are these nerve-fibres,

Fig. 59. — Section of Spinal Cord, with Roots of Spinal Xi.p.yls. Fboni View

it is probable that each of them pursues an unbroken, isolated
course, from its origin, in the brain or elsewhere, to that par-
ticular point which it is intended to serve. For, although their
extremities are often only a hair's breadth distant from each
other, the impression which any one of them communicates is
perfectly distinct, and is referred to the exact point whence
it came.

16. This may be illustrated in a simple manner, thus : if two
fingers be pressed closely together, and the point of a pin be
carried lightly across from one to the other, the eyes may be
closed, and yet we can easily note the precise instant when
the pin passes from one finger to the other. If the nerve-
fibres were less independent, and if it were necessary that they
should blend with and support each other, all accuracy of
perception would be lost, and all information thus afforded
would be pointless and confused. These silvery threads must,
therefore be spun out with an infinite degree of nicety. Imag-
ine, for instance, the fibre which connects the brain with some

16. How may we illustrate the fact ?
foot?

The fibre connecting the brain with a [mint in the

THE NERVOUS SYSTEM 217

point on the foot — its length cannot be less than one hundred
thousand times greater than its diameter, and yet it performs
its work with as much precision as fibres that arc compara-
tively much stronger, and less exposed. (Bead Note •-'.)

17. The Sympathetic System. — The sympathetic system of
nerves remains to be described. It consists of a double chain
of ganglia, situated on each side of the spinal column, and
extending through the cavities of the trunk, and along the
neck into the head. These ganglia are made up for the most
part of small collections of gray nerve-cells, and are the nerve-
centres of this system. From these, numerous small nerves
are derived, which connect the ganglia together, send out
branches to the cranial and spinal nerves, and form networks
in the vicinity of the stomach and other large organs. A con-
siderable portion of them also follows the distribution of the
large and small blood-vessels, in which the muscular tunic
appears. Branches also ascend into the head, and supply the
muscles of the eye and ear, and other organs of sense.

2. How Bodily Sensations are Located. — "A nervous fibre which ends
in the skin forms, as far as its anion with the brain or curd is concerned,
one long, fine, unbroken thread. The fibres, thus ending in the skin,
very soon join to form small brandies, and finally in thick nerve trunks,
but in no case do two nerve fibres coalesce so as to lose their identity.
Every part of the skin has its own separate connections with the centre
of the nervous systems, which unite there just as telegraph wires unite
at a terminus. The brain is the terminus of these lines of nerves, and,
as it were, receives and explains the messages sent to it. It distinguishes
very clearly by what particular fibre such a message has come, and just
as the clerk in a telegraph office, where a great many wires meet from all
si<les. knows by experience from what direction each wire brings its
. bo the brain also knows by experience what part of the skin
is involved when a sensation reaches it along a certain nerve fibre. It is
probable that the brain, by its imaginative faculty, has formed a complete
picture of the surface of the body — a kind of chart slowly made, and
always being more highly perfected, by means of which, with each im-
pression from without, there arises in the brain a picture of the spot upon
the skin where the irritation has taken place. Now. if an irritation were
to pass from one nerve fibre to another, it is very plain, the brain could
not tell the place from which it came, and could not localize impressions
received from the world about us." — Bernstein's Five Senses of Man.

17. The sympathetic system ol nerves? of what does it consist ?

218 THE NERVOUS SYSTEM

18. In this manner the various regions of the body are
associated with each other by a nervous apparatus, which is
only indirectly connected with the brain and spinal cord, and
thus it is arranged that the most widely separated organs of
the body are brought into close and active sympathy with each
other, so that " if one member suffers, all the other members
suffer with it." From this fact, the name sympathetic system,
or the great sympathetic nerve, has been given to the compli-
cated apparatus we have briefly described. Blushing and
pallor are caused by mental emotions, as modesty and fear,
which produce opposite conditions of the capillaries of the
face by means of these sympathetic nerves. ( Read Note 3.)

19. The Properties of Nervous Tissue. — We have seen that
in all parts of this system there are only two forms of nervous
tissue, namely, the gray substance and the white substance, so
called from their difference of color as seen by the naked eye ;

3. The Wonderful Operations of the Sympathetic System. — Blush-
ing or " Shame-redness." — " A blow upon the head will knock a man
senseless, but he still lives and survives ; a blow of like violence upon
the pit of the stomach is followed by instant death, because the great
centre of the organic nerves lies there, and the vital actions are suspended
by the blow, so that the system never lives to recover, but abolition of
function and of life at once follows. Other actions also belong to this
organic nervous system. It controls the caliber of the blood-vessels, for
which end filaments run along each of them. The body temperature is
maintained by the production and dispersion of heat thus regulated, a
continuous oscillation going on betwixt the internal vessels and those of
the skin. It is connected with the emotions ; and so the heart beats per-
ceptibly with excitement, and the maiden's cheek blushes before words
that should never be spoken, or thoughts that should never arise. The
momentary dilatation of the vessels of the skin constitutes the blush (in
the German, ' shame-redness'), which is not confined to the face, though
of course it is only seen there — the body being hid by the clothes." —
Fothergill on the Maintenance of Health.

"There is an old tradition that when the executioner of Charlotte
Corday lifted her severed head high in air, and smote the face with his hand,
the cheeks were seen to resent the insult with a blush. This reddening is
not impossible, for a decapitated head certainly may exhibit, for a time,
certain reflex movements. But whether sensibility is retained cannot be
known."

18. Association of the various regions of the body ? If one member suffers ? Blushing?
in. Properties of nervous tissue ? Office of the gray substance ? Of the white ? The
nervous centres ? White tibres ?

THE NERVOUS SYSTEM 219

or the nerve-cell, and the nerve-fibre, so called from their
microscopic appearance. Now these two tissues are not com-
monly mingled together, but cither form separate organs or
distinct parts of the same organs. This leads us to the con-
clusion that their respective uses arc distinct. And this proves
to be the simple fact ; wherever Ave find the gray substance, we
must look upon it as performing an active part in the system
— that is, it originates nervous impulses; the white matter, on
the contrary, is a passive agent, and serves merely as a con-
ductor of nervous influences. Accordingly, the nervous centres
composed so largely of the gray cells, are the great centres of
power, and the white fibres are simply the instruments by
which the former communicate with the near and distant
regions of the body under their control.

20. We may compare the brain, then, to the capital, or seat
of government, while the various ganglia, including the gray
matter of the cord, like so many subordinate official posts, are
invested with authority over the outlying provinces ; and the
nerves, with the white matter of the cord, are the highways
over which messages go and return between these provinces
and the local or central governments. But both forms of ner-
vous tissue possess the same vital property called excitability,
by which term is meant that, when a nerve-cell or fibre is
stimulated by some external agent, it is capable of receiving
an impression, and of being by it excited into activity. A ray
of light, for example, falling upon one extremity of a fibre in
the eye, excites it throughout its whole length; and its other
extremity within the brain, communicating with a nerve-cell,
the latter in its turn is excited, and the sensation of sight is
produced. (Read Note 4.)

4. The Relations of the Brain and Sympathetic Nerve. — " Buried in
the hidden recesses of the body, between the spinal column and the great
organs of nutrition, there is a double row of small knots of nervous sub-
stance, bound together by a series of nerves running from one to another.
in succession, from the neck to the base of the column. The whole
appears like a long, line cord, with knots at various distances — a collec-

20. What comparison is made between the brain and the nation's capital? The vital
property, excitability f What example Is given t

220 THE NERVOUS SYSTEM

21. What sort of change takes place in the nervous tissue
when its excitability is aroused, is not known ; certainly none
is visible. On this account, it has been thought by some that
the nerve-fibre acts after the manner of a telegraph wire ; that
is, it transmits its messages without undergoing any material
change of form. But though the comparison is a convenient
one, it is far from being strictly applicable, and the notion
that nerve-force is identical with electricity has been fully
proved to be incorrect.

22. The Functions of the Nerves. — The nerves are the in-
struments of the two grand functions of the nervous system —
Sensation and Motion. They are not the true centres of either
function, but they are the conductors of influences which occa-
sion both. If the nerve in a limb of a living animal be laid
bare, and irritated by pinching, galvanizing, or the like, two
results follow, namely: the animal experiences a sensation,
that of pain, in the part in which the nerve is distributed, and
the limb is thrown into convulsive action. When a nerve in a
human body is cut by accident, or destroyed by disease, the
part in which it ramifies loses both sensation and power of
motion; or, in other words, it is paralyzed. We accordingly
say that the nerves have a two-fold use — a sensory and a
motor function.

tion of little brains, if I may use a rather crude expression. It is, as the
Swiss would say, the 'great council' of this federative republic, which
counterpoises that cerebral royalty within us. It has been well named
the great sympathetic nerve, and this it is which makes the laws by
which our interior life is governed. The nutritive apparatus of a country,
its commerce, its industry, the incessant labor of its citizens, by which
the public wealth is built up — and also let us add, the throbs of the
national heart — all this the sympathetic system full plainly shows us
should be left to itself. It would be a fine affair if the brain had to
watch over the service of the stomach, or if, at its convenience, it regu-
lated the movements of the master who disposes of its life. Besides,
what would become of the poor body if the least drowsiness attacked the
universal centre ? Happy it is for us — and let us not he slow to own it —
that nature has armed herself against these encroachments of power." —
Mace's The Little Kingdom.

21. Change in the nervous tissues ? Nerve force ami electricity 1

22. Functions of the nerves? In the case of the nerve of a living animal? Of
human body f

THE NERVOUS SYSTEM

221

ng TriE Functions of the

,i. Xi:i:vi>

Divided <i( it. — [rritated at 1 : pain,
muscular contraction

23. If a nerve that has been exposed be divided, and the
inner end. or that still in connection with the nerve-centres be
irritated, sensation is produced, but no movement takes place.
But if the outer end,
or that still connected
with the Limb, lie irri-
tated, then no pain is
felt, hut muscular con-
tractions are produced.
Thus we prove that
there are two distinct
sets of fibres in the
nerves — one of which,
the sensory fibres, conduct toward the brain, and another, the
motor fibres, conduct to the muscles (see Fig. 60). The
former may be said to begin in the skin and other organs
and end in the brain, while the latter begin in the nervous
centres and end in the muscles. They are like a double line
of telegraph wires, one for inquiries, the other for responses.

24. We have already spoken of the two roots of the spinal
nerves, called, from their points of origin in the spinal cord,
the anterior and posterior roots. These have been separately
cut and irritated in the living animal, and it has been found
that the posterior root contains only sensory fibres, and the
anterior root has only motor fibres. So that the nerves of a
limb may be injured in such a way that it will retain power of
motion and yet lose sensation; or the reverse condition, feeling
without motion, may exist. Between these two sorts of fibres
no difference of structure can be found; and where they have
joined to form a nerve, it is impossible to distinguish one sort
from the other.

25. Occasionally a nerve is so compressed as to be tempo
rarily unable to perform its functions: a transient paralysis

28, If an exposed nerve be divided ? What is proved? The coarse of the sensory set
of fibres? or tin- motor set ! To what are they likened I

24. The two roots of the Bpinal nerves ': What has been found? Difference of the two
sorts of tibrcs ? Result of their union ?

25. Transient paralysis? When .such is the case with the leg? What other fact is
observed !

222 THE NERVOUS SYSTEM

then takes place. This is the case when the leg or arm " gets
asleep," as it is expressed. When such is the condition with
the leg, and the person suddenly attempts to walk, he is liable
to fall, inasmuch as the motor fibres cannot convey orders to
thf muscles of the limb. Another fact is observed: there is
no sensation in this nerve at the point of its compression ; but
the whole limb is numb, and tingling sensations are felt in the
foot — the point from which the sensory fibres arise.

26. This illustrates the manner in which the brain inter-
prets all injuries of the trunk of a nerve. Sensation or pain
is not felt at the point of injury, but is referred to the outer
extremities of the nerve, where impressions are habitually
received. This is the reason why. after a limb has been
amputated by the surgeon, the patient appears to suffer pain
in the member that has been severed from the body ; while
some form of irritation at the end of the nerve in the wound,
or stump, is the real source of his distress. Again, when the
'■funny-bone" — that is, the ulnar nerve at the elbow — is
accidentally struck, the tingling sensations thus produced are
referred to the outer side of the hand and the little finger, the
parts to which that nerve is distributed.

27. All the spinal nerves, and two from the brain, are con-
cerned in both sensation and motion. Of the remainder of
the cranial nerves, some are exclusively motor, others exclu-
sively sensory; and still others convey, not ordinary sensa-
tions, but special impressions, such as sight, hearing, and
smell, which we have yet to consider. However much the
functions of the nerves seem to vary, there is but little dif-
ference discoverable in the nerves themselves, when examined
under the microscope. Whatever difference exists must be
aid muted for in consequence of the nerves communicating
with different portions of the gray matter of the brain. The
rate of motion of a message, to or from the brain along a

26. What does this illustrate? Sensation? The feeling after a limb has been ampu-
tated ? Striking of the " funny-bone » "

27. The spinal nerves, and two from the brain ? Of the remainder? Difference in the
nerves? How accounted for ? The rate of conduction along a nerve ? As compared with
electricity ?

THE NERV0V8 SYSTEM 223

nerve, has been measured by experiment upon the lower ani-
mals, and estimated in the case of man at about two hundred
feet per second. As compared with that of electricity, this is
a very slow rate, but, in respect to the size of the human
body, it is practically instantaneous. I Bead Note •".

28. The Functions of the Spinal Cord. — As the anterior and
posterior roots of the spinal nerves have separate functions, so
the anterior and posterior columns of the cord are distinct
in function. -The former are concerned in the production of
motion, the latter in sensation. If the cord lie divided, as
before in the case of the nerve, it is found that the parts
below the point of injury are deprived of sensation and of
the power of voluntary motion on both sides of the body — a
form of paralysis which is called paraplegia.

29. This form of disease — paraplegia — is sometimes seen
among men, generally as the result of a fall, or some other
severe accident, by which the bones of the spine are broken,
and the cord is crushed, or pierced by fragments of bone.
The parts which are supplied by nerves from the cord above
the point of injury are as sensitive and mobile as before. The
results are similar, whether the division happens at a higher
or lower portion of the spinal cord; but the danger to
life increases proportionately as the injury approaches the
brain. When it occurs in the neck, the muscles of inspira-

5. The Speed of Sensation and Thought. — "The rate of nervous
m<l mental action is n it the same in all individuals. In comparing the
records made by astronomers, it has been found that an appreciable dif-
ference exists in the rapidity with which the same occurrence may be
noted by different observers. This is known as the 'personal equation,1
and is allowed for with the greatest nicety in the making up of astro-
nomical reports. With very delicate apparatus for marking time, the
various nervous impulses have been observed; from forty to a hun-
dred feet in a second are the estimates of different experiments as to the
speed of sensation ; or, as it has been expressed, it would take a full-
grown whale a second to feel the stroke of a harpoon in his tail."

S8. Functions of the anterior and posterior columns of the cord? If the cord be
divided *

29. Paraplegia » Result and danger to life ? When the injury occurs in the neck !

224 THE NERVOUS SYSTEM

tion are paralyzed, since they are supplied by nerves issu-
ing from that region; and as a result of this paralysis,
the lungs are unable to act, and life is speedily brought to
a close.

30. When the spinal cord of an animal has been cut, in
experiment, it may be irritated in a manner similar to that
alluded to when considering the nerves. If, then, the upper cut
surface be excited, it is found that pain, referable to the parts
below the cut, is produced ; but when the lower cut surface is
irritated, no feeling is manifested. So we conclude that in
respect to sensation, the spinal cord is not its true centre, but
that it is merely a conductor, and is therefore the great sensory
nerve of the body. When the lower surface of the cut is irri-
tated, the muscles of the parts below the section are violently
contracted. Hence we conclude that, in respect to the move-
ments ordered by the will, the spinal cord is not their source,
but that it acts only as a conductor, and is, accordingly, the
great motor nerve of the body.

31. Direction of the Fibres of the Cord. — If one lateral half
of the spinal cord be cut, or injured, a very singular fact is
observed. All voluntary power over the muscles of the corre-
sponding half of the body is lost, but the sensibility of that
side remains undiminished. This result shows that the motor
fibres of the cord pursue a direct course, while its sensory
fibres are bent from their course. And this has been proved to
be the fact; for immediately after the posterior roots — the
conductors of sensory impressions — join the posterior columns,
they enter the gray matter of the cord, and passing over,
ascend to the brain on the opposite side. Accordingly, the
sensory fibres from the right and left sides interlace each other
in the' gray matter; this arrangement has been termed the
decussation, or crossing of these fibres. This condition serves
to explain how a disease or injury of the cord may cause a
paralysis of motion in one leg, and a loss of sensation in the
other.

8!>. Experiment of cutting the spinal cord of an animal ? What inference is drawn ?
81 . W hat singular fact i- noticed ? What does the result show ?

THE XX R VOL'S SYSTEM 225

32. The direction of the anterior, or motor columns of the
ciud. is downward from the brain. In the cord itself, the
course of the motor fibres is for the most part a direct one ;
but in the medulla oblongata, or upper extremity of the cord,
and therefore early in their career, these fibres cross from side
to side in a mass, and not separately, as in the case of the
posterior fibres just mentioned. This arrangement is termed
the decussation of the anterior columns of the medulla.

33. From this double interlacing of fibres results a cross
action between the original and terminal extremity of all
nerve-fibres which pass through the medulla — namely, those
of all the spinal nerves. Consequently, if the right hand be
hurt, the left side of the brain feels the pain ; and if the left
foot move, it is the right hemisphere which dictates its move-
ment. For the same reason, when a loss of sensation and
power of motion affecting the right side of the body alone is
observed, the physiologist understands that the brain has been
invaded by disease upon its left side. This affection is termed
hemiplegia, or the "half-stroke." The full-stroke, which often
follows the rupture of a blood-vessel in the brain, is commonly
called paralysis.

34. The Reflex Action of the Cord. — We have already con-
sidered the cord as the great motor and sensory nerve of the
body, but it has another and extremely important use. By
virtue of the gray matter, which occupies its central portion, it
plays the part of an independent nerve centre. The spinal
cord not only conducts some impressions to the brain, but it
also arrests others; and, as it is expressed, "reflects** them
into movements by its own power. This mode of nervous
activity is denominated the reflex action of the cord.

35. A familiar example of this power of the cord is found in
the violent movements which agitate a fowl after its head has

82. Direction of the anterior <>r motor columns? In the cord itself? In the medulla
oblongata J The decussation J

:;::. Basalt of the doable interlacing of fibres? Where is the seat of pain when the right
land is hurt ■'. The moving of the foot ( Lose of sensation in one aide of the body?

34. What other Important use has the cord i What is the activity denominated ?

35. Example of the fowl ? Centipede ? Frog ? What do they prove ?

226 THE NERVOUS SYSTEM

been cut off. The cold-blooded animals also exhibit reflex
movements in an astonishing degree. A decapitated centipede
will run rapidly forward, and will seemingly strive to over-
turn, or else climb over obstacles placed in its way. A frog
similarly mutilated will sustain its headless body upon its feet,
in the standing posture, just as it might do if it were still
alive. If pushed over, it will regain its feet ; and if the feet
are irritated, it will jump forward. There can be no doubt
that, in the lower animals, movements may take place which
are completely divorced from the will, sensation and conscious-
ness ; for in those animals, as well as in man, these faculties
have their principal seat within the brain.

36. An irritation is necessary, in most instances, to awaken
reflex movements. In the case of the decapitated fowl, its
muscles are excited to convulsive action by reason of its being
thrown upon the hard ground and roughly handled. Let it be
treated differently, and the convulsions will not take place :
let it be laid gently upon soft cotton, and the body will remain
comparatively quiet. It may comfort some people to know
that the convulsions which follow decapitation are not attended
with pain, nor are they a necessary part of the " act of death,"
as some suppose.

37. In the human body, likewise, actions are excited that
are entirely distinct from the ordinary voluntary efforts. It is
not permissible, desirable, nor even necessary to decapitate a
man that the body may be disconnected from his brain, in
order to test the effect of irritation upon the spinal cord —
although the bodies of beheaded criminals have been experi-
mented upon, and caused to move by powerful galvanic bat-
teries. Such experiments are rendered unnecessary by the
occurrence of certain deplorable cases of disease and injury,
which effectually sever all communication between the brain
and a large part of the body.

38. Thus, the cord by an accident may be so far injured as

36. What is necessary in most cases to awaken reflex movements ? In the case of the

fowl ? Convulsions which follow decapitation ?

87. Actions in the human body distinct from Toluntary efforts ?

83. Reflex action after injury of the cord ? Why not due to the muscles ?

THE NERVOUS SYSTEM 227

to terminate all sensation and voluntary motion in the lower
half of the body, the patient seeming lifeless and powerless fr< >m
the waist downward. And yet, by tickling or pinching either
foot, the leg of the same side may be made to jerk, or even
to kick with considerable force; but, unless the patient is ob-
serving his limbs, he is wholly unconscious of these movements,
which are, therefore, performed independently of the brain.
And they are in nowise due to the muscles of the limb ; for,
if the cord itself become diseased below the point of injury,
the muscles cease to contract.

39. For the production of this form of nervous action, three
things are requisite — (1) a nerve to conduct messages from
the surface of the body, one of that variety formerly described
as sensory, but which are now known to be incapable of awaken-
ing sensation ; (2) a portion of uninjured spinal cord, which
shall reflect or convert impressions into impulses ; and (3) a
motor nerve to conduct impulses outward to the muscles. The
power of the cord to enforce reflex acts resides in the gray
matter, into which the reflex nerves enter and from which
they depart, by means of their posterior and anterior roots
respectively.

40. The Uses of the Reflex Action. — The reflex activity of
the cord is exhibited in the healthy body in many ways, but
since it is never accompanied with sensation, we do not readily
recognize it in our own bodies. Reflex movements are best
studied in the cases of other persons, when the conditions en-
able us to distinguish between acts that are consciously, and
those that are unconsciously performed. For example, if the
foot of a person soundly asleep be tickled or pinched, it will
be quickly withdrawn from the irritation.

41. Similar movements may be observed in cases where the
consciousness and sensation are temporarily obliterated by
disease, or by means of narcotic poisons. If the arm of a per-
son who has been rendered insensible by chloroform be raised,

89. What are the requisites for ttie production of this form of nervous action ?

40. Why do we not readily recognize the reflex activity of the cord in our own bodies ?
How best studied in others ? Example ?

41. Similar movements ? Arm of a person ? Melted wax or heated coin on the hand f

228 THE NERVOUS SYSTEM

and then allowed to fall, it will be noticed that the limb does
not drop instantly, like a lifeless member, but a certain amount
of rigidity remains in its muscles, which resists or breaks the
force of its descent. Again, when a substance like melted
sealing-wax, or a heated coin, falls upon the hand, the limb is
snatched away at once, even before the feeling of pain has
been recognized by the brain. When jolted in a rapidly mov-
ing car, we involuntarily step forward or backward, so as to
preserve the centre of gravity of the body.

42. These and similar acts are executed by the same mechan-
ism as that previously described in the case of paralysis from
an injury of the spinal cord. The muscles thus called into
play are those which are ordinarily under the SAvay of the will,
but which in these cases act through this reflex action of the
cord, altogether independently of the will. A healthful reflex
activity produces an elasticity, or " tone," in the voluntary mus-
cular system, which in a great measure explains the existence
in the young and vigorous of a feeling of buoyancy and reserve
power. Its possessor is restlessly active, and it may appropri-
ately be said of him, "he rejoiceth as a strong man to run a
race." But this reflex energy may be deficient. This is true
when the blood is poor and wanting in its solid ingredients, or
the circulation is feeble; the muscles, then, are flabby and
weak, and the person himself is said to be " nerveless," or in-
disposed to exertion. Shivering from cold and trembling from
fear may, in part, be referred to a temporary loss of tone,
resulting from a powerful impression upon the brain. (Bead
Note 6.)

6. On Nervous Health, or Tone. — " That state of general vigor, which
we call 'tone,' depends upon the healthy action of the nervous centres.
It consists in the habitual moderate contraction of the muscles, due to a
constant stimulus exerted on them by the cord, and is valuable less for
itself than as a sign of a sound nervous balance. Tone is maintained
partly by healthful impressions radiated upon the spinal cord through the
nerves from all parts of the body, and partly by the stimulus poured
down upon it from the brain. So it is disturbed by whatever conveys
irritating or depressing influences in either direction. A single injudi-

42. Result of healthful reflex activity ? When may the reflex energy he deficient*

THE NERVOUS SYSTEM 229

43. An excess of this activity may also be observed in
disease. In this condition, the excitability of the cord is
unnaturally aroused, and frequent and violent movements of
the limbs and body, called convulsions, are the result. The
convulsions of young children, and the nervous agitation of
chorea, or St. Vitus's dance, are reflex in character, as are also
the symptoms attending poisoning by strychnine, and those
terrible diseases, tetanus, or "locked jaw," and hydrophobia.
The severity of the convulsions is not the same in all cases of
these disorders ; but, in those last mentioned, the most violent
spasmodic movements are provoked by the slightest form of
irritation — such as the sound of pouring water, the sight of
any glittering object, the glancing of a mirror, the contact
of cool air, or even the touch of the bed-clothes.

44. Another variety of reflex motions takes place in certain
involuntary muscles, and over these the cord exercises supreme
control. They are principally those movements which aid the
performance of digestion and nutrition, the valve-action of the
pylorus, and other movements of the stomach and intestines.

cious meal, a single sleepless night, a single passion or piece of bad news,
will destroy it. On the other hand, a vivid hope, a cheerful resolve, an
absorbing interest will restore it as if by magic. Fur in man. these lower
officers in the nervous hierarchy draw their very breath according to the
bidding of the higher powers. But the dependence of the higher on the
lower is no less direct. The mutual action takes place in each line. A
chief condition of keeping the brain healthy is to keep these unconscious
nervous functions in full vigor, and in natural alterations of activity and
repose. We see evidence of this law in the delightful effect of a cheerful
walk after a depressed or irritated state of mind. Every part of the ner-
vous system makes its influence felt by all the rest. A sort of constitu-
tional monarchy exists within us ; no power in this small state is absolute
or can escape the checks and limitations which the other powers impose.
Doubtless the Brain is King, but Lords and Commons have their seats
below and guard their privilege with jealous zeal. If the 'constitution'
of your personal realm is to be preserved intact, it must be by the efforts
of each part, lawfully directed to a common end.*' — Hinton on Health
and its Condition.

43. Excess of this activity in disease t Hydrophobia, etc. ? The difference in severity
of the convulsion*?

44. Another variety of reflex motions J What are they} What is stated of the mind
in connection with these movements J

230 THE NERVOUS SYSTEM

In these movements the mind shares no part. And it is well
that this is so ; for, since the mind is largely occupied with
affairs external to the body, it acts irregularly, becomes
fatigued, and needs frequent rest. The spinal cord, on the
contrary, is well fitted for the form of work on which depends
the growth and support of the body, as it acts uniformly, and
with a machine-like regularity.

45. These operations are not accompanied by consciousness ;
for, as a general rule, the attention is only called to them when
they become disordered. Many a person does not know where
his stomach is situated until he discovers its position by reason
of a feeling of distress within it, produced by giving that
organ improper work to perform. In this manner the higher
and nobler faculties of the mind are liberated from the simple
routine duties of the body, and we are thus left to direct the
attention, the reason, and the will to the accomplishment of
the great ends of our existence. If it were otherwise, we
could only find time to attend to our ordinary physical wants.

46. The objects of the reflex activity of the cord are three-
fold. In the first place, it acts as the protector of man in his
unconscious moments. It is his unseen guardian, always ready
to act, never growing weary, and never requiring sleep. Nor
does its faithful action wholly cease with the cessation of life
in other parts. In the second place, it is the regulator of
numerous involuntary motions that are necessary to the nutri-
tion of the body. Here its actions are entirely independent
of the brain, and are performed in a secret and automatic
manner. And, thirdly, it acts as a substitute, and regulates
involuntary movements in the muscles usually under the influ-
ence of the will. It thus takes the place of the higher facul-
ties in performing habitual acts, and permits them to extend
their operations more and more beyond the body and its
material wants.

47. The Functions of the Medulla Oblongata. — The prolonga-

45. Consciousness in these operations f Physical wants?

46. How many objects may the reflex activity be said to have? State the first. The
second. The third.

47. IIow does the medulla oblongata resemble the cord ?

THE NERVOUS SYSTEM 231

tion of the spinal cord within the skull has been previously
spoken of as the medulla oblongata. It resembles the cord, in
being composed of both white and gray matter, and in con-
ducting sensory and motor influences. It likewise gives rise
to certain nerves, Avhich are here called cranial nerves (from
cranium, the skull). All except two of these important nerves
spring from the medulla, or the parts immediately adjoining
it ; the exceptions are the two nerves taking part in the special
senses of sight and smell, which nerves have their origin at
the base of the cerebrum.

48. The decussation, or crossing of the motor columns, has
been previously described, when treating of the direction of
the nerve-fibres of the cord; and the singular fact has been
alluded to, that when one side of the brain is injured, its
effects are limited to the opposite side of the body. One more
fact remains to be observed in this connection) namely, this
cross action does not usually take place in the cranial nerves.
Accordingly, when apoplexy, or the rupture of a blood-vessel,
occurs in the right hemisphere of the cerebrum, the left side
of the body is paralyzed, but the right side of the face is
affected ; this is because that part of the body is supplied by
the cranial nerves.

49. A portion of the medulla presides over the important
function of respiration, and from it arises the pneumogastric
nerve, so called because its branches serve both the lungs and
stomach. The feelings of hunger, thirst, and the desire for
air are aroused by means of this nerve. The wounding of the
gray matter of the medulla, even of a small portion of it,
near the origin of the pneumogastric nerve, at once stops the
action of the lungs and causes death. In consequence of the
importance of this part, it has been termed the "vital knot."
We find, also, that its location within the skull is exceedingly
well protected, it being quite beyond the reach of any ordinary
form of harm from without.

4?. What final fact is observed in the crossing of the motor columns ?

49. The pneumogastric nerve ? The feelings aroused by it f The " vital knot ? '

232 THE XERYOUS SYSTEM

50. The Functions of the Cranial Ganglia. — The uses of the
smaller gray masses lying at the base of the brain are not
well ascertained ; and, on account of their position, so remote
from the surface, it would at first seem well-nigh impossible
to study them. But, from the results following diseases in
these parts, and from experiments upon inferior animals, they
are becoming gradually better understood ; and there is reason
to believe that eventually the physiological office of each part
will be clearly ascertained and defined. It is believed, how-
ever, but not absolutely proved, that the anterior masses, like
the anterior roots of the spinal nerves and the anterior col-
umns of the cord, are concerned in the production of motion ;
in fact, that they are the central organs of that function. The
posterior gray masses are, on the contrary, supposed to be the
seat of sensation.

51. The Function of the Cerebellum. — The function of the
cerebellum, or " little brain," is the direction of the movements
of the voluntary muscles. When this organ is the seat of
disease or injury, it is usually observed that the person is
unable to execute orderly and regular acts, but moves in a
confused manner as if in a state of intoxication. Like the
larger brain, or cerebrum, it appears to be devoid of feeling ;
but it takes no part in the operations of the mind.

52. The Function of the Cerebrum. — The cerebrum, or brain
proper, is the seat of the mind ; or, speaking more exactly, it
is the material instrument by which the mind acts ; and, as it
occupies the highest position in the body, so it fulfils the lofti-
est uses. All the other organs are subordinate to it : the
senses are its messengers, which bring it information from the
outer world, and the organs of motion are its servants, which
execute its commands. Here, as in the nervous apparatus of
lower grade already considered, the gray matter is the element
of power; and in proportion as this substance increases in
extent, and in proportion to the number of convolutions in
the hemispheres, do the mental faculties expand.

50. The uses of the smaller gray masses at the base of tin- brain ?

51. Function of the cerebellum ? Whim it is diseased '!

52. Where is the seat of the mind ! The subordination of the other organs ? The gray
matter ?

THE NERVOUS SYSTEM 233

53. There have been a few, but only a few, men of distin-
guished ability whose brains have been comparatively small in
size — the rule being that great men possess large brains. The
relative weight of the brain of man, as compared with the
weight of the body, dues not, in all instances, exceed that of
the inferior animals; the canary and other singing-birds have
a greater relative amount of nervous matter than man ; but
man surpasses all other creatures in the size of the hemi-
spheres of the cerebrum, and in the amount of gray substance
which they contain. {Bead Notes 7 and 8.)

54. It is a singular fact that this cerebral substance is insen-
sitive, and may be cut without causing pain. The removal of

7. The Alliance of Mind and Body. — '-The regular routine of our
daily life is the counterpart of the mental routine. A healthy man wakens
in the morning with a flush of spirits and energy ; his first meal confirms
and reinforces the state. The mental powers and susceptibilities are
then at a maximum; as the nutrition is used up in the system they
gradually fade, but may be renewed once and again by refreshment and
brief remission of toil. Towards the end of the day lassitude sets in, and
fades into the deep unconsciousness of healthy sleep. . . . The influ-
ence- that affect the body extend not only to the grosser modes of feel-
in-, and to such familiar exhibitions as after-dinner oratory, but also to
the highest emotions — love, anger, aesthetic feeling, and moral sensibility.
Health keeps an Atheist in the dark. Bodily affliction is often the cause
of a total (mange in the moral nature." — Bain's Mind and Body.

8. Large Brains. — •• As a rule the size of the brain is proportional to
the mental development in human beings. The rule is not strictly main-
tained in eveiy instance ; occasionally a stupid man has a larger brain
than a clever man. But these are only individual exceptions to a prevail-
ing arrangement. The following are the brain weights of several distin-
guished men:

Cuvier 64.5 oz.

Abercrombie 03. "

Daniel Webster. . . . 53.5 "

Lord Campbell 53.5 oz.

Agassiz 53.4 "

De Morgan 52.7 ••

"The average male brain in Europeans is 4'.»."> oz. ; the female, 44 oz.
Among idiots the weights have run from 27 to 8.5 oz. The brains of the
insane are below the average of the sane. Tall men. as a rule, have
larger brains than small men.'" — Bain's Mind, and r»»bj.

58. What is stated of men in connection with the Bize of their brain ? With the brains
of other animals !

54. Sensitiveness of the brain substance? The removal of a portion of the brain}
State the remarkable ease mentic

234 THE NERVOUS SYSTEM

a considerable quantity of the brain has taken place, as the
result of accident, without causing death, and without even
affecting seriously the intellect. A remarkable case of injury
of the brain is recorded, in which, from the accidental explo-
sion of gunpowder used in blasting a rock, the " tamping-iron "
was driven directly through the skull of a man. This iron
rod, three feet and seven inches long, an inch and a quarter
In diameter, and weighing more than thirteen pounds, entered
the head below the ear and passed out at the top of the skull,
carrying with it portions of the brain and fragments of bone.
The man sustained the loss of sight on one side, but otherwise
recovered his health and the use of his faculties. Moreover,
disease has occurred, compromising a large portion of the
brain, without impairing the faculties of the mind, when the
disease was limited to one side only. (Bead Note 9.)

9. The Emotions Influence the Bodily Health. — "The exciting emo-
tions which are pleasurable, such as joy and hope, are of a kind that
seldom tend to a dangerous excess, and may be regarded as exercising
generally an eminently healthful influence upon the body. Hilarity is a
great refresher and strengthener of life. Laughter is a wholesome exer-
cise, which, beginning at the lungs, diaphragm, and connected muscles, is
continued to the whole body, 'shaking the sides,' and causing that jelly-
like vibration of the frame of which we are so agreeably conscious when
under its influence. The heart beats more briskly, but with a safe regu-
larity of action, and sends the blood to the smallest and most distant
vessel. The face glows with warmth and color, the eye brightens, and
the temperature of the whole body is moderately raised. With the uni-
versal pleasurable sensation there comes a disposition of every organ to
healthy action. When hilarity and its ordinary expression of laughter
become habitual, the insensible perspiration of the skin is increased, the
breathing quickened, the lungs and chest expanded, the appetite and
digestion strengthened, and nutrition consequently increased. The old
proverb, 'Laugh and grow fat,' states a scientific truth. The influence
of laughter upon the body is recognized by Shakespeare, in his descrip-
tion of the 'spare Cassius' — 'Seldom he smiles.' 'To be free-minded
and cheerfully disposed at hours of meat, and sleep, and exercise, is one
of the best precepts of long-lasting.' Such is the testimony of Lord Bacon
to the favorable influence of the pleasurable emotions upon the body.
The depressing emotions, such as fear, anxiety, and grief, are always
fatal to health, and frequent causes of death. There is an Eastern
apologue which describes a stranger on the road meeting the Plague
coming out of Bagdad. ' You have been committing great havoc there,'
said the traveler, pointing to the city. ' Not so great,' replied the Plague.

THE NERVOUS SYSTEM 235

55. Impressions conveyed to the hemispheres from the
external world arouse the mental operations called thought,
emotion, and the will. These are the godlike attributes which
enable man to subjugate a world, and afterwards cause him
to "sigh for other worlds to conquer;" which enable him
to acquaint himself with the properties of planets millions
of miles distant from him, and which give him that creative
power by which he builds and peoples the new worlds of
poetry and art.

56. All these mental acts, and many others, are developed
through the action of the brain ; not that the brain and the
mind are the same, or that the brain secretes memory, imagi-
nation, or the ideas of truth and justice, as the stomach
secretes gastric juice. But rather, as the nerve of the eye,
stimulated by the subtile waves of light, occasions the notion
of color, so the brain, called into action by the mysterious
influences of the immaterial soul, gives rise to all intellectual,
emotional, and voluntary activities.

57. The cerebrum, according to our present knowledge of
it, must be regarded as a single organ, which produces different
results, according as it is acted upon by the immaterial mind
in different ways. Eecent investigations, however, seem to
prove that the faculty of language is dependent upon a small
part of the left hemisphere of the cerebrum near the temple.
At least, in almost every instance where this part is diseased,
the patient can no longer express himself in speech and writing.
(Bend Note 10.)

'I only killed one-third of those who died; the other two-thirds killed
themselves with fright.' " — The Book of Health.

10. Mental Exercise Necessary to Perfect Health. — "The improve-
ment of the memory is a familiar instance of an increase of mental power
produced by exercise ; and the beating sense of fulness and quickened
circulation in the head induced by intense study or thought shows that
an organic process goes on when the brain is in activity, similar to that
which takes place in the muscular system under exercise. On the con-
trary, when the organ is little used, little expenditure of its power and

55. Thought, emotion, and will ? What power do they give us?

56. Are the brain and the mind identical ?

57. What do we know of the cerebrum and its powers ?

236 THE NERVOUS SYSTEM

58. The Reflex Action of the Brain. — The reflex function of
the organs within the skull is very active and important. Like
that of the cord, it protects the body by involuntary move-
ments, it regulates the so-called vegetative acts, and it takes
the place of the vail in controlling the voluntary muscles,
when the attention is turned in other directions. The reflex
power of the medulla governs the acts of respiration, which
are absolutely and continuously essential to life. Respiration
is, as we have seen, partly under the influence of the will ; but
this is due in part to the fact that respiration is indirectly con-
cerned in one of the animal functions — that of speech.

59. Reflex action also occasions coughing and sneezing,
whenever improper substances enter the air-passages. Wink-
ing is an act of the same sort, and serves both to shield the
eyes from too great glare of light, and to preserve them by
keeping the cornea moist. Looking at the sun or other strong
light, causes sneezing by reflex action. Laughing, whether
caused by tickling the feet or by some happy thought, and
also sobbing, are reflex acts, taking place by means of the
respiratory muscles.

60. Certain of the protective reflex movements call into
play a large number of muscles, as in the balancing of the
body when walking along a narrow ledge, or on a slippery
pavement. The dodging motion of the recruit, when the first
cannon ball passes over his head, is reflex and involuntary.

substance takes place, little blood and little nervous energy are required
for its support, and, therefore, little is sent ; nutrition in consequence
soon becomes languid, and strength impaired. To all these laws the
brain is subject equally as the rest of the body. Frequent and regular
exercise gives it increased susceptibility of action, with power to sustain
it, the nervous energy acquiring strength as well as the vascular. Dis-
use of its functions, or, in other words, inactivity of intellect and of feel-
ing, impairs its structure and weakens the several powers which it serves
to manifest. The brain, therefore, in order to maintain its healthy state,
requires to be duly exercised." — Barlow on Physical Education.

58. The reflex function of the organs within the skull? The reflex power of the
medulla ? Respiration ?

59. What else does reflex action occasion ? Winking? Other examples ?

60. Muscles called into play by certain reflex movements ? The somnambulist?

THE NERVOUS SYSTEM 237

The fact that these involuntary reflex acts are performed with
great precision, will explain why it is that accidents seldom
befall the somnambulist, or sleep-walker, although he often
ventures in the most perilous places.

61. Walking, sitting, and other acts of daily life, become
automatic, or reflex, from habit; the mind is seldom directed
to them, but delegates their control to the medulla and spinal
cord. Thus a person in walking may traverse several miles
while absorbed in thought, or in argument with a companion,
and yet be conscious of scarcely one in a thousand of the acts
that have been necessary to carry his body from one point to
another. By this admirable and beautiful provision the mind
is released from the charge of the ordinary mechanical acts of
life, and may devote itself to the exercise of its nobler facul-
ties. And it is worthy of notice, that the more these faculties
are used, the more work does the reflex function assume and
perform; and thus the employment of the one insures the
improvement of the other. {Bead Notes 11 and 12.)

11. Automatic Action of the Brain. — "A large part of our mental
activity consists of this unconscious work of the brain. There are many
cases in which the mind has obviously worked more clearly and more
successfully in this automatic condition, when left entirely to itself, than
when we have been cudgeling our brains, so to speak, to get the solution.
An instance, well authenticated, is related of a college student ; he had
been attending a class in mathematics, and the professor said to his
students one day : ' A question of great difficulty has been referred to me
by a banker — a very complicated question of accounts, which they have
not themselves been able to bring to a satisfactory issue, and they have
asked my assistance. I have been trying, and I cannot resolve it. I
have covered whole sheets of paper with calculations, and have not been
able to make it out. Will you try?' He pave it to them as a sort of
problem, and said he would be extremely obliged to any one who would
bring him the solution by a certain day. This gentleman tried it over and
:> d many slates with figures, but did not succeed.
He was • (nit on his mettle,1 and determined to achieve the result. But
he went to bed on the uighl before the solution was to lie given in with-
out having succeeded. In the morning, when he went to his desk, he
found the whole problem worked out and in his own hand. He had
risen in the night and unconsciously worked it out correctly, as the

fil. What is said of walking ami other acts in connection with the office performed
the medulla and spinal cord 1

238 THE NERVOUS SYSTEM

62. Effects of Alcohol upon the Brain. — The brain under the
influence of small and occasional doses of alcohol shows no
serious changes other than an increased supply of blood to the
head. Very serious changes, however, result from the habitual
use of alcohol ; the brain becomes harder and tougher than is
natural, and its cell elements show a wasting away, its sub-
stance appears shrunken, and an undue amount of watery fluid
fills the cavities in the brain, in order to make up the dimin-
ished bulk. The blood-vessels of the brain are sometimes
found to be in a weakened condition, and from this various
diseased conditions may follow. (Bead Note 13.)

result proved ; and what is more curious still, the process was very
much shorter than any of his previous trials." — W. B. Carpenter on
Unconscious Action.

12. The Mind should be Intelligently Cultivated. — " The cultivation
of the mind should be carried on with judgment, and in due submission
to the requirements of the body. If study be the duty of the youth, let
him pursue it diligently, but with such intervals of rest and bodily exer-
tion as may maintain good appetite and health.

" The proportion of hours of study and bodily exercise may vary with
the degree of mental work, the healthfulness of the room and surround-
ing air, the natural strength of the body, and the degree of health ; but
as a general rule it may be doubted whether any young person can sit at
close study for more than two hours at a time without requiring bodily
exertion to sustain vital action, and rest to recruit the mind. Two hours'
mental work, and a quarter to half an hour's bodily exercise, will be
quite compatible with the greatest progress in study.

" Moreover, it may be doubted whether such a student can work with
advantage for more than eight hours a day, in addition to the intervals of
rest, for the issue will not turn on the number of hours devoted to work,
but the intensity of the attention given." — Edward Smith on Health.

13. Trembling due to Alcohol. — " Another condition is trembling due
to alcohol. The hands are shaky, or unsteady, even when at rest, or if
the hand is held out it is seen to vibrate slightly, or in more advanced
condition, ' shakes like an aspen leaf.' I have seen this in a spirit-drinker,
a barber, as almost the only symptom : he worked night and day, in shav-
ing, and to 'steady his hand,' partook repeatedly of spirits — at first to
relieve fatigue and then, because he saw that if he discontinued, his hand
was too shaky to use the razor. Complete abstinence from alcohol and
strong coffee quite removed his tremblings and his desire for spirits." —
Dr. W. S. GreenfieM.

62. How is the brain changed by alcohol?

THE NERVOUS SYSTEM 239

63. Effects of Alcohol on the Mind. — Alcohol produces an
artificial insanity, in which, according to the quantity taken,
the various types of mental diseases are distinctly manifest.
The perceptions are bewildered, there is sleeplessness, loss of
memory, delusion, clouded reasoning power, and benumbed
moral sense following in the train of alcohol drinking. There
is also a monomania caused by the prolonged use of alcohol —
a craving for drink that knows no bounds, and but rarely a
cure ; this is dipsomania, or thirst-madness. {Read Note 14.)

64. The Impairment of the Will. — The direct result of the
taking of alcohol is seen in the loss of self-control. " The worst
estate of man is that wherein he loses the knowledge and gov-
ernment of himself." It is in the formation of the drinking
habit that alcohol too often works the absolute ruin of its devo-
tee, in both body and mind. It is apt to be a continuous habit,
having for its sequel the dethronement of the will. It may be
stated, as the rule, that after forty years of age, a man who
has formed this habit is unequal by his own strength of will to
abandon it. Man}' men of fine intellectual capacity and amia-
ble qualities have become intemperate, and have so continued,
as long as their efforts to get free again have not been supple-
mented by outside and enforced restraint.* It is for such as
these that inebriate asylums have been built. Other hard
drinkers drift into violence and crime, and finally find a cura-

14. Alcohol a Poison of the Intellect. — "In the normal state of a
man's mind, all the faculties, the imagination, the judgment, the memory,
the association of ideas, are regulated by another superior faculty, viz..
the attention. The attention of the will is the man himself ; it is the ego
which, being in the full possession of the resources of which it disposes,
takes them where it will, when it will, to do whatever it pleases. Now in
drunkenness, even at the very beginning, the will and the attention have
disappeared. Nothing is left but the imagination and the memory, which,
left to themselves, without regulation and without guides, produce the
most irrational results. "— Charles Bichet.

* " Alcohol in small doses super-excites certain intellectual faculties —
the imagination, the memory, and the association of ideas; but it para-
lyzes others, especially the will, the reflection, and judgment. Yet, with

fi3. What changes are noticed in the mind?
64. <ii\r effect of alcohol upon the will.

240 THE NERVOUS SYSTEM

tive restraint within prison walls. The benumbing effects of
drinking habits upon the moral being of man is universally
known. " All delicacy, courtesy, and self-respect are gone ; the
sense of justice and of right is faint or quite extinct ; there
is no vice into which the victim of drunkenness does not easily
slide, and no clime from which he can be expected to refrain.
Between this condition and insanity there is but a single step,"
and death, in a worldly sense a deliverance, in spite of many
an effort to rally, " terminates the miserable scene ; one by one
lights have been removed from the banquet of folly, and the
last is now extinguished." {Head Notes 15 and 16.)

65. An illustration of the disadvantage of drunkenness to
the moral tone of a community may be drawn from the results
of the labors of Father Mathew, about forty years ago, as a

a stronger dose all trace of intelligence disappears. When old Sly is
stretched on the ground insensible from drink and snoring in the mud,
he excites compassion and disgust :

O monstrous beast ! how like a swine he lies !

Grim death, how foul and loathsome is thine image ! "

Charles Richet, in Revue des Deux Mondes.

15. Drunkenness and Insanity. — "The connection between drunken-
ness and crime and drunkenness and poverty, is close and unvarying in
its effect upon society. The remarkable increase of insanity in recent
years may in part be traced to the use of intoxicating beverages. It has
been asserted that at least seven-tenths of all the crime and poverty and
calamity to the people of the United States spring from the abuse of
liquors." — Dr. J. E. Reeves.

16. The Effects of Mild Stimulation. — " Words of caution to young
men concerning the injurious effects of tobacco, as well as indulgence in
wine or the pleasures of the table, elicit, in ninety-nine out of one hun-
dred cases, the reply, ' It does not hurt me.' Does not hurt you ! Wait
and see. In years to come, when you ought to be in your prime, you
will be a poor, nervous, irritable, nerve-dried creature. Your hands will
tremble, your head will ache, your sleep be fitful and disturbed, your
digestion impaired — in short, the unnatural and transient pleasure at
one end of your life will be more than counterbalanced by the discomfort
and misery at the other. It is a truth of the greatest moment, which
ought to be so impressed upon the mind as to be always rising up within
it, that transgressions of the laws of health, not punished at one end of
life, an' sure to be at the other." —J. R. Black on the Ten Laid o)
Health.

65. Give results of Father Mathew' s work.

THE NERVOUS SYSTEM 241

temperance reformer. In the five years — 1838-1842 — the
consumption of whiskey in Ireland fell 50 per cent. ; the crimes
of violence falling from 64,520 to 47,027, and executions from
59 in the first year to 1 in the last year. (Read Note 17.)

66. The Poisonous Effects of Alcohol. — Alcohol is, in the
main, a narcotic poison in its effect upon human beings,
although the visible results vary immensely according to the
quantity taken. If a sufficient quantity is taken to cause any
visible result, a condition known as stimulation is observed.*
If an extremely large dose is taken, a state of stupor follows,
and death has been known to result in some cases. Between
these two extremes there may be a variety of manifestations.
As a stimulant, it appears to many to have a kindly action, to
cause a glow and sense of warmth, to increase muscular activity,
and to make the mind and organs of speech more nimble. Alco-

17. Alcohol and Crime. — "Thirty years of judicial experience have
taught me that of the crimes which judges are called upon to try, and
upon which sentences of the law are pronounced, more than eight-tenths
of them involving any degree of violence in their character are directly
traceable to the liquor shops. How often have I had young men look up
at me when I asked them what they had to say why the sentence of the
law should not be pronounced, and declare, 'I should never have done this
crime if it were not for drink. Hum was my ruin ; rum struck the blow,
and not my hand, that killed the man for whose death I am tried ; rum
has caused me to beat my wife, and injure my helpless child, and to do
the act which now confines me to a prison." — Tudge Noah Davis.

* ■' Suppose, for instance, you measure your muscular strength with a
'health lift' or dynamometer (by which muscular exertion can be accu-
rately measured), and then take some of the drink in the strength-
inspiring power of which you have most confidence, and when you are
most exhilarated by it, and feel as if you could shoulder a large fragment
of Mount Olympus, measure your strength again. The drink has fooled
you, that is all. You felt that you were stronger than natural; you find
that the narcotic has been true to its paralyzing nature, and that you are
weaker. Then, after a time, when the drug has spent itself, and reaction
(so called) comes on, and you feel weak and prostrated, measure your
strength once more. Fooled again ; the stuff has fooled you twice.
When you felt yourself strong you were weak, and now when you feel
yourself weak, you find yourself stronger — your natural strength is
returning, and what you have called reaction is in reality recovery from
the weakening effects of the narcotic." — Dr. A. F. Kinne.

66. Poisonous effieota of alcohol 1

242 THE NERVOUS SYSTEM

hoi is not the only narcotic poison that exercises this influence,
which is not kindly, but is in fact the first indication of a
paralysis of a portion of the nervous system. Most of the
habitual takers of alcohol freely admit that they are injured
by it in one way or another, and still they continue in their
indulgence. In such cases the mental balance is already lost ;
for a person to crave that which he knows to be hurtful to him
is manifestly not the sign of a sound mind. {Bead Note 18.)

67. Tobacco and its Effects. — Tobacco, familiarly known as
" the weed," is an annual plant said to be a native of America.
It grows to a height of several feet, with leaves of a pale green
color. These leaves, when dried, are made into cigars, chew-
ing and smoking tobacco, and snuff, which are extensively
used throughout the civilized world.

68. Tobacco as a Poison. — Tobacco is a poison to the young,
and is far more hurtful to the adult than is generally supposed.
It may be stated, as a rule, that there are few persons who use
it habitually that do not suffer injury from it. The injury is
mainly caused by what is known as " nicotine," one of the nar-
cotic poisons, and particularly prominent in tobacco. Some of
the effects of its limited use are nausea, vomiting, vertigo, and
weakness; and its prolonged use, by those who are sensitive

18. " Here is a company of 'jolly good fellows,' all standing on their
feet, their faces red and radiant, and all swinging their arms and talking
at once. These men have been taking alcohol, and, surely, you will say,
it has stimulated them. But if you will attend for a moment to what
they are saying, you will see that there is no true brain-stimulation about
it. We shall be reminded rather of what Addison says of the difference
between the mind of the wise man and that of the fool : There are infi-
nite, numberless extravagancies, and a succession of vanities which pass,
through both. The great difference is that the first knows how to pick
and cull his thoughts for conversation, by suppressing some and com-
municating others ; whereas the other lets them all indifferently fly out
in words.' The case with these revelers is precisely this. The poison
which they have taken has paralyzed their conservative faculties, and the
talking propensity is running on without anything to hold it in check and
regulate it." — Dr. A. F. Kinne.

67. Describe the tobacco plant.

68. What is its effect upon the nerves ?

THE NERVOUS SYSTEM 243

to it, often results in convulsions and other like symptoms.
together with an irritability and weakened condition of the
heart, known to physicians as the " tobacco-heart,"

69. Effects on the Young. — Of the pernicious influence of
the use of tobacco upon the young, the testimony of the Naval
and .Military Academies of the country is very decided. It
has at times been allowed in both institutions, but at present
it is forbidden, on the ground that its use is attended with
serious damage to health. It is stated that its prohibition
at the Naval Academy in 1881 was received with unanimous
approval by the officers in charge, and with "great joy by
many of the cadets." Tremor of the muscles, caused by smok-
ing, was very noticeable in the drawings that form so impor-
tant a part of the cadets' work. A teacher of drawing of
fourteen years' experience has said that he can always tell
from the character of the lines in the drawings, whether or not
the pupils use tobacco.* Its avoidance has resulted in the
reduced number of minor ailments that swelled the sick-list in
years when its use was unrestricted. Athletes and other per-
sons who engage in running matches and the like, are com-
monly not allowed to use either alcohol or tobacco while they
are " in training ; " their use interferes with the fullest devel-
opment of muscular strength. (Head Xote 19.)

* " Prof. Mantegazza, of Florence, Italy, a distinguished sanitarian
and physician, testifies that ' Tobacco is never necessary ; it is always
hurtful to boys and young men, to weak people, and those disposed to
consumption. * * * * All good citizens should try to put a stop to the
genera] invasion of tobacco, which threatens to involve the whole of
Europe in a dense cloud of smoke, which poisons even those who do not
smoke.' "

19. "The end of all science is to secure long life and good health to
the individual and the race, and it ought to be a part of the rational
creed of every good man and woman to abjure the use of tobacco, and
keep others from falling into the vice." — Dr. C. B. Dry»

" Of tobacco, Eranklin said that he could not think it had ever done
much good in the world, since he never knew a person who used it
habitually who would recommend another to do the same."

"Tobacco is certainly not a food for man, nor has it much value as a

69. Give the effects of tobacco upon the young !

244 THE NERVOUS SYSTEM

70. Cigarette-Smoking. — This form of taking tobacco is in-
jurious in two particulars that do not apply to the other forms.
The smoker of cigarettes, either voluntarily or involuntarily,
takes into his lungs a very large amount of smoke, and with
it that hurtful element, carbonic oxide. Again, there is an
excessive amount of adulteration of the tobacco in cigarettes ;
and one substance, opium, is largely so used, and is extremely
injurious.

71. Snuff-Taking. — In addition to the hurtful effects of
tobacco generally, snuff -taking is notoriously injurious to the
senses of smell and taste, and to the voice.

72. Narcotics. — The term narcotic is applied to different
substances derived chiefly from the vegetable kingdom, which
have the wonderful property of quieting pain and causing
sleep. Next in importance to alcohol, which belongs to the
narcotics, are opium (and its preparations), chloral hydrate,
hasheesh, and chloroform.

73. Opium. — Opium is the thickened juice of the poppy-
plant of India, and is commonly regarded as the most impor-
tant of the narcotics. Its active principle is morphine, which
gives the soothing property to laudanum, paregoric, and Dover's
powders. It is also used in nostrums to put infants to sleep :
but, unwisely used, often brings on a sleep that knows no
waking.

74. Effects of Opium. — Opium is particularly injurious to
the young, even small doses sometimes producing alarming
symptoms. Upon adults the external effects are not as notice-
medicine. The tobacco-worm is the only animal known to thrive upon
it." — F. H. Hamilton.

"An illustration of the depressing influence of tobacco is given by
Dr. Jacob Bigelow, who states that soldiers, when wishing to shirk duty
and get on the sick-list, sometimes succeed in bringing on the symptoms of
alarming sickness by wearing a piece of tobacco under each armpit. The
skin absorbs sufficient of the poison to affect the system to a marked
degree."

70. What is said of cigarette-smoking ? 73. What is opium »

71. Snuff-taking ? 74. What are the effects of using opium ?

72. What do you understand by narcotics ?

THE NERVOUS SYSTEM 245

able as are those of alcohol, but the mind is more deeply Btirred
and the flow of ideas more copious.

75. Danger from Opiates. — The use of opium for relieving
pain has been known for hundreds of years. The enchanting
sense of relief to suffering wrought by opiates leads to the mor-
phine habit, commonly called opium-eating. It will be seen,
therefore, why such great care is exercised by physicians in
administering opiates, lest their patients afterward fall into the
habit of taking them without medical advice. (Bead Note 20.)

76. Physiological Effects of Opium. — The frequent use of
opium disturbs and weakens the stomach as well as the other
digestive organs ; hence we invariably find the opium-eater to
be a lean, yellow, sallow person. His muscular and mental
powers are impaired, and his will is terribly enfeebled. This
dreadful habit can be broken only with unspeakable suffering
to its victim.

77. Chloral Hydrate. — Chloral hydrate, commonly called
chloral, is produced from alcohol ; but its power as a sedative
was not generally known until within the past twenty years.
It also is a destroyer of appetite as well as of digestion, unless
prescribed in proper doses, and the unfortunates once given
over to it find themselves unable to sleep without its continued
use. It should never be taken except under the direction of a
physician.

20. '-The opium-eater loses none of his moral sensibilities or aspira-
tions ; he wishes and longs as earnestly as ever to realize what he believes
possible, and feels to be exacted by duty ; but his intellectual apprehen-
sion of what is possible infinitely outruns his power, not of execution
only, but even the power to attempt. He lies under the weight of incu-
bus and nightmare; he lies in sight of all that he would fain perform,
just as a man forcibly confined to his bed by the mortal languor of a
relaxing disease, who is compelled to witness injury and outrage offered
to some object of his tenderest love; he curses the spells which chain
him down from motion ; he would lay down his life if he might but get
up and walk ; but he is powerless as an infant, and cannot even attempt
to rise." — Be Quinceifs Confessions of an Opium-Eater.

T5. What the danger 1

"6. What effect upon the system :-

77. What do VOU know of chloral hydrate?

246 THE NERVOUS SYSTEM

78. Hasheesh. — Hasheesh, the juice of Indian hemp, is said
to be used by millions of the inhabitants of Asia. It is not
much known in the western countries. In the East the excite-
ment caused by its use takes the form of furious madness, lead-
ing its victim to commit acts of violence and murder. Hence
the term " hasheeshers " in our language has come to be synony-
mous with assassins. (Read Note 21.)

79. Chloroform. — Chloroform, another product from alcohol,
is used by inhalation when surgical operations are to be per-
formed. As it is very powerful and subtile in its action, the
unskillful use of it is dangerous in the extreme. The habit of
taking chloroform by those who are great physical sufferers, or
whose constitutions have been wrecked by the use of other
narcotics, should be discouraged. It too often happens that
the career of such is short, for the drug may easily be taken
in excess and so cause death.

80. Sleep Produced by Narcotics. — Opium and the opiates
have the power of quieting the activity of the brain, and of
compelling sleep. This may be a blessed action if skillfully
applied by the physician, but not so applied it is the source of
infinite peril. The sleep so caused differs from natural, restful
slumber, especially in the fact that the after-effects are com-
monly depressing and disturbing to the brain to the extent of
being harder to bear than the wakefulness on account of which
the drugs are taken. Very young persons are especially
subject to injury by sleep-producing medicines; and many
are the deaths that have been caused among infants by the
giving of " soothing syrups," " cordials," and " anodynes,"

21. " As everybody knows, the intoxication caused by alcoholic liquors,
by hasheesh, by opium, after a first period of excitement, brings about a
notable impairment of the will. The individual is more or less con-
scious of this ; other persons see it more clearly. Soon — especially under
the influence of alcohol — the weakening of the will becomes excessive.
The extravagances, violences, and crimes committed in this state are
innumerable." — Dr. T. Bibot.

78. What is hasheesh ? Its use ?

79. Chloroform ? Its use ?

80. What kind of Bleep produced b.

THE NERVOUS SYSTEM 247

that are so freely made and sold for the purpose of compelling
sleep.

81. Results of the Use of Narcotics. — The use of any of
these narcotics, without proper medical advice, is their abuse.
In this way they become powerful for harm. They are no
longer remedies, but poisons. Self-prescribed, they have a
thousand times been the instrument of unintentional suicide.
{Bead Note 22.)

22. The Narcotics and Digestion. — "The habitual use of opium and
other narcotic drugs is unfriendly to digestion, leading to nausea and a
distaste for wholesome food. The vigor of the organs of digestion is
impaired.

" The disturbing effects of tobacco, in producing nausea and vomiting,
is well known, and is almost the invariable experience of all beginners in
the use of that substance ; loss of appetite is a very frequent result of
the habitual use of it."

81. What the results of the use of narcotics ?

248

THE NERVOUS SYSTEM

TOPICAL OUTLINE

Pia mater .
Coverings J Arachnoid .

I Dura mater
' Cerebrum .

Structure

Cerebellum

Medulla

f Cerebrum

Functions J Cerebellum

NERVOUS
SYSTEM .

NERVE SUB-
STANCE . . .

NERVE
FIBRES

I Cerebro-
spinal . . .

Sympathetic

J Cellular . .

Fibrous . .

Fresh . . .
I After death

Afferent . .

■j Efferent . .

[ Mixed . . .

f Inner, delicate, vascular.
-I Closely invests the brain.
i Follows all the convolutions.

A serous membrane.

Tough, fibrous.
J Outer surface rough, and in contact with the
j skull.

{ Inner surface smooth.
I Right and left hemispheres.

Surface convoluted.
J Fills all upper portion of cranium.
I Gray matter outside.
[ Right and left hemispheres.
I Surface drawn into folds.
| Fills occipital portion of cranium.

Gray matter outside,
i Connects the brain with the cord.
' Gray matter inside.
f Chief seat of sensation.

i The organ of the will and voluntary motion.
I The seat of the intelligence.
t The seat of muscular seuse.
' Co-ordinates muscular movements.
f Governs the muscles of respiration and deglu-
I tit ion.

I A conducting medium between the brain and
I the cord.

Brain and its nerves.

Consists of

' Spiual cord and its nerves.

f Consists of

■ci.-u j- . ., . , \ Organs of sense.
Fibres distributed to ■ „ ? . ,

i \ oluntary muscles.

("Double chain of ganglia, on

each side of the vertebral

column.

I Various disconnected ganglia.

| The internal organs.

I. Fibres distributed to -! The walls of blood-

[ vessels.

Grayish — in nerve centres.
s Nerve fibres — forms nerves, and enters into
' the structure of nerve centres.

A simple semitransparent filament,
t A tube, containing a white opaque sub-
' stance.

t Convey impressions to a centre only.
' Also called sensory nerves.
f < 'onvey impressions from a centre only.
-j Fibres terminate in muscular fibres.
t Also called motor nerves.

Contain both afferent and efferent fibres.

THE NERVOUS SYSTEM

249

THE SPINAL
CORD ....

Reflex action

, In the spinal canal formed by the vertebral
I column.
About eighteen inches.
Extends from the medulla oblongata to the first

Lumbal vertebra.
About one-third of an inch.
I'm muter — delicate, vascular.
Arachnoid — serous, forming a loose bag.
Dura mater — tough, fibrous.
| (A layer of fatty tissue lies between the dura
I mater and the bony canal.)
Gray mutter internal.
White mutter external.
Anterior fissure.
; Posti rior fissure — deeper and narrower.
L Central canal — microscopic.
f Thirty-one pairs — between the vertebrae.

Crowded at the lower extremity of the cord —
I camt" < quina.

I Each trunk formed by the union of two roots.
| Anterior — motor.
' Posterior — sensory.
f Conduction of impressions.
I A centre for reflex action (gray matter).

Si nsory fibres — cross as they enter the cord.
I Motor fibres — cross in the medulla oblongata.
[ A disturbed condition of sensory fibres —
I Conducted to a nerve centre —
j Reflected by the nerve centre along motor fibres to thei»

terminations in muscles —
[ Muscular contraction.

Position .

Length .

Thickness

Coats . .

Structure

Nerves ,

Functions

Roots

QUESTIONS FOR TOPICAL REVIEW

PAGJ

1. State fully what is meant by the term vegetative function 207

2. To what does man owe his position as the head id the animal creation ? 208

3. What can you state on the subject of special organs for separate

functions ? 209

4. Describe, as fully as you can, the structure of the nervous system. 208,209

5. Describe the brain, its location, size, shape, and structure 209-211

6. Describe the brain proper, or cerebrum ' 211, 212

7. Describe the little brain, or cerebellum 213, 214

8. Describe the spinal cord 214, 215

9. What are the spinal nerves, and how are they arranged '.' 215

10. What is the character and substance of their tissues? 215, 216

11. State and illustrate how the nerve-fibres perform their office 216, 217

12. Describe the sympathetic system of nerves 217. 21S

13. State tlie properties of nervous tissue, and illust rate 21S-220

14. Explain the functions of the nerves 220

16. What is meant by transient paralysis of a nerve? Illustrate .... 221.222

Hi. What can you state of the rate of message-motion along a nerve?. ■ --^

250 THE XEBVOrs SYSTEM

PAGE

17. What are the functions of the spinal cord ? 223

18. State what you can of the form of paralysis known as paraplegia. . 223

19. What experiments, with results, upon the spinal cord are noted?. 223, 224

20. Give the direction of fibres of cord 224. 225

21. How does the left side of brain feel pain in right band '.' 225

22. What is understood by the reflex action of the cord ? 225

23. What experiments are mentioned to prove this power of the cord ? 225-227

24. What are the uses of the retiex action of the cord ? 227-230

25. What is the medulla oblongata and its function ? 230, 231

26. What can you state of the functions of the cranial ganglia? 232

27. What are the functions of the cerebellum ? 232

28. What is the function of the cerebrum ?. 232

29. In what way does the size of the brain generally indicate the

character ? 233

30. What facts show that the gray substance of the brain is insensi-

tive ? 2:;::, 234

31. Upon what does the faculty of language seem to depend ? 235

32. Of what importance is the reflex action of the brain ? 236

33. In what ways is this importance made manifest ? 23(:, 237

34. Give the effects of alcohol upon the brain 238

35. How does it affect the mind ? 239

3i>. What is said of the effect upon the will ? 239

37. How is the whole system affected ? 241. 242

38. What is said of tobacco? 242-244

39. Define and illustrate the term narcotic 244

40. Give the statement regarding opium 244, 245

41. State what you can of chloral 245

42. What is hasheesh and its effect ? 246

43. What is said of chloroform ? 246

44. Give general results of use of narcotics 247

CHAPTER X

THE SPECIAL SENSES

The Production of Sensations — Variety of Sensations — General Sensi-
bility— Pain and its Function — Special Sensation, Touch, Taste,
Smell, Sight, and Hearing — The Hand, the Organ of Touch — The
Sense of Touch — Delicacy of Touch — Sensation of Temperature and
Weight — The Tongue, the Organ of Taste— The Nerves of Taste —
The Sense of Taste and its Relations with the other Senses — The
Influence of Education on the Taste — The Xasal Cavities, or the
Organs of Smell — The Olfactory Nerve — The Uses of the Sense of
Smell — The Sense of Sight — Light — The Optic Nerve — The Eye-
ball and its Coverings — The Function of the Iris — The Sclerotic,
Choroid, and Retina — The Tears and their Function — The Move-
ments of the Eyeball — The Function of Accommodation — The Sense
of Hearing and Sound — The Ear, or the Organ of Hearing — The
External, Middle, and Internal Eur

1. Production of Sensations. — We have already seen that the
true centre of sensation is some organ within the skull, proba-
bly among the gray masses at the base of the brain ; but the
mind never perceives impressions at that point; on the con-
trary, it always refers them to the external organs of sensa-
tion. Hence, it is convenient to say that those outer parts
possess the property of sensibility. For instance, we say that
we hear with the ear, taste with the tongue, and feel with the
fingers. That this is not the exact truth is proved by the fact
that, whenever the nerve connecting one of these organs with
the brain is severed, it at once loses its capacity for sensation.

2. Consciousness, another faculty of the brain, is necessary
to complete a sensation. During sleep, and in other uncon-

1. True centre of sensation ? Place of the mind's impressions ? What is it convenient
to say ? What further is stated J

2. Consciousness? During sleep? In profound insensibility J

•2ol

252 THE SPECIAL SENSES

scious states, the usual impressions are presented to the ear,
the nose, and the skin; but they fail to excite sensations,
because the nerve-centres are inactive. In profound insensi-
bility, from chloroform or ether, a limb may be removed with-
out occasioning the least feeling.

3. Variety of Sensations. — All animals have some degree of
sensibility. It is, of course, feeble aud indistinct in the lower
forms of life, but increases in power and variety as we ascend
the scale. In the earth-worm, the nervous system is very
simple, the sensibility being moderate and alike in all parts;
hence, if its body be cut into two pieces, each piece will have
the same degree of feeling as before. As we approach man,
however, the sensations multiply and become more acute; the
organs are more complex, and special parts are endowed with
special gifts. These special organs cannot be separated from
the rest of the body without the loss of the functions they are
designed to exercise.

4. The lowest form of sensation — that of simple contact —
is possessed by the lowest of the animal creation. The highest
forms are those by which we are enabled to know the proper-
ties of external objects, such as shape, size, sound, and color.
A variety of means of communicating with the outer world is
the necessary possession of a high intelligence. Sensations are
modified by use. They become more acute and powerful by
moderate exercise, or they are dulled by undue excitement.
The former is shown by the acute hearing of the Indian, by the
sharp sight of the sailor, and by the delicate touch of the
blind. The latter is exemplified by the impaired hearing of
the boiler-maker, and the depraved taste of him who uses
pungent condiments with his food. Again, impressions habitu-
ally presented may not be consciously felt, as is the case with
the rumbling of carriages in a neighboring street, or the regular
ticking of a clock. All sensations become less vivid with the
advance of age, especially hearing and vision.

8. Sensibility in animals ? In the earth-worm ? In man ?

4. The lowest form of sensation ? The highest ? Sensations, how modified ? Wha>
further can you state as to habitual impressions ?

THE SPECIAL SEXSES 253

5. General Sensibility. — There is a property possessed by
nearly all parts of the human body which we call general
sensibility. We have recently seen that the brain is wholly
insensitive, and may be cut or pinched without pain. The
same is true of the nails, hair, the scarf-skiu or external cover-
ing of the body, and a few other structures. In these parts no
nerves are found. On the other hand, the sensibility of the
true skin, and of mucous membranes, as of the eye and nose, is
exquisite, these organs having a large supply of sensory nerve-
fibres. The bones and tendons have less of these fibres, and
are only moderately sensitive.

6. The sensibility of any part of the body, then, depends
upon the number of nerves present; and, as a rule, the nervous
supply is proportional to the importance of the part, and to its
liability to injury. When, therefore, a surgical operation is
performed, the most painful part of it is the incision through
the skin — the muscles, cartilage, and bone being comparatively
without sensation. Hence, if we could benumb the surface,
certain of the lesser operations might be undergone without
great inconvenience. This is, in fact, very successfully accom-
plished by means of the cold produced by throwing a spray of
ether, or of some other rapidly evaporating liquid upon the
part to be cut.

7. Tickling is a modification of general sensibility. At first
it excites a pleasurable sensation, but this soon passes into
pain. It is only present in those parts where the sense of
touch is feeble. But all impressions are not received from
without ; there are, also, certain internal sensations, as they are
called, which depend upon the condition of the internal organs,
such as appetite, hunger, thirst, dizziness when looking down
from some lofty position, drowsiness, fatigue, and other feel-
ings of comfort or discomfort. General sensibility, whether of
the internal or external organs of the body, chiefly depends

5. General sensibility? What have we seen as regards the brain? Of what other
structures is tin- same true ?

6. The cause of sensibility ? Painful part in a surgical operation ? Benumbing the
surface ? How done by ether ?

7. Tickling:- Internal sensations ? The nerves of general sensibility ?

254 THE SPECIAL SENSES

upon the sensory fibres of the spinal nerve. The face, how-
ever, is supplied by the sensory cranial nerves. The sympa-
thetic system has a low grade of feeling in health, but disease
in the parts served by it arouses an intense degree of pain.

8. The Sensation of Pain. — What then is 'pain? Is it iden-
tical with ordinary sensibility ? There seems to be some
necessary connection between the two feelings, for they take
place through the same channels, and they are alike intense in
the same situations. But sensibility habitually contributes to
our sources of pleasure — the very opposite of pain ; hence,
these feelings cannot be identical.

9. Pain must, therefore, be a modification of the general
sensibility which follows an excessive degree of excitement of
the nerves, there being a natural limit to the amount of stimu-
lation which they will sustain. So long as this limit is observed,
the part excited may be said to be simply sensitive ; but when
it is exceeded, the impression becomes painful. This difference
between sensibility and pain is well shown by the effects of
sunlight upon the eye. The indirect illumination of the sun
arouses only the former feeling, and is indispensable to our
comfort and existence, while the direct ray received into the
eye occasions great pain.

10. The Uses of Pain. — The dread of pain is a valuable
monitor to the body. It puts us on our guard in the presence,
of danger, teaches moderation in the use of our powers, indi-
cates the approach of disease, and calls attention to it when
present. The word disease, in fact, according to its original*
use, had reference simply to the pain, or want of ease, which
commonly attends disordered health. When we observe the
serious mishaps which occur when sensibility and pain are
absent, we cannot fail to appreciate its value. For example, a
paralytic, in taking a foot-bath, forgets to test its temperature,
and putting his limbs into water while it is too hot, is severely
scalded without knowing it.

8. Connection between pain and sensibility?

9. Explain the difference between pain and sensibility.

10, Dread of pain ': Bow may its value be appreciated ? Example ?

THE SPECIAL SENSES 255

11. A traveler, overcome by cold and fatigue, lies down and
falls asleep near a large lire, and when he is aroused in the
morning, it is discovered that one of his feet has been insen-
sibly destroyed. A grain of sand, lodging in an insensitive
eye, may cause inflammation, and even the loss of sight. If
intense light were not painful to the eye. many a child would
innocently gaze upon the glories of the sun to the ruin of his
sight.

12. Fain is, indeed, a present evil, but its relations with the
future prove its mission merciful. Painful impressions cannot
be recollected from past experience, and they cannot be called
into existence by the fancy. Considered in the light of results,
pain has a use above that of pleasure ; for, while the immod-
erate pursuit of the latter leads to harm, the tendency of pain
is to restrict the hurtful courses of life, and in this manner to
protect the body.

13. The relations of pain to pleasure are thus described by
the eminent physiologist, Magendie: — " By these sensations
Nature induces us to concur in the order which she has estab-
lished among organized beings. Though it may appear like
sophistry to say that pain is the shadow of pleasure, yet it is
certain that those who have exhausted the ordinary sources of
pleasure have recourse to the causes of pain, and gratify them-
selves by their effects. Do we not see in all large cities, that
men who are debauched and depraved find agreeable sensations
where others experience only intolerable pain?" (Head Note 1.)

1. Pain is "Nature's Harbinger of Mischief." — " It must, there-
fore, be evident that pain is, under certain circumstances, really beneficial.
It is often a great boon to have a sensitive stomach ; for those who suffer
pain after food are less apt habitually to err in diet, and thus to become
dyspeptic or gouty, than those whose orpins receive everything uncom-
plainingly. Pain in the stomach is frequently due (in well-to-do people)
to the fact that they won't work and will eat ; not that the stomach itself
is weak (as they think), but that the supply of food being greater than
the demand, the system becomes overstocked. In dyspepsia the cause is
very often far away, and the stomach is no more the cause of the malady

11. The ease of the traveler ? Grain of sand? The son and child ?

IS, Mission of pain ? Painful Impressions compared with those of pleasure?

13. What (loo Magendie say of the relation of pain to pleasure ?

256 THE SPECIAL SENSES

14. As to painful sensation among the inferior animals, the
plan of Nature seems to be, that the higher the intelligence of
the creature, and the more complete its power of defence, the
more acute is its sensibility. We infer, therefore, that animals
low in the scale of existence, and helpless, are not very liable
to suffer pain.

15. Special Sensation. — The sensations of simple contact
and pain are felt by nearly all parts of the system, whether
external or internal, and are the necessary consequence of the
general sensibility ; but, so far as the objects which surround
us are concerned, these impressions are vague and passive in
character, and inform the mind of none of the properties or
powers of these objects. Besides these feelings, therefore,
man is endowed with certain special sensations, which are
positive and distinct in character, and which he can call into
exercise at will, and employ in the pursuit of knowledge. For
reasons relating to the original constitution of the body, these
sensations are to be regarded as modifications of the general
sensibility already alluded to, constructed with special refer-
ence to the different forces of Nature of which we have any
knowledge, such as heat, motion, gravity, sunlight, and the
like. {Read Note 2.)

than the big toe is of the gout ; but if the stomach gave no signs of per-
turbation, the evil would be allowed longer to exist unnoticed. We should
always give early attention to pain, and discover its causes before they
become too complex to be unraveled, and before the derangement which
its presence indicates becomes permanent. The following incident well
illustrates the extent to which pain may be dependent on fancy : ' A
butcher was brought into the druggist's from the market-place opposite,
laboring under a terrible accident. The man, on trying to hook up a
heavy piece of meat above his head, slipped, and the sharp hook pene-
trated his arm so that he himself was suspended. On being examined,
he was pale, almost pulseless, and expressed himself as suffering acute
agony. The arm could not be moved without causing excessive pain, and
in cutting off the sleeve he frequently cried out ; yet, when the arm was
exposed, it was found quite uninjured, the hook having only traversed
the sleeve of the coat ! ' The sensation here was perfectly real, but
originated in a change of the brain and nerves, instead of in the external
senses." — Notes on Pain.

14. The law of Nature as regards painful sensations among- animals f

15. The sensation of contact and pain ? Special sensations of man ? How regarded ?

THE SPECIAL SENSES 257

16. These distinct and active faculties are termed the
special senses, and are five in number, viz., Touch, Taste,
Smell, Sight, and Hearing. For the exercise of these senses,
special organs are furnished, such as the hand, the tongue, the
nose, the eye, and the ear. The manner in which the nerves

2. The Mutual Relations of the Special Senses. — "A blind man.
attempting to express his notion of scarlet, said it resembled the sound of
a trumpet. We are constantly reminded of the impressions of one sense
by the operations of another. To my ear the bass note in music is what
a dull black is to the eye. The reverberations of deep thunder seem like
boulders with worn angles — with profiles blunt and irregular, as if drawn
by the jerking pencil of the lightning ; and one who never had the pleas-
ure of seeing stars from a blow on the head may get a tolerably correct
idea of that kind of galaxy by snuffing at a bottle of volatile salts.

" Language is full of effort to report the impressions of one sense by
the symbols of another. We say that an apple is sweet, that a rose is
sweet, a face is sweet, a strain of music is sweet, and love is sweet, not
to mention the saccharine reaction of the -uses of adversity.' Here
taste, smell, sight, hearing, and a social sentiment use the same word for
that pleasurable sensation experienced by the mind through each distinc-
tive organ. We assist the organ of one sense by that of another. We
open the lips and part the teeth a little when we are eager to hear ; we
listen and turn the eyes' attention inward when we would detect a deli-
cate taste, or remember a faded impression.

"But this mutual accommodation of the senses is not so marvelous as
it may seem, when we remember that the whole five, six, or seven, as you
please, are but one power of nervous perception, specialized into a variety
of functions, differentiated, as the learned say. that we may have more
perfect work by a division of labor. The same necessity which developed
nerve-contact into sight on the one hand and hearing on the other might
also express through one of these the sensations proper to the other, when
the other was wanting. Seal up the eyes of a bat, say the naturalists,
and let it loose in a room crossed with wires in every direction, and he
will fly clear of them all, as if he had other means of perception as
sensitive as the optic nerve.

"Laura Bridgman, with neither sight, hearing, nor smell, could detect
the presence of a stranger in the room, without contact. Her mind then
must have as distinct an imaae of every person as we have, yet not one
of what we call our senses could go to the making up of that image. It
could not be form as we know it. nor a voice, nor an odor, but it was
itself other than all. exciting emotions ,,i love, or hate, gratitude or
repugnance, and the thought it excited must have had shape, though it
is not easy to imagine how." — The SchoolmasU r.

16. What are the special senses ? Special organs for them ?
R

258 THE SPECIAL SENSES

of special sense terminate varies in the case of each organ, so
that each is adapted to one set of sensations alone, and is
incapable of perceiving any other. Thus the nerve of hearing
is excited by the waves of sound, and not by those of light,
while the reverse is true of the nerve of sight ; and the nerve
of smell can appreciate neither of them, being capable only
of taking cognizance of the odorous properties of bodies.
(Bead Note 3.)

17. By some writers six senses are accorded to man, the
additional one being either the sense of temperature — for, as
we shall presently see, this is not the same as touch — or,
according to others, the muscular sense by which we are
enabled to estimate the weights of bodies. The latter also
differs in some respects from the sense of touch.

18. Organs of Touch. — The sense of touch is possessed by
nearly all portions of the general surface of the body, but it
finds its highest development in the hands. The human hand
is properly regarded as the model organ of touch. The minute
structure of the skin fits it admirably for this form of sensa-
tion ; the cuticle, or scarf-skin, is fine and flexible, while the
cutis, or true-skin, contains multitudes of nerve-filaments,
arranged in rows of papillce or cone-like projections, about one
one-hundredth of an inch in length. It is estimated that there
are 20,000 of these papillae in a square-inch of the palmar sur-
face of the hand. Now, although the nerves of the cutis are
the instruments by which impressions are received and trans-
mitted to the brain, yet the cuticle is essential to the sensation
of touch. This is shown by the fact that whenever the true-
skin is laid bare, as by a burn or blister, the only feeling that
it experiences from contact is one of pain, not that of touch.

3. Variation in Structure in the Nerves of Special Sense. — "While
in the more intellectual senses — Sight, Hearing, and Touch — the nerves
have their protecting and isolating sheaths corresponding with the dis-
tinctness and separateness of the parts of the impression, in Smell the
nerves are a plexus of unsheathed fibres, corresponding with the fusion of
the odorous impression into one whole, without distinction of parts." —
Herbert Spencer.

17. What is said in relation to one more than the five senses ?

18. The sense of touch, how prevalent ? What is said of the haid 1

THE SPECIAL SENSES 259

19. The office of the cuticle is thus made evident ; it is to
shield the nerve-filaments from direct contact with external ob-
jects. At the tips of the fingers, where touch is most delicate.
the skin rests upon a cushion of elastic material, and receives
firmness and permanence of shape by means of the nail placed
upon the less sensitive side. Besides these favorable condi-
tions, the form of the arm is such, and its motions arc so easy
and varied, that we are able to apply the test of touch in a great
number of directions. The slender, tapering fingers, with their
pliant joints, together with the strong opposing thumb, enable
the hand to grasp a great variety of objects ; so that, great as
are the delicacy and grace of the hand, it is not wanting in the
elements of power.

20. Its beauty and adaptation to the wants of man have made
the hand an attractive theme for philosophers. They do not,
however, always agree in their conclusions. One has the opin-
ion that man has acquired his intelligence and achieved his
place as "lord of creation," because he has this organ. Buffon.
in effect, declares that with fingers twice as numerous, and twice
as long, we would become proportionally wiser: but Galen long
ago took a more reasonable view, when he taught that " man
is the wisest of animals, not because he possesses the hand, but
because he is the wisest, and understands its use ; for his mind,
not his hand, has taught him the arts.'" Another has well said.
that " no one can study carefully the human hand and fail to be
convinced of the existence of the Deity."

21. The Sense of Touch. — Touch is the simplest of the senses.
It is that which the child first calls into exercise in solving the
early problems of existence, and it is that which is in the most
constant use throughout life. We are brought by the tench
into the most intimate relations with external objects, and by
it we learn the greater number, if not the most important. >>f the
properties of these objects, such as size, figure, solidity, motion,
and smoothness or roughness of surface.

19. • utiee of the cuticle * Tips of the finders ? The fingers with thumb ?

20. What special Importance is attributed to the hand?

21. The simplicity of touch ? What does it teach us ?

260 THE SPECIAL SENSES

22. The sense of touch assists the other senses, especially
that of sight, giving foundation and reality to their perceptions.
Without it, the impressions received by the eye would be as
vague and unreal as the figures that float through our dreams.
A boy who had been blind from birth, at the age of twelve
years received sight by means of a surgical operation ; at first,
he was unable to distinguish between a globe and a circular
card of the same color before he had touched them. After
that, he at once recognized the difference in their form. He
knew the peculiarities of a dog and a cat by feeling, but not
by sight, until one day, happening to take up the cat, he recog-
nized the connection of the two sorts of impressions — those of
touch and sight; and then, putting the cat down, he said:
" So, Puss, I shall know you next time."

23. Of all the senses, touch is considered the least liable to
error ; yet, if that part of the skin by which the sense is
exercised is removed from its customary position, a false
impression may be, created in the mind. This is well illus-
trated by an experiment, which dates from the time of Aris-

totle. If we cross the middle finger behind the forefinger,
and then roll a marble or some small object upon the tips of
the fingers (see Fig. 61), the impression will be that two mar-
bles are felt. If the fingers, thus transposed, be applied to
the end of the tongue, two tongues will be felt. When the
nose is accidentally destroyed, the surgeon sometimes performs

22. Importance of the sense of touch to the development of the other senses?

23. Liability of touch to err ? Describe the illustration.

THE SPECIAL SZXSES 261

an operation for the purpose of forming a new one, by trans-
planting a partially removed piece of the skin of the forehead
upon the injured part; then, if the new nose be touched or
pinched, the feeling is referred to the forehead. This fact
illustrates one important truth — that the nerves will re-unite
after they have been cut and feeling will be restored; if it
were otherwise, a succession of slight cuts upon the fingers
would seriously impair their tactile sensibility.

24. The Delicacy of Touch. — Although the hand is the
proper organ of this sense, yet it is exercised by various parts
of the body, their degree of sensibility being proportional to
the number of papillae they contain. The varying degrees of
tactile delicacy of the different parts of the surface have been
measured in an ingenious maimer, by means of a pair of com-
passes, tipped with small pieces of cork. The two points of
the compasses are touched at the same moment to the skin, the
eyes being closed, and it is found that, in sensitive parts, the
distance between the points may be quite slight, and yet cadi
be plainly felt ; while, in less sensitive parts, the points of the
compasses are felt as a single point, although they are sepa-
rated one or two inches.

25. At the tips of the fingers, the distance between the
points being one-twentieth of an inch, a double impression is
felt. The distance must be twice as great for the palm, four
times as great for the lips, and, on the forehead, it must be
twenty times greater. At the middle of the back, where the
touch is least acute, the points must be separated more than
two inches before they can be separately felt. Therefore, the
sense of touch in the fingers is said to be fifty times more
delicate than upon the posterior surface of the body.

26. Exquisite delicacy of touch is attained by practice.
This is shown in many of the lighter and more graceful
employments of daily life. Without it. the skill of the
painter, sculptor, and musician would be rude indeed. By

24. Tlu- delicacy of touch i Experiments with a pair of compasses ?

25. Further experiments and

20. Exquisite delicacy of touch i The same among the blind ?

262 The special senses

training, also, the physician acquires the tactus eruditus, or
discriminating touch ; but among the blind, delicacy of touch
is most remarkable, and it there finds its highest value; for
its possession, in a measure, compensates for the loss of sight
by enabling them to read, by means of raised letters, to work
with certain tools, and even to play upon musical instruments.
A person born without sight, and without hearing or voice,
may, by the education of the touch, be rescued from apparent
imbecility, and be taught not only to read and write, but even
to perform household and other useful labors.

27. Sensations of Temperature and Weight. — Each of these
sensations has been described by the physiologists as a special
sense, and they are rival candidates, so to speak, for the posi-
tion and title of the sixth sense. In the sensation of temper-
ature, or the thermal sense, touch bears a part, but the two
feelings appear to be distinct. In proof of this, we observe,
firstly, that they are not alike intense in the same situations ;
as, for example, the skin of the face and elbow, where the
sense of touch is feeble, is very sensitive to impressions of
heat and cold. Secondly, the ability to recognize temperature
may be lost by paralysis, while the sensibility of touch remains
unaffected. When the skin comes in contact with a very hot
substance, the sensation felt is that of pain — not of touch.
In like manner, a very cold substance causes pain, not the
feeling of cold. So that a red-hot iron, and solid carbonic acid
(the temperature of which is 108° below zero), feel alike ; and
each, if pressed slightly, will produce a blister. {Bead Note 4.)

4. Qualities Determined by the Sense of Touch. — "The eye, by
the aid of certain signs, is often able to tell whether a body is hot —
when, for instance, it is glowing or steaming — but a perception of
warmth is not possessed by the eye. This is had by the skin alone,
and it is of great importance to our preservation that this property is
spread over the entire surface ; for it surrounds the body like a pro-
tecting wall against its worst enemy — cold — which, if not thus guarded
against at all points, would speedily destroy life. We are warned, how-
ever, of the approach of the enemy by a common sensation of the
skin, and an inward chill, which is only caused by a coolness of the

Rival candidates for the sixth sense ? Oive the two reasons on the siile

the special SENSES lit;:;

28. The muscular -sense, by some considered distinct from
touch, gives rise to the sensations of weight, and other forms
of external resistance. That this feeling exists, is shown by
the following simple experiment: if the hand be placed flat
upon a table, and a somewhat heavy weight be put into it,
touch alone is exercised, and a feeling of pressure residts ; but
if the hand be raised, a certain amount of muscular effort must
be put forth, and thus the sensation of weight is recognized.
Through the muscular sense, precision of effort is rendered pos-
sible ; for by it we learn to adjust the force exerted to the
weight of the object to be lifted, moved, or carried. Without
it all our movements would necessarily become ill-regulated
and spasmodic. In cases of disease, where the sensibility of
the lower limbs is lost while power of motion remains, the
patient is able to stand erect so long as he can see his limbs ;
but just as soon as his eyes are closed, he begins to waver, and
Avill fall unless supported.

29. The Organ of Taste. — The tongue is the special organ
of the sense of taste ; but the back part of the mouth always
possesses this faculty. The tongue is a muscular organ, the

skin. The skin, in like manner, protects the body against the approach
of a hurtful degree of heat. Thus, you see, the skin has certain quali-
ties of sensation. Just as the eye, in looking at a wafer, perceives
that it is both red and circular, distinguishing both the color and form
of bodies, so the sensitive skin by contact with an object distinguishes
the qualities of form, firmness, hardness, liquidity, pressure, and tempera-
ture. * * * Weber has discovered the interesting fact that warm
bodies feel lighter than cold ones : if a cold coin be placed upon the
forehead of some person, whose eyes are shut, and then upon the same
spot two warm coins, the weight would seem to him the same, whilst
he could distinguish correctly in the case of cold weights. * * * If
we place the elbow in hot water, we experience heat only in the part
immersed, not in the whole arm, although the nerve just under the skin
runs throughout the arm and hand. What we feel is a dull sense of
pain in the whole arm if the water is too hot. So, too, if the elbow
is placed in ice- water the pain is just the same in the arm ; proving
that the nerve trunk can feel neither warmth nor cold." — Bernstein's
Five Senses of Man.

28. The muscular sense? State what is said to illustrate the subject.
89. The or^au of taste? The tongue? It- powers of motion ':

264 THE SPECIAL SENSES

muscles composing it being so numerous and interwoven as to
give it the freedom and variety of motion which it possesses.
It can curve itself upward or downward ; it can extend or con-
tract itself; and, with its point, can sweep the cavity of the
mouth, in all directions, in the search for scattered particles of
food.

30. The upper surface of the tongue is peculiar, being
marked by the presence of innumerable papillce? some of which
are of microscopic size, resembling those that abound in the
fingers, and in other parts of the body that have the sense of
touch. Others are much larger, and give to the tongue its
roughness of feeling and appearance. Through the medium
of these papillae, the tongue receives impressions of touch and
temperature, as well as taste : indeed, its extremity is fully as
delicate, in respect to tactile sensations, as the tips of the fin-
gers themselves. It can recognize the two points of the com-
passes when separated not more than one twenty-fourth of an
inch ; the back of it is much less sensitive to touch, while at
the same time it is more highly sensitive to impression of
taste.

31. Each lateral half of the tongue resembles the other in
structure, and each receives the same number of nerves —
three. One of these regulates motion, the other two are nerves
of special sense. One of the latter supplies the front half
of the tongue, and is called the gustatory nerve. This is a
branch of the great cranial nerve, called the "fifth pair," which
ramifies in all parts of the face. The back of the tongue is
endowed with the power of taste, through a nerve known as
the glosso-pliaryngeal, because it is distributed both to the
tongue and throat. This difference in the nervous supply of
the tongue becomes significant, when we learn, as we shall
presently, that each part of it perceives a different class of
flavors.

32. The Sense of Taste. — Taste is the special sense by means

80. Peculiarities of the tongue ? Uses of the papillae?

81. Resemblai in the parts of the tongue? Powers and functions of the parts ?

32. Taste? What are the requisites to taste ?

THE SPECIAL SENSES 265

of which we discover the savors, or flavoring properties of the
substances which come in contact with the tongue. Mere con-
tact with the surface of the tongue, however, is not sufficient,
but contact with the extremities of the nerves of taste within
the papilla? is required. In order that the substance to be
tasted may penetrate the cells covering the nerves, it must
either be liquid in form, or readily soluble in the watery secre-
tion of the mouth — the saliva. The tongue must be moist
also. If the substance be insoluble — as glass or sand — or
the tongue dry, the sense of taste is not awakened. In sick-
ness, when the tongue is heavily coated, the taste is very defec-
tive, or, as is frequently said, " nothing tastes aright."

33. All portions of the tongue are not alike endowed with
the sense of taste, that function being limited to the posterior
third, and to the margin and tip of this organ. The soft pal-
ate, also, possesses the sense of taste ; hence, an article that
has an agreeable flavor may very properly be spoken of as pal-
atable, as is often done. All parts of the tongue do not per-
ceive equally well the same flavors. Thus, the front extremity
and margin, which is the portion supplied by the " fifth pair "
of nerves, perceives more acutely sweet and sour tastes ; but
the base of the tongue, supplied by the glosso-pharyngeal nerve,
is especially sensitive to salt and bitter substances. The nerve
of the front part of the tongue, as before stated, is in active
sympathy with those of the face, while the relations of the
other nerve are chiefly with the throat and stomach ; so that
when an intensely sour taste is perceived, the countenance is
involuntarily distorted, and is said to wear an acid expression.
On the other hand, a very bitter taste affects certain internal
organs, and occasions a sensation of nausea, or sickness of the
stomach. {Read Note 5. )

5. Flavors and Sense of Taste. — "The cause and intimate nature
of tastes are no better understood than those of odors. Flavors elude
analysis and defy classification, even that which divides them into agree-
ahle and disagreeable, for the taste of individuals and of nations singu-
larly differs in this respect. The Laplander and the Esquimau drink

33. Portions of the tonpue endowed with taste ? Where else does the sense lodgre !
What i- stated in respect to swee \n '■ Keflex effects mentioned ?

26G THE SPECIAL SENSES

34. Relations of Taste with other Senses. — Taste is not a
simple sense. Certain other sensations, as those of touch, tem-
perature, smell, and pain, are blended and confused with it ;
and certain so-called tastes are really sensations of another
kind. Thus an astringent taste, like that of alum, is more
properly an astringent feeling, and results from an impression
made upon the nerves of touch that ramify in the tongue. In
like manner, the qualities known as smooth, oily, watery, and
mealy tastes, are dependent upon these same nerves of touch.
A burning or pungent taste is a sensation of pain, having its
seat in the tongue and throat. A cooling taste, like that of
mint, pertains to that modification of touch called the sense of
temperature.

35. Taste is largely dependent upon the sense of smell. A
considerable number of substances, like vanilla, coffee, and gar-
lic, which appear to possess a strong and distinct flavor, have
in reality a powerful odor, but only a feeble taste. When the
sense of smell is interfered with by holding the nose, it becomes
difficult to distinguish between substances of this class. The

great quantities of train-oil, which for them is a greatly-esteemed
article of food, and is most admirably adapted to the exigencies of a
Polar climate ; the Abyssinians eat raw flesh, and find its flavor
excellent, while the inhabitant of the West partakes of it with the
greatest repugnance and only as a medicine. Oysters, which are so
generally esteemed in our country, are to some persons disagreeable
and nauseous ; and truffles, the delight of the gourmand, are rejected
by the uninitiated on account of their flavor and their perfume. It is
the same with almost all alimentary substances ; they are eagerly
sought after by some, and despised or abhorred by others. Let us
remember the proverb ' de gustibus non disputandum,' and not dispute
in regard to tastes ; each is suited to its own country, and goodly
numbers acclimatize themselves, to the great advantage of peoples
among whom at first they seem exceedingly strange. Man should
control his taste, and habituate it to all wholesome aliment ; this
neither excludes choice, nor blunts the delicacy of the sense ; and
while we resist its seductions, we should give timely heed to its
instincts and its counsels, for they are often invaluable." — The Won-
ders of the Human Body.

34. What is stated of the relations of taste to the other senses ?
85. Its dependence on smelly on sight?

THE SPECIAL SENSES 267

same effect is frequently observed when smell is blunted during
an ordinary cold in the head. Sight also contributes to taste.
With the eyes closed, food appears comparatively insipid; and
a person smoking tobacco in the dark is unable to determine by

the taste whether his cigar is lighted or not. Accordingly, it
is not a bad plan to close the nose and shut the eyes when
about to swallow some disagreeable medicine.

36. Influence of Education on the Taste. — The chief use of
the sense of taste appears to be to act as a guide in the
selection of proper food. Hence its organs are properly placed
at the entrance of the digestive canal. As a general rule,
those articles which gratify the taste are wholesome ; while the
opposite is true of those which impress it disagreeably. This
statement is more exact in reference to the early than to the
later years of life, when, by reason of improper indulgence, the
sense of taste has become dulled or perverted. The desires of
a child are simple ; he is fully satisfied with plain and whole-
some articles of diet, and must usually "learn to like" those
which have a strongly marked flavor. Accordingly, it is far
easier at this age to encourage the preference for plain food.
and thus establish healthful habits, than later in life to uproot
habits of indulgence in stimulating substances, after their ill
effects begin to manifest themselves.

37. The tastes of men present the most singular diversities,
partly the result of necessity and partly of habit or education.
The Esquimaux like the rank smell of whale-oil, which is ;i
kind of food admirably suited to the requirements of their icy
climate; and travelers who go from our climate to theirs arc
not slow to develop a liking for the same articles that the
natives themselves enjoy. The sense of taste is rendered very
acute by education, as is shown in an especial manner by those
who become professional "tasters " of tea and wine.

38. The Sense of Smell — the Nasal Cavities. — The sense of
smell is located in the delicate mucous membrane which lines

36. The chief use of the sense of taste ? The position of the organs ? The rule as
regards wholesome and unwholesome food ? Remarks respecting the rule ?

87. Diversity in tastes of men ? How shown ? The education of the sense of taste J

88. Location of the sense of smell ? The nose ? " Roof of the mouth ? "

268 THE SPECIAL SENSES

the interior of the nose. That prominent feature of the face,
the nose, which is merely the front boundary of the true nasal
organ, is composed partly of bone and partly of cartilage. The
upper part of it is united with the skull by means of a few
small bones, to which circumstance is due its permanence of
shape. The lower portion, or tip of the nose, contains several
thin pieces of cartilage, which render it flexible and better able
to resist the effects of blows and pressure. Behind the nose we
find quite a spacious chamber, separated from the mouth by
the hard palate, forming the " roof of the mouth," and also by
the soft palate (see Fig. 62) ; and divided into two cavities by a
central partition running from before backward.

39. These nasal cavities, constituting the true beginning of
the air-passages, extend from the nose backward to the upper
opening of the throat, and rise as high as the junction of the
nose with the forehead. The inner wall of each cavity is
straight and smooth ; but from the outer wall there jut into
each cavity three small scroll-like bones. The structure of
these bones is very light, and hence they have been called the
" spongy " bones of the nose. In this manner, while the extent
of surface is greatly increased by the formation of these wind-
ing passages, the cavities are rendered extremely narrow; so
much so, in fact, that a moderate swelling of the mucous mem-
brane which lines them, as from a cold, is sufficient to obstruct
the passage of air through them.

40. The Nerve of Smell. — The internal surface of the nasal
passages is covered by a delicate and sensitive mucous mem-
brane. Its surface is quite extensive, following as it does all
the inequalities produced by the curved spongy bones of the
nose. Only the upper portion of it is the seat of smell, since
that part alone receives branches from the "first pair" of
cranial nerves, or the olfactory nerve, which is the special
nerve of smell (see Fig. 62). In Fig. 62 is shown the distribu-
tion of this nerve, in the form of an intricate network upon the
two upper spongy bones. The nerve itself (1) does not issue

39. Cavities of the nose ? I obstruction of the passage of air through them 1

40. The special nerve of smell ? Its location ?

THE SPECIAL SENSES

269

from the skull, but rests upon a thin bone which separates
it from the cavity of the nose; and the branches which proceed
from it pass through this bone by means of numerous small
openings. The engraving represents Tin- outer surface of the
right nasal cavity; the three wave-like inequalities, upon which
the nervous network is spread out, are due to the spongy bones.
The left cavity is supplied in the same manner.

41. The nerves which ramify over the lower part of the
membrane, and which endow it with sensibility to touch and
pain, are branches of the
"fifth pair" of nerves.
An irritation applied to
the parts where this nerve
is distributed occasions
sneezing — that is, a spas-
modic contraction of the
diaphragm, the object of
which is the expulsion of
the irritating cause. The
manner in which the ol-
factory nerve-fibres termi-
nate is peculiar. Unlike the extremities of other nerves, which
are enclosed by a greater or less thickness of tissue, these come
directly to the surface of the mucous membrane, and thus are
in very close contact with the odorous particles that are carried
along by the respired air. The surface is at all times kept in
a moist condition by an abundant flow of nasal mucus ; other-
wise it would become dry, hard, and insensitive from the con-
tinual passage of air to and fro in breathing. Birds, which
respire more actively than men, have a special gland for secret-
ing a lubricating fluid, located in the air-passages of the head.

42. The Uses of the Sense of Smell. — Smell is the special
sense which enables us to appreciate odors. Touch, as we have
seen, is largely concerned with solid bodies, and taste with

Fig. 62. — Section of the Right Nasal Cavity

41. Branches of the " fifth pair " of nervo> ? N'a.-al mucus ? Birds ?

42. Smell? Touch? Taste? Design of smell ? Invisible and gaseous particles? The
extreme fineness of the particles ? Musk ? In other cases ?

270 THE SPECIAL SENSES

fluids, or with solids in solution. Smell, on the other hand, is
designed to afford us information in reference to substances
in a volatile or gaseous form. Invisible particles issue from
odorous bodies and are brought by the respired air in contact
with the terminal filaments of the olfactory nerve, upon which
an agreeable or disagreeable impression is produced. The fine-
ness of the particles that constitute odors is often so extreme
that they elude all attempts to measure or weigh them. A
piece of musk, for instance, may be kept for several years,
constantly emitting perfume without any appreciable loss of
weight. In other cases, a loss of substance is perceptible, as
in the essential oils, which enter into the composition of the
ordinary perfumes.

43. Smell, like taste, aids us in the choice of proper food,
leading us to reject such articles as have a rank or putrid odor,
and which are, as a rule, unfit to be eaten. The highest use-
fulness of this sense, however, consists in the protection it
affords to the organs of respiration. Stationed at the gateways
of the air-passages, it examines the current of air as it enters,
and warns us of the presence of noxious gases, and of other and
generally invisible enemies to health. Not all dangerous vapors
are offensive, but almost all offensive vapors are unfit to be
breathed. A number of small stiff hairs grow from the margin
of the nostrils to prevent the entrance of dust and other atmos-
pheric impurities, which would be alike injurious to the olfac-
tory mucous membrane and to the lungs. The benevolent
design of the Maker of our bodies may be observed in all parts
of their mechanism; but, probably, in none is it more clearly
displayed than in connection with the sense of smell. {Bead
Note 6.)

6. The Protective Function of the Sense of Smell. — " Smell seems
to be regarded as an endowment bestowed simply for pleasure, serving to
promote no important or vital end. That its main use is to signal danger
to internal parts is not duly appreciated. The detection of an offensive
odor is thought to be the only bad thing about it, and which, to those
habituated to it, is of no subsequent importance. Men even pride them-
on becoming accustomed to offensive odors, and quite enjoy the

48. Aid given by smell ? The highest use of the sense 1 Explain the manr

THE SPECIAL SENSES L'71

44. The sense of smell is developed in a remarkable degree
in certain of the inferior animals, and is especially acute in
reference to the peculiar odors that characterize the different
animals. The lion and other carnivorous beasts scent their
prey from a great distance ; and the fox-hound is able to track
the fox through thickets and over open country for many miles ;
while the timid, helpless herbivora, such as the deer and sheep,
find in the sense of smell a means of protection against their
natural enemies, of whose approach they are in this manner
warned. By training this sense in the dog, and making it sub-
servient to his use, man is able to hunt with success certain shy
and very fleet animals, which otherwise he could but seldom
approach. Among men. individuals differ greatly in respect to
the development of this sense ; and especially in certain savage
tribes it is found to be extremely delicate. Humboldt states
that the natives of Peru can by it distinguish in the dark
between persons of different races. (Read Note 7.)

sight of one whose nerve of smell is not benumbed like their own. In-
stead of seeking to blunt the sensibilities of this nerve, it should be a
study to improve it, as the most delicate and available test of air im-
purity — far superior, under ordinary circumstances, to the tests of
science. In this way all ordinary atmospheric impurities may be quickly
detected ; and it is truly remarkable how, by a little attention, this sense
can be so improved as to detect instantly even slight impurities to
which it had before been insensible. In many houses, by the total
neglect of this sense, there is an ever-present family odor, produced by
some special kind of household impurity, and of which the inmates do
not seem to be aware. To those accustomed to pure air, house odors are
always perceptible and disagreeable. This ought to be accepted as suffi-
cient evidence of their unhealthful tendencies ; not perhaps of an instant
or violent sort, yet enough so to give rise to many sensations of slight dis-
comfort, and producing, when long continued, a state of the body very
favorable to the beginning and growth of virulent diseases." — Black'*
Ten Laws of Health.

7. The Effects of Certain Odors. — "I have not seen it anywhere laid
down as a general rule, but I believe it might be affirmed, that we art-
intended to be impressed only sparingly and transiently by odor. There
is a provision for this in the fact that all odors are vapors or gases, or
otherwise volatile substances ; so that they touch but the inside of the
nostril, and then pass away.

44. Sense of smell in Inferior animals ? How. and In what cases illustrated

272 THE SPECIAL SENSES

45. The Sense of Sight. — Sight, or vision, is the special
sense by means of which we appreciate the color, form, size,
distance, and other physical properties of the objects of exter-
nal nature. Primarily, this sense furnishes us with informa-
tion concerning the different shades of color and the different
degrees of brightness : these are the simple sensations of sight,
such as the yellowness and glitter of a gold coin. In addition
to these, there are composite visual sensations, produced by the
joint action of the other senses and by the use of the memory
and judgment ; such as, in the case of the coin, its roundness,
solidity, size, its distance and direction from us. So that many
of our sensations, commonly considered as due to sight, are in
reality the results of intellectual processes which take place
instantaneously and unconsciously.

46. This faculty not only is valuable in the practical every-
day affairs of life, but it contributes so largely to the culture
of the intellect and to our higher forms of pleasure, that some
writers are disposed to rate it as the first and most valuable of
the senses. Others, however, maintain that the sense of hear-
ing does not yield in importance to that of sight ; and they cite

" In conformity with this fleeting character of odorous bodies, it is a
law in reference to ourselves, to which, as far as I know, there is no
exception, that there is not any substance having a powerful smell of
which it is safe to take much internally. The most familiar poisonous
vegetables, such as the poppy, hemlock, henbane, monk's-hood, and the
plants containing prussic acid, have all a strong and peculiar smell.
Nitric, muriatic, acetic, and other corrosive acids, have characteristic
potent odors, and all are poisons. Even bodies with agreeable odors,
like oil of roses, or cinnamon, or lavender, are wholesome only in very
small quantities, and, when the odor is repulsive, only in the smallest
quantities. So far as health is concerned, the nostril should be but
sparingly gratified with pleasing odors or distressed by ungrateful ones.
No greater mistake can be made in sick-rooms than dealing largely in
aromatic vinegar, eau de cologne, lavender water, and other perfumes.
This hiding of one odor by another is like trying to put away the taste of
bitter aloes by that of Epsom salts. Physical comfort is best secured by
rarely permitting an infraction of the rule that the condition of health is
no odor at all." — Wilson on the Five Gateways of Knowledge.

45. What is sight ? What information does it furnish ? Composite visual sensations ?

46. Comparison between sight and hearing ? Relative capacity of deaf and blind f

THE SPECIAL SENSES 273

in support of their position the fact that the blind are com-
monly cheerful ami gay, while the deaf are inclined to be
morose and melancholy. In respect to the relative capacity
for receiving education in the deaf and blind, it is found that
the former learn more quickly, but their attainments are not
profound; while the blind acquire more slowly, but are able
to study more thoroughly.

47. Light — The Optic Nerve. — Unlike the senses previously
considered — touch, taste, and smell — sight does not bring us
into immediate contact with the bodies that are examined ; but,
by it, we perceive the existence and qualities of objects that are
at a greater or less distance from us. In the case of the stars,
the distance is incalculable, while the book we read is removed
but a few inches. Light is the agent which gives to this sense
its wide range. The nature of this mysterious force is not
known, and it is not here to be discussed, since its study
belongs more properly to the province of natural philosophy.

48. It is sufficient, in this connection, to state that the theory
of light now generally accepted, and which best explains the
facts of optics, is that known as the undulatory theory. This
theory supposes that there exists an intangible, elastic medium,
which rills all space, and penetrates all transparent substances,
and which is thrown into exceedingly rapid undulations or
waves, by the sun and every other luminous body — the undu-
lations being propagated with extreme rapidity, and moving
not less than 186,000 miles in a second.

49. These waves are thought to produce in the eye the sen-
sation of light, in the same manner as the sonorous vibrations
of the air produce in the ear the sensation of sound. That
part of the eye which is sensitive to these waves is the expan-
sion of the optic nerve. It is sensitive to no other impression
than that of light, and it is the only nerve which is acted upon
by this agent. The optic nerve, also called the " second pair "
of cranial nerves, is the means of communication between the
eye and the brain.

47. Bight unlike the other senso ? In the case of the stars ?

48. The umlulatory theory of light ? What does the theory suppose 1

49. The sensation of light ? Optic nerve?

L'74 THE SPECIAL SENSES

50. The two nerves constituting the pair arise from ganglia
lying at the base of the cerebrum — one of them on each side
— from which points they advance to the eyes, being united
together in the middle of their course in the form of the letter
X (Fig. 57, 2). By this union the two eyes are enabled to act
harmoniously, and in some respects to serve as a double organ.
By reason of this same intimate nervous communication, when
serious disease affects one eye, the fellow-eye is extremely
liable to become the seat of sympathetic inflammation ; and this,
if neglected, almost certainly results in hopeless blindness.

51. The Organ of Sight — The Eye. — The proximity of the
eye to the brain, and the important part it performs in giving
expression to the emotions, have given it the name of "the
window of the soul." The exceeding beauty of its external
parts, and the high value of its function, have long made this
organ the subject of enthusiastic study. It is chiefly within
the last twenty years, however, that this study has been suc-
cessful and fruitful of practical results. Several ingenious
instruments have been invented for the examination of the eye
in health and disease, and new operations have been devised
for the relief of blindness and of impaired vision. As a result,
it is now a well-marked fact that, in civilized lands, the num-
ber of those who suffer from loss of sight is proportionally
much less than in countries where science is less known and
cultivated.

52. The most obvious fact in respect to the apparatus of
sight is that there are two eyes, which may either act together
as one, and be fixed upon one object, or one eye may be used
independently of the other. In consequence of this arrange-
ment, the loss of one eye does not necessitate blindness, and,
in fact, it not infrequently happens that the sight of one eye
may be long impaired or lost before the fact is discovered.
We next notice that the eyes are placed at the most elevated

50. The two nerves constituting the pair of nerves ?

51. Why is the eye called " the window of the soul " ? Why the subject of enthusiastic
study ?

52. The most obvious fact ? The consequence '( The next thing- noticed ? Its range of
view ? Of what does the organ of vision consist ?

THE SPECIAL SEXSES L'7.")

part of the body, in front, and near the brain. Tiny also con -
mand a wide range of view, being moved with greal rapidity,
and being further aided by the free motion of the head and
neck. The organ of vision consists essentially of two parts:
the optical instrument itself — the eyeball — and its envelop-
ing parts, or the case in which The instrument is kept free from
harm. The latter, which are external, and which we shall first
consider, are chiefly the orbits, the eyelids, and the apparatus
for the tears.

53. The Orbits. — The eyeball, which is a delicate organ, is
well defended against external injury within the orbits or bony
sockets of the head. These are deep conical hollows, bounded
in part by the bones of the skull, and in part by those of the
nose and cheek. The orbit juts out beyond the most exposed
portion of the eyeball, as may be seen by laying a book over
the eye, when it will be found that no part of the eyeball,
unless it be very prominent, will be touched by the book ; so
that the only direction in which an injury is liable to be
received is immediately in front of the eye. The overhanging
brow is itself covered by a layer of thick skin, studded with
short, stout hairs, which are so bent as to prevent the perspira-
tion from running into the eye and obscuring vision. Through
a hole in the bottom of the orbit, the nerve of sight passes out-
ward from the brain. The orbit also contains a considerable
amount of a fatty tissue, upon which, as upon an elastic
cushion, the eye rests.

54. The Eyelids. — The eyelids are two movable curtains, or
folds, which, when shut, cover the front part of the orbit, and
hide the eye from view. The upper lid is the larger, has a
curved margin, and moves freely, while the lower lid is com-
paratively short and straight, and has but a slight degree of
motion (Fig. 63). Skin covers the exterior of the lids, while a
fine mucous membrane lines their inner surface, and is likewise
spread out over the entire front of the eyeball. This membrane.

58. The protection of the eyeball against injury ? The overhanging brow J The opening
for the optic nerve ?

54. What are the eyelids? The upper ltd? The lower one ? The mucous membrane of
the eve ?

v,

THE SPECIAL SEXSES

which is called the conjunctiva, is highly sensitive, and thus
plays an important part in protecting the eye against the lodg-
ment of sand, ashes, chaff,
and other foreign particles
that are blown about in the
air. This sensitive mem-
brane will not endure the
presence of these particles.
If any dust finds access, b
causes a constant winking,
a flow of tears, and other
signs of irritation, until it
is removed. I A'""' Note 8.)

55. The long, silky eye-
lashes, which garnish the
edges of the lids, act like a
sieve to prevent the entry of
dust and other irritants ; and
together wutli the lids, they
regulate the amount of light which is permitted to enter the
eye, so that it is shielded from a sudden flood or glare of light.
The little points seen in the figure just within the line of the
lashes, especially on the lower lid, represent the mouths of
numerous little sebaceous glands (Fig. 64, d, d), such as are
always found in the neighborhood of hairs. These glands sup-
ply a thick, oily material which greases the edges of the lids
and prevents their adhering together, and likewise prevents
the overflow of the tears upon the cheek.

Fig. 63. —Front View of Bight Eye
(Natural Size)

1. The Lachrymal, or tear gland, lying be-
neath the upper eyelid

2. The Nasal Duct is shown by the dotted
line. The * marks the orifice in the lower lid

The central black spot is the pupil; sur-
rounding it is the iris; and the triangular
white spaces are the visible portion of the
sclerotic

8. How to Remove Foreign Bodies from the Eye. —"Lay your
finger on the cheek, and draw the lower lid gently down, while the person
looks as much upward as possible, and we shall see about the whole ex-
tent of the lower portion of the conjunctiva, and thus, if any foreign
substance is there, it will be readily detected, and easily wiped away with
a fold,-,! soft rag or handkerchief. Both lids have a piece of cartilage in
them to stiffen them, like pasteboard, and keep them fitting close to the
eyeball. The upper portion of this conjunctival sac can only be seen by
turning over the upper lid. The way to do this is to let the person look

55. The eyelashes ? The little points within the line of the lashes? Of what use are
these glands ?

THE SPErr.iL SEXSES 277

56. The Lachrymal Fluid, or the Tears. Just within tin-
outer part of the bony arch of the brow, where the bone may
be felt to be sharper than in other positions, is lodged a little
organ called the lachrymal gland, the situation of which is
indicated in Fig. 03, 1. This is the gland whence Mows the
watery secretion, commonly called the tears, which is designed
to perform an exceedingly important duty in lubricating tin-
lids, and in keeping the exposed surface of the eyeball moist
and transparent. For. without this or some similar liquid, the
front of the eye would speedily become dry and lustreless, like
that of a fish which has been removed from the water ; the
simple exposure of the eye to the air would then suffice to
destroy vision.

57. This secretion of the tears takes place at all times,
during the night as well as the day ; but it is seldom noticed,
unless when under the influence of some strong mental emo-
tion— whether of sorrow or happiness — it is poured forth
in excess, so as to overflow the lids. Strong light or a rapid
breeze will, among many other causes, excite the flow of the
tears. That portion of this secretion which is not used in
moistening the eye is carried off into the nose by a canal situ-
down with the eyes closed. Taking hold of the lashes with one hand,
and applying a pencil, or some small, round, smooth object, over the lid
above the globe, we lift the lashes out and up, warning the person to still
keep lookinu down. The lid will suddenly turn over with a little spring
from the bending of the cartilage. In this way nearly the whole of the
conjunctival sac will be exposed, and any foreign body wiped away, as
above described. But suppose no friend or oculist is by us to do this.
The next best thing is to take hold of the lashes of the upper lid, and
draw it forward and downward over the Lower one, blowing the nose
violently with the other hand at the same time.

'•If the foreign substance is on the cornea, take a strip of paper not
stiffer than ordinary writing-paper, about a quarter of an inch wide, and
roll it up as if you wrere going to make a candle-lighter. Look at the
lower end, and you will see it comes to a point. With this point now you
may safely attempt to remove any foreign substance from the cornea.
The tears which will flow soften the paper, and prevent injury to the
delicate covering membrane of the cornea." — Dr. B. Jay Jeffries.

56. The location of the lachrymal gland ': The um- of the sdand ?

57. When does the Becretion of the tears ocoorJ The secretion not used fur the
Location of the nasal duct ? Its use 1 The overflow of tears in old people ?

278 THE SPECIAL SENSES

ated near the inner angle of the eye, called, the nasal duct.
This duct is shown in Fig. 63, 2, and is connected with each
lid by delicate tubes, which are indicated by dotted lines in
the figure ; the asterisk marks the little opening in the lower
lid, by which the tears enter the nasal duct. By gently turn-
ing the inner part of that lid downward, and looking in a mir-
ror, this small " lachrymal point " may be seen in your own
eye. In old people, these points become turned outward, and
do not conduct the tears to the nasal cavity, thus causing an
overflow of tears upon the face.

58. Thus Ave observe that the gland which forms the tears
is placed at the outer part of the eye, while their means of
exit is at the inner angle of the eye; which fact renders it
necessary that this watery fluid shall pass over the surface of
the eyeball before it can escape. This arrangement cannot be
accidental, but evinces design, as it thus secures the perfect
lubrication of the surface of the eye, and cleanses it from the
smaller particles of dust which may enter it, in spite of the
vigilance of the lids and lashes. The act of winking, which
is generally unconsciously performed, and which takes place
six or more times in a minute, assists this passage of the tears
across the eye, and is especially frequent when the secretion
is most abundant.

59. The Eyeball. — The eyeball, or globe of the eye, upon
which sight depends, is, as the name indicates, spherical in
shape. It is not a perfect sphere, since the front part projects
somewhat beyond the rest, and at the posterior part the optic
nerve (Fig. 64, n) is united to it, resembling the junction of
the stem with the fruit. In its long diameter — that is, from
side to side — it measures a little more than an inch ; in other
directions it is rather less than an inch. In structure the ball
of the eye is firm, and its tense round contour may in part be
felt by pressing the fingers over the closed lids.

60. The eyeball is composed chiefly of three internal, trans-
parent media, called humors, and three investing coats, or

58. The watery fluid passing over the eyeball ? Design of the arrangement f Winking ?

59. Describe the shape of the eyeball. Its structure.

60. Of what is the eyeball composed ? State how.

THE SPEC! A/. SENSES

279

tunics. The former are the aqueous humor, Fig. <', 1. a, the
crystalline lens i.. and the vitreous humor v. Of these the lens
alone is solid. The three coats of the eyeball arc called the
sclerotic s, the choroid Ch, and the retina b. This arrangemenl
exists in respect to five-sixths of the globe of the eye, but in
the anterior one-sixth, these coats are replaced by the cornea c,
which is thin and transparent, so that the rays of light pass
freely through it. as through a clear window-pane.

61. In shape, the cornea is circular and prominent, resem-
bling a miniature watch-glass, about ^z of an inch thick. In

Fig. 64. — Ykrtk

3 A I.

Se(

tion of the Eye (Enlarged)

C. The Cornea

Ch, The Choroid

A, The Aqueous Humor

R, The Retina

I. The Iris

N, The Optic Nerve

P, The Pupil

DD, The Eyelids

L, The Crystalline Lens

X, The Levator Muscle of the Upper

H, The Ligament of the Lens

Lid

B, The Ciliary Process

Y, The Upper Btraight Muscle of the

V, The Cavity containing the Vitreous Humor

Eye

S, The Sclerotic

Z, The Lower Straight Muscle

structure, it resembles horn (as the name signifies), or the nail
of the finger, and is destitute of blood-vessels. The sclerotic

The shape of the cornea 1

The " white of the eve'

280 THE SPECIAL SEXSES

(from scleros, hard) is composed of dense, white fibrous tissue,
and gives to the eyeball its firmness of figure and its white
color ; in front, it constitutes the part commonly called " the
white of the eye." It is one of the strongest tissues in the
body. It possesses very few vessels, and is not very sensitive.
It affords protection to the extremely delicate interior parts
of the eye, and the little muscles which effect its movements
are inserted into the sclerotic a short distance behind the
cornea (see Fig. 61, t, z). It is perforated posteriorly to
admit the optic nerve.

62. The choroid is the second or middle coat of the eyeball,
and lies closely attached to the inner surface of the sclerotic.
Unlike the latter, its structure is soft and tender ; it is dark
in color, and possesses a great abundance of blood-vessels. Its
dark color is due to a layer of dark brown or chocolate-colored
cells spread out over its inner surface. This "dark layer serves
to absorb the rays of light after they have traversed the trans-
parent structures in front of it. If the rays were reflected
from side to side within the eye, instead of being thus absorbed,
confused vision would result from the multitude of images
which would be impressed upon the optic nerve.

63. This mechanism has been unconsciously imitated by the
opticians, who, when they make a microscope or telescope, take
care that the interior of its tube shall be coated with a thick
layer of black paint or lamp-black ; for without it, a clear
delineation of the object to be viewed is impossible. The
albinos, in whom these dark cells of the choroid are wanting,
have imperfect vision, especially in the daytime and in strong
lights. The dark cells are also wanting in white rabbits,
and other animals that have red or pink eyes ; their vision
appears to be imperfect in the presence of a bright light.

64. The Iris. — Continuous with the choroid, in the front
part of the globe of the eye, is a thin, circular curtain, which

C2. The second or middle coat of the eyeball ? Its dark color ?

63. Similar mechanism in microscopes ? The albinos? White rabbits ?

64. What is the iris '! Its construction J How is the Bize of the ]>u]>il regulated I

THE SPECIAL SENSES

281

Fig. 66.— Fro*
viewed fkos

PEN80BY Lie.

M , l [ON "I TUB Y.\ IV. Ml,

bbiiind, am> showing 808-
ent, Iris, and Pupil

occasions the brown, blue, or gray color of the eye in different
individuals. On account of the varieties of its color, this
membrane has received the

name Iris, which is the
Greek word for " rainbow "
(see Fig. 64, i). A front
view of it is shown in Fig.
63. The iris is pierced in
its centre by a round open-
ing, called the pupil (p),
which is constantly vary-
ing in size. In olden times
it was spoken of as the
"apple of the eye." The
hinder surface of the iris,
except in albinos, has a
layer of dark coloring mat-
ter resembling that of the

choroid. The iris is a muscular organ, and contains two
distinct sets of fibres, one of which is circular, while the
other radiates outward from the pupil. Their action regulates
the size of the pupil ; for when the circular set acts, the open-
ing contracts. Their action is involuntary, and depends on
the reflex system of nerves, which causes the contraction of
the pupil when a strong light falls upon the eye, and its expan-
sion when the illumination is feeble. The suspensory ligament
holds the crystalline lens in its place. (Fig. 65.)

65. The iris, accordingly, serves a very useful purpose in
regulating the admission of light to the eye (see Fig. 65). It,
however, does not act instantaneously; and hence, when we
pass quickly from a dark room into the bright sunlight, the
vision is at first confused by the glare of light, but as soon as
the pupil contracts, the ability to see becomes perfect. On the
other hand, when we enter a dark apartment, such as a cellar,
for a short time we can see nothing clearly ; but as soon as the

65. The admission of litrht to the eye? The action of the iris under different circum-
stances ? The lustre of the eye, how affected in youth and old age f

282 THE SPECIAL SENSES

pupil expands and admits more light, we are enabled to distin-
guish the surrounding objects. Animals of the cat species,
and others which prowl around after nightfall, are enabled to
see in the dark by having the iris very dilatable. The size of
the pupil affects the lustre of the eye. When it is large, as it
usually is during youth, the eye appears clear and brilliant ;
while in old age the pupil is small and the eye is dull. The
brilliancy of the eye is in part, at least, dependent upon the
reflection of light from the front surface of the crystalline
lens.

66. Certain poisonous vegetables have the property of caus-
ing the pupil to dilate, and have been used in small doses to
increase the beauty of the eye. One of these drugs has been
so largely used by the ladies for this purpose that it has
received the name belladonna, from the Italian words meaning
" beautiful lady." This hazardous practice has resulted more
than once in the death of the person desiring thus to increase
her personal attraction. The common English name for bella-
donna is "deadly nightshade." (In the diagram on page 290
the shape and relations of the iris are more accurately shown
than in the figures referred to above.)

67. The Retina constitutes the third and inner coat of the
globe of the eye. This, the important part of the eye that is
sensitive to light, is a kind of nervous membrane, formed by
the expansion of the optic nerve. Its texture is soft, smooth,
and very thin ; it is translucent and of an opaline, or grayish-
white color. It is sensitive to light alone ; and if any form of
mechanical irritation be applied to it, the sensations of touch
and pain are not experienced, but flashes of fire, sparks, and
other luminous appearances are perceived. Thus an electric
shock given to the eyeball occasions a flash of light; and a
sudden fall, or a blow upon the eye, is often apparently accom-
panied by the vision of " stars."

68. These phenomena are due to what is termed the " specific

66. Means used to increase the beauty of the eye ? The injurious consequences?

67. What part does the retina istitute? How formed? Its texture? Color? Sensi-
tiveness ?

66. Specific energy of the optic nerve ? Trial in Germany ?

THE SPECIAL SENSES 283

energy " of the optic nerve, which nerve, in common with the
other nerves of the special sense, obeys a general law of nature,
which requires that, whenever one of these nerves is stimulated,
it shall respond with the sensation peculiar to itself. These
flashes of retinal light have no power to illuminate external
objects, although the opposite of this statement has been main-
tained. On the occasion of a remarkable trial in Germany, it
was claimed by a person who had been severely assaulted on a
very dark night, that the flashes of light caused by repeated
blows upon the head enabled him to see with sufficient distinct-
ness to recognize his assailant. But the evidence of scientific
men entirely refuted this claim, by pronouncing that the eye,
under the circumstances named, was incapacitated for vision.
Too intense light occasions a feeling of pain, but it is of a
peculiar kind, and is termed "dazzling;"

69. All parts of the retina are not equally sensitive, and
singularly enough, the point of entry of the nerve of sight in
the back part of the eyeball is entirely insensible to light, and
is called the " blind spot." The existence of this point may
be proved by a simple experiment. Hold the accompanying
figure, on page 283, directly in front and parallel with the eyes.

Close the left eye, and fix the sight steadily on the left-hand
circle ; then, by gradually varying the distance of the figure
from the eye, at a certain distance (about six inches), the right-
hand circle will disappear, but nearer or further than that, it
will be plainly seen. The other eye may be also tried, with a
similar result: if the gaze be directed to the right-hand circle,
the left one will seem to disappear. The experiment may be

69. Sensitiveness of all parts of the retina 1 Experiment to prove the existence of the
"blind »pot " ?

284 THE SPECIAL SENSES

repeated by using two black buttons on the marble top of a
bureau, or on some other white surface. The blind spot does
not practically interfere with vision, since the eye is seldom
fixed immovably on an object, and the insensitive parts of the
two eyes can never be directed upon the same object at the
same time.

70. Impressions made upon the retina are not at once lost,
but continue a measurable length of time, and then gradually
fade away. Thus, a bright light, or color, gazed at intently,
cannot be immediately dismissed from sight by closing or turn-
ing away the eyes. A stick lighted at one end, if whirled
around rapidly in the dark, presents the appearance of an un-
broken luminous ring; and the spokes of a rapidly revolving
carriage-wheel seem to be merged into a plane surface. If an
object move too rapidly to produce this sort of lasting impres-
sion, it is invisible, as in the case of a cannon-ball passing
through the air in front of us.

71. If a card, painted with two primary colors — as red and
yellow — be made to rotate swiftly, the eye perceives neither
of them distinctly ; but the card appears painted with their
secondary color — orange. The average duration of retinal
images is estimated at one-eighth of a second ; and it is because
they thus endure, that the act of winking, which takes place
so frequently, but so quickly, is not noticed and does not inter-
rupt the vision. The retina is easily fatigued or deprived of
its sensibility. After looking steadfastly at a bright light, or
at a white object on a black ground, a dark spot corresponding
in shape to the bright object, presents itself in whatever direc-
tion we look. This spot passes away as the retina resumes its
activity.

72. If a bright color be gazed at intently, and the eyes then
be turned to a white surface, a spot will appear ; but its color
will be the complement of that of the object. Fix the eye
upon a red wafer upon a white ground, and on removing the

70. Duration of impressions upon the retina i How illustrated ?

71. What further illustration '! Winking, why it is not noticed ? Ease with which the
retina is fatigued or deprived of sensibility 1 How shown ?

72. How further shown ? How is the result accounted for ? "Color-blindness"?

THE SPECIAL SENSES 285

wafer a greenish spot of the same shape takes its place. This
result happens because a certain portion of the retina has
exhausted its power to perceive the red ray, and perceives only
its complementary ray, which is green. The color thus sub-
stituted by the exhausted retina is called a physiological or
accidental color. In some persons the retina is incapable of
distinguishing different colors, when they are said to be affected
with " color-blindness." Thus, red and green may appear alike,
and then a cherry-tree, full of ripe fruit, will seem of the same
color in every part. Railroad accidents have occurred because
the engineer of the train, who was color-blind, has mistaken the
color of a signal. {Bead Note 9.)

73. The Crystalline Lens. — Across the front of the eye, just
behind the iris, is situated the crystalline lens, enclosed within
its own capsule. It is supported in its place partly by a deli-
cate circular ligament, and partly by the pressure of adjacent
structures. It is colorless and perfectly transparent, and has
a firm but elastic texture. In shape, it is doubly convex, and
may be rudely compared to a small lemon-drop. The front
face of the lens is flatter than the other, and is in contact with
the iris near its pupillary margin, as is represented in the dia-
gram of page 290. It is only one-fourth of an inch thick.

9. Color-blindness. — " Daltonism, or color-blindness, receives its
name from the eminent English chemist who described this infirmity
as it existed in his own case. It arises from an unnatural condition
of the organs of vision which prevents the discrimination of certain
colors. Some persons will mistake red for green ; so that ripe cherries on
a tree appear the same as the leaves; others recognize only black and
white. Persons thus affected are sometimes incapable of discriminating
musical tones. The healthy eye ordinarily fails to discriminate between
certain colors, blue and green especially, when viewed by artificial
light. But even this may in a measure be overcome by training, so
that an expert dealer in silk obtains a knowledge of the shades of blue,
green, and violet, which is proof against the confusing influence of gas-
light and tinted curtains. The eyes of persons who have much to do with
colors are more liable to Income overstrained than those dealing chiefly
with rays of white light." — Flint's Physiology (in part).

73. The location of the crystalline lens ? How supported ? Its color and texture ?
Shape ? Size ?

286 THE SPECIAL SENSES

74. When this little body becomes opaque, and no longer
affords free passage to the rays of light, as often happens with
the advance of age, an affection termed " cataract " is produced.
Between the crystalline lens and the cornea is a small space
which contains the aqueous humor (see Fig. 64, a). This humor
consists of five or six drops of a clear, colorless liquid very
much like water, as its name implies. That part of the globe
of the eye lying behind the lens is occupied by the vitreous
humor, so called from its fancied resemblance to melted glass
(Fig. 64, v). This humor is a transparent, jelly-like mass,
enclosed within an exceedingly thin membrane. It lies very
closely applied to the retina, or nervous membrane of the eye,
and constitutes fully two-thirds of the bulk of the eyeball.

75. The Uses of the Crystalline Lens. — A convex lens has the
property of converging the rays of light which pass through it ;
and the point at which it causes them to meet is termed its

The Retinal Image

focus. If a lens of this description, such as a magnifying or
burning-glass, be held in front of an open window, in such a
position as to allow its focus to fall upon a piece of paper, it
will be found to depict upon the paper a miniature image of the
scene outside of the window. It will be further noticed that
the image is inverted, or upside down, and that the paper at
the place upon which the image is thrown is much brighter
than any other part.

74. Cataract ? Aqueous humor ? Vitreous humor ?

75. What is a lens and its focus f The miniature image, how produced ?

THE SPECIAL SENSES 287

76. Now all the transparent structures of the eye, but es-
pecially the crystalline lens, operate upon the retina, as the
convex lens acts upon the paper — that is, they paint upon the
retina a bright, inverted miniature of the objects that appear in
trout of the eye (Fig. 67). That this actually takes place may
be proved by experiment. If the eyeball of a white rabbit, the
walls of which are transparent, be examined while a lighted
candle is held before the cornea, an image of the candle-name
may be seen upon the retina.

K77. The form and structure of the crystalline lens endow it
with a remarkable degree of refractive power, and enable it to
converge all the rays of light that enter it through the pupil,
to a focus exactly at the surface of the retina. When this lens
is removed from the eye, as is frequently done for the cure of
cataract, it is found that the rays of light then have their focus
three-eighths of an inch behind the retina; that the image is
four times larger than in the healthy eye; that it is less bril-
liant, and that its outline is very indistinct. From this we
learn that one of the uses of the crystalline lens is to make the
retinal image bright and sharply defined, at the same time that
it reduces its size. Indeed, the small size of the image is a
great advantage, as it enables the limited surface of the retina
to receive, at a glance, impressions from a considerable field of
vision.

78. As the image upon the retina is inverted, how does the
mind perceive the object in its true, erect position? Many
explanations have been advanced, but the simplest and most
satisfactory appears to be found in the fact that the retina
observes no difference, so to speak, between the right and left
or the upper and lower positions of objects. In fact, the mind
is never conscious of the formation of a retinal image, and
until instructed, has no knowledge that it exists. Conse-
quently, our knowledge of the relative location of external
objects must be obtained from some other source than the ret-

76. How are figures painted upon t ho retina ? How proved ?

77. What can be said in respect to the form and structure of the crystalline tana !
7S. How is the inverted Image upon the retina presented in its true position to the i

288 THE SPECIAL SENSES

ina. The probable source of this knowledge is the habitual
comparison of those objects with the position of our own
bodies; thus, to see an elevated object, we know we must raise
the head and eyes ; and to see one at our right hand, we must
turn the head and eyes to the right.

79. Long-sight or Hyperopia, and Short-sight or Myopia. —

The eye is not in all cases perfectly formed. For example,
persons may from birth have the cornea too prominent or too
flat, or the lens may be too thick or too thin. In either of
these conditions sight will be more or less defective from the
first, and the defect will not tend to disappear as life advances.
The most common imperfection, however, is in the shape of
the globe; which may be short (Fig. 68, h), as compared with
the natural eye, n, or it may be too long, m.

80. When the globe is short, only objects that are at a
distance can be clearly seen, and the condition of the vision is
known as " long-sight," or hyperopia. It will be observed, by

Fiii. (K — Tin-: Different Shapes of the Globe of the Eye

N, The Natural Eye M, The Short-sighted Eye

H, The Long-sighted Eye S, Parallel Eays from the Sun

reference to Fig. 68, that the focus of the rays of light would
fall behind the retina of this eye. When the globe is too long,
only objects that are very near to the eye can be clearly seen,
and the condition resulting from this defect is termed " short-
sight," or myopia. The focus of the rays of light is, in this
case, formed in the interior of the eye in front of the retina.

T9. The uniform perfection of the eye ? Examples ? The most common imperfection ?
80. How is "long-sight " explained ? " Short-sight " ?

THE SPECIAL SENSES 289

81. Long-sight, or hyperopia, is common among school-chil-
dren, nearly as much so as short-sight, and must no\ be
confounded with tin- defect known as the " far-si; gh t " of old
people; although in both affections the sight is improved by
the use of convex glasses. Children not infrequently discover
that they see much better when they chance to put on the
spectacles of old persons. For the relief of short-sight, con-
cave glasses should be employed ; as they so scatter the rays
of light as to bring the focus to the retina, and thus cause the
vision of remote objects to become at once distinct. That form
of "squint," in which the eyes are turned inward, is generally
dependent upon long-sight, while that rarer form, when they
turn outward, is due to short-sight. (Bead Note 10.)

82. The Function of Accommodation. — If, after looking
through an opera-glass at a very distant object, it is desired
to view another nearer at hand, it will be found impossible
to obtain a clear vision of the second object unless the adjust-
ment of the instrument be altered, which is effected by means
of the screw. If an object, like the end of a pencil, be held
near the eye, in a line with another object at the other side of

10. On the Production of Short-Sight. — ;; The observations of Colin
in the schools ami University of Breslau, of Kruger in Frankfort-on-the-
Main, of Erismann in St. Petersburgh, of Von Hoffmann in Wiesbaden,
and others abroad, prove most conclusively that one of the bad effects of
school and college life is to produce diseases of the eves. They have
shown that near-sightedness increases rapidly in frequency as you go up
in the scale of schools from the primaries of the rural districts to the
universities. The gravity of this finding may be appreciated when we
remember that near-sightedness is a disease, and that it very frequently
descends from one generation to another, marked by such organic changes
in the eyes as tend to the production of the worst forms of the malady,
and to blindness. In 18G7, Cohn, of Breslau, published the results of the
examination of the eyes of 10,060 scholars. UN examinations covered
the entire range of school life. He found that 1,750 of the 10,060 children
had defective vision — about seventeen per cent. He also examined,
without selection, 410 of the 9f>4 students of the Breslau University, and
found that not one-third had normal eyes.'* — Dr. r. R. Agm w.

81. Long-sight, how common ? With what must it not be confounded ? Kind
for short-sight ? Why? BquintJ

82. What is stated in connection with the opera-glass ? Experiment with pencil and dis-
tant object f

290 THE SPECIAL SENSES

the room, or out of the window, and the eye be fixed first
upon one and then upon the other, it will be found that when
the pencil is clearly seen, the further object is indistinct ; and
when the latter is seen clearly, the pencil appears indistinct,
and that it is impossible to see both clearly at the same time.
Accordingly, the eye must have the capacity of adjusting itself
to distances, which is in some manner comparable to the action
of the screw of the opera-glass.

83. This, which has been called the function of accommoda-
tion, is one of the most admirable of all the powers of the
eye, and is exercised by the crystalline lens. It consists
essentially in a change in the curvature of the front surface
of the lens, partly through its own elasticity, and partly
through the action of the ciliary muscle. When the eye is
at rest — that is, when accommodated for a distant object —

^ic. ii'.t. — 1 ill-: hi'M'Tios of Accommodation

The right half of the diagram shows the eye at rest. The left half shows the lens
accommodated for near vision

the lens is flatter and its curvature diminished (see Fig. 69) ;
but when strongly accommodated for near vision, the lens
becomes thicker, its curvature increases, and the image on
the retina is made more sharp and distinct. Since a strong
light is not required in viewing near objects, the pupil con-
tracts, as is shown in the left-hand half of the diagram.

83. Function of accommodation ? Tn what does it consist? How is the function
explained f

THE SPECIAL SE.XSES 291

84. Old-sight, or Presbyopia. — But this marvellously beauti-
ful mechanism becomes worn with use ; or, more strictly speak-
ing, the lens, like other structures of the body, becomes harder
with the approach of old age. The material composing the
lens becomes less elastic, the power to increase its curvature is
gradually lost, and as a consequence, the person is obliged to
hold the book further away when reading, and to seek a
stronger light. In a word, the function of accommodation
begins to fail, and is about the first evidence that marks the
decline of life. By looking at the last preceding diagram, and
remembering that the increased curvature of the lens cannot
take place, it will be at once understood why old-sight is bene-
fited in near vision by the convex lens, such as the spectacles
of old people contain. It acts as a substitute for the deficiency
of the crystalline lens. (Bead Note 11.)

11. The Choice of Glasses. — " The perfectly healthy, normal eye
begins to need a glass for ordinary work at between forty and forty-five
years of age — of course, we here exclude all debilitated conditions of the
body resulting from disease. Now, then, comes the question — shall we
put on glasses, and of what strength ? To answer some prevalent fallacies
handed down from one generation to another, we cannot do better than
quote from the highest authority, Prof. Donders, who says : ' The opinion
is rather general that we should refrain as long as possible from the use
of convex glasses. But, is it not folly to weary the eyes and the mind
together, without necessarily condemning ourselves to guess, with much
trouble, at the forms which we could see pretty well with glasses ? '

"Strangely enough, people have fallen also into the opposite fault.
Some have thought, by the early use of spectacles, to be able to preserve
their power of vision, and have recommended and employed ' conservative
glasses.' If I am not mistaken, self-interest had something to do with
this recommendation. So long as the eye does not err, and remains free
from fatigue in the work required of it, its own power is sufficient, and it
is inexpedient to seek assistance in the use of convex glasses. Having
made up their minds that they require glasses, how are they to know what
glasses to procure, or what number is correct ? Generally, people go
to the nearest spectacle-vender, and purchase what they see best with at
the time. We say distinctly, once for all, that the ophthalmic surgeon is
the one to be consulted as to the wearing of glasses. He, by testing the
eye, can alone decide whether any, and what glasses, should be worn.
Opticians and spectacle-venders know nothing about the laws which
govern the refraction and accommodation of the eye. It is not their

84. Change of sight with the approach of old age ? Explain the change.

292 THE SPECIAL SENSES

85. The Sense of Hearing — Sound. — Hearing is the special
sense by means of which we are made acquainted with sound.
What is sound ? It is an impression made upon the organs of
hearing, by the vibrations of elastic bodies. This impression
is commonly propagated by means of the air, which is thrown
into delicate undulations in all directions from the vibrating
substance. When a stone is thrown into smooth water, a wave
of circular form is set in motion from the point where the
stone struck, which, as it advances, constantly increases in size
and diminishes in force.

86. Somewhat resembling this is the undulation, or sound-
wave, which is imparted by a sonorous vibration to the
surrounding atmosphere. Its shape, however, is spherical,
rather than circular, since it radiates upward, downward, and
obliquely, as well as horizontally, like the wave in water.
The rate of motion of this spherical wave of air is about 1050
feet per second, or one mile in five seconds. In water, sound
travels four times as fast as in air, and still more rapidly
through solid bodies ; along an iron rod its velocity is equal
to two miles per second.

87. The earth, likewise, is a good conductor of sound. It
is said that the Indian of our western prairies can, by listening
at the surface of the ground, hear the advance of a troop of
cavalry while they are still out of sight, and can even discrim-
inate between their tread and that of a herd of buffaloes. Solid
substances also convey sounds with greater power than air.

business, any more than it is the apothecary's to know about disease.
The advice of the ophthalmic surgeon will also be found invaluable as to
how to wear glasses, whether springs or spectacles, so as not to fatigue
the eyes by straining them from improper use of these invaluable aids to
man's happiness. We conclude by saying, that all advice in this article
applies to those having normal, healthy, strong eyes." — Dr. B. Joy
Jeffries.

85. Hearing? What is sound ? How propagated commonly J Stone thrown in water?

86. Sound-wave in the atmosphere ? Its shape? Hate of motion ? Sound in water, air,
and solid bodies ?

87. The earth as a conductor of sound? What has the Western Indian been taught?
Solid substances as conductors? As regards sound, in what respect is air necessary?
Sound in a vacuum ?

THE SPECIAL SEXSES 293

If the ear be pressed against one end of a long beam, the
scratching of a pin at the other extremity may be distinctly
heard, which will not be at all audible when the ear is removed
from the beam. Although air is not the besl medium for con-
veying sound, it is necessary for its production. Sound can-
not be produced in a vacuum, as is shown by ringing a bell in
the exhausted receiver of an air-pump, for it is then entirely
inaudible. But let the air be re-admitted gradually, then the
tones become more and more distinct, and when the receiver is
again full of air, they will be as clear as usual.

88. All sonorous bodies do not vibrate with the same degree
of rapidity, and upon this fact depends the pitch of the sounds
that they respectively produce. The more frequent the num-
ber of vibrations within a given time, the higher will be the
pitch; and the fewer their number, the lower or graver will it
be. Now, the rate of the successive vibrations of different
notes has been measured, and it has thus been found that if
they are less than sixteen in a second, no sound is audible;
while, if they exceed 60,000 per second, the sound is very
faint, and is painful to the ear. The extreme limit of the
capacity of the human ear may be considered as included
between these points, but the sounds which we ordinarily hear
are embraced between 100 and 3000 vibrations per second.

89. The ear, which is the proper organ of hearing, is the
most complicated of all the structures that are employed in
the reception of external impressions. The parts of which it
is composed are numerous, and some of them are extremely
small and delicate. Nearly all these parts are located in an
irregularly shaped cavity hollowed out in the temporal, or
" temple " bone of each side of the head. That part of the
bone in which the auditory cavity is placed has the densest
structure of all bones of the body, and has. therefore, been
called the •• petrous," or rocky part of the temporal bone. In
studying the ear, it is necessary to consider it as divided into
three portions, which are called, from their relative positions,

88. Pitch ? To what due ? Capacity of ear ?

89. The ear. Its divisions.

294

THE SPECIAL SENSES

the external ear, the middle ear, and the internal ear. (In the
diagram, Fig. 70, a, the first is not shaded, the second is lightly-
shaded, and the last has a dark background.)

90. The External Ear. — The external portion of the organ
of hearing, designated in Fig. 70, a, includes, first, that outer
part (a), which is commonly spoken of as " the ear," but which

Fig. 70. — The Ear and its Different Parts

A, Diagram of the Ear
a, b, External Ear d, Middle Ear

c, Membrana tympani e, Internal Ear

B to B"\ Bones of the Middle Ear (magnified)
C, The Labyrinths or Internal Ear (highly magnified)

in fact is only the portal of that organ; and, secondly, the
auditory canal (b). The former consists of a flat, flexible piece
of cartilage, projecting slightly from the side of the head,
attached to it by ligaments, and supplied with a few weak
muscles. Its surface is uneven, and curiously curved, and from
its resemblance to a shell it has been called the concha. It
probably serves to collect sounds, and to give them an inward
direction, although its removal is said not to impair the acute-
ness of hearing more than a few days.

90. Of what does the external portion of the organ of hearing consist? Describe the
>ortal of that organ known as the ear. Its u«c?

THE SPECIAL SENSES l'U5

91. In those animals whose hearing is more delicate than
that of man, the corresponding organ is of greater importance]
it being larger, and supplied with muscles of greater power,
so that it serves as a natural kind of ear-trumpet, which is
easily movable in the direction of any sound that attracts the
attention of the animal. Bold, preying animals generally have
the concavity of this organ directed forward, while in timorous
animals, like the rabbit, it is directed backward. Fishes have
no outer ear, but sounds are transmitted directly through the
solid bones of the head, to the internal organ of hearing.

92. The auditory canal (Fig. 70, a, b), which is continuous
with the outer opening of the ear, is a passage an inch and
a quarter in length, its inner extremity being bounded by a
closely fitting, circular membrane. This canal is of oval form,
is directed forward and inward, and is slightly curved, so that
the inner end is ordinarily concealed from view. The pouch
of the skin which lines this passage is smooth and thin,
especially at the lower end, where it covers the membrane
just mentioned.

93. As in the case of the nostrils, a number of small, stiff
hairs garnish the margin of the auditory canal, and guard it,
to some extent, against the entrance of insects and other for-
eign objects. The skin, too, covering its outer half, is furnished
with a belt of little glands which secrete a yellow, bitter sub-
stance, called "ear-wax,'1 which is especially obnoxious to small
insects. As the outer layer of this wax-like material loses its
useful properties it becomes dry, and falls out of the ear in the
form of minute, thin scales, a fresh supply being furnished
from the little glands beneath. In its form, the auditory canal
resembles the tube of an ear-trumpet, and serves to convey the
waves of sound to the middle portion of the ear.

94. The Middle Ear, or Tympanum, — The middle ear is a
small cavity, or chamber, of irregular shape, about one-fourth
of an inch across from side to side, and half an inch long (see

91. The ear in the animals of delicate hearing ? Rabbit ? Fishes ?

92. What is the auditory canal f Describe it.

93. How is it guarded and protected f "Ear-wax"?

94. What is the middle ear ? Why called tympanum t

296

THE SPECIAL SEXSES

Fig. 70, a, cl). From the peculiar arrangement of its various
parts it has very properly been called the tympanum, or the
" drum of the ear." The middle, ear, like the external canal,
contains air.

95. The circular membrane, already mentioned as closing the
auditory canal, is the partition which separates the middle
from the external ear, and is called the membrana tympani (c),
and may be considered as the outer head of the drum of the
ear. It is sometimes itself spoken of as the " drum," but this

Fig. 71. — Showing the Internal Mechanism of the Ear (greatly enlarged)

is incorrect, since a drum is not a membrane, but is the hollow
space across which the membrane is stretched. This mem-
branous drum-head is very tense and elastic, and so thin as to
be almost transparent ; its margin is fastened into a circular
groove in the adjacent bone. Each wave of sound that touches
this delicate membrane causes it to vibrate, and it, in turn,
excites movements in the parts beyond.

96. Within the tympanum is arranged a chain of remark-
able " little bones," or ossicles. They are chiefly three in

95. What i> tin- membrana tympani ? Describe it.

;«'.. What are the ossicles ? Their number and names ? Their arrangement ?

THE SPECIAL SENSES 297

number, and from their peculiar shapes bear the following
names: malleus, or the mallet; incus, or the anvil; and stapes,
or the stirrup. A fourth, the smallest bone in the body, in
early life intervenes between the incus and the stapes, but at
a later period it becomes a part of the incus. It is called the
orbicular bone. Small as are these ossicles — and they, together,
weigh only a few grains — they have their little muscles, carti-
lages, and blood-vessels, as perfectly arranged as the larger
bones of the body. One end of the chain of ossicles, the mal-
let, is attached to the membrane of the tympanum, or outer
drum-head, while the other end, the stirrup, is firmly joined
by its foot-piece to a membrane in the opposite side of the
cavity. The chain, accordingly, hangs suspended across the
drum between the two membranes; and when the outer one
vibrates under the influence of the sound-wave, the "chain
swings inward and transmits the vibration to the entrance of
the inner ear.

97. The musical instrument, the drum, is not complete if
the air within be perfectly confined; we therefore find in all
instruments of this kind a small opening in the side, through
which air may pass freely. By this means the pressure of the
air upon the vellum which forms the head of the drum is made
equal upon all sides, and the resonance of the drum remains
unaffected by the varying density of the atmosphere. It will,
therefore, emit its proper sound, whether it be struck in the
rarefied air of the mountain-top, or in the condensed air of a
mine. The tympanum, or drum of the ear, in like manner has
an opening, by means of which it communicates freely with
the external air. This opening is a narrow canal, about an
inch and a half long, called the Eustachian tube, after the name
of its discoverer, Eustachius.

98. The course of this passage is indicated in Fig. 71,
directed downward and inward: its other extremity opens
into the upper part of the throat. The passage itself is ordi-
narily closed, but whenever the act of swallowing or gaping

97. The Eustachian tube ? Describe it, and state its use.

98. What can you state of the action of the Eustachian tube ?

298

THE SPECIAL SENSES

takes place, the orifice in the throat is stretched open, and the
air of the cavity of the tympanum may then be renewed. Air
may at will be made to enter through this tube, by closing the
mouth and nose, and then trying to force air through the latter.

Fig. 72. —Section of toe Right Ear

A, The Concha

B, Auditory Canal

C, Membrane of the Drum

(the lower half)

D, A Small Muscle

E, Incus, or Anvil

M, Malleus, or Mallet

I, Eustachian Tube

G, Semicircular Canals

H, Cochlea, or Snail's Shell

When this is done, a distinct crackle or clicking sound is per-
ceived, due to the movement of the membranes, and of the
little bones of the ear.

99. The Eustachian tube serves, also, as an escape-pipe for
the fluids which form within the middle ear ; and hence, when
its lining membrane becomes thickened, in consequence of a
cold or sore throat, and the passage is thus more or less choked
up, the fluids are unable to escape as usual, and therefore
accumulate within the ear. When this takes place, the vibra-
tions of the membrane are interfered with ; the sounds heard

99. What other purpose does the Eustachian tube serve? How is this shown:
' Tkrtat-deafness " ? Primary use of the Eustachian tube ?

THE SPECIAL SENSES 299

appear muffled and indistinct ; and a temporary difficulty of
hearing, which is known as " throat-deafness," is the result.
This result resembles the effect produced by interrupting the
vibrations of a sonorous body, such as all are familiar with ;
if the finger be placed upon a piano-string or bell when it La
struck, the proper sound is no longer fully and clearly emitted.
But the primary use of this tube is to afford a free communi-
cation between the middle ear and the external atmosphere,
and thus secure an equal pressure upon both sides of the mem-
brane of the drum of the ear, however the density of the atmos-
phere may vary. If, from undue tension of the membrane,
pain is experienced in the ears, when ascending into a rare
atmosphere, as in a balloon, or descending into a dense one,
as in a diving-bell, it may be relieved by repeating the act of
swallowing, from time to time, in order that the inner and
outer pressure may thus be promptly equalized.

100. The Internal Ear, or Labyrinth. — The most essential
part of the organ of hearing is the distribution of the auditor'/
nerve. This is found within the cavity of the internal ear.
which, from its exceedingly* winding shape, has been termed
the labyrinth (see Fig. 70, c). This cavity is hollowed out in
dense bone, and consists of three parts — the vestibule (a), or
ante-chamber, which is connected with the other two; the coch-
lea (b), or snail's shell; and the three semicircular canals (c).
The manner in which the nerve of hearing is distributed is
remarkable, and is peculiar to this nerve. In the vestibule
and the canals its fibres are spread out over the inner surface.
not of the bony cavity, but of a membranous bag. which con-
forms to and partially fills that cavity, and which floats in it,
being both filled and surrounded with a clear, limpid fluid.

101. A singular addition to the mechanism of hearing is
observed within this membranous bag of the labyrinth. This
consists of two small oval ear-stones, and a quantity of fine
powder of a calcareous nature, which is called ••ear-sand."
When examined under the microscope, these sandy particles

100. The essential part of the organ of hearing ? Its location ? Formation r

101. Where is the "ear-sand" found ? Oive the theory as to its use. '

300 THE SPECIAL SENSES

are seen to lie scattered upon and among the delicate filaments
of the auditory nerve ; and it is probable that, as the tremulous
sound-wave traverses the fluid of the vestibule, the sand rises
and falls upon the nerve-filaments, and thus intensifies the
sonorous impression.

102. In the cochlea, or snail's shell, which contains the
fluid, but no membrane, the nerve branches upon a spiral
shelf, which, like the cochlea itself, takes two and a half
turns, growing continuously smaller as it winds upward. As
many as three thousand nerve-fibres of different lengths have
been counted therein; these, it has been thought, form the
grand, yet minutely small key-board, upon which strike all the
musical tones that are destined to be conveyed to the brain.
The vestibule, it is also supposed, takes notice of noise as
distinguished from musical sounds ; while the office of the
semicircular canals is, in part at least, to prevent internal
echoes, or reverberations.

103. The vestibule communicates with the chain of bones of
the middle ear by means of a small opening, called the " oval
window," or fenestra ovalis. Across this window is stretched
the membrane, which has already been alluded to as being
joined to the stirrup-bone of the middle ear. Through this
window, then, the sound-wave, which traverses the external
and middle ear, arrives at last at the labyrinth. The limpid
fluid which the latter contains, and which bathes the terminal
fibres of the nerve of hearing, is thus agitated, the nerve-fibres
are excited, and a sonorous impression is conducted to the
brain, or, as we say, a sound is heard.

104. Protection of the Sense of Hearing. — From what has
been seen of the complicated parts which compose the organ of
hearing, it is evident that while many of them possess an
exquisite delicacy of structure, Nature has well and amply
provided for their protection. We have observed the concealed

102. In the cochlea, or snail's shell ? "Key -board" in the internal ear? The vestibule ?
Semicircular canals ?

103. With what does the vestibule communicate ? What is the method by which sound
[g conducted to the brain ?

104. The formation of the organ of hearing with a view to its protection ?

THE SPECIAL SENSES 3<M

situation of the most important parts of the mechanism of the
ear — the length of its cavity, its partitions, the hardness of
its walls, and its communication with the atmosphere; all
these provisions rendering unnecessary any supervision or care

on our part in reference to the interior of the ear. But in
respect to its external parts, which are under our control and
within the reach of harm, it is otherwise. We may both
observe the dangers which threaten them, and learn the means
necessary to protect them.

105. Caution. — One source of danger to the hearing consists
in loweriiiL;' the temperature of the ear. especially by the intro-
duction of cold water into the auditory canal. Every one is
familiar with the unpleasant sensation of distension, and the
confusion of sounds which accompany the filling of the ear
with water when bathing: the weight of the water within it
really distends the membrane, and the cold chills the adjacent
sensitive parts. It is not surprising, therefore, that the fre-
quent introduction of cold water, and its continued presence in
the ear, enfeebles the sense of hearing. Care should be taken
to remove water from the ear after bathing, by holding the
head on one side, and, at the same time, slightly expanding
the outer orifice, so that the fluid may run out. For a like
reason, the hair about the ears shoidd not be allowed to remain
wet, but should be thoroughly dried as soon as possible.

106. It may be stated as a general rule, to which there are
hut few exceptions, that no cold liquid should ever be allowed
to enter the ear. When a wash or injection is rendered neces-
sary, it should always he warmed before use. The introduction
of cold air is likewise hurtful, especially when it pours through
a crevice directly into the ear. as it may often do through the
broken or partially (dosed window of a car. The avoidance of
this evil gives rise to another almost as great, namely, the
introduction of cotton or other soft substances into the ear to
prevent it from " catching cold." This kind of protection
tends to make the part unnaturally susceptible to changes of

105. Danger to which hearing may be sabjeeted 1 A. hire.

106. The general rule as to the use of water for the ear ?

302 THE SPECIAL SENSES

temperature, and its security seems to demand the continued
presence of the "warm" covering. As a consequence of its
presence, sounds are not naturally conveyed, and the sensitive-
ness of the nerve of hearing is gradually impaired.

107. The chief source of injury, however, to the ear is
from the introduction of solid substances into the auditory
canal, with the design of removing insects or other foreign
objects that have found their way into the ear, or with the
design of scraping out the ear-wax. For displacing a foreign
object, it is usually sufficient to syringe the ear gently with
warm water, the head being so held that the fluid easily
escapes. If a live insect has gained entrance to the ear, it
may first be suffocated by pouring a little oil upon it, and
afterward removed by syringing the ear as just mentioned.

108. The removal of ear-wax is generally unnecessary ; for,
as we have before seen, Nature provides that the excess of it
shall become dry, and then spontaneously fall out in the form
of fine scales. The danger from the introduction of solid
implements into the outer ear is chiefly found in the fact that
the membrane which lies at the bottom of it is very fragile,
and that any injury of it is liable to impair permanently the
hearing of the injured ear.

109. How Alcohol affects the Special Senses. — The narcotic
or benumbing influence of alcohol is felt by all forms of ner-
vous tissue, and among them the nerves of special sense. Vision
is more susceptible of injury by this poison than any of the
other senses, and it may be either slightly impaired or wholly
lost. There is, in such cases, a progressive loss of power in
the optic nerve that can only be remedied by a perpetual
abandonment, on the part of the sufferer, of alcoholic drink ;
and even this must not be delayed too long after dimness of
sight has commenced.

110. Alcohol and Color-Blindness. — Progressive loss of
color-perception has been noticed by physicians in persons

107. Chief source of injury to the ear? Directions for removing foreign objects from
the ear ? Of a live insect f

109. Do those who drink alcohol have good vision ?

110. What about their perception of color f

THE SPECIAL SENSES 363

who use liquor habitually, though not to the extent of intoxi-
cation. This form of gradually growing " color-blindness "
becomes a matter of highest importance, since it may occur
in a railroad engineer, or pilot, who drinks, or in the case of
some official responsible for the lives and limbs of travelers by
steam. No persons avIio indulge in alcoholic beverages can
safely be allowed to occupy trusts of this nature.

111. Effect of Alcohol on Other Senses. — Hearing and taste
are dulled by alcohol. Touch is indirectly robbed of its
efficiency in a certain proportion of cases, where a tremor of
the muscles of the arm, or the " palsy of drunkards," occurs.
Fine penmanship or drawing, and the use of keen-edged tools,
depend upon a delicate employment of touch ; but with a hand
that shakes like the palsied limb of an aged man, this becomes
an impossibility. In this way has alcohol deprived many a
man of the means of his livelihood. This is said to be espe-
cially true of those who belong to the class of topers who
drink little and often. (Read Note \5,page 238.)

112. False Apparitions due to Alcohol — Delirium Tremens. —
In certain diseases the eyes appear to see objects that do not
in reality exist within their view. High fever is one of these
diseases ; delirium tremens, or " the horrors," experienced by
some hard drinkers, is another. The latter condition is marked
by a variety of terrifying and loathsome creatures ; if there
be any form of reptile that is especially repulsive to the
delirious person, this is the form that is most liable to haunt
him. These false images may be dimly seen at first, but as
the disease progresses they generally become perfectly distinct,
and real, and torturing; many a victim has thrown himself
down from a window, regardless of its height, in his eager
haste to escape from his unreal visions. Alarming sounds, also,
are heard in some cases of this disorder.

113. The Effect of Tobacco upon Vision. — Oculists are nearly
unanimous in the opinion that impairment of sight and even

HI. Other senses?

112. Are unreal objects ever seen as real 1 How Is delirium tremens described ?

118. Has tobacco any influence over vision ?

304

THE SPECIAL SENSES

its utter loss may result from tobacco smoking, the optic nerve
being gradually impaired, as in the case of those who lose their
sight by alcohol, as described in the foregoing paragraph of
this Chapter, Section 109. There is a relief for this approach-
ing blindness if the patient will consent to wholly abstain from
tobacco ; and yet, " there are those who would rather smoke
than see," and persist in the injurious habit in spite of every
proper medical caution.

114. Certain narcotic substances have an injurious influence
over the sense of hearing ; among these are tobacco and coffee
used in excess. The opium habit is injurious to the sense of
sight.

Contents of the Orbit

Lids

TOPICAL OUTLINE

Eyeball.
Muscles.
Blood-vessels.
Nerves.
Fatty tissue.
I Lachrymal or tear apparatus.
Consist of folds of the skin.

Lined with a mucous membrane (the conjunc-
tiva), which is also reflected over the front of
the ball.
Closed by the circular orbicularis muscle.
. Upper lid raised by a special muscle.

( Superior — turns the eyeball up-
j wards.

| Inferior — turns the eyeball down-
wards.
External — turns the eyeball

outwards.
Internal — turns the eyeball in-
wards.
r Superior — turns the eyeball
J outwards and downwards.
| Inferior — turns the eyeball out-
wards and upwards.
I Lachrymal gland — in the upper and outer part
of the orbit,
lachrymal i geveral small duet8>

i Constant.
Secretion . . i Moistens the eyeball.

I Carried off by the nasal duct.

Muscles

apparatus

4 Recti

. 2 Oblique

114. Have alcohol and tobacco together any influence ? Other injuries f

THE SPECIAL SENSES

.105

Coats

Lens

THE EYE .

(continued)

Optics

Outer . .

Sclerotic

[ Cornea

Choroid

Middle

Iris.

Interior . . . Retina ,

1 Tough, fibrous,

opaque.
Transparent.
( lovers the front cen-
tral portion of the
eye.
Contains black pig-
ment.
Terminates in front
by the ciliary
processes.
A circular perforated
I diaphragm.
Aperture called the

pupil.
Pupil contracted by
circular muscular
'• fibres : and
) Dilated by radial

fibres.
j Nervous structures.
' Connective tissue.
Situated just behind the iris.
Double convex. Elastic.

Hack surface mor< nvex than the front.

Enclosed in a capsule.

Held by the suspensory ligament at its circum-
ference.
Ligament relaxed by the contraction of the
ciliary muscle.

Between the iris and the cornea.
Contains a watery fluid.
Includes the greater portion of

the ball.
('..mains a transparent jelly-like
I substance.
The eye a camera obscura or dark chamber.
Hays of light converge as they enter the cornea.
Convergence increased by the U ns.
Image (inverted) falls on the n Una.

, ( lornea or lens too convex.

I Remedy— wear ooncavi glass -

j Cornea or lens too flat.

' Remedy — wear convex glasses.

I At entrance of Optic to rve.
1 Totally insensitive to light.
f i\j of an inch outside the blind
; spot.
Marked by a slight depression.
Most sensitive pari of the retina.
Retina retains impressions for about ■ of a sec-
ond after its exciting cause ceases.

Aqueous

Vitreous

Short-sight .
Long-sight .
Blind spot .

Yellow spot

306

THE SPECIAL SENSES

0ut«r

Middle

2<

Internal

f Pinna

l. Canal ....

An irregular
Bones . . . .

I Openings

Osseous
labyrinth

Membranous
labyrinth

f Cartilaginous framework.
j Fatty tissue.
J Muscles.
I Skin.

I Collects sound waves and reflects
them into the auditory canal.
1\ inch long.
I Closed internally by the drum.
| Glands — secrete "wax."

Hairs —directed outwards,
cavity in the temporal bone.
I Malleus.
; Incus.
' Stapes.

i Fenestra ovalis — closed by the
j stapes.

I Fenestra rotunda — closed by a
I membrane.

j Central portion.
1 Fenestra ovalis.
f Three in number.
Canals . . - Open into the vesti-
L bule.
r A spiral tube.
2j turns round the

modiolus.
Fenestra rotunda.
Within the osseous.
Similar in shape.
Surrounded by perilymph.
1 Contains endolymph.

Otoliths and hair-like processes.
[ Terminal fibres of auditory nerve.

Vestibule

I Cochlea

QUESTIONS FOR TOPICAL REVIEW

PAOR

1. What is said of the production of sensation ? 251, 252

2. What is said of the variety of sensation? 252

3. What is said of the general sensibility ? 253, 254

4. What is said of the sensation of pain ? 254

5. What is said of the uses of pain ? 254-256

6. Say what you can of the special sensation 256-258

7. Say what you can of the organs of touch 258, 259

8. Say what you can of the sense of touch 259-261

9. Say what you can of the delicacy of touch 261, 262

10. What is understood of the sensations of temperature and weight?. 262, 263

11. What is understood by the organ of taste ? 263, 264

12. What is understood by the sense of taste ? 264, 265

13. What is understood by the relations of taste 266, 267

14. Explain the influence of education, etc 267

15. Explain the sense of smell 267, 268

THE SPECIAL SENSE8 .307

PAGE

16. Explain the nerve of smell 268, 269

17. Explain the uses of the sense of smell 269-271

18. Explain the sense of sight 272, 27:;

19. Give the statement concerning light and the optic nerve 273, 274

20. Give the statement concerning the organ of sight 274, 275

21. Give the statement concerning the orbits 275

22. Give the statement concerning the eyelids 275, 276

23. Give the statement concerning the lachrymal fluid 277, 278

24. Give the statement concerning the eyeball 278-280

25. Give the statement concerning the iris 280-282

26. Give the statement concerning the retina 282-285

27. Give the statement concerning the crystalline lens

28. What are the uses of the lens ? 286-288

2!). What about long and short sight ? 288, 289

30. Explain the function <>f accommodation 289, 290

31. Explain old sight or presbyopia 291

32. Explain hearing and sound 292-294

33. Explain the external ear 294, 295

34. Explain the middle ear 295-299

35. Explain the internal ear 299, 300

36. What is said of the protection of the sense of hearing? .300, 301

37. What caution is given ? 301 , 302

.'58. How does alcohol affect the special senses? 302, 303

39. How does alcohol affect hearing, taste, and touch? 303

40. Effect of tobacco upon vision ? 303, 304

CHAPTER XI

THE VOICE

Voice and Speech — The Larynx, or the Organ of the Voice — The Vocal
Cords — The Laryngoscope — The Production of the Voice — The Use
of the Tongue — The Different Varieties of Voice — The Change of
Voice — Its Compass — Purity of Tone — Ventriloquy

1. Voice and Speech. — In common with the majority of the
nobler animals, man possesses the power of uttering sounds,
which are employed as a means of communication and expres-
sion. In man these sounds constitute the voice ; in the animals
they are designated as the cry. The song of the bird is a
modification of its cry, which is rendered possible from the fact
that its respiratory function is remarkably active. The sounds
of the animals are generally produced by means of their
breathing organs. Among the insects, they are sometimes
produced by the extremely rapid vibrations of the wings in
the act of flight, as in the case of the mosquito ; or by the
rubbing together of hard portions of the external covering of
the body, as in the cricket. Almost all kinds of marine ani-
mals are voiceless. The tambour-fish and a few others have,
however, the power of making a sort of noise in the water.
{Bead Note 1.)

2. But man alone possesses the faculty of speech, or the
power to use articulate sounds in the expression of ideas, and

1. Voice in Man and Animals. — "The human voice, taking male
and female together, has a range of nearly four octaves. Man's power
of speech, or the utterance of articulate sounds, is due to his intel-
lectual development more than to any great structural difference between
him and the Apes. Song is produced by the glottis, speech by the
mouth. The parrot and mocking-bird use the tongue in imitating
human sounds." — Orton's Zoology.

1. The uttering of sounds by animals ? How produced ?

2. The evidence of msn'i superior endowment? What is »tated of the idiot ? Farr»tf
Raven ?

308

THE VOICE 309

in the communication of mind with mind. Speech is thus an
evidence of the superior endowment of man. and involves the
culture of the intellect. An idiot, while he may have complete
vocal organs and full power of uttering sounds or cries, is
entirely incapable of speech ; and, as a rule, the excellence of
the language of any people will be found to be proportional to
their development of brain. Man. however, is not the only
being that has the power to form articulate sounds, for the
parrot and the raven may also be taught to speak by rote ; but
man alone attaches meaning to the words and phrases he
employs.

3. Relation to Hearing. — Speech is intimately related to the
sense of hearing. A child born deaf is, of necessity, dumb
also ; not because the organs of speech are imperfect, for he
can utter cries and may be taught to speak, and even to con-
verse in a rude and harsh kind of language ; but because he
can form no accurate notion of sound. A person, whose hear-
ing is not delicate, or as it is commonly expressed, who "has
no ear for music," cannot sing correctly. A person who has
impaired hearing commonly talks in an unnaturally loud and
monotonous voice. These examples show the necessary rela-
tion of intelligence and the sense of hearing with that form of
articulate voice which is termed speech. {Read Note 2.)

2. Certain Peculiarities of the Voice. — Ci Voice is a sound produced
in the throat by the passage of the air through the glottis, as it is expelled
from the lungs. It is grave and strong in man, soft and higher in women ;
it varies according to age. It is alike in both sexes in infancy, but is
modified in youth ; then the voice is said to 'change.' In the young
woman il descends a note or two and becomes stronger. In the young
man the change is much more strongly marked. At the fourteenth or
fifteenth year the voice loses its regularity, becomes harsh and unequal ;
the high notes cannot be sounded, while the grave ones make their
appearance. A year is generally sufficient for this change to be complete,
and the voice of the child gives place to that of the man. Exercise of the
voice in singing should be very moderate, if not entirely suspended, while
this change is going on. Voice is divided into singing and speaking
voice. One differs from the other almost as much as noises do from
musical sounds. It is the short duration of speaking sounds Which dis-

8. Speech and hearing ? A. deaf child? Person having " no ear for music " ? Impaired
bearing » What do the examples show !

310 THE VOICE

4. The Organ of the Voice. — The essential organ of the voice
is the Larynx. This has been previously alluded to in its
relation to the function of respiration ; and, in the chapter on
that subject, are figured the front view of that organ (Fig. 48),
and its connection with the trachea, tongue, and other neigh-
boring parts (Fig. 51). It is situated at the upper part of the
neck, at the top of the trachea, or tube by which air passes
into and out of the lungs. The framework of the larynx is
composed of four cartilages, which render it at once very
strong and sufficiently flexible to enable it to move according
to the requirements of the voice.

5. The names of the cartilages are (1) the thyroid, which is
a broad, thin plate, bent in the middle and placed in the
central line of the front part of the neck, where it is known
as the pomum Adami, or Adam's apple (Fig. 73, b), and where
it may be felt moving up and down with each act of swallow-
ing ; (2) the cricoid, which is shaped like a seal ring, with the

tinguishes them from those of singing. This is proved by the fact that if
we prolong the intonation of a syllable, or utter it like a note, the musical
sound becomes evident. And if we pronounce all the syllables of a phrase
in the same tone, the speaking voice closely resembles psalm-singing.
Every one must have noticed this in hearing school-boys recite or read in
a monotone, and the analogy is complete when the last two or three
syllables are pronounced in a different tone. Spoken voice is moreover
always a chant more or less marked, according to the individual and the
sentiment expressed. The accentuation peculiar to certain languages also
gives the speech the character of a chant ; to a French ear an Italian
preacher seems always to sing. A chant also is caused by those inflec-
tions of the voice, which express our emotions and our passions. They
extend from the feeble murmur, which the ear scarcely perceives, to the
piercing cry of pain. Affectionate, sympathetic, imperious, or hostile,
they sometimes charm, sometimes irritate, and always move us. It
is related of Gretry, that he amused himself by noting as exactly as
possible the ' Bonjour, monsieur ! ' of the persons who visited him ; and
these words expressed by their intonation, in fact, the most opposite
sentiments, although literally the same. Baron, the comedian, moved
his audience to tears by his recitation of the stanzas of the song, ' Si le
roi m'avait donne Paris sa grancTville ' — 'If the king had given me Paris
his great city.' " — Le Pileur on Wonders of the Human Body.

4. Organ of the voice ? Where situated ? Of what is its framework compoied r

5. Names, formation, and situation of the cartilages *

THE VOICE

311

'ith a very sensitive

broad part placed posteriorly (Fig. 73, e). At the top of the
cricoid cartilage are situated the two small arytenoid cartilages,
the right one of which is shown in Fig. 73, c. These latter
little organs are much more movable than the other two, and
are very important in the production of the voice. They have
a true ball-and-socket joint, and several small muscles which
contract and relax with as perfect regularity and accuracy as
any of the larger muscles of the body.

6. The interior of the larynx is lined
mucous membrane, which is much more
closely adherent to the parts beneath
than is usually the case with membranes
of this description. The epiglottis (a),
consisting of a single leaf-shaped piece
of cartilage, is attached to the front part
of the larynx. It is elastic, easily moved,
and fits accurately over the entrance to
the air-passages below it. Its office is
to guard these delicate passages and the
lungs against the intrusion of food and
other foreign articles, when the act of
swallowing takes place. It also assists
in modifying the voice.

7. The Vocal Cords. — Within the
larynx, and stretched across it from the
thyroid cartilage in front to the ary-
tenoid cartilages behind, are placed the
two sets of folds called the vocal cords.
The upper of these, one on each side,
are the false cords, which are compara- A- The Epiglottis

. / ... rm. B, The Thyroid Cartilage

tively fixed and inflexible, lhese are c, Arytenoid Cartilage
not at all essential to the formation of £• J*™?* °l-,the Larynx

E, Cricoid Cartilnere

vocal sounds, for thev have been injured, f. Right vocal Cord

, , , . ' i , i H. The Trachea

in those lower animals whose larynx

resembles that of man. without materially affecting their

characteristic cries. Below these, one on each side, are the

Fig. 73. — Section or thk
Larynx and Trachia

<l. Lining of the Interior of the larynx J The epiglottis !

T. Where are the vocal cords ? The false corda J The true eordi r

312

THE VOICE

two vocal cords (Fig. 73, f), which pursue a similar direction
to the false cords — namely, from before backward. They are
composed of a highly elastic, though strong tissue, and are
covered with a thin, tightly fitting layer of mucous membrane.
Their edges are smooth and sharply defined, and when they
meet, as they do in the formation of sounds, they exactly
match each other.

8. Between the true and false vocal cords is a depression on
each side, which is termed the ventricle of the larynx (Fig.
73, d). The integrity of these two cords, and their free vibra-
tion, are essential to the formation of the tones and the modu-
lation of the natural voice. This is shown by the fact that, if
one or both of these cords are injured or become diseased.
voice and speech are weakened ; or when the mucous mem-
brane covering them becomes thickened, in consequence of a
cold, the vocal sounds are rendered husky and indistinct.
When an opening is made in the throat below the cords — as
not infrequently occurs in consequence of an attempt to com-
mit suicide — voice is impossible except when the opening is
closed by external pressure.

9. The interval or space between the true cords of the voice is
constantly varying, not only when their vocal function is in ex-
ercise, but also during the act
of respiration. Every time
the lungs are inflated, the
space increases to make wide
the entrance for the air, and
diminishes slightly during ex-
piration. So that these little
cords move gently to and fro
in rhythm with the expansion
and contraction of the chest
in breathing. These move-

Fi». 74. — a View of the Vocal cords bt ments and others may be

MriN- of the Laetngo , , , .p ,,

seen to take place, it a small

8. Where is the ventricle of the larynx ? The essentials to the formation of the tones
•nd modulation of the voice?

9. Variation in the interval between the true cords of the voice ? Experiment with the

THE VOICE 313

mirror attached to a long handle be placed back into the
upper part of the throat; the handle near the mirror must
be bent at an angle of 45°, so that we may look " around
the corner," so to speak, behind the tongue. The position
which the mirror must assume will be understood by refer-
ence in Fig. 51. A view of what may be seen under favor-
able circumstances, during tranquil inspiration, is represented
in Fig. 74. The vocal cords are there shown as narrow,
white bands, on each side of the central opening, and since
the image is inverted, the epiglottis appears uppermost. The
rings partly seen through the opening belong to the trachea.
This little mirror is the essential part of an instrument, which
is called the laryngoscope, and simple as it may seem, it is
accounted one of the most valuable of the recently-invented
appliances of the medical art.

10. The Production of the Voice. — During ordinary tranquil
breathing, no sound is produced in the larynx, true vocal tones
being formed only during forcible expiration, when, by an

B C

#0

Fig. 75. —The Different Positions of tiif. Vocal Cords

A, The position during inspiration. B, In the formation of low notes. C, In the formation
of high notes

effort of the will, the cords are brought close together, and are
stretched so as to be very tense. The space between them is
then reduced to a narrow slit, at times not more than y^ of
an inch in width ; and the column of expired air being forced
through it causes the cords to vibrate rapidly, like the strings
of a musical instrument. Thus the voice is produced in its
many varieties of tone and pitch ; its intensity, or loudness,
depending chiefly upon the power exerted in expelling the air

10. The formation of true vocal ton«i ?

314 THE VOICE

from the lungs. When the note is high, the space is dimin-
ished both in length and width ; but when it is low, the space
is wider and longer (Fig. 75, b, c), and the number of vibra-
tions is fewer within the same period of time.

11. The personal quality of the voice, or that which enables
us to recognize a person by his speech, is mainly due to the
peculiar shape of the throat, nose, and mouth, and the reso-
nance of the air contained within those cavities. The walls of
the chest and the trachea take part in the resonance of the
voice, the air within them vibrating at the same time with
the parts above them. This may be tested by touching the
throat or breast-bone, when a strong vocal effort is made. The
teeth and the lips also are important, as is shown by the
unnatural tones emitted by a person who has lost the former,
or by one who is affected with the deformity known as " hare-
lip." The tongue is useful, but not indispensable to speech ;
the case of a woman is reported, from whom nearly the whole
tongue had been torn out, but who could, nevertheless, speak
distinctly and even sing.

12. The Varieties of voice are said to be four in number;
two, the bass and tenor, belonging to the male sex ; and two,
the contralto or alto, and soprano, peculiar to the female. The
baritone voice is the name given to a variety intervening
between the bass and tenor. In man, the voice is strong and
heavy ; in woman, soft and high. In infancy and early youth,
the voice is the same in both sexes, being of the soprano
variety : that of boys is both clear and loud, and being sus-
ceptible of considerable training, is highly prized in the choral
services of the church and cathedral. At about fourteen years
of age the voice is said to change — that is, it becomes hoarse
and unsteady by reason of the rapid growth of the larynx. In
the case of the girl, the change is not very marked, except
that the voice becomes stronger and has a wider compass ; but
in the boy, the larynx nearly doubles its size in a single year,
the vocal cords grow thicker, longer, and coarser, and the voice

11. To what is the personal quality of the voice mainly due ? What aids are there f

12. Varieties of voice ? The baritone ? The voice in early youth ?

THE VOICE M15

becomes masculine in character. During the progress of this
change, the use of the voice in singing is injudicious.

13. The ordinary range of each of the four varieties of the
voice is about two octaves ; but this is exceeded in the case of
several celebrated singers. Madame Parepa Rosa had a com-
pass of three full octaves. When the vocal organs have been
subjected to careful training, and are brought under complete
control of the will, the tension of the cords becomes exact,
and their vibrations become exceedingly precise and true.
Under these circumstances the voice is said to possess " purity "
of tone, and can be heard at a great distance, and above a
multitude of other sounds. Some years ago the power of a
pure voice to make itself heard was exemplified in a strik-
ing manner at a musical festival held in an audience-room of
extraordinary size ; and amid an orchestra of a thousand instru-
ments and a chorus of twelve thousand voices, the artist named
above also sang ; yet such was the purity and strength of her
voice that its notes could be clearly heard rising above the
vast waves of sound produced by the full accompaniment of
chorus and orchestra. {Bead Note 3.)

3. The Benefits of Vocal Exercise. — " Reading aloud and recitation
are more useful and invigorating musical exercises than is generally imag-
ined, at least when managed with due regard to the natural powers of the
individual, so as to avoid effort and fatigue. Both require the varied
activity of most of the muscles of the trunk to a degree of which few are
conscious, till their attention is turned to it. In forming and undulating
the voice, not only the chest, but also the diaphragm and abdominal
muscles are in constant action, and communicate to the stomach and
bowels a healthy and agreeable stimulus ; and consequently, where the
voice is raised and elocution rapid, as in many kinds of public speaking,
the muscular effort comes to be even more fatiguing than the mental.
When care is taken, however, not to carry reading aloud so far at one
time as to excite the least sensation of soreness or fatigue in the chest,
and it is duly repeated, it is extremely useful in developing and giving
tone to the organs of respiration, and to the general system. To the
invigorating effects of this kind of exercise, the celebrated Ouvier was in
the habit of ascribing his own exemption from consumption, to which, at
the time of his appointment to a professorship, it was believed he would
otherwise have fallen a sacrifice. The exercise of lecturing gradually

18. The ranje of the voice? Result ofcarefnl training nf the rocal organs!

316 THE VOICE

14. In the production of the articulate sounds of speech,
the larynx is not directly concerned, but those sounds really
depend upon alterations in the shape of the air-passages above
that organ. That speech is not necessarily due to the action of
the larynx is proved by the following simple experiment. Let
an elastic tube be passed through the nostril to the back of the
mouth. Then, while the breath is held, cause the tongue, teeth,
and lips to go through the form of pronouncing words, and, at
the same time, let a second person blow through the tube into
the mouth. Speech, pure and simple, or, in other words, a
whisper is produced. Still further continue the experiment,
while permitting vocal sounds to be made, and there will be
produced a loud and whispering speech at the same moment ;
thus showing that voice and speech are the result of two dis-
tinct acts. Sighing, in like manner, is produced in the mouth
and throat ; if, however, a vocal sound be added, the sigh is
changed into a groan.

15. Ventriloquism is a peculiar modification of natural
speech, which consists in so managing the voice that words
and sounds appear to issue, not from the person, but from
some distant place, as from the chimney, the cellar, or the
interior of a chest. The original meaning of the word ventril-
oquism (that is, speaking from the belly) indicates the early
belief that this mode of speech was dependent upon the
possession and use of some special organ besides the larynx
and mouth; but at the present time it is known that it is
produced by these organs alone, and that the sources of decep-
tion consist, on the part of the performer, in the dexterous
management of the voice, together with a talent for mimicry ;
and, on the part of the auditory, in the liability of the sense
of hearing to error in respect to the direction of sounds. The

strengthened his lungs and improved his health so much that he was never
afterward threatened with any serious pulmonary disease. But, of course,
this happy result followed because the exertion of lecturing was not too
great for the then existing condition of his lungs." — Combe's Physiology.

14. The production of the articulate founds '! What experiment is mentioned ?

15. What is ventriloquism ? Indication of the original meaning of the word ? He
tk* v»ntriloquous sounds produced ?

thx roici 31T

ventriloquist not only seems to "throw his voice," as it is said,
or simulates the sound as it usually appears at a distance with
but little motion of the lips and face, but he imitates the voices
of an infant and of a feeble old man, of a drunken man dis-
puting with an exasperated wife, the broken language of a
foreigner, the cry of an animal in distress, demonstrating that
the performer must be proficient in the art of mimicry. Ven-
triloquism was known to the ancient Komans and Greeks ; and
it is thought that the mysterious responses that were said to
issue from the sacred trees and shrines of the oracles at
Dodona and Delphi were really uttered by priests who had
the power of producing this form of speech. {Bead Notes 4 and 5. )

4. Improvement of Conversation by Vocal Training. — "For years
I had fallen into a low, drawling, lazy tone of voice in my ordinary con-
versation ; my utterance came forth in a cloud, and had its dwelling there.
From divers experiments and observations I had long ago assured myself
that this was a capital defect ; but this assurance had brought with it no
reform. Now, at last, I attempted it in good earnest. I studied to bring
myself out of my listlessness, to acquire a rapid, distinct, and articulate
enunciation. No man can miss this acquisition unless from some organic
infirmity, provided only that he pursue it steadily and earnestly. I em-
ployed a variety of exercises for the voice, as recitation, the frequent
repetition of the same passage, slowly at first, and then more quickly, up
to my highest pitch of rapidity, the pronunciation of foreign languages, —
Greek for the sake of fullness, and French for distinctness and despatch.
As a result, I became comparatively a clear and satisfactory speaker ; and
as my talk was more distinct my thoughts were all the more pointed and
precise. I acquired an evenness of tone, a confidence, a complacency ;
my conversation, as the French say of their language, went of itself ; I
had leisure to look chiefly to my direction, to march on to my object." —
Self- Formation, by C'apel Lofft.

5. Ventriloquism and Sound-Painting. — "Ventriloquism bears the
same relation to other phenomena of sound that perspective does to
optical phenomena. The art of perspective consists in portraying upon a
flat surface the appearance of objects at a distance from it, so that the
same effect shall be produced upon the eye by the picture as would be
produced by the objects themselves. In order to do this, the form, tints,
and shades are reproduced, not as they really are, but as they are modified
by position and distance. Or it may be said to consist in making and
arranging a group of objects so that when viewed at a given distance they
shall produce the same optical effect produced by another set of objects
arranged in different positions and at different distances.

•• Ventriloquism consists in making and arranging sounds so that when
heard at a given distance they shall produce the same effect upon the ear

318

THE VOICE

that another set of sounds produce arranged in different positions and at
different distances.

" Sounds from a distance are of course weakened, and they also have
another quality which may be compared to the indistinctness of outline
in objects seen at a distance. In proportion as the fine ear of the ven-
triloquist can appreciate these modifications will be his success in imitating
distant sounds. For as to see correctly is the first essential to success in
drawing, so is hearing correctly the first essential in ventriloquism.

"There are many sounds which cannot be imitated by voice merely,
such as the singing of birds, the strident noise of a saw, the whistling of
a plane, etc. Such and similar unmusical sounds are imitated by means
of the teeth, the lips, or the soft parts of the mouth. Thus, the noise of
a saw is like that produced by hawking, only much prolonged, and modi-
fied by the cheeks ; singing of birds may be imitated by whistling through
the teeth ; the foaming of soda-water by breathing with open lips into a
tumbler, etc. To persons having a fine ear this amusing art is not difficult,
but we object to the name applied to it. It ought to be called sound-
painting."

TOPICAL OUTLINE

LARYNX

Thyroid
Cricoid .

...j

Arytenoid

Glottis

Epiglottis

Vocal cords

The upper cartilage.

Wide in front ; open behind.

A complete ring of cartilage.

Wide behind ; narrow in front.
f Small pyramidal.

J Surmount the upper posterior edge of th«
J cricoid.

I Jointed with the cricoid.

f The communication between the pharynx and
■j the larynx.

1 Bounded on each side by the vocal cords.
I A thin movable layer of cartilage.
\ Closes the glottis during the act of swal-
lowing.

Bands of elastic fibres.

Embedded in mucous membrane.

Relaxed during quiet breathing.

Stretched during speaking and singing.

Attached to arytenoid cartilages behind, and
to the thyroid in front.

QUESTIONS FOR TOPICAL REVIEW

1. What distinction is made between speech and voice ? 308

2. What is said of each ? 308, 309

3. What does speech usually indicate ? 309

4. How is speech related to hearing? 309

THE VOICE ^19

P vi. r

5. Name and describe the organ of the voice 310

6. What other organs are concerned ? 310

7. What offices have the cartilages? 310, 311

8. Explain and locate the epiglottis 311

9. Say what you can of the vocal cords 311-313

10. State how a cold affects the voice 31L'

11. What does the laryngoscope reveal to us'.' 313

12. Upon what does quality of voice depend ? 314

13. What change takes place when the voice is raised ? 313, 314

14. How do the chest and trachea take part ? ;<14

16.« How the teeth, lips and tongue ? 314

16. What are the varieties of voice ? 314

17. What changes take place with age ? 314, 31fi

18. Mention the ordinary range of voice and instance an exception 315

19. What further is said of speech '.' 316

20. What is ventriloquism ? 316

21. How produced ? 316

22. What mysteries does it help to explain ? 317

CHAPTER XII

THE USE OF THE MICROSCOPE IN THE STUDY
OF PHYSIOLOGY

The Laic of Tissues — Xecessity of the Microscope — Different Kinds of
M icroscopes — Additional Apparatus — Preliminary Studies — The
Study of Human Tissues — Tissues of the Inferior Animals — Incen-
tives to Study

1. The Law of the Tissues. — The will of an infinite Creator
is obeyed by atoms as well as by worlds. He lias seen fit to
commit all the functions of life to structures or tissues so small
as to be invisible to the naked eye. A muscle, for example, as
we have already learned, is composed of innumerable filaments,
visible only by the aid of the microscope ; and the power of
the muscular mass is but the sum of the contractile power of
the filaments which enter into its composition. Again, each
cell of the liver, invisible to unassisted sight, is a secreting
organ, and the liver performs as much duty as the sum of these
minute organs renders possible.

2. The Necessity of the Microscope. — If, therefore, we would
know the real structure of the human body, we must make use
of the microscope. Our eyes are constructed for the common
offices of life, to provide for our wants and guard us from the
ordinary sources of danger ; but by arming them with lenses,
the real structure of plants and animals is revealed to our intel-
ligence ; and enemies, otherwise invisible, that lie in wait in
the air we breathe, and in our daily food and drink, to destroy
life, are guarded against.

1. The will of the Creator, by what obeyed ? The power of a muscle ! A mount of duty
performed by the liver ?

2. Necessity for using the microscope ! The advantages gained by its u»e ?

320

THE MIt ROSroPE .^Jl

3. Convex Lenses, or magnifying glasses, are disks of glass
or other transparent substances, which have the prop
picturing upon the retina of the eye an image of an object
larger than the image produced there without their aid. The
glasses used in microscopes are either double convex lei
or plano-convex lenses (b). If either of these lenses be placed
over a hole in the shutter of a darkened room, or over the key-
hole of a door, and a piece of paper be held at a proper dis-
tance, a picture of all objects in front of the lens will be thrown
on the paper, as in the camera-obscura or the magic-lantern.
Now, in the same manner, a lens throws a picture of i
to which it is directed on the retina of the eye, and when that

a b

* >

picture is larger than the image made in the eye by the object
without the aid of the lens, it is magnified, or the lens has
served as a microscope, so called from its use in seeing small
objects, from mzkros, small, and skopeo, to see.

4. Different Kinds of Microscopes. — Microscopes are either
simple or compound. The glasses of magnifying spectacles,

I'.ke those commonly used by aged persons, are simple micro
scopes. Magnifying glasses, mounted in frames, such
ior sale by opticians and others for the detection of counter-
feit money, are simple microscopes, and are useful in studying
the coarser structure of plants and animals.

5. The most powerful simple microscopes are made by melt-
ing in a flame a thread of spun glass, so as to form a minute

■i. What are onnvox lenses? Kin. I of lenses used ia microscopes I Kxperiuient ?
Picture thrown upon the eyes! Derivation of the word nii<ro>cope?
4. Kinds of microscopes 1 What are simple mlw now

-traction of the most powerful simple microscopes ? In practice? A doublet?
Triplet ? Why are Coiopvuml microscopes superior to siuiple ones ?

322 THE MICROSCOPE

globule or bead, which, when set in a piece of metal and used
to examine objects on a plate of glass held up to the light,
gives a high magnifying power. In practice, however, it is
found better to use several magnifying glasses of moderate
power than a simple lens alone of high power. A combination
of two lenses is called a doublet — of three, a triplet. All sim-
ple microscopes throw an enlarged image of the object upon
the retina. Compound microscopes are so constructed that the
enlarged image of an object is again magnified by a second
lens, and hence their magnifying power is vastly superior to
that of simple microscopes.

6. The accompanying diagrams will explain the action of
the compound microscope compared with that of the simple
microscope. In Fig. 77, which represents the working of the
simple microscope, the rays from the object (a b), passing
through the lens (l), form an image (a' b1) in the retina of the
eye (e), and as all images are inverted in the eye, the object is

Fig. 77. — Simple Microscope

seen as all other objects are, and appears erect. In Fig. 78 is
seen the action of the compound microscope. An inverted
image (a' b1) of the object (a b) is magnified by the second lens
(l'), and an erect image is thrown upon the retina, which, as
all other objects seen erect with the naked eye are inverted,
gives to the image a contrary direction, or inverts it to the
mind.

7. A Compound Microscope consists of two portions : the
optical portion, or the lenses, and the mechanical portion, or
the instrument which bears the lenses. The glasses of a com-

6. Explain, by means of the diagram, the action of the compound microacwpe.
V. Portions, in a compound microscope ? The glasses?

THE MICROSCOPE

323

pound microscope are two : the object-glass and the lower lens
of Fig. 78, and the ocular or eye-piece and the upper piece of
Fig. 78. Both the object-glass and the eye-piece may. and
usually do, consist of more than one Lens, for, as lias been pre-
viously mentioned, better results arc obtained by a combina-
tion of lenses of moderate power than by
single lenses of high power and great curva-
ture.

8. How to Choose and Use a Microscope. —
Xo attractiveness in the mechanical part of
a microscope can compensate for inferior
lenses ; and the very first consideration in
the choice of an instrument should be the
excellence of the optical part of the instru-
ment. In the use of the instrument, care
should be exercised to keep the lenses clean,
free from dust, not to press the object-glass
upon the object under observation, and not
to wet it in the water in which most objects
are examined. A good microscope requires
its own table ; and when not in use, should
be covered by a bell glass, or a clean linen
cloth.

9. The mechanical portion of the instru-
ment varies greatly in different instruments.
That one is the best which is the simplest,
the most solid and most easily managed,
Most objects in human anatomy are exam-
ined in water or in other liquids, or they are
themselves liquids; hence an oblique stage
is often inconvenient.

10. Additional Apparatus. — As almost all
objects in human anatomy are examined by lM,p ,v compoobd
transmitted light thrown up from the mir-

B. How to choose a microscope ? How to use it I

9. The characteristics of the best Instrument! What special requisites should he
Insisted upon* Why, as to a horizontal stage ?

10. Slides? Covers, square ami ciiriuar T How kept?

324 THE MICROSCOPE

ror beneath the stage through the object to the eye, they must
be placed upon strips of clear glass about three inches long
and one inch wide, commonly called " slides." These should
be procured with the microscope. Again, most objects seen
with high powers require to be covered with a thin plate of
glass, very properly called a " cover," that the moisture of the
specimen may not tarnish the object-glass. Square or circular
covers of very thin glass are therefore provided ; and a good
supply of these should be always on hand. These glasses
should be kept in a covered dish rilled with a mixture of alco-
hol and water. Simple water will not remove the fatty matter
which exists in all animal tissues, and, therefore, the glasses
cannot be thoroughly cleaned with it alone.

11. "When glasses are required for use, they should be
removed from the liquid and wiped clean and dry with a soft
linen handkerchief. Delicate knives, scissors, needles mounted
in handles, forceps, pipettes or little tubes for taking up water,
should be obtained ; these are essential to all microscopical
study. The table should be supplied with glass-stoppered
bottles containing the various liquids ordinarily used in the
study of physiology. Thus, tincture of iodine is indispensable
in studying vegetable structure, acetic acid in the study of
animal tissues ; and other articles will have to be added from
time to time, as your progress in study demands them.

12. Preliminary Studies. — In order to prepare the way for
the study of any department of science with the aid of the
microscope — for the microscope is but an eye, and can be
turned in almost any direction for purposes of investigation
— it is necessary to become acquainted with the many objects
which are liable to complicate the examination of particular
structures. Both air and water are full of floating bodies,
and the most common of these should first occupy the atten-
tion. In the city, particles of starch are always floating in the
air. Take a very minute portion of wheat flour, place it in the
mni'ile of a clean glass " slide," drop upon it a drop of pure

11. Cleaning the glasses ? Knives, scissors, etc. ? Various liquids ?

12. Bodies; in air and wuter ? The examination of starch ? . .

THE MICROSCOPE 825

water, cover it with a plate of thin glass, and examine it with
a power of from one hundred to six hundred diameters. It
will be found to be composed of minute grains or granules, the
largest of which are made up of coats or layers, like an onion,
arranged around a central spot called the hilum.

13. Make another preparation in the same manner, and,
after adding the water and before covering with the thin glass
cover, add a small drop of a solution of iodine. Now, upon
examining the specimen, every grain will be seen to be of a
beautiful deep blue color. After thus studying wheat starch,
the starch of Indian corn, of arrow-root, and of various grains,
should be examined in like manner, and their resemblances
and differences noted. The granules of potato-starch are as
distinctly marked as any.

14. Fibres of cotton, lint, and wool are liable to be found in
every specimen prepared for microscopical examination. In
order to study these, any cotton, woollen, or linen fabric
or garment, may be scraped, and the scrapings placed on
a piece of glass moistened with water, covered with the thin
glass plate or cover as before, and examined with the same
magnifying power, namely, from one hundred to six hun-
dred diameters. Vegetable hairs or down are constantly
floating in air and water. These are of very various forms,
are simple or grouped, and form very interesting objects of
study. They are readily procured from the epidermis or outer
membrane of the leaves or stems of plants, by cutting with a
delicate knife.

15. The tissues of plants, epidermis, ducts, and woody fibres
are constantly found in microscopic preparations. They may
be studied in delicate sections made with a sharp knife, or by
tearing vegetable tissues apart with needles. The down of
moths, the hairs of different animals, the fibres of paper, the
most common animalcules in water, the dust of shelves, and
generally the structures found in all vegetable and animal sub-

18. The examination with solution of Iodine ? Advice respecting other articles?

14. Directions for examining cotton ami other fibres i Vegetable bain I

15. Directions for examining various lis.-ii-.- f Down of moths and other structures?

326 THE MICROSCOPE

stances by which we are surrounded, should be studied as a
preliminary to any special line of microscopical investigation.

16. The Study of Human Tissues. — When this has been done
and familiarity with the use of the instrument has been ob-
tained, proceed to the study of the human body, for human
physiology is our subject. If the end of the finger be pricked
with a pin, a drop of blood may be procured for examination.
Place this on one of the glass slides, cover it with a thin piece
of glass, press down the cover so as to make a thin layer, and
then examine with the magnifying power just mentioned. Do
not add water, for that will cause the blood corpuscles to dis-
appear. If the drop of blood is placed under the microscope
at once after being drawn from the finger, most interesting
phenomena will be observed. The red corpuscles will be seen
to arrange themselves in rows, like piles of coin, while the
blood is coagulating. The spherical, white corpuscles will be
left out of the rows of red discs, and, if the highest power be
used, will be seen to change their shape constantly.

17. If you scrape with a dull knife the inside of the cheek,
the flattened scales of "pavement epithelium," or of the
insensible covering which, analogous to the scarf-skin on the
outer surface of the body, lines the cavities of its interior,
may be readily studied. They have the appearance of trans-
parent tiles, each enclosing a round or oval body, called its
nucleus. Dandruff and the scrapings from the skin of the
body are composed of scales like those of the mouth, but they
differ somewhat in being hardened by horny matter, and in
having a very faint central body or nucleus.

18. The Tissues of the Inferior Animals. — The warm-blooded
animals do not differ in the tissues or microscopic structures
that compose them, but only in the amount and arrangement
of these tissues. Milne-Edwards says these tissues "do not
differ much in different animals, but their mode of association

16. Directions for examining a drop of blood ?

17. Examination of the scales of the month ? Dandruff?

13. In what, as respects the tissues, do the warm-blooded animals differ'
of Milne-Edwards?

THE MICROSCOPE 327

varies, and it is chiefly by reason of the differences in the com-
bination of these associations in various degrees, that each
species possesses the anatomical properties and characters
which are peculiar to it."

19. Hence the butcher's stall will furnish all the materials
for the study of the microscopic tissues. The structure of the
heart, lungs, liver, brain, and muscle, may all be studied, and
well studied, by using minute pieces of the flesh of the lower
animals, especially of the quadrupeds. Such portions of these
animals as are not exposed for sale can be readily obtained by
order from the slaughter-house. To examine with the powers
of which we have been speaking, it is only necessary to cut off
exceedingly small pieces, tear them apart with needles, or make
very delicate sections with a sharp knife.

20. Incentives to Study. — A complete knowledge of all
minute structures is not to be expected at once, for you are
here introduced into a new realm of Nature, a world of little
things as vast, as wonderful, and as carefully constructed as
the starry firmament — that other realm of grand objects which
the astronomer rightly scans with the telescope. It will not
appear singular, therefore, if, at first, you feel strange and
awkward in this new creation. With a little perseverance,
however, and with the attention directed towards simple ob-
jects at the outset, it will not be long before an increasing
experience will engender confidence.

21. If to all this there be added an enthusiastic study of
the standard authorities on the subject, the rate of progress
will be much more rapid. As compared with similar studies,
few possess more interest than microscopy, and to the one who
pursues it with fondness, it constantly affords sources of pleas-
ure and agreeable surprises ; and in the end often leads to new
and valuable additions to the sum of human knowledge. The
depths which the microscope is employed to fathom are no
more completely known than are the heights above us explored
and comprehended by the astronomer.

19. How to procure materials f.>r the stn '. i>f the tis.-iu-.-. of ma.. .

328 THE MICROSCOPE

QUESTIONS FOR TOPICAL REVIEW

PA OB

1. Say what you can of the law of the tissues 320

2. What, then, is the necessity of the microscope ? 320

3. Define and state use of convex lenses 321

4. Name some of the kinds of microscopes '. 321, 322

5. Explain action of compound microscope 322

(i. Of what parts does it consist ? 322, 323

7. What parts are of most importance ? 323

8. How would you prepare specimens ? 323, 324

9. What further directions are given ? 324

10. What is said of preliminary studies ? 324-326'

11. Give statement regarding study of human tissues 326

12. Tissues of inferior animals 326, 327

CHAPTER XIII

FIRST HELP IN ACCIDENTS

1. Shock. — The term shock is applied to a condition of more
or less severe prostration, the result of some severe injury,
accident, or fright. It may or may not be accompanied by
loss of consciousness. The part affected is the nervous sys-
tem at large, and hence almost all the organs in the body suffer
more or less. Persons are differently affected by the same
injury ; in some, a comparatively slight accident produces a
profound degree of shock, and in others, a severe injury only
a very slight degree. The lighter forms of shock usually pass
off in a short while, but in the severer forms a person may die
without any injury being present. A person suffering from
shock will be found completely prostrated, unable to stand, his
body limp, face pale and anxious, covered with cold perspira-
tion, respiration feeble and shallow, pulse either very feeble
or imperceptible, and he may be conscious or unconscious.

The great danger to this person lies in heart failure, and
if the shock is profound, death may ensue, unless help
is promptly given. Much can be done before medical aid
arrives, and a life may be saved by prompt action. As the
heart is the chief organ affected through the nervous system,
everything to promote its action should be done. Place the
sufferer flat upon his back, with the head low ; loosen all tight
clothing about the neck and chest ; give whiskey or brandy in
hot water in small doses at intervals of fifteen minutes or
half an hour ; surround the body with hot-water bottles, and
keep the patient warm and quiet.

2. Fainting. — This is the result of deficiency of blood in
the brain. Some people, especially women, faint very easily ;

1. Shock, Its causes and symptoms ? Danger? Treatment?

2. Fainting, Its causes and treatment)

330 FIRST HELP IN ACCIDENTS

the sight of blood or surgical instruments, a gruesome story,
the recital of an accident, are sufficient causes. As a rule, the
faint is of short duration, and all that is necessary is to place
the person upon the back, with the head low ; loosen all cloth-
ing about the neck and chest ; open a window to admit fresh air,
and sprinkle the face with cold water. If the faint occurs at
church or at some public gathering, remove the person promptly
to the outer air ; for foul air is frequently the cause of the
trouble. If after the above means have been employed a
person does not regain consciousness, give small doses (tea-
spoonful) of whiskey and water, equal parts, and if that is not
sufficient, elevate the legs and body, so as to promote as much
as possible the flow of blood to the brain.

3. Vertigo. — This is " a rush of blood to the brain." The
body should be placed in a sitting posture, with the head erect.
If the blood escapes into the brain by reason of the rupture of
a blood-vessel within it, the case is very grave, and the physi-
cian should be summoned at once. Meanwhile, let the position
be as above stated. Apoplexy is known, in very many cases,
by the helpless condition of an arm or leg, or both.

4. Hemorrhage, or Bleeding. — There is no doubt that many
a life has been lost, from severe hemorrhage, which could have

been saved, had intelligent aid been at
hand to stop the bleeding-point. As a
rule, the bleeding of a small wound,
although profuse, can be readily con-
trolled by firm pressure over it, or by
tying a strip of bandage round it ; but
in the severer forms of hemorrhage,
where large vessels are torn or cut,

$$%^y^*$%^%>^ ^s *s no* so eas^y accomplished.
Learn the difference between the two
kinds of bleeding, "arterial" and "ve-
nous." Arterial is bright red, and comes
in jets (or throbs corresponding to the

3. Vertigo, it* treatment ? Apoplexy, how known J

4. Hemorrhage, or Bleeding, its treatment? Difference between "arterial" and
' venous " bleeding ? Treatment of each ? Outfit for every household ?

FIRST HELP IN ACCIDENTS

331

pulse) ; venous is dark-colored, and flows continuously. If a
larger vessel of the arm or leg has been injured, and cannot be
controlled by direct pressure, tie a
cord or handkerchief loosely around
the limb away from the wound on
the side nearest the heart, put a
stick through it and twist until the
bleeding stops. In addition to this.
tie a pad firmly on the wound. Loss
of blood from arteries is apt to be
more rapid and dangerous than that
from veins, and when the cut vessel
is a large one, the skill of the sur-
geon will ordinarily be required in
order to close the bleeding artery
permanently and securely.

It is well, in every household, to
have, in some handy and well-known
place, some strips of old muslin and
some lint, or oakum, a bandage or

two, and some adhesive plaster, a soft sponge, and needles and
thread in a basket or box by themselves. In this way, valu-
able time may be saved in the staunching of blood, flowing in
consequence of some accidental cut or other injury.

5. Fractures and Dislocations. — A broken bone in surgical
language is called a fracture ; a bone out of its joint is called
a dislocation. When, in addition to the fracture, there is pre-
sent a laceration of the soft parts surrounding it, the muscles
and the skin, so that the broken end of a bone protrudes
through the latter, we speak of it as a compound fracture. The
symptoms of a fracture are : pain and inability to move the
affected limb ; there will be mobility at the point of the frac-
ture, and the broken ends of the bone may be felt to grate
upon each other ; if the leg be broken at any point the patient
will be unable to stand upon it.

The symptoms of a dislocation are : altered shape of the

5. Describe a fracture ; a dislocation ; a compound fracture ; symptoms of each. What
can be done for each, pending the arrival of surgical aid ?

332 FIRST HELP IN ACCIDENTS

limb; inability to move it; great pain in and about the joint
upon the slightest attempt at motion.

Much can be done for the comfort of a patient, pending the
arrival of surgical aid. First of all, remember that a person
with a broken bone may, without suffering harm, wait several
hours and even a day for the so-called " setting " of the bone.
Kest and support of the injured member are the two things to
be accomplished. First remove all clothing from the arm or
leg, best by slitting the garments open, and not by pulling
them off ; then firmly tie a strip of wood on either side of the
limb, protecting the skin by padding the wood well with any-
thing soft, cotton, pieces of clothing, etc. A good support is
given by tying a pillow firmly around the arm or leg. In

moving a person suffering from a fractured leg or arm, some
one should carry the broken limb carefully and evenly, so as
to avoid all jarring and all motion at the seat of the fracture,
which would be extremely painful. Should some hours have
to elapse before the surgeon arrives, the limb should be in-
spected from time to time to see that the cords are not tied too
tightly, for considerable swelling follows each fracture.

The help in dislocations lies chiefly in the proper support of
the limb in the position in which it is found. In moving
a person suffering from a dislocation, let one person support
the limb, and after the patient is at rest, place it in the posi-
tion which proves the most comfortable for the sufferer, sup-
porting it on either side with pillows, stones, or pieces of wood.
Cold water compresses to the joint, if there is much pain, will
feel most grateful.

FIRST HELP IN ACCIDENTS 333

6. Sprains. — A sprain is a severe straining or tearing of
the ligaments surrounding a joint. In the milder forms these
are only greatly stretched, but in the more severe cases they
are torn entire or in part, in some cases being even complicated
by a tearing off or breaking of the ends of the bones forming
the joint. Every joint may suffer from a sprain, although it
is most frequently met with in the ankle.

The symptoms of a sprain are : severe pain in the affected
joint, both upon motion and at rest; swelling sets in usually
soon after the receipt of the injury, and blood soon makes its
appearance under the skin, coming from the ruptured blood-
vessels.

The best immediate relief that can be given is to place the
joint in hot water, as hot as can be borne, and keep it there
for several hours, or until the doctor arrives, adding hot water
as it cools. Should medical aid not be obtainable, then take
the limb out of the hot water after two hours, and bandage it
firmly, well below and above the joint, so as to give the great-
est support and prevent all motion.

7. Burns and Scalds. — The secret of the best treatment of
these injuries is to exclude the air from the wounded surfaces.
When they are slight, and the skin is not destroyed, but merely
blistered, prevent the displacement of the skin as much as
possible. Let the blisters be punctured, if necessary, to let
out the liquid, and then keep the skin in place by cotton cloth
or lint, wet with a solution of one teaspoonful of carbolic acid
in a quart of water, or a strong solution of baking soda. The
cloth should be kept wet constantly, but do not irritate the
wound by taking off the dressing too often.

Extensive burns are much worse than deep burns. In the
former case, the outlook is grave, and the patient will probably
require the best aid, both medical and surgical, of some
physician.

Scars after Bums. — If a burn be on the face, neck, or near

6. Sprains, description, symptoms, Immediate relief? How treated if medical aid Is not
obtainable ?

7. Burns and scalds, best treatment? What are tlie worst burns ? What about scars ?
Spontaneous fcombualio* 1 Wkst should be done when a woman's clothes are on nVe F

334 FIRST HELP IN ACCIDENTS

a joint, it is not well to hasten the healing process, on account
of the contraction that always takes place as the scar is formed.
" Fire is a source of danger, and is very destructive to life
at times. Spontaneous combustion of the human body when
saturated with alcohol is a myth, though perhaps the alcohol-
ized body does burn more readily than one free from inflam-
mable fluid. When a lady is on fire, she should not and
ought not to be permitted to run; that fans the flames
amazingly. She must be laid down and rolled up in the
nearest woollen article, — rug, coat, or blanket. Such wrap-
ping up in a non-inflammable article is a most effective method
of extinguishing the flames. Immersion in water is, unfortu-
nately, rarely practicable." — Fothergill.

8. Illuminating Gas is dangerous in two ways. If it escapes
into a tightly closed room in sufficient quantities, it causes the
death of the inmates by suffocation, unless some one from
without discovers the perilous situation. If not too late,
remove the patient into fresh air, undo the clothing, dash cold
water on the face and neck, and employ artificial respiration,
as in drowning (see p. 336). Again : If it escapes freely into
an apartment, it forms an explosive compound by mixing with
the air. If then a light is unguardedly taken into the place,
an explosion that may be destructive to life will result.
Always thoroughly air any room that has the odor of escaping
gas before a light is taken in.

9. Kerosene is the cause of even more " accidents " than gas.
Too much care cannot be taken in its use. Buy only that
which has been tested, but remember that not all that are
marked as " safe " are truly so. If a responsible oil- man certi-
fies that the oil will not " flash " under 140 degrees, it may be
regarded as safe if properly used. Lamps should be filled only
in the daytime. Never attempt to fill a lamp that is lighted,
and never put kerosene in the stove for the purpose of kindling
a fire. Very small lamps are dangerous, as also is a lamp that
has burned a long time, and has but very little oil in it.

8. Illuminating gas, in what two ways dangerous T

9. Kerosene, what kind to use ? Cautions tt> be observed- In ustog ?

FIRST HELP IN ACCIDENTS 336

10. Frost-bites. — Keep away from the fire and in a cool
room. Rub the nose, or other part that has been " bitten," with
snow or ice-water until the blood is warmed again and circulat-
ing in the part. Chilblains should not be brought to the fire :
if the skin is unbroken, it should be hardened by brushing it
over with alcohol having tannin in it.

11. Sunstroke is seldom produced in this climate in persons
who have not labored too hard. Fatigue and sun-heat are
commonly the joint causes of sudden prostration in summer;
although "heat-stroke" may occur in an artificially heated
atmosphere, without exposure to the sun. In the tropics, the
least possible exertion is put forth by the natives during the
midday hours. On very hot days, therefore, avoid fatigue and
open-air labor as much as possible. Keep the head cool. If
any unusual, dizzy feeling comes on, apply cold water to the
head and neck. If a person falls unconscious, and the skin
is decidedly hot and dry, he should be taken to a cool place.
If the face and head are red and hot, apply ice-water on
cloths. If pale, give stimulants gradually, and use cold water
sparingly.

12. Fits or Convulsions. — These may be trivial or grave.
If the patient is a young woman, the attack is probably hyster-
ical, and, as a rule, not dangerous, and a sprinkle of cold water
will bring relief. If the patient struggles with regularity of
movement, and there is bloody froth on the lips, it is a case of
epilepsy, and requires a physician's attendance. Meanwhile,
protect the head from injury by putting a pillow or some soft
article beneath it; a cork introduced between the teeth will
prevent the biting of the tongue. Prevent the person from
falling or injuring himself, but do not attempt to forcibly hold
him quiet.

In children apply cloths dipped in water to the head; disturb
the child as little as possible; do not use a warm bath until
directed by the doctor.

10. Frost-bites and chtlblains,treatment of each ?

11. Sunstroke, causes? Precautions against ? Treatment?
It. Fit* or Convutetons, kinds of ? Treatment Vt ew* r .

336 FIRST HELP IN ACCIDENTS

13. Drowning. — Marshall Hall's " Beady Method " of treat-
ment in asphyxia from drowning, chloroform, coal-gas, etc.

1st. Treat the patient instantly on the spot, in the open air,
freely exposing the face, neck, and chest to the breeze, except
in severe weather.

2d. In order to clear the throat, place the patient gently on
the face, with one wrist under the forehead, that all fluid, and
the tongue itself, may fall forward, and leave the entrance into
the windpipe free.

3d. To excite respiration, turn the patient slightly on his
side, and apply some irritating or stimulating agent to the
nostrils, as veratrine, dilute ammonia, etc.

4th. Make the face warm by brisk friction ; then dash cold
water upon it.

5th. If not successful, lose no time ; but, to imitate respira-
tion, place the patient on his face, and turn the body gently,
but completely, on the side, and a little beyond; then again on
the face, and so on, alternately. Repeat these movements
deliberately and perseveringly, fifteen times only in a minute.
(When the patient lies on the thorax, this cavity is compressed
by the weight of the body, and expiration takes place. When
he is turned on the side, this pressure is removed, and inspira-
tion occurs.)

6th. When the prone position is resumed, make a uniform
and efficient pressure along the spine, removing the pressure
immediately, before rotation on the side. (The pressure aug-
ments the expiration, the rotation commences inspiration.)
Continue these measures.

7th. Rub the limbs upward, with firm pressure, and with
energy. (The object being to aid the return of venous blood
to the heart.)

8th. Substitute for the patient's wet clothing, if possible,
such other covering as can be instantly procured, each
bystander supplying a coat or cloak, etc. Meantime, and
from tirae to time, to excite inspiration, let the surface of the
body be slapped briskly with the hand.

13. Drowning. What is Hall's ready method of treatment in asphyxia from drowning,
chloroform, wal-gas, etfr. f

FIRST HELP IX ACCIDENTS 337

9th. Rub the body briskly until it is dry and warm, then
dash cold water upon it. and repeat the rubbing.

Avoid the immediate removal of the patient, as it involves a
dangerous loss of time; also, the use of bellows, or any forcing
instrument; also, the warm bath, and all rough treatment.

14. Poisons and their Antidotes. — Accidents from poisoning
axe of such frequent occurrence, that every one should be able
to administer the more common antidotes, until the services of
a physician can be obtained. As many poisons bear a close
resemblance to articles in common use, no dangerous substance
should be brought into the household without having the word
poison plainly written or printed on the label ; and any pack-
age, box, or vial, without a label, should be at once destroyed]
if the contents are not positively known.

When a healthy person is taken severely and suddenly ill
soon after some substance has been swallowed, we may suspect
that he has been poisoned. In all cases where poison has been
taken into the stomach, it should be quickly and thoroughly
expelled by some active emetic, which can be speedily ob-
tained. This may be accomplished by drinking a tumblerful
of warm water, containing either a tablespoonful of powdered
mustard or of common salt, or two teaspoonfuls of powdered
alum in two tablespoonfuls of syrup. When vomiting has
already taken place, it should be continued by copious draughts
of warm water or mucilaginous drinks, such as gum-water or
flaxseed tea, and tickling the throat with the finger until there
is reason to believe that all the poisonous substance has been
expelled from the stomach.

The following list embraces only the more common poisons,
together with such antidotes as are usually at hand, to be used
until the physician arrives: —

Acids. — Hydrochloric acid ; muriatic acid (spirits of salt);
nitric acid (aquafortis); sulphuric acid (oil of vitriol).

Antidote. — An antidote should be given at once to neutral-
ize the acid. Strong soapsuds is an efficient remedy, and can
always be obtained. It should be followed by copious draughts

M. Give class, character, and antidote of each poison mentioned above.
T

338 FIRST HELP IN ACCIDENTS

of warm water or flaxseed tea. Chalk, magnesia, soda, or sale-
ratus (with water), or lime-water are the best remedies. When
sulphuric acid has been taken, water should be given sparingly,
because, when water unites with this acid intense heat is pro-
duced.

Oxalic acid.

ANTir ote. — Oxalic acid resembles Epsom salts in appear-
ance, and may easily be mistaken for it. The antidotes are
magnesia, or chalk mixed with water.

Prussic acid ; oil of bitter almonds ; laurel water ; cyanide
of potassium (used in electrotyping).

Antidote. — Cold douche to the spine. Chlorine water, or
water of ammonia largely diluted, should be given, and the
vapor arising from them may be inhaled.

Akalies and their Salts. — Ammonia (hartshorn), liquor or
water of ammonia. Potassa : — caustic potash, strong lye, car-
bonate of potassa (pearlash), nitrate of potassa (saltpetre).

Antidote. — Give the vegetable acids diluted, as weak vine-
gar, acetic, citric, or tartaric acids dissolved in water. Castor
oil, linseed oil, and sweet oil may also be used ; they form
soaps when mixed with the free alkalies, which they thus
render harmless. The poisonous effects of saltpetre must be
counteracted by taking mucilaginous drinks freely, so as to
produce vomiting.

Alcohol. — Brandy, wine ; all spirituous liquors.

Antidote. — Give as an emetic ground mustard or tartar
emetic. If the patient cannot swallow, introduce a stomach
pump ; pour cold water on the head.

Gases. — Chlorine, carbonic acid gas, carbonic oxide, fumes of
burning charcoal, sulphuretted hydrogen, illuminating or coal gas.

Antidote. — For poisoning by chlorine, inhale, cautiously,
ammonia (hartshorn). For the other gases, cold water should
be poured upon the head, and stimulants cautiously adminis-
tered ; artificial respiration. (See Marshall HalVs Ready
Method, page 336.)

Metals. — Antimony, tartar emetic, wine of antimony, etc.

Antidote. — If vomiting has not occurred, it should be pro-
duced by tickling the throat with the finger or a feather, and

FISST HELP IX ACCIDENTS 339

the abundant use of warm water. Astringent infusions, such
as common tea, oak bark, and a solution of tannin, act as
antidotes.

Arsenic. — White arsenic, Fowler's solution, fly powder, cobalt,
Paris green, etc.

Antidote. — Produce vomiting at once with a tablespoonful
or two of powdered mustard in a glass of warm water, or with
ipecac. The antidote is Ivvdrated peroxide of iron. If Fow-
ler's solution has been taken, lime-water must be given.

Copper. — Acetate of copper (verdigris), sulphate of copper
(blue vitriol), food cooked in dirty copper vessels, or pickles
made green by copper.

Antidote. — Milk or white of eggs, with mucilaginous
drinks (flaxseed tea, etc.), should be freely given.

Iron. — Sulphate of iron (copperas), etc.

Antidote. — Carbonate of soda in some mucilaginous drink,
or in water, is an excellent antidote.

Lead. — Acetate of lead (sugar of lead), carbonate of lead
(white lead), water kept in leaden pipes or vessels, food cooked
in vessels glazed with lead.

Antidote. — Induce vomiting with ground mustard or com-
mon salt in warm water. The antidote for soluble prepara-
tions of lead is Epsom salts ; for the insoluble forms, sulphuric
acid largely diluted.

Mercury. — Bi-chloride of mercury (corrosive sublimate),
ammoniated mercury (white precipitate), red oxide of mercury
(red precipitate), red sulphuret of mercury (vermilion).

Antidote. — The white of eggs, or wheat flour beaten up
with water and milk, are the best antidotes.

Silver. — Nitrate of silver (lunar caustic).

Antidote. — Give a teaspoonful of common salt in a
tumbler of water. It decomposes the salts of silver and
destroys their activity.

Zinc. — Sulphate of zinc, etc. (white vitriol).

Antidote. — The vomiting may be relieved by copious
draughts of warm water. The antidote is carbonate of soda
administered in water.

Narcotic Poisons. — Opium (laudanum, paregoric, salts of

340 FIRST HELP IN ACCIDENTS

morphia, Godfrey's cordial, Dalby's carminative, soothing
syrup, cholera mixtures), aconite, belladonna, hemlock, stra-
monium, digitalis, tobacco, hyosciamus, nux vomica, strychnine.

Antidote. — Evacuate the stomach by the most active emet-
ics, as mustard, alum, or sulphate of zinc. The patient should
be kept in motion, and cold water dashed on the head and
shoulders. Strong coffee must be given. The physician will
use the stomach pump and electricity. In poisoning by nux
vomica or strychnine, etc., chloroform or ether should be in-
haled to quiet the spasms.

Irritant Vegetable Poisons. — Croton oil, oil of savine, poke,
oil of tansy, etc.

Antidote. — If vomiting has taken place, it may be ren-
dered easier by copious draughts of warm water. But if
symptoms of insensibility have come on without vomiting, it
ought to be immediately excited by ground mustard mixed
with warm water, or some other active emetic, and after its
operation an active purgative should be given. After evacuat-
ing as much of the poison as possible, strong coffee or vinegar
and water may be given with advantage.

Poisonous Fish. — Conger eel, mussels, crabs, etc.

Antidote. — Evacuate, as soon as possible, the contents of
the stomach and bowels by emetics (ground mustard mixed
with warm water or powdered alum) and castor oil, drinking
freely at the same time of vinegar and water. Ether, with
a few drops of laudanum mixed with sugar and water, may
afterward be taken freely.

Poisonous Serpents. — Antidote. — A ligature or handker-
chief should be applied moderately tight above the bite, and
a cupping-glass over the wound. The patient should drink
freely of alcoholic stimulants containing a small quantity of
ammonia. The physician may inject ammonia into the veins.

Poisonous Insects. — Stings of scorpion, hornet, wasp, bee, etc.

Antidote. — A piece of rag moistened with a solution of
carbolic acid may be kept on the affected part until the pain
is relieved; and a few drops of carbolic acid may be given
frequently in a little water. The sting may be removed by
making strong pressure around it with the barrel of a small
watch-key.

FIRST HELP IN ACCIDENTS 341

QUESTIONS FOR TOPICAL REVIEW

PAGE

1. What is a frequent accompaniment of severe accidents? 329

2. What would you do for a person suffering from shock? from faint-

ness ? from vertigo ? 330

3. How would you recognize and check arterial bleeding?

4. What is the difference hetween a fracture and a dislocation '.' 331, 332

5. What can you do for each until a physician arrives ? 332

G. What are the causes, symptoms, and treatment of a sprain ? 333

7. What is the treatment for burns and scalds?

8. What is the treatment for asphyxia from inhaling illuminating gas

9. What is the best thing to do when your nose or ears are frost-bitten

10. What are the signs of sunstroke, and what would you do for any

one suffering from it ? 335

11. What is said about tits and convulsions'.' 335

12. Give a careful account of the way to treat a person apparently

drowned? 331

13. Take up each of the poisons mentioned and give its antidote 3J7, ;vpj

APPENDIX

THE CARE OF THE SICK-ROOM

The sick-room should be bright and airy, and •• sweetness and
light" its motto. Other things being equal, it is best on one of the
upper floors — in the case of some '-catching" disease on the top
floor. Let it be on the sunny side of the house. If for any reason
the light of the sun is temporarily to be avoided — as when the
eyes are sensitive or have been operated upon — let the light be shut
out by a proper arrangement of blinds or curtains. The air-supply to be
breathed by the sick person should be pure. Those who, in health, find
themselves in an impure air can quit it ; they are not compelled to suffer
from it ; but a sick person may be incapable of recognizing the bad
quality of the air, as well as helpless to free himself from it.

To keep the air pure, the windows should be opened as often as three
times a day, care being taken to protect the patient from being chilled,
while the room is being aired.

Unless the physician should direct differently, one window — that most
remote from the bed — should be open an inch or more both day and
nidit. and in all seasons. The extent to which the sash should be lowered
must be governed largely by the weather and the direction of the wind.

A fire, in an open fireplace, except in summer weather, will be a great
help towards keeping the air pure. The upward current through a chim-
ney-flue, if unobstructed, is equal to or not far below 20,000 cubic feet
per hour; an outlet sufficient for a room occupied by ten persons.

The inlet of air, however, must not be forgotten, otherwise the air in
the room tends to become both impure and too thin. A* our houses are
generally constructed, the inlet of air is best secured by a win;
being lowered from the top.

Take special care that no stationary wash-basin or other sewer-con-
nected convenience is improperly plumbed, and that sewer gas cannot by
any possibility escape into the sick-room.

The swinging of doors to create a current is not an efficient means of
ventilation, as it agitates the air of the room without purifying it, and
often disturbs the patient.

W3 .

344 APPENDIX

A draught of air is to be avoided ; it will seldom occur that the air of
the room requires to be so speedily changed that the patient need be
exposed to a draught ; never, when care has been taken to provide con-
tinuous and gradual ventilation.

It should be borne in mind that cold air is not necessarily pure air,
and that ventilation is not less needed in winter than in warm weather.

Sleep is a great necessity to the sick. If a well person slumbers in the
day-time, it will interfere with his sound .repose at night, but with the
sick this is generally not the case. The more they sleep the more favor-
able are the chances for their recovery : so that it will be readily seen
how important it is to avoid noise and jar in the sick-room, especially if
the disease is acute.

Bear in mind that even slight noises, as the rustling of garments, the
creaking of doors, whispering, or noisy footfalls, may be sufficient to dis-
turb a brain that is rendered sensitive by pain or wakefulness.

The clothing next the skin should be changed more frequently in sick-
ness than in health. These changes must be quickly and deftly made,
and with as little disturbance as possible.

Under some conditions of disease, the best welfare of the patient is
accomplished by having two beds in the room instead of one.

The temperature of the room must be watched. To that end a ther-
mometer should always be present, and easily approached. It is better
not to have it directly in the view of the patient. The temperature
should not be allowed to vary much from Go0 F., unless the doctor other-
wise directs.

Let the furniture be as plain and as free from upholstery as possible ;
not many pieces are required. Movable carpets or rugs are better than
those that are permanently laid. Curtains about the windows are out of
place in a sick-room : so are flowering plants and birds, as a general rule.
Florence Nightingale, however, makes an exception in the case of chronic
invalids, and consents to the comforting influence of a pet bird or two.

In regard to the admission of visitors, and conversation, much will
depend upon the strength of the patient and the kind of sickness: at
many times these are to be forbidden, as having a disquieting influence.
When contagious ■disease is in the house, the sick-room must be avoided
by all except those who have' the care of the patient, and those having
this care should avoid coming in contact with the other members of the
household, especially the children.

Bear in mind that everything brought in contact with the sick is liable
to endanger the health of the well.

No articles in use by the invalid should be removed or used by others
until thoroughly disinfected ; the dishes and spoons should be put in boil-
ing water before being taken from the room. The room itself should be
fumigated with sulphur when the person is removed from it. ...

APPENDIX 345

Old pieces of muslin, etc., should be used instead of handkerchiefs to
receive the poisonous discharges from the nose, mouth, and thr< >at.
These can be destroyed by fire, and thus prevent the danger of conveying
the disease to others.

"Taking the breath" and kissing should be avoided by those in atten-
dance upon the case.

The bottles of medicine and other reminders of illness should, as far
as convenient, be withdrawn from the view of the sick.

Such as are to be kept always at hand should be arranged in an
orderly way upon a tidily-covered bed-side table. The sight of a siphon
bottle of aerated water is agreeable to most patients ; that may be kept
in the room, but the vessels containing milk, drinking-water, etc., should
be kept elsewhere.

DISINFECTION

Filth fosters or produces certain diseases ; it should, therefore, be
removed as soon as possible. When it is difficult to remove it, dis-
infectants come into play, as they have the power to rob it of some of
its disease-breeding force. But let it be remembered that disinfection is not
cure ; it is not a substitute for cleanliness and pure air. The true cure is
the removal of filth ; and when our homes are concerned in some question
of drainage where the filth is out of our sight, it may be necessary to
consult and employ the plumber or some other artisan.

In times gone by, it was the custom to mask bad smells by burning
pastilles, coffee, cascarilla, and the like. These are not now much used;
for most persons have come to understand that the fumes thus created do
not remove, but simply overpower the evil odors.

Chemistry has advanced to such a point that various pungent chemical
substances, formerly not well known, can be furnished at small cost, and
these substances have the power, in varying degrees, to check vile odors.
Carbolic acid, chloride of lime, and Labarraque's solution are among the
best known of these, but there are also certain of the salts of iron, and
zinc, and permanganate of potash that may be used. Sulphur is much
used for the fumigation of rooms that have been infected.

Another cheap disinfectant is a solution of chloride of lead. It is in-
odorous, effective, and the cost is small. Take half a drachm of the
nitrate and dissolve it in a pint or more of boiling water. Dissolve two
drachms of common salt in a pail or bucket of water ; pour the two solu-
tions together and allow the sediment to sink. A cloth dipped in this
solution, and hung up in a room, will correct a bad odor promptly, or if
the solution be thrown down a drain, or upon foul-smelling refuse, it will
have the same effect.

The room to be purified with sulphur should be made as tight as pos-
sible, so that no fumes can escape, either by window, dooi. or chimney.

346 APPENDIX

Put three pounds of sulphur in an iron pot, which should not stand upon
woodwork or carpet, lest they be burned, but in a large pan of ashes, or
upon a layer of bricks ; on this sulphur pour a tablespoonful of alcohol.
This is then set on fire, and everybody immediately withdraws from the
room. The room should remain closed ten hours, after which it should be
thoroughly aired before it is occupied, for the fumes of the sulphur are
irritating to the lungs.

The chemicals above mentioned should be known and labelled as
poisons. Many persons have been injured, if not killed, by incautiously
or ignorantly drinking those that are of a liquid form.

Heat is one of the best, if not the best, disinfecting agent. Articles of
bedding and furniture that cannot well be treated otherwise can be puri-
fied by a long exposure to a temperature of 240° F. In some cities, es-
pecially in England, furnaces are made for the reception of bulky articles
that have become infected.

Fresh air is another powerful agent. If woven fabrics, clothing, and
the like are for a long time aired out of doors, they cease to be infective ;
probably by the enormous dilution, if not destruction, of the elements of
danger.

Certain diseases are "catching" ; they have the power of spreading
from one person to another, chiefly by the particles that pass off from the
body of the patient. Among these diseases are small-pox, measles,
scarlet fever, and diphtheria. The articles that are worn or used by the
patient become " infected," and they should be disinfected before they
are used by others. As a rule, of course, a doctor will be called in to
attend to these diseases. When that is so, follow his directions as to dis-
infection, as well as every other part of the treatment of the case. For
substances that are not injured by being washed, a good and cheap dis-
infectant is sulphate of zinc (" white vitriol ") and common salt dissolved
in water, boiling hot if possible, using eight tablespoonfuls of the zinc
and four of salt to the gallon of water. This is useful for clothing, bed-
linen, towels, handkerchiefs, etc. After these articles have lain for an
hour or two in this solution, they should be allowed to stand in boiling
water before being washed. Infected articles that are of little value
should, of course, be destroyed by fire.

The United States Treasury Department has published the following
formula for the disinfection of the rags coming from Egypt: " 1. Boiling
in water for two hours under a pressure of fifty pounds per square inch ;
2. Boiling in water for four hours without pressure ; or, 3. Subjection to
the action of sulphur fumes for six hours, burning one and one-half to
two pounds of roll-brimstone in each 1,000 cubic feet of space, with the
rags well scattered upon racks." Any one of these three methods is
accepted as sufficiently thorough to prevent the spreading of cholera by
means of rags.

APPENDIX 347

THE HOME AND HEALTH

The location of the house should be airy, dry, and sunny.

A certain amount of elevation is necessary, in order to secure proper
drainage. Too much shade must not fall upon the house, as sunlight is
very necessary to a proper degree of animal vigor. Young children, as
is well known, especially profit by the tonic influence of sunlight.

The cellar is an important part of the dwelling ; therefore, ifhless care
be taken for its ample ventilation, it will be the source from which is sup-
plied much of the air breathed in the upper chambers of the house. If
the cellar is damp the house is liable to become so, and if vegetables are
stored in the cellar, an especial degree of care is needed to ventilate it
thoroughly and constantly.

House Drainage. — An English writer has stated that "the most
important part of the house is the drains." This, no doubt, sounds
strangely to the ears of many, who have been brought up to view the
parlor or drawing-room as the true centre of the house ; and yet it is no
foolish saying, when we reflect that with a bad system of drainage to a
house every dweller therein stands in peril of several forms of disease
that, mild as the cases may be, are a source of anxiety, and when severe,
too often have a fatal termination. Drain-diseases, such as typhoid
fever, dysentery, diphtheria, and scarlet fever, often destroy entire fami-
lies. These diseases do not always come upon a home through defective
drainage, but when they do, they frequently show themselves in a very
violent form.

Drainage (as applied to dwellings) consists in conveying away from
the house the liquid and solid impurities that would otherwise accumulate
in or near the dwelling. Waste is a necessary accompaniment of all
animal life, to the preparation and taking of food, to the clothing of the
body, to bathing and other simple acts of daily life. The waste material
of houses tends to decay and to become offensive. It must, therefore,
not only be put out of sight and smell, but must be removed so far away
that it cannot return in the form of dangerous, invisible gases of decom-
position.

The best house-drains are made of iron or glazed earthenware, care-
fully selected and well laid. The joints of the pipes should be gas-tight
The soil-pipe should be carried up to and through the roof. All the
waste-pipes from basins, etc., in the rooms should be joined in a gas-tight
manner to the soil-pipe, and each and every basin and other fixture
should have a separate trap. What is a trap? It is a device that is
designed to retain a certain portion of the water running through it —
called the " water-seal " — so that the ascent of air or gas, from the drain
back into the room, is prevented. It "traps" the sewer gas away from
us. Whenever a fixture has been used and there is not, beyond all

348 APPENDIX

doubt, a sufficiency of water to fill the trap, additional water should be
poured in. Traps are of various sizes, and of an infinite variety of pat-
terns and patents, and must vary greatly according to their situation ;
but one thing should be made sure of in their use — namely, that they
hold not less than two inches of water as a " seal."

There is at almost all seasons of the year an upward, because warmer,
current of air through the main pipes. It is therefore better to have a
fresh-airinlet pipe near the point where the drain leaves the house-wall.
This helps to prevent the unsealing of traps. It also brings about a
purer condition of the air in the interior of the system of pipes — so use-
ful in this air-current through the soil-pipe that if applied there is little
danger of the escape of sewer gas into the living rooms.

What is sewer gas or sewer air ? It varies greatly in different places
and at different times. It is not a definite gas, like oxygen, nitrogen,
etc., but varies in composition, and what is still more worthy of note, it
varies in its dangerous qualities. It is not always offensive, although it
is'generally so ; its odor has been described as being "sweetish and sick-
ish." Its dangerous qualities have not yet been determined by chemistry
or the microscope, but one practical' point may be borne in mind —
namely, that when a case or cases of contagious disease occur in any
house along any given line of sewer pipes, it is best to use disinfectants
in the drainage of the other dwellings along the same line of sewer.
Children should avoid playing over or around the sewer-gratings in the
streets at all times, and especially when scarlet fever and like contagious
diseases are known to be in the neighborhood ; for the exit of sewer air
at these points is always very free, unless it be directly after rainfall.

One other point must be remembered — that the best-laid system of
house-plumbing is not indestructible. In the course of time, defects will
arise, breaks will occur ; for this reason it would be well for every house-
holder to have an examination made at intervals, of every joint and along
the whole line of the house connection with the sewer or drain.

It is thought by many that sewer gas is not found in the country
because there are no sewers — they have been misled by the word. If
the words "drain air" or "filth gas" had been adopted, the universal
production of this injurious substance, in close connection with every
abode of man, wherever located, might have been better understood. In
country houses there are, perhaps, fewer dangers of contamination of the
air we breathe by waste products, because there are fewer water-closets,
wash-basins, sinks, etc., and the rooms are less exposed to impure air.

But in the country danger is apt to come by or through the pollution
of the water supply. The well, which furnishes that cool and refreshing
draught, is the point to be watched. It is convenient to have the well near
the house, because when the snow is on the ground and the weather is
cold, the distance to the well from the house is a matter of no small

APPEXDIX 349

moment. Near the house must be the stable and pens for animals — the
■waste from the house goes upon the ground, and not very far away from
the house — the chamber slops and the more offensive matters go into
a pit, which must not be too distant. The result of all these conditions
is a pollution of the soil at all these points — a pollution which spreads
with every rainfall, and which, sooner or later, reaches the well ; yet the
wTater may appear as pure as ever. It only remains to have the suitable
disease-germ lodged in this polluted territory to bring down the whole
household with a fever. This is the kind of soil-pollution which is hard
to cure, and which, in long-settled countries, causes laws to be enacted
requiring all vaults for the reception of house and human waste to be
made water-tight, so as to save the soil from its poisoning influence.

This is the kind of poisoning which, in the Dark Ages, caused so much
unrighteous persecution of the innocent. In those days, no care whatever
was taken in the towns, high-walled, crowded, and unsewered, to protect
the water supply from pollution — as a result, some terrible epidemic of
fever would arise. Then the angry populace would, in their ignorance,
cry out : " The Jews have poisoned the wells." The wells were poisoned,
no doubt, but the Jew was no more worthy of blame than were his ac-
cusers. Nevertheless, the Jews -were not spared — they were robbed,
imprisoned, executed.

Drainage in the city is a comparatively easy problem when the city's
sewers are laid in the streets. In the country it is more difficult, and on
this account the fewer fixtures or " modern improvements " there are in
the house the better it will be. There should be no less care within the
country house, where waste-pipes are put in, than in the city house. The
material should be well selected, tightly joined, and properly ventilated.
The water-closet should be remote from the house. Earth closets are
better than the ordinary vaults — house-waste from kitchen and laundry
should be taken to a considerable distance from the house, and far away
from the well, and either deposited in a water-tight cesspool, or conveyed
away, by a system of subsoil drainage tiles, arranged so as to fertilize
some unoccupied plot of ground.

ON GOING INTO THE COUNTRY
To spend the summer in the country would be the choice of all city
dwellers, whenever their purses will permit of it. And there are not a
few advantages in such a course ; the change of scene is good, the moun-
tains and the seaside give a purer and cooler air — an air that invigorates
and aids in restful sleep at night, so different from the midsummer atmos-
phere in hot cities. There are fewer excitements in the country ; we do
not " live so fast," and there is full scope for healthful life and activity in
the open air, with the green and blue of nature all about us, instead of
the monotonous walls of towering houses.

350 APPENDIX

But this course, pleasant and helpful to so many, is not without its
danger. Many who go away for a vacation are brought home sick on
account of fever or other sickness caused by defects and faults of drain-
age existing in these temporary summer homes. Scarcely a year goes by
that one or more summer resorts have not gained the ill name of being
the hotbeds of typhoid fever, dysentery, and the like.

In view of this, how important it becomes that we exercise judgment,
and seek skilled advice in the selection of our summering places.

Again, there is another danger that must not be overlooked. Let us
suppose that the summer vacation has passed by without accident ; that
we return invigorated by the experience, and that the home in the city
has been empty and closed during our absence ; what has happened that
the air in the rooms newly reopened should be foul and stifling ? This
has taken place : the water that stands in the traps of house pipes, and
shuts off gases from the sewer when the rooms are in use and water is
daily entering the different wash-basins, etc., has during our absence been
evaporated. For weeks, perhaps, there has been no " water-seal " in the
traps, and the ascent of sewer air has been going on continuously, so that
not only is the air utterly unfit to live in, but all the curtains, carpets, and
other absorbing materials have become saturated with the pollution thus
allowed to enter. Let it be remembered that when a sink, etc., is not in
use, it is gradually losing the trap-water by the evaporation.

What is the remedy, you will ask, for the condition of things caused by
closing up the house, as above stated ? To this the reply is, that the house
should from time to time be opened and aired, and water should be poured
down each and every sanitary fixture, in sufficient quantity to renew the
supply of water in the trap of each.

APPEXl'IX

361

EXERCISES FOR HOME GYMNASTICS

».See i if

Fig. 1. — Position foe Exercising

Fig. 2. —To develop Mcbcus
tiie Upper 15a. k

Fig. 3. —To develop Front Arm. Ciiest. Pis. 4. To dktslof Lower Back

AitiM.MFN. Front Leg vnp Middle R\'K

Note -The out* of the above illustrations were kindlv furni<he'l hy the Narrajransett
Machine Company, inanufactiir.Ts of the apparatus. Providence, R.I.

352

APPENDIX

Fig. 6. — To develop Chest Muscles
and Front Arm

Fio. 7. —To df.vei.op Side-waist
Muscles

Fig. 8. — To develop Upper and
Lower Back, Shoulder, Back
Arm, and Back Leo

APPEM>1\

353

Fig. 9. — To develop Abdomen; i<> deepes the Thorax

FlG. 10.— To widen the THORAX AMD DEVELOP the Bh>KS Ol Waist

V^W

Fig 11.— To develop tite Abdominal MtjsoxM and fin M> a ua of Uma Leo

GLOSSARY

Ab-do'men (Latin abdo, to conceal). The largest cavity of the body,
containing the liver, stomach, intestines, etc. ; the belly.

Ab-sor'bents (L. ab and sorbeo, to suck up). The vessels which take
part in the process of absorption.

Ab-sorp'tion. The process of sucking up fluids by means of an animal
membrane.

Ac-com-mo-da'tion of the eye. The alteration in the shape of the crys-
talline lens, which accommodates or adjusts the eye for near and
remote vision.

Ac'id, Lactic (L. lac, milk). The acid ingredient of sour milk ; the gas-
tric juice also contains it.

Al-bu'men, or Albumin (L. albus, white). An animal substance resem-
bling white of egg.

Al-bu'mi-nose (from albumen). A soluble animal substance produced
in the stomach by the digestion of the albuminoid substances.

Al-bu'min-oid substances. A class of proximate principles resembling
albumen ; they may be derived from either the animal or vegetable
kingdom*.

Al'i-ment (L. alo, to nourish). That which affords nourishment ; food.

Al-i-ment'ary Ca-nal (from aliment). A long tube in which the food is
digested, or prepared for reception into the system.

An-as-thet'ics (Greek av, an, without, aiad-qaia, aisthesia, feeling).
Those medicinal agents which prevent the feeling of pain, such as
chloroform, laughing-gas, etc.

An-i-mal'cule (L. animal'culum, a small animal). Applied to animals
which can only be seen with the aid of the microscope. Animalculum
(plural, animalcula) is used with the same meaning.

A-or'ta (Gr. dopreo/xat, aorteomai, to be lifted up). The largest artery of
the body, and main trunk of all the arteries. It arises from the left
ventricle of the heart. The name was first applied to the two large
branches of the trachea, which appear to be lifted up by the heart.

A'que-ous Humor (L. aqua, water). A few drops of watery colorless
fluid occupying the space between the cornea and crystalline lens.

A-rach'noid Mem'brane (Gr. apaxvy, arachne, a cobweb, and «'5os, eidos,
354

GLOSSARY 356

like). An extremely thin covering of the brain and spinal cord. It

lies between the dura mater and the pia matt r.
Ar'bor Vi'tae (L). Literally, "the tree of life"; a name given to the

peculiar appearance presented by a section of the cerebellum.
Ar'ter-y (Gr. ar/p, aer, air, and riipuv. terein, to contain). A vessel by

which blood is conveyed away from the heart. It was Bupposed by

the ancients to contain air ; hence, the name.
Ar-tic-u-la'tion (L. articulo, to form a joint;. The more or less movable

union of bones, etc.; a joint.
A-ryt'e-noid Car'ti-la-ges (Gr. dpuraiua. arutaina, a pitcher). Two small

cartilages of the larynx, resembling the mouth of a pitcher.
As-sim-i-la'tion (L. ad, to, and similis, like). The conversion of food

into living tissue.
Au-di'tion (L. audio, to hear). The act of hearing sounds.
Au'di-to-ry Nerve. One of the cranial nerves ; it is the special nerve

of hearing.
Au'ri-cle (L. auris, the ear). A cavity of the heart.
Bar'i-tone (Gr. papvs, burns, heavy, and tovos, tonus, tone). A variety of

male voice between the bass and tenor.
Bel-la-don'na (It. beautiful lady . A vegetable narcotic poison. It has

the property of enlarging the pupil, and thus increasing the brilliancy

of the eye ; so called from its use by Italian ladies.
Bi-cus'pid (L. bi, two, and cuspis, prominence). The name of the

fourth and fifth teeth on each side of the jaw ; possessing two

prominences.
Bile. The gall, or peculiar secretion of the liver; a viscid, yellowish

fluid, and very bitter to the taste.
Bron'chi (Gr. Ppoyxos, bronchos, the windpipe). The two first divisions

or branches of the trachea ; one enters each lung.
Bron'chi-al Tubes. The smaller branches of the trachea within the sub-
stance of the lungs, terminating in the air-cells.
Bron-chi'tis (from bronchia, and ids, a suffix signifying inflammation).

An inflammation of the larger bronchial tubes; a "cold" affecting

the lungs.
Cal-ca're-ous (L. cit.r. lime). Containing lime.
Ca-nal' (L.). In the body, any tube or passage.
Ca-nine' | L. cants, ;i dog . Name given to the third tooth on each Bide of

the jaw ; in the upper jaw it is also known as the eye-tooth, pointed

like the tusks of a dog.
Cap'il-la-ry (L. capil'lus, a hair, capilla'ris, bair-like). Tin name of

the extremely minute blood-vessels which connect the artti :

the veins.
Car'bon Di-ox'ide (00»). Chemical name for carbonic acid gas,
Car-bon'ic A'cid. The gas which is present in the air expired from the

356 GLOSSARY

lungs ; a waste product of the animal kingdom, and a food of the

vegetable kingdom.
Car'di-ac (Gr. Kapdla, kardia, the heart). The cardiac orifice of the

stomach is the upper one, and is near the heart ; hence its name.
Car-niv'or-ous (L. ca'ro, flesh, and vo'ro, to devour). Subsisting upon flesh.
Ca-rot'id Ar'ter-y. The large artery of the neck, supplying the head

and brain.
Car'ti-lage. A solid but flexible material, forming a part of the joints,

air-passages, nostrils, etc. ; gristle.
Ca'se-ine (L. ca'seus, cheese). The albuminoid substance of milk; it

forms the basis of cheese.
Cer-e-bel'lum (diminutive for cer'ebrum, the brain). The little brain,

situated beneath the posterior third of the cerebrum.
Cer'e-brum (L.). The brain proper, occupying the entire upper portion

of the skull. It is nearly divided into two equal parts, called "hemi-
spheres," by a cleft extending from before backward.
Cho'roid (Gr. x°P'0,,> chorion, a membrane or covering). The middle

tunic or coat of the eyeball.
Chyle (Gr. x^s, chulos, juice). The milk-like fluid formed by the

digestion of fatty articles of food in the intestines.
Chyme (Gr. x^os, chuinos, juice). The pulpy liquid formed by digestion

within the stomach.
Cil'i-a (pi. of cil'i-um, an eyelash). Minute, vibratile, hair-like pro-
cesses found upon the cells of the air-passages, and other parts that

are habitually moist.
Cir-cu-la'tion (L. cir'culus, a ring). The circuit, or course of the blood

through the blood-vessels of the body, from the heart to the arteries,

through the capillaries into the veins, and from the veins back to

the heart.
Co-ag-u-la'tion (L. coag'ulo, to curdle). Applied to the process by

which the blood clots or solidifies.
Coch'le-a (L. coch'lea, a snail-shell). The spiral cavity of the internal ear.
Con'cha (Gr. kovxv, konche, a mussel-shell). The external shell-shaped

portion of the external ear.
Con-junc-ti'va (L. con and jun'go, to join together). A thin layer of

mucous membrane which lines the eyelids and covers the front of the

eyeball ; thus joining the latter to the lids.
Con-trac-til'i-ty (L. con and tra'ho, to draw together). The property of

muscle which enables it to contract, or draw its extremities closer

together.
Con-vo-lu'tions (L. con and vol'vo, to roll together). The tortuous

foldings of the external surface of the brain.
Con-vul'sion (L. convel'lo, to pull together). A more or less violent agi-
tation of the limbs or body.

GLOSSARY 357

Cor'ne-a (L. cor'nn, a horn). The transparent, horn-like substance which

covers the anterior fifth of the eyeball.
Cor'pus-cles, Blood (L. dim. of cor'pus, a body). The small bi-concave

discs which give to the blood its red color ; the white corpu-

globular and larger.
Cos-met'ic (Gr. Koantw, kosmeo, to adorn). Beautifying ; applied to

articles which are supposed to increase the beauty of the skin, etc.
Cra'ni-al (L. cra'nium, the skull). Pertaining to the skull. The nerves

which arise from the brain are called cranial nerves.
Cri'coid (Gr. xpiKos, kri'kos, a ring). A cartilage of the larynx resembling

a seal-ring in .shape.
Crys'tal-line Lens (L. crystal' lum, a crystal). One of the so-called

humors of the eye ; a double convex body situated in the front part of

the eyeball.
Cu'ti-cle (L. dim. of cu'tis, the skin). The scarf-skin ; also called the

epider'mis.
Cu'tis (L. skin or hide). The true skin, lying beneath the cuticle ; also

called the der'mis.
De-cus-sa'tion (L. decus'sis, the Roman numeral ten. X). A reciprocal

crossing of fibres from side to side.
Di'a-phragm (Gr. Siacppdja-u, diaphrasso, to divide by a partition). A

large, thin muscle which separates the cavity of the chest froin the

abdomen ; a muscle of respiration.
Dif-fu'sion of Gases. The power of gases to become intimately mingled,

without reference to the force of gravity.
Duct (L. du'co, t<> lead). A narrow tube ; the thoracic duct is the main

trunk of the absorbent v -
Du-o-de'num L. duode'ni, twelve). The first division of the small intes-
tines, about twelve fingers1 breadth long.
Du'ra Ma'ter (L.). Literally, the hard mother; the tough membrane

whicb envelops the brain.
Dys-pep'si-a (Gr. Svs, dus, difficult, and we-n-Tw. pepto, to digest). Diffi-
cult or painful digestion : a disordered condition of the stomach.
E-mul'sion (L. emvVgeo, to milk). Oil in a finely divided state sus-
pended in water.
En-am'el (Fr. email). The dense material which covers the crown of

the tooth.
Endocardium (Gr. ^5o, endo, within, and icapSia. Icardia, tin1 heart. The

lining membrane of the heart.
En'er-gy. Specific, of a Nerve. When a nerve of special sense is excited,

whatever be the cause, the sensation experienced is that peculiar to

the nerve; this is said to be the law of the specific energy of the

nerves.
Ep-i-glot'tis (Gr. eiri, epi. upon, and *,\u;rTis. glottis, the entrance to the

358 GLOSSARY

windpipe). A leaf -shaped piece of cartilage which covers the top of

the larynx during the act of swallowing.
Ex-cre'tion (L. excer'no, to separate). The separation from the blood of

the waste particles of the body ; also the materials excreted.
Ex-pi-ra'tion (L. expi'ro, to breathe out). The act of forcing air out of

the lungs.
Ex-ten'sion (L. ex, out, and ten' do, to stretch). The act of restoring a

limb, etc. , to its natural position after it has been flexed, or bent ; the

opposite of Flexion.
Fe-nes'tra (L.). Literally, a window ; the opening between the middle

and internal ear.
Fi'brine (L. fi'bra, a fibre). An albuminoid substance found in the

blood ; in coagulating it assumes a fibrous form.
Flex'ion (L.flecto, to bend). The act of bending a limb, etc.
Fol'li-cle (L. dim. of foi'lis, a bag). A little pouch or depression in a

membrane ; it has generally a secretory function.
Fun'gous Growths (L. fun'gus, a mushroom). A low grade of vegetable

life.
Gan'gli-on (Gr. 76177X401', ganglion, a knot). A knot-like swelling in the

course of a nerve ; a smaller nerve-centre.
Gas'tric (Gr. yaar-tip, gaster, stomach). Pertaining to the stomach.
Gland (L. glans, an acorn). An organ consisting of follicles and ducts,

with numerous blood-vessels interwoven ; it separates some particular

fluid from the blood.
Glos'so-phar-yn-ge'al Nerve (Gr. y\Gi<r<xa, glossa, the tongue, and <pdpvy£,

pharunx, the throat). The nerve of taste supplying the posterior third

of the tongue ; it also supplies the throat.
Glu'ten (L.). Literally, glue; the glutinous albuminoid ingredient of

wheat.
Gran'ule (L. dim. of gra'num, a grain). A little grain ; a microscopic

object.
Gus-ta'tion (L. gusto, to taste). The sense of taste.
Gust'a-to-ry Nerve. The nerve of taste supplying the front part of the

tongue, a branch of the "fifth " pair.
Hem'or-rhage (Gr. al/m, hai'ma, blood, and p^yvv/j.i, regnumi, to burst).

Bleeding, or the loss of blood.
Hem-i-ple'gi-a (Gr. ^V«™s, hemisus, half, and w'Kfa™, plesso, to strike).

Paralysis, or loss of power, affecting one side of the body.
Hem'i-spheres (Gr. acpalpa, sphaira, a sphere). Half a sphere, the lateral

halves of the cerebrum, or brain proper.
He-pat'ic (Gr. rfirap, hepar, the liver). Pertaining to the liver.
Her-biv'o-rous (L. her'ba, an herb, and vo'ro, to devour). Applied to

animals that subsist on vegetable food.
Hu'mor (L.). Moisture: the humors are transparent contents of the

eyeball.

GL0S8AR1 359

Hy-dro-pho'bi-a (Gr. v8wp, hudor, water, and <po(ttw, phobeo, to fear). A
disease caused by the bite of a rabid dog or other animal. In a person
affected with it, convulsions are occasioned by the sigh) of a glittering
object, like water, by the sound of running water, and by almost any
external impression.

Hy'gi-ene (Gr. vyUia, hugieia, health). The art of preserving health and
preventing disease.

Hy'per-o'pi-a. Abbreviated from Hy'per-me-tro'pi-a (Gr. virip. huper,
beyond, p.irpov, metron, the measure, and w\p, ops, the eye). A defect
of vision dependent upon a too short eyeball ; so called because the
rays of light are brought to a focus at a point behind the retina ; the
true "far sight.''

In-ci'sor (L. inci'do, to cut). Applied to the front teeth oj^both jawB,
which have sharp cutting edges. !k^L4J/rnjC* *~/ J'UtoaJcXM/*

In'cus (L.). An anvil ; the name of one of the bones of the middle 4ar.

In-sal-i-va'tion (L. in, and sa-li'va, the fluid of the mouth). The min-
gling of the saliva with the food during the act of chewing.

In-spi-ra'tion (L. in, and spi'ro, to breathe). The act of drawing in tin-
breath.

In-teg'u-ment (L. in, and te'go, to cover). The skin, or outer covering
of the body.

In-tes'tine (L. in'tus, within). The part of the alimentary canal which
is continuous with the lower end of the stomach ; also called the intes-
tines, or the bowels.

I'ris (L. i'ris, the rainbow). The thin muscular ring which lies between
the cornea and crystalline lens, and which gives the eye its brown.
blue, or other color.

Ju'gu-lar (Jj.ju'gulum, the throat). The name of the large veins which
run along the front of the neck.

Lab'y-rinth (\aj3vpivdos, laburin'thos, a building with many winding pas-
sages). The very tortuous cavity of the inner ear, comprising the
vestibule, semi-circular canals, and the cochlea.

Lach'ry-mal Apparatus (L. lach'ryma, a tear). The organs for forming
and conveying away the tears.

Lac'te-als (L. lac, lac'tis, milk). The absorbent vessels of the small
intestines ; during digestion they are filled with chyle, which has a
milky appearance.

La-ryn'go-scope (Gr. \dpvy£, larunx, the larynx, and <™oWa>, skopeo, to
look at). The instrument by which the larynx may be examined in
the living subject.

Lar'ynx (Gr.) The cartilaginous tube situated at the top of the wind-
pipe, or trachea ; the organ of the voice.

Lens (L.) Literally, a lentil; a piece of transparent glass or other sub-
stance so shaped as either to converge or disperse the rays of light.

360 GLOSSARY

Lig'a-ment (L. li'go, to bind). A strong, fibrous material binding bones

or other solid parts together ; it is especially necessary to give strength

to joints.
Lig'a-ture. A thread of silk or other material used in tying around an

artery.
Lymph (L. lym'pha, spring-water). The colorless, watery fluid conveyed

by the lymphatic vessels.
Lym-phat'ic Vessels. A system of absorbent vessels.
Mal'le-us (L.). Literally, the mallet ; one of the small bones of the mid-
dle ear.
Mar'row. The soft, fatty substance contained in the central cavities of

the bones : the spinal marrow, however, is composed of nervous tissue.
Mas-ti-ca'tion (L. mas'tico, to chew). The act of cutting and grinding

the food to pieces by means of the teeth.
Me-dul'la Ob-lon-ga'ta. The " oblong marrow," or nervous cord, which

is continuous with the spinal cord within the skull.
Mem-bra'na Tym'pan-i (L.). Literally, the membrane of the drum; a

delicate partition separating the outer from the middle ear ; it is

sometimes incorrectly called the drum of the ear.
Mem'brane. A thin layer of tissue serving to cover some part of the

body.
Mi'cro-scope (Gr. /xiKp6s, mikros, small, and aKoiriw, slcopeo, to look at).

An optical instrument which assists in the examination of minute

objects.
Mo'lar (L. mo'la, a mill). The name applied to the three back teeth

of each side of the jaw ; the grinders, or mill-like teeth.
. Mo'tor (L. mo'veo, mo'tum, to move). Causing motion ; the name of

those nerves which conduct to the muscles the stimulus which causes

them to contract.
Mu'cous Mem'brane. The thin layer of tissue which covers those inter-
nal cavities or passages which communicate with the external air.
Mu'cus. The glairy fluid which is secreted by mucous membranes, and

which serves to keep them in a moist condition.
My-o'pi-a (Gr. /jlvu, muo, to contract, and u>\p, ops, the eye). A defect of

vision dependent upon an eyeball that is too long, rendering distant

objects indistinct ; near-sight.
Na'sal (L. na'sus, the nose). Pertaining to the nose ; the nasal cavities

contain the distribution of the special nerve of smell.
i I Nerve (Gr. vevpov, neuron, a cord or string). A glistening, white cord of

cylindrical shape, connecting the brain or spinal cord with some other
, organ of the body.

Nerve Cell. A minute, round and ashen-gray cell found in the brain and

other nervous centres.
Nerve Fi'bre. An exceedingly slender thread of nervous tissue found in

GLOSSARY 3G1

the various nervous organs, but especially in the nerves ; it is of a

white color.
Nu-tri'tion (L. nu'trio, to nourish). The processes by which the nour-
ishment of the body is accomplished.
(E-soph'a-gus (Gr.). Literally, that which carries food; the tube Lead-
ing from the throat to the stomach ; the gullet.
O-le-ag'i-nous (L. o'leum, oil). Of the nature of oil: applied to an

important group of food principles — the fats.
01-fac'to-ry (L. olfa'cio, to smell). Pertaining to the sense of smell.
Oph-thal'mo-scope (Gr. 6<pda.\p.6s, ophthalmos, the eye, and <tkow€w, skopeo,

to-look at). An instrument devised for examining the interior of the

globe of the eye.
Op'tic (Gr. opdcj, 6^/otiai, fut. opsomai, to see). Pertaining to the sense

of sight.
Or'bit (L. or'bis, the socket). The bony socket or cavity in which the

eyeball is situated.
Os'mose (Gr. w<r/j.6s, osmos, a thrusting or impulsion). The process by

which liquids are impelled through a moist membrane.
Os'se-ous (L. os, a bone). Consisting of, or resembling bone.
Pal'ate (L. pala'tum, the palate). The roof of the mouth, consisting of

the hard and soft palate.
Pal'mar. Relating to the palm of the hand.
Pan'cre-as (Gr. wav,pan, all, and tcpias, kreas, flesh). A long, flat gland

situated near the stomach ; in the lower animals the analogous organ

is called the sweet-bread.
Pa-pil'lae (L. papil'la). The minute prominences in which terminate

the ultimate fibres of the nerves of touch and taste.
Pa-ral'y-sis. A disease of the nervous system marked by the loss of

sensation, or voluntary motion, or both ; palsy.
Par-a-ple'gi-a (Gr. TrapawX-qaaw, paraplesso, to strike amiss). A form of

paralysis affecting the lower half of the body.
Pa-tel'la (L. dim. of pat'ina, a pan). The knee-pan ; a small bone.
Pel'vis (L.). Literally, a basin; the bony cavity at the lower part of

the trunk.
Pep'sin (Gr. r£rrw, pepto, to digest). The organic principle of the

gastric juice.
Per-i-car'di-um (Gr. irepl, peri, and Kap5ia, kardia, the heart). A porous

membrane enclosing the heart, and secreting a lubricating fluid.
Per-i-stal'tic Move'ments (Gr. irepio-rtWu), peristello, to contract). The

slow, wave-like movements of the stomach and intestines.
Per-i-to-ne'um (Gr. wepireivw, periteino, to stretch around). The invest-
ing membrane of the stomach, intestines, and other abdominal organs
Per-spi-ra'tion (L. perspi'ro, to breathe through). The sweat, or •••

exhalation of the skin ; when risible, it is railed sensible perspiration ;

when invisible, it is called insensible perspiration.

362 GLOSSARY

Pe'trous (Gr. irtrpa, petra, a rock). The name of the hard portion of the
temporal bone, in which is situated the drum of the ear and labyrinth.

Phar'ynx (Gr. <pdpvy£, pharunx, the throat). The cavity between the
back of the mouth and gullet.

Phys-i-ol'o-gy (Gr. <pv<ris, phusis, nature, and \6yos, logos, a discourse).
The science of the functions of living, organized beings.

Pi'a Ma'ter (L.). Literally, the tender mother; the innermost of the
three coverings of the brain. It is thin and delicate ; hence the name.

Pleu'ra (Gr. irXevpd, a rib). A membrane covering the lung and lining
the chest. There is one for each lung.

Pleu'ri-sy. An inflammation affecting the pleura.

Pneu-mo-gas'tric (Gr. iri>evp.ui>, pneumon, the lungs, and yaarrip, gaster,
the stomach). The name of a nerve distributed to the lungs and
stomach ; it is the principal nerve of respiration.

Pneu-mo'ni-a (Gr.). An inflammation affecting the air-cells of the
lungs.

Pres-by-o'pi-a (Gr. wpia^vs, presbus, old, and &\p, ops, the eye). A defect
of the accommodation of the eye, caused by the hardening of the
crystalline lens ; the "far-sight" of adults and aged persons.

Proc'ess (L. proce'do, proces'sus, to proceed, to go forth). Any projec-
tion from a surface. Also, a method of performance ; a procedure.

Pty'a-lin (Gr. tttvoXov, ptualon, saliva). The peculiar organic ingre-
dient of the saliva.

Pul'mo-na-ry (L. pul'mo, pulmo'nis, the lungs). Pertaining to the lungs.

Pulse (L. pel'lo, pul'sum, to beat). The striking of an artery against
the finger, occasioned by the contraction of the heart, commonly felt
at the wrist.

Pu'pil (L. pupil1 la). The central, round opening in the iris, through
which light passes into the depths of the eye.

Py-lo'rus (L. irv\up6s, puloros, a gate-keeper). The lower opening of
the stomach, at the beginning of the small intestine.

Re'flex Action. An involuntary action of the nervous system, by which
an external impression conducted by a sensory nerve is reflected, or
converted into a motor impulse.

Res-pi-ra'tion (L. res'piro, to breathe frequently). The function of
breathing, comprising two acts : inspiration, or breathing in, and
expiration, or breathing out.

Ret'i-na (L. re'te, a net). The innermost of the three tunics or coats of
the eyeball, being an expansion of the optic nerve.

Sac'cha-rine (L. sac'charim, sugar) ; Of the nature of sugar; applied
to the important group of food substances which embraces the dif-
ferent varieties of sugar, starch, and gum.

Sa-li'va (L. ). The moisture or fluids of the mouth, secreted by the
salivary glands, etc.

GLOSSARY

Scle-rot'ic (Gr. <tk\t)p6s, skleros, hard). The tough, fibrous outer tunic

of the eyeball.
Se-ba'ceous (L. se'bum, fat). Resembling far ; the name of the oily

secretion by which the skin is kept flexible and soft.
Se-cre'tion (L. secer'no, secre'tum, to separate). The process of -

ing from the blood some essential important fluid ; which fluid is

also called a secretion.
Sem-i-cir'cu-lar Canals. A portion of the internal ear.
Sen-sa'tion. The perception of an external impression by the nervous

system ; a function of the brain.
Sen-si-bil'i-ty, General. The power possessed by nearly all parts of the

human body of recognizing the presence of foreign objects that come

in contact with them.
Se'rum (L.). The watery constituent of the blood, which separai

the clot during the process of coagulation.
Skel'e-ton (Gr.). The bony framework of an animal, the different parts

of which are maintained in their proper relative positions.
Spec'tro-scope (from spec'trum and aKoneu, skopeo, to examine the spec-

trum). An instrument employed in the examination of the spectrum

of the sun or any cither luminous body.
Sphyg'mo-graph (Gr. ff<pvy/j.6s, aphugmos, the pulse, and ypd<pw, grapho,

to write). An ingenious instrument by means of which the pulse is

delineated upon paper.
Sta'pes (L.). Literally, a stirrup ; one of the small bones of the tympa-
num, or middle ear, resembling somewhat a stirrup in shape.
Sym-pa-thet'ic System of Nerves. A double chain of nervous ganglia,

connected together by numerous small nerves, situated chiefly in front

of and on each side of the spinal column.
Syn-o'vi-a (Gr. avv, sun, and w6i>, oon, egg, resembling an egg). The

lubricating fluid of joints, so called because it resembles the white of

egg-
Sys'to-le (Gr. owtAXw, sustello, to contract). The contraction of the

heart, by which the blood is expelled from that organ.
Tac-tile (L. tac'tus, touch). Relating to the sense of touch.
Tem'po-ral (L. tem'pus, time, and tem'pora, the temples). Pertaining to

the temples ; the name of an artery ; so called because the bail

begins to turn white with age in that portion of the scalp.
Ten'don (L. ten'do, to stretch). The white, fibrous cord or band bj

which a muscle is attached to a bone ; a sinew.
Tet'a-nus (Gr. relvw. teino, to stretch). A disease marked by p

contractions of all or some of the voluntary muscles ; those of the jaw

are sometimes solely affected , the disorder is then termed locki
Tho'rax (Gr. du>pa$, thorax, a breast-plate). The upper cavity of tli.

trunk of the body, containing the lungs, heart, etc. ; tie

364 GLOSSARY

Thy'roid (Gr. dvpeds, thitreos, a shield). The largest of the cartilages of
the larynx ; its angular projection in the front of the neck is called
"Adam's apple."

Tra'che-a (Gr. rpaxvs, trachus, rough). The windpipe, or the largest of
the air-passages ; composed in part of cartilaginous rings, which render
its surface rough and uneven.

Trans-fu'sion (L. transfun'do, to pour from one vessel to another). The
operation of injecting blood taken from one person into the veins of
another ; other fluids than blood are sometimes used.

Tri-chi'na Spi-ra'lis (L.). A minute species of parasite or worm, which
infests the flesh of the hog, and which may be introduced into the
human system by eating pork not thoroughly cooked.

Tym'pa-num (Gr. Tvixwavov, tumpanon, a drum). The cavity of the
middle ear, resembling a drum in being closed by two membranes,
and in having communication with the atmosphere.

U're-a (Gr.). A substance secreted from the blood by the kidneys.

U'vu-la (L. uva, a grape). The small pendulous body attached to the
back part of the palate.

Vas'cu-lar (L. vas'culum, a little vessel). Pertaining to, or containing,
blood-vessels.

Ve'nous (L. ve'na, a vein). Pertaining to, or contained within, a vein.

Ven-ti-la'tion. The introduction of fresh air into a room or building in
such a manner as to keep the air within it in a pure condition.

Ven-tril'o-quism (L. ven'ter, the belly, and lo'quor, to speak). A modifi-
cation of natural speech by which the voice is made to appear to come
from a distance. The ancients supposed that the voice was formed in
the belly ; hence the name.

Ven'tri-cles of the heart. The two largest cavities of the heart, situated
at its apex or point.

Ver'te-bral Column (L. ver'te-bra, a joint). The back-bone, consisting of
twenty-six separate bones, called vertebrae, firmly jointed together ;
also called the spinal column and spine.

Ves'ti-bule. A portion of the internal ear, communicating with the semi-
circular canals and the cochlea ; so called from its fancied resemblance
to the vestibule or porcli of a house.

Vil'li (L. vil'lus, the nap of cloth). Minute thread-like projections found
upon the internal surface of the small intestine, giving it a velvety
appearance.

Vit're-ous (L. vi'trum, glass). Having the appearance of glass; applied
to the humor occupying the largest part of the cavity of the eyeball.

Viv-i-sec'tion (L. vi'vus, alive, and se'co, to cut). The practice of oper-
ating upon living animals, for the purpose of studying some
physiological process.

Vocal Cords. Two elastic bands or ridges situated in the larynx ; they
are the essential parts of the organs of the voice.

INDEX

PAGE

Absorbent vessels 188-185

Absorption 1:53-135

by blood vessels 188

by the lacteals 184

of the food 133-135

Accommodation, Function of 289,290

Achilles, Tendon of 36

Adam's apple 310

Ague-cake 139

Air. atmospheric 1S5, 186

Changes in, in respiration 186-1S8

Composition of 185, 186

Dust in the 192, 198

Effects of impure 194-196

Impurities in 191, 192

Provision for purifying 197-199

Renovation by ventilation 199, 200

Air-cells of the lungs ITS

Air-passages ITS— 182

Albinos 58

Albumen 80

of the blood 146

Albuminoid substances So

Varieties of SO

Properties of SO

Alcohol, as a fat-producer 170

as a food 10T, 108

a poison to the intellect 289

Cold promoting properties of 108, 109

Effects of, on digestion 139, 140

Effects of, on the brain 23S

Effects of, on the heart 169-171

Effects of, on the kidneys 141

Effects of, on the liver 140, 141

Effects of, on the mind 289

for thirst 10S

History of 100

Hostility of, to life 110

in the army 107

im paii- the will 289

Kind- of 106, 107

Properties of 107

Proper use of 110

Trembling due to 288

Alimentary canal 116

Animal functions 20T, 808

PAGE

Animal heat

How produced -'"1

regulated by perspiration

Animals, Relative strength of 88

Apoplexy 281

Aqueous humor 279

Arachnoid membrane -11

Arbor vita? -'14

Arterial blood 151, 1-;'. 190

differs from venou 161, 1-'.'. 190

Arteries 160, 101

A rrangement of 160, 161

Carotid 162

Pulsation of 161, 102

Radial 102

Temporal 102

Arytenoid cartilage 311

Asphyxia 336

Assimilation 168

Audition 292

Auditory canal 295

nerve 299

Auricles of the heart 154

Back-bone 25, 20

Bathing 62

Importance of 62, 68

Time and manner of 65, 66

Baths 64

Different kinds of 64-67

Belladonna 282

Use of. as a cosmetic 282

Bile 181, 182

Secretion of. in the liver 181, 182

Accumulation of, in the gall-blad-
der 181, 132

132

Biliary duct 1S1

Bladder . V 138

Gall

Bleeding, how stopped 169

Blind-spot

Blood 145, 146

Arterial 151, 1-.'. 190

( hanire of color 151

Circulation of 169

305

366

INDEX

PAGE

Blood, Coagulation of 148, 1 49

Composition of 140

corpuscles 146-148

fluid 145-148

Microscopic appearance of 147

Respiratory changes in 188, 189

Uses of the 149-151

Venous 151, 189, 190

Blood-vessels 133

Absorption by 133

Injuries to the 169

Body, Renovation of the 93

Bones 17, 18

Form and composition of 18, 19

Growth of 27

Microscopic structure of 21

Repair of 27, 28

Structure of 19-22

Uses of 17

Brain 209-211

Anatomical structure of 209-211

Function of the 232, 233

Injuries of the 233, 234

Membranes of the 211

Reflex action of the 236, 237

Bread 100, 101

Bronchial tubes 179

Bronchitis 182

Burns 333, 334

c

Canals, Semicircular 299

Capillary blood-vessels 164-167

Circulation in the 165

Carbonic acid 186

exhaled from the lungs 186

in the air 193-196

Retention of, in the blood 190

Cartilage 24

Arytenoid 311

Cricoid 310

Thyroid 310

Caseine 81

Cataract 252

Cells, Nerve 208, 218

Ciliated 181, 182

Cerebellum 213, 214

Function of the 232

Cerebrospinal nervous system 209

Cerebrum 211-213

Function of the 232-235

Cheese 81

Chest, Framework of ."*". 22

Contents of the 22, 23

Chloral hydrate 245

Effects of 245

Chloroform, Use of 246

Chocolate 100

Chorea 229

Choroid coat of the eye 279

PAGE

Chyle 132

Chyme 130

Cigarette smoking 244

Cilia 181, 182

Circulation 152

in the frog's foot 165

of the blood 152

Rapidity of 167, 168

through the heart 156, 157

through the lungs 177

Clothing 67, 68

Coagulation of milk 80

of the blood 148, 149

Cochlea 299

Coffee 104, 105

Effects of 104, 105

Collar-bone 23

Color-blindness 2S5

Column, Spinal 25, 26

Combustion, Spontaneous 208, '-'04

Complexion 58

Concha of the ear 294

Conjunctiva 276

Contraction of heart 155

Contraction of muscles 36-38

Convulsions 335

Cooking 97-99

Cords, Vocal 311-313

Cornea 279, 280

Corpuscles, Blood 140-148

Cosmetics 69, 70

Countiy, On going into the 349, 350

Cranial ganglia 209

Functions of 232

Cranial nerves 231

Cricoid cartilage 310

Crystalline lens 285, 286

Uses of 286-288

Cuticle 54

Function of 259

Cutis 54

D

Decussation of motor and sensory fibres

of spinal cord 224

Dentition of infancy 117

Diaphragm, Movements of the. in res-
piration 182, 183

Diastole of the heart 155

Diet, Mixed 86, 87, 93-95

Necessity for changing 86

Necessity of a regulated 86, 87

The best 86, 87

Digestion 115-142

Circumstances affecting 135-138

Gastric 129, 130

Intestinal 131, 132

Nature of 115

Organs of 116

Disinfection 345, 346

IXDEX

367

Dislocations 831, 332

Drainage 847-849

Drain diseases 347

Drowning 886, 887

Duct, Biliary 181

Nasal 277. 27s

Pancreatic 181

Thoracic 184

Dura mater 211

E

Ear 298, 294

External 294, 295

Internal 299, 800

Middle 295-299

Foreign bodies in the 802

Drum of the 295, 296

Bones of the 296, 297

Ear-sand 299, 800

Ear-stones 299

Ear-wax 295

Eggs 96

Composition of 96

Emulsion of fats, in digestion 132

Endocardium 154

Epiglottis 180

Uses of 180

Eustachian tube 297

Exercise ■'•'.>-{'

Different modes of 41, 42

Effects of 89-41

importance of 39

Open-air 42

Exercises for home gymnastics 851

Expiration. Movements of 182, 183

Extensor muscles 34

Eye 274. 275

Eyeball 278-282

Eyelashes 276

Eyelids 275, 276

F

Fainting 839, 880

Pats, Emulsion of 81, 82

Source of, in food si, ..-j

Fenestra oralis 3(10

Fibres. Muscular 86

Nervous 208-218

Fibrine in food 81

of the blood si

Fish, as food 99

Fits 885

Plexor muscles 34

Food 89

Animal 94

Dafly quantity of 91, 99

ingredients of 78, 74

Necessity tor s;»

Source of 78, 71

Food, Vegetable 94, 99

Fractures

Frost-bites 335

G

Gall-bladder 1:11. 182

Ganglia, cranial. Functions of the 209

Gases, interchange of, in the lungs.... ]s;i

Gastric digestion 129, 180

Gastric juice 126, 127

Action of 127

Daily quantity of 127

Genera] sensibility

Glands, Perspiratory 59,60

Salivary '. 181, 122

Sebaceous 58, 59

Glossary 354

Glosso-pharyngeal nerve 264

Gullet 180

Gum 85

as food 85

Gustatory nerve 264

Gymnastics 43

for schools and colleges 43

H

Hemorrhage .330, 881

Hair 56, 57

57

Easheesh

Hearing, Sense of 292-294

Protection of 1 ,801

Heart 153, 154

Cavities of the 154

Circulation through the 156, 157

Frequency of action l.\7, 158

Movements of the 159, 160

Valves of the 157

II<-at, Animal 201-208

Production of 201

Regulation of 202, 2i 3

Hemiplegia 226

Home and health

Borne Gymnastics, Exercises tor :'..">1

blouse, Location of 347

Humor, Aqueous 879

Crystalline 879

Vitreous 279

Hunger 90

Seat of t he sensation of 90

Hydra 808

Hydrophobia 229

Hygiene 15

Hyperopia 888, 289

I

Illuminating gas

Incus 891

Inorganic substances in food 75

Iusalivation 121-125

368

PAGE

Insensible perspiration 60

Inspiration 182

Intestinal juice 132

Action of 132

Intestines 131

Complete digestion in the small 131

Villi of the 133, 134

Iris 280,281

Function of 281, 2S2

Iron 79

Proportion in the blood 79

Proportion in the food 79

J

Joints 23-25

Varieties of 25

Juice, Gastric 126, 127

Intestinal 132

Pancreatic 131, 132

K

Kidneys 13S

Kerosene 334

L

Labyrinth 299

Lachrymal canals 277, 278

gland 277,278

Lacteals 134

Absorption by 134

Lactic acid in gastric juice 127

Lactometer 96

Large intestines 131

Laryngoscope 312,313

Larynx 179, 180

Production of the voice in the 180

Lens, Crystalline 286-887

Ligaments 23, 24

Light, Theory of 273

Lime in the bones 78, 79

in the food 78, 79

Importance of 78, 79

Liver 131

Secretion of the 131

Locked jaw 229

Long-sight 288, 289

Lungs 177, 178

Capacity of 184, 185

Structure of 177, 178

Lymph 134, 135

Lymphatic vessels 134, 135

M

Magendie, on pain 255

Magnesia, Compounds of, in food 79

Malleus 297

Marrow of the bones 21

Mastication 116-126

Importance of 124, 125

Meats 96

PAGE

Meats, The cooking and preservation of 97

Membrane of the tympanum 296

Medulla oblongata 214

Function of the 230, 231

Microscope 321

Simple 321, 322

Compound 322, 323

The use of the 323

Milk 95

Composition of 95

Specific gravity of v 96

Milk-teeth ." 117

Morphine 244

Mucous membrane of air-passages. ..1S0-182

Muscles, Function of the 33, 34

Flexion and extension of 34

Voluntary and involuntary 34

Muscular contraction 36-38

fibres 36

sense 263

Myopia 288, 289

N

Nails 56

Uses of the 57

Nasal cavities 267, 268

duct 277,278

Narcotics, Kinds of 244

Property of 244

and sleep 246, 247

and digestion 247

Nerve, Auditory 299

Glosso-pharyngeal 264

Gustatory 264

Olfactory 26S

Optic -j::}. -274

Sympathetic 217. 218

Nerve cells 208,218

Nerve-fibres 208, 218

Nerves. Cranial 231

Spinal 216-217

Functions of the ..220 222

Sensory, functions of the 221

Motor, functions of the 221

Sympathetic system of 217, 218

Nervous system 208, 209

Cerebro-spinal 209

Nervous tissue, Properties of 218-220

Nicotine 242

Nose 268

Nutrition, Processes of 115

0

CRsofihagus 180

oil. Sources of, in food 73

Old-sight 291

i llfectory nerve 268

( »[.ti.- nerve 273, 274

Opiates, Effects of 245

INDEX

369

PASS

Opium, and its effects 244. 245

Orbicular bone 297

Orbit of the eye 275

t Irgazilc substances as food T9, 80

( n-gan s of circulation 186

on 116

Respiration 177-182

Sight 274,275

Voice 808

Oxygen ISO

Amount of, consumed in respiration. 1S6
Continually supplied by the atmos-
phere 10s

P

Pain, Relations of, to pleasure 255

Sensation of 254

Uses of 254-256

Pancreatic juice 181, 182

Uses of 132

Pancreatin 182

Paraplegia 223

Parlor gymnasium 45

Passages, Air 17S-1S2

Pelvis 22

Pepsin 127

Pepfe 180

Pericardium 154

Peristaltic action of the stomach 128

Peritoneum 131

Perspiration, Daily amount of Go

Sensible and insensible 60

Uses of 60,61

Perspiratory glands 59, 60

Physical strength 38, 39

Culture 42

- 13

Animal 13

Comparative 13

Human 18

Vegetable 13

Pia mater 211

Plasma Of the blood 140

Pleura 17S

Pleurisy 182

Pneumogastric nerve 231

Pneumonia 1S2

Poisons and their antidotes 337-340

Potash in the blood 79

Potato 101, 102

Presbyopia 291

Preservation of the teeth 120, 121

Ptyalta 123

Pulsation of the heart 159, 160

Of the arteries 101. 102

Pulse 162

form of the 102

writer 102

Pvlbrus 126

2A

R

I'AOE

Radial artery 102

Red corpuscles Of the t.1 1 14''., 147

Reflex action of the spinal curd. .

Requisites lor -^r,

Uses of ■■■:: 280

Causing convulsions 226

| >bji cts of 225-227

of the brain 286

Rennet si

Respiration 177

Change of blood in 188, 189

Frequency of 188, 1-4

Movements of 1>'J

Object of 177

Organs of 1 77-1 82

Respiratory labor 190, 191

Best, Necessity for t7. 4-

Retina 282-285

Retinal light 282-285

Bibs, Movements of. in respiration — 182

Saccharine substances 86

Saliva 121

Importance of 124. 125

Secretion of ...: 121, 189

Salivary glands 121 . 122

-alt. Common 76-78

Importance of 70. 77

Scalds 333

Scars from burns 333, 334

Sclerotic coat of the eyeball 279

Sebaceous glands 58, 59

Secretion of 59

Semicircular canals 299

of pain 254

Relations of. to pleasure 255

of temperature 262

of weight 263

Modification of 254

Production of 251, •J.''-.'

Variety of 259

Sense of hearing 298-29 ^

Bight 979, 278

smell 967,968

taste -04. 865

touch 269-861

Sense, Muscular 966

Thermal

Senses, Special 86T, 958

Sensibility, General

Sewers, Danger from 348

Shock

Short-sight

Sick-room, Care of the

- 186 of 272. 27:!

Organ of

Sinews 35

370

PAGE

Skeleton 22, 23

Skin, Structure of 54-56

Skull, and its uses 22

Sleep, Necessity for 47

Amount required 48

Small intestines 181

Smell, Sense of -JOT, 268

Nerve of 268, 269

Uses of 269-271

Smoking, Eifects of 242

Cigarette 244

Soda in the food 79

Sound, Production of 292-294

Special senses 257, 258

Spectroscope 147

Speech 308, 309

Relation of, to the sense of hearing. . 309

Sphygmograph 162

Spinal column 25, 26

Spinal cord 214, 215

Decussation of the 225

Direction of fibres in 224, 225

Functions of the 223, 224

Nerves of 215-217

Reflex action of 225-227

Spleen 139

Sprains 333

Spontaneous combustion 203, 204

Stapes 297

Starch 84, 85

Its change into sugar 85

Different kinds 84

Effect of boiling 84

Microscopic appearance 84

Stimulating substances 85

Stimulation 240

Stomach 125, 126

Digestion 129, 180

Movements of 128

Secretion of 126, 127

St. Vitus' dance 229

Sugar, Varieties S3

Sources of S3, 84

Sun-bath 66, 67

Sunstroke 335

Sympathetic system of nerves 217, 218

Synovia 25

Systole of the heart 155

T

Taste, Association of 266, 267

Education of 267

Organ of 263, 264

Sen i Of 204,205

Tea, Effect of 105, 106

Tears 277,27-^

Teeth, Temporary set of 117

Permanent set of 117

Bicuspid 113

PAGE

Teeth, Canine 118

Incisor 117

Molar 118

Arrangement of 118

of different animals 119, 120

Preservation of 120, 121

Temperature of the body 203, 204

Extremes of 203, 204

Sensations of 2G2

Tendon of Achilles 80

Tendons 35, 36

Tetanus 229

Thermae 66

Thermal sense 262

Thirst 90, 91

Thoracic duct 134

Thorax 134

Thyroid cartilage 310

Tissues, Intimate structure of the

Human 326

of the lower animals 326, 327

Tobacco 242

as a poison 242, 243

Effects on the young 243

when in training 243

Tongue 263, 264

Nerves of 264

Sensibility of 265

Touch, Delicacy of 261, 262

Organs of 25S, 259

Sense of 259-261

Trachea 178, 179

Transfusion 150, 151

Trap 347

water 347

Trichina spiralis 99

Trunk 22

Tympanum of the ear 296

Membrane of 296

U

Urea 138

Ureter 138

V

Valves of the heart 157

of the veins 163, 164

Vapor, Animal, in breath 186

Vegetable food 94, 99

Vegetative functions 207

Veins, Valves of 163, 164

Venous blood 151, 189, 190

Changes of, in respiration L88, 189

Ventilation 199, 200

by window 199, 200

Ventricles of the larynx 312

of the heart l&t

371

PAGE

Ventriloquism 316, 31 T

Vertebrae 25, 26

Vertigo 330

Vestibule of the internal ear 299

Villi of the intestines 133, 134

Absorption by 133, 134

Vital knot 231

Vitreous humor '279

Vocal cords 311-313

Observation of, with laryngoscope. 312, 313

Voice 308

Organ of 810, 311

Production of 313, 314

Varieties of 314-316

W

PA61

Waste-pipes 347

Water 76, 76

Action of, on lead 103, 104

Chemically pure 109

exhaled with the breath 1S6

from springe and wells 102

Proportion of, in the blood 75

of, in the tissues and Ilui'l 7.".

of the body 75

Water-seal 347

Walking, as a means of exercise 41

Well, Care of the 348

White corpuscles of the blood 147, 14s

Wisdom teeth US

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