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PEELIMINAEY COUESE LECTUEES

ON
PHYSIOLOGY.

Entered according1 to Act of Congress, in the year 1875,
In the office of the Librarian of Congress, at Washington, D. C.

PHYSIOLOGY:

PRELIMINARY COUESE LECTURES,

BY

JAMES T. WHITTAKER, M.A., M.D.,

PROFESSOR OF PHYSIOLOGY AND CLINICAL MEDICINE IN THE MEDICAL

COLLEGE OF OHIO; LECTURER ON CLINICAL MEDICINE AT THE

GOOD SAMARITAN HOSPITAL; MEMBER OF THE CINCINNATI

ACADEMY OF MEDICINE, AND OF THE CINCINNATI

JCIETY OF NATURAL HISTORY:

SOCI

ON THE INFLUENCE OF PHYSIOLOGY UPON PRACTICE; ON
THE CONSERVATION OF FORCE; ON THE ORIGIN OF LIFE,
AND THE EVOLUTION OF ITS FORMS ; AND ON PRO-
TOPLASM, BONE, MUSCLE, NERVE AND BLOOD.

ILLUSTRATED.

CINCINNATI:

CHANCY R. MURRY, 103 W. Sixth St.
1879.

Die Natur weisz allein was sie will.

Goethe; Sprueche.

To make man mild and sociable to man
^o cultivate the wild licentious savage
"With wisdom, discipline and liberal arts
Th' embellishments of life.

Addison; Cato.

I DEDICATE

\iz Jpl? mt&

fttt&mfe

AT THE

MEDICAL COLLEGE OF OHIO.

J. T. W.

PEEFACE.

I have endeavored in the delivery of these lectures
to put within the reach and comprehension of the
first course student the foundation facts and princi-
ples upon which the stately edifice of physiology is
built. And in the publication of them, which I have
only presumed to venture in consequence of repeated
requests on the part of the students of my class, I
have adhered strictly to the spirit, and as far as I
could, to the letter of the delivery. This explanation
will suffice, I hope, to excuse the latitude of expres-
sion and selection which would be accorded to off-
hand, lecture-room, delivery, and which might be
inexcusable in a text-book compiled for the more
careful study of leisure hours.

J. T. W.

100 West Eighth St.,
Dec, 1878.

CONTENTS.

LECTURE I.

THE INFLUENCE OF PHYSIOLOGY UPON PRACTICE AND
UPON THE PRACTITIONER.

Dr. Jacob Primrose — The Exercitatio de Motu Cordis, etc. — Science
vs. Practice — The Fallacy of Experience — Some Old Receipts — Opin-
ions of Noted Men — Sterne, Shakespeare and Moliere — The Royal
Touch and the Caul — Contributions of Physiology to Practice — The
University of Naples — The Modern Physician — Gladstone's Response
— Harvey and Haller — Characteristics of Physiologists 1-23

LECTURE II.

THE CONSERVATION OF FORCE.

The Alphabet of Science— Indestructibility of Matter — No Matter
without Force — Solar Origin of Heat of Coal — Correlation of Forces —
Machinery, a Means of Changing Force — Clocks, Water-Wheels,
Winds, Windmills and Steam Engines — The Equivalence of the
Forces — The Conservatory of Arts and Trades — Motion from Heat —
Motion from Electricity — The Electric Light — The Sun as the Source
of Power — Source of Solar Force — The Nebular Hypothesis — The
Channel of Mt. Pilatus — The Perpetuity of Force — Physiological
Force — Excretions, the Products of Combustion — Animal Bodies as
Machines — The Force Value of Foods — Physiological, Correlative
with Physical Force 23-46

LECTURE III.

THE ORIGIN AND EVOLUTION OF.LIFE.

Definitions of Physiology — Ancient Definitions of Life — Modern
Definitions of Life — Difference between Organic and Inorganic Matter
— The Property of Assimilation — Period of Development of Life—
The Theory of Evolution — Palaeontology — The Cataclysms of Cuvier
— The Operation of Existing Causes — The Age of the Earth — The
Evolution of Fossil Forms 47-63

X CONTENTS.

LECTURE IV.

THE EVOLUTION OF FORMS OF LIFE.

Comparative Anatomy — Of the Eye and the Ear — Order of Develop-
ment— Jean Lamarck — Wilhelm von Goethe — The Intermaxillary
Process — Erasmus Darwin — Anatomical Resemblances — The Hand
and its Homologues — Comparative Embryology — Ernst Haeckel —
The Rudimentary Organs — Bone Rudiments — Muscle Rudiments —
Rudiments from the Digestive System — Other Rudiments — Explana-
tions of Rudiments 64-83

LECTURE V.

THE EVOLUTION OF FORMS OF LIFE.

The Law of Inheritabiiity— Transmission of Acquired Defects — Ho-
mochronous Transmission — Atavism — The Physics of Reproduction —
Adaptation to External Conditions — Difficulty of Classification — Arti-
ficial Selection — The Struggle for Existence — Natural Selection —
Protective Colors — Warning Colors — Sexual Selection — Complications
in Natural Selection — Preservation of the Individual and of the Race
—General Summary „ 84-104

LECTURE VI.

PROTOPLASM AND ITS PROPERTIES.

The History of Histology — The Invention and Use of the Microscope
— The Discovery and Doctrine of The Cell — Derivation and Im-
port of The Cell— The Cell Wall— The Nucleus and Nucleolus— The
Cell Contents or Protoplasm — The Amoeba — The Properties of Proto- ■
plasm — Motion — The Color Changes of the Chameleon — Ciliary Mo-
tion— Motion of Other Cells — Molecular Motion — Molecular Changes
in the Ovum — Parthenogenesis — Motion as the Essence of Repro-
duction 105-128

LECTURE VII.

PROTOPLASM AND ITS PROPERTIES.

The Chemistry of Organic Matter — The Ultimate Elements — The
Proximate Principles — Albumen and its Products — The Chemistry
of the Cell — Absorption and Assimilation — Metabolism — Oxidation
Processes — Oxidation in the Ovum — Oxidation in Muscle — Oxidation
in the Blood — Oxidation in Nerve Tissue — The Quantity of Oxygen
in the Body — The Genesis of Protoplasm — Spontaneous Generation —
Omne Vivum ex Ovo — Reproduction and Nutrition — Modes of Cell
Genesis — Death of Cells — Recapitulation — Classifications of the
Tissues 128-149

CONTENTS. XI

LECTURE VIII.

BONE AND ITS PROPERTIES.

Anatomical Dignity of Bone — Relation of Bone to Nerve Tissue —
The Skeleton — The General Properties of Bones — The Histology of
Bone — The Haversian Canals — The Lamellae — The Bone Corpuscles
and Lacunae — The Canaliculi — The Chemistry of Bone— Difficulties
Attending the Study of Osteology — Bones as Fuel — Gelatine as an
Aliment — The Resistance and Resilience of Bone — Constancy of
Chemical Composition — Rachitis and Osteo-Malacia — The Phosphate
of Lime — The Preservation of Bone — Bone a Connective Tissue —
The Formation of Bone — The Periosteum — The Centre of Ossification
— The Determination of Age — The Femoral Epiphyseal Centre — The
Excavation of Bone — Air in Bout: — The Marrow — Studies in Living
Bone — Bone as a Symbol of the Body , 150-175

LECTURE IX.

MUSCLE AND ITS PROPERTIES.

Etymology of Muscle — Muscular Motion — Striped and Smooth Mus-
cle— The Color of Muscle — The Anatomy of Voluntary Muscle — The
Sarcolemma — The Muscle Fibre — Muscle Protoplasm — General Prop-
erties of Muscles — Names of Muscles — Form and Shape of Muscles —
Smooth Muscle — Disposition of Smooth Muscle — The Chemistry of
Muscle— The Reaction of Muscle — Specific Properties of Muscle —
The Elasticity of Muscle— The Tonicity of Voluntary Muscle—,
Tonicity, a Reflex Phenomenon— Tonicity of Involuntary Mxiscle —
The Sensibility of Muscle— Sensibility and Sensation— The Sensation
of Fatigue — The Exercise of the Muscular Sense .....175-195

LECTURE X.

MUSCLE AND ITS PROPERTIES.

Contractility of Muscle — Effects of Muscular Contraction — Degree of
Contraction — Change of Form— Agents which Induce Contraction —
Direct and Indirect Excitation— Thermal Excitation— Electric Excita-
tion—The History of Galvanism — The Action of Induced Electricity
— The Action of Nerve Force — The Sound of Muscle Contraction —
The Muscular Wave — Independence of Muscular Force — The Action
of the Sulphocyanide of Potassium and Curare— The Generation of
Heat — The Generation of Electricity — Du Bois-Reymond's Theory
of Muscular Action— Rigor Mortis— Post-Mortem Changes in Muscle
— The Fuel of Muscle— The Oxygen Supply— The Dependence of
Muscle upon Blood— The Muscles as Levers — The Absolute Power
■of Muscle— The Power of Muscle in General— Differences of the
Sexes— Differences in Different Animals— The Velocity and Delicacy
■of Muscular Action...^ , 195-222

Xii CONTENTS.

LECTURE XI.

NERVE AND ITS PROPERTIES.

The Prime Function of Nervous Tissue — Subordination to Other Tis-
sues— Independence of Nerve Force — Genesis of Nerve Force — Ar-
rangement of Nerve Tissue — White and Gray Matter — The Cerebro-
spinal and Sympathetic Systems — The Nerve Cells — The Nerve Fibres
—The Neurilemma— The Axis Cylinder— The Gray Fibres— The Prop-
erties of Nerves — Terminations of Sensitive Nerves — Terminations
of Motor Nerves — Course of Nerve Fibres — Identity of Nerve Fibres
— Indifference of Direction of Nerve Force — The Chemistry of Nerve
Tissue — The Action of Electricity upon Nerve Tissue — The Nature
of Nerve Force — Rate of Conduction of Nerve Force — Nerve Force
and Electricity — Comparative Velocity of Nerve and Other Forms of
F'orce — The Reception and Perception of Impressions — Ancient Sig-
nificance of Nerves — The Effects of Use and Disuse and of Age 223-24S

LECTURE XII.

THE BLOOD AND ITS PROPERTIES.

The Value of the Blood— The Transfusion of Blood— The Constitu-
tion of the Blood — The Color of the Blood — Reaction of the Blood
—The Odor of the Blood— The Taste of the Blood— The Temperature
of the Blood— The Weight of the Blood— The Quantity of the Blood
— The Morphology of the Blood — The Red Blood Corpuscles — Size
of the Red Corpuscles — Number of the Red Corpuscles — Elasticity
of the Red Corpuscle — Constitution of the Red Corpuscles — Use of
the Red Corpuscles — The Colorless Blood Corpuscles — The Blood
Plasma — The Coagulation of the Blood — The Blood as the Substitute
of the Body 247-272

Index 273-28*

PRELIMINARY COURSE LECTURES.

LECTURE I.

THE INFLUENCE OF PHYSIOLOGY UPON PRAC-
TICE AND UPON THE PRACTITIONER.

The Address Introductory to the Course on Physiology at the Medical
College of Ohio, September 1, 1878.

C ONTENTS.

Dr. Jacob Primrose — The Exercitatio de Motu Cordis, etc. — Science vs.
Practice — The Fallacy of Experience — Some Old Receipts — Opinions
of Noted Men — Sterne, Shakespeare and Moliere — The Roj-al Touch
and the Caul — Contributions of Physiology to Practice — The Uni-
versity of Naples — The Modern Physician — Gladstone's Response
— Harvey and Haller — Characteristics of Physiologists.

Nobody in this hall ever heard, I venture to say, of Dr.
Jacobus Primerosius. But Primrose made a good deal of
noise in his day, and many were they who thought him a
great physician. I pick out Primrose to-night from among
all the notabilities of his time because he was a representative
man. He made himself the exponent of his class. When
the immortal Harvey proclaimed that startling truth about
the circulation of the blood, which electrified the every-day
world as well as the world of science and our branch of it to
such degree that physicians met in counsel and gravely
looked in each others faces and distressedly asked "what is
now to become of us?" Primrose arose and said : "Pah ! The
Ancients made good cures before Harvey was born."

Thereupon Primrose proceeded to put Harvey down.
Harvey had worked twenty years over his study before he

2 HARVEY'S WORK.

could solve it to his own satisfaction. Then only did he
preach his doctrine. He worked on nine years more. He
repeated all his old experiments. He made new ones. He
called in all his friends whom he considered competent and
secured their confirmation. Then only did he publish it.
Harvey was fifty years old, it was in '1628, when he pub-
lished this first and of all the most brilliant triumph of ex-
perimental physiology. It was written in the purest spirit
of science, expressed with an accuracy the most rigid and
impressed with a modesty all through it in accord with its
title. He called it

"An Attempt."

It was only a short manuscript, seventy-two pages in all, a
fact in itself which put it in wonderful contrast to the
gigantic folios of speculation composed at that time. There
is a spirit of reverence all through it for the labors of his
predecessors, especially for those of Galen. It lies now, the
original paper, upon the shelves of the British museum;
as to the truths contained in it, what child but knows that
its heart beats with pulses of blood. There followed after
Harvey in later years the next great man in physiology.
This man, a Swiss, Albert Haller by name, said of Harvey :
"His name is second only to Hippocrates." "Libellus aureus"
he said of his book.

Primrose felt towards Harvey, the keen envy of ignorance
and pretense towards solid knowledge and sound truth. He
hurried out his book under a high-sounding title in just
fourteen days. The same Haller said of it: "It is subtle in
cavil, in experiment empty." Harvey never noticed it
at all.

I would like to use this incident in illustration of the sub-
ject of my theme. Had the respective studies of these two
men, Primrose and Harvey (I will scarcely be pardoned now

SCIENCE VS. TRACTICE. 3

for mentioning their names together), anything to do with
their characters as men and physicians.

Besides this vindication of the study of physiology I would
like to use the opportunity to speak of the influence of
physiology upon practical medicine as well as upon the status
of the medical practitioner.

Science vs. Practice.

It may seem strange to the non-professional observer that
there could be any possible question as to the general use of
physiology. A man would hardly entrust his watch for re-
pair to an operator who was not familiar with its mechanism
and the manner of its work when in good working order,
but there are those in the profession now, hard as it sounds,
just as there were in Harvey's day, who believe, or affect to
believe, that scientific investigation unfits a man for practice.
John Aubrey, who was at Harvey's funeral and "helpt to
carry him into the vault," writes : '*T have heard him
(Harvey) say, that after his booke of the Circulation of the
Blood came out, he fell mightily in his practice, and t'was
believed by the vulgar that he was crack-brained ; and all
the physitians were against his opinion and enoyed him.
All his profession wTould allow him to be an excellent
anatomist, but I never heard of any that admired his thera-
peutique way. I knew several practitioners in this town
(London) that would not have given 3d. for one of his bills
(prescriptions), and that a man could hardly tell by one of
his bills what he did aime at." We shall see shortly how
much to be admired was the "therapeutique way" of
Harvey's contemporaries.

It is meet that we should consider these questions now
while we stand on the threshold. If we can become fully
convinced of the use of its study we shall enter with more

4 THE FALLACY OF EXPERIENCE.

earnest zeal. Nothing so dampens enthusiasm, so hampers
progress, as doubt of the utility of the work.

I might, if I chose, content myself with merely pointing
to the discovery of the circulation, the event which marked
a new era in practical medicine. The skeptic must shut his
eyes on this discovery before he can discuss the question
at all.

Is there any disease or accident incident to man in the
recognition or treatment of .which we do not hold this ele-
ment in mind like letters of the alphabet in reading the
page. Take coarser facts. Could any one diagnosticate
the character of a valve disease of the heart without a
knowledge of the round of the circulation. Does not the
treatment of wounded arteries or diseased, as in aneurism, by
placing ligatures on the vessels between the heart and tne
accident or disease rest upon this established course of the
torrent of blood. "The active mind of John Hunter," says
Mr. Hodgson, "guided by a deep insight into the powers of
the animal economy, substituted for a dangerous and un-
scientific operation, an improvement founded upon a
knowledge of those laws which influence the circulating
fluids and absorbent system ; and few of his brilliant
discoveries have contributed more essentially to the benefit
of mankind."

But I do not wish to rely for our foundation simply upon
the great corner stone. I would rather upon this occasion
enter into some details that you may be impressed the
more firmly, that rational practice is based on the dis-
closures of physiology, that you may be convinced that the
art of medicine, practice, is, or is fast becoming, but a
dependent upon its science, physiology.

The Fallacy of Experience.
Before any knowledge was possessed of the physiological

THE FALLACY OF EXPERIENCE. 6

action of medicines, disease could only be treated by em-
piricism. Experience was the great physician. See how
blindly experience worked. Suppose 1 should read you a
few receipts from the prescription books of some of the
notabilities of their times, times close about that of the
discovery of the circulation. It is the age of Shakespeare,
of Francis Bacon, luminaries so glorious in literature and
philosophy that there is still no defalcation in the lustre of
their rays. And who was the representative man in medi-
cine in that illustrious day? Theophrastus Paracelsus
Bombastus. A name which has become the synonim of the
grossest charlatany. He it was, who openly ridiculed all
scientific investigation, who publicly burned the works of
Galen and Avicenna and boasted that he treated disease by
his superior intuitive knowledge. Maxwell, Greatrake,
Digby, foremost men at this time, were theosophic enthusiasts
who regarded diseases as the consequence of sin and the
work of demons. It was the age of conjury and witch-
craft and priestcraft. It was the period of the so-called
ont61ogical conception of disease. Diseases were peculiar
beings or things with special properties or powers which
had to be exorcised or conjured away. This doctrine held
sway long aftet Harvey's day. It was only when the
natural functions of organs had been fully described that
the present physiological view, that disease proceeded from
lesion of structure or function, was developed. So in the
olden time there were special formulas for special diseases.
Bulleyn prescribed for a young child, suffering with some
nervous disease, "a small young mouse roasted." Sterne
writes : "My physicians have almost poisoned me
with what they call bouillons refraichissants. 'Tis a cock
flayed alive and boiled with poppy seeds, then pounded in
a mortar and afterwards passed through a sieve. There
is to be one craw-fish in it, and I was gravely told it must

6 THE FALLACY OF EXPERIENCE.

be a male one ; a female would do me more hurt than good."
Of one receipt, a regular salmagundi, from the Elizabethan
age, its author remarks : "To tell the virtues of this water
against colds, phlegme, dropsy, heaviness of mind, coming
of melancholy, I cannot at this present, the excellent virtues
thereof are such, and also the time were too long." Of
another which contained gold and silver, sapphires and
pearls, with spices and various perfumes : "This healeth
cold diseases of ye brain, heart, stomach. It is a medicine
proved against the tremblyings of the heart, fainting and
swooning, the weakness of ye stomacke, pensiveness, soli-
tariness. Kings and noble men have used this for their
comfort. It causeth them to be bold-spirited, the body to
smell well and engendereth good colour."

Even up to less than fifty years ago they bled patients
for the cure of consumption. In the annals of Louis XIV,
two centuries ago, is an account of the illness with con-
sumption of one of the principal ladies of the court. On
consultation, the doctors bled her in the arm. Next week
they bled her again, this time in the temple. Strange to
relate she was still worse on the following week, and the
consultation was more anxious still. But there were re-
sources in medicine in the days of the great emperor. The
doctors bled her again, this time in the toe ! They never
bled her any more.

Small-pox was treated in accordance with the' doctrine of
signatures. The bed covers were red to bring the pustules
to the surface. The bed furniture and bed-hangings were
all red, and red substances were to be looked upon by the
patient. The very drinks were red. John, of Gaddesden,
physician to Edward II, directed his patients to be wrapped
up in scarlet dresses ; and he says that when the son of the
renowned King of England (Edward II) lay sick of the
small-pox I took care that every thing around the bed

OPINIONS OF NOTED MEN. 7

should be of a red color, which succeeded so completely
that the prince was restored to perfect health without a
vestige of a pustule remaining. About the middle of the
seventeenth century, the doctrine of signatures was sub-
stituted by the system of expelling the peccant humors by
the perspiration. We have a fine picture of this practice
in the writings of Diemerbroeck, a Dutch physician and
Professor. "Keep the patient," says Diemerbroeck, "in a
chamber close shut. If it be winter let the air be corrected
by large fires. Take care that no cold gets to the patient's
bed. Cover him over with blankets. Red blankets have
always been preferred — not that the color is material, but
because in the times of our ancestors all the best, thickest
and warmest blankets were dyed red. Never shift the
patient's linen till after the fourteenth day, for fear of
striking in the pock to the irrecoverable ruin of the patient.
Far better it is to let the patient bear with the stench than
to let him change his linen and thus be the cause of his own
death. Nevertheless, if a change be absolutely necessary,
be sure that he puts on the foul linen that he put off before
he fell sick, and above all things, be sure-that this semi-clean
linen be well warmed. Sudorific expulsives are in the
meantime, to be given plentifully, such as molasses,
pearls and saffron."

Fantastic and nauseous things were used in the treatment
of disease, the raspings of a skull for epilepsy, lizards, the
excretions, etc., ad nauseam.

Opinions of Noted Men.

Is it any wonder that the shrewd author of Tristam Shandy
should express his opinion of medicine and medical men in
the manner in which he spoke of his treatment at the hands
of the physicians of his day : "I was ill of an epidemic vile
fever," he writes, "which killed hundreds about me. The.

8 OPINIONS OF NOTED MEN.

physicians here are the erran test charlatans in Europe or the
most ignorant of all pretending fools. I withdrew what was
left of me out of their hands and recommended myself en-
tirely to Dame Nature. She (gentle goddess) has saved me
in fifty different pinching bouts, and I begin to have a kind
of enthusiasm now in her favor, and in my own, that one or
two more escapes will make me believe I shall leave you all
at last by translation, and not by death." Is it any wonder
that a man of Shakespeare's penetration (Shakespeare had
been dead three years when Harvey announced his discovery)
should depict for us his Dr. Caius in the Merry Wives of
Windsor as a boisterous, blustering, ignorant knave, his Dr.
Pinch in the Comedy of Errors as a poor fool whose beard is
singed by an indignant patient, and whose sacred person is
defiled by "great pails of puddled mire." Is it any wonder
that he should tell his people, in another place, what to do
with physic !

"Believe me," said Napoleon to Antomarchi, his physician
at St. Helena, "we had better leave off all these remedies.
Life is a fortress which neither you nor I know anything
about. Why then throw obstacles in the way of its defense ?
Its own means are superior to all the apparatus of your
laboratories. Corvisart candidly agreed with me that all
your filthy mixtures are good for nothing. Medicine is a
collection of uncertain prescriptions, the results of which,
taken collectively, are more fatal than useful to mankind.
Water, air, cleanliness, are the chief articles in my pharma-
copeia." Moliere most keenly satirised the credulity of his
time in medical matters when he wrote : "11 ne faut pas
mourir sans Vordonnance du medicin" (Let no one dare to die
without drugs from the doctor). Poor Moliere fell upon
the stage suffocated with hemoptysis, in the midst of his
bitterest tirade against medical men. Whereupon an old
physician remarked : "Faitcs des comedies contre nous si vous

THE ROYAL TOUCH. 9

voulez; metis la medecine vous defend dc les jouer sous peine de
la vie."

The Hoyal Touch.

Who lias not heard of the glory and the grandeur of the
reign of Louis XIV ? How few of us know of the abject
misery and horrible disease which all this glory and grandeur
cost. History is full of its pomp and its ceremony. Let us
read but one page of its ignorance and credulity.

The day is Sunday in early spring, Easter Sunday. 168G.
The grand monarch is on the throne. Around him are the
tapestries and clothes of gold, the rich hangings, the polished
floors, mosaics, marbles, gold and precious stones. About
him stand obsequeous countiers. Behold the King by the
grace of God !

One thousand six hundred miserable wretches are crowded
together outside the door. These are not subjects come to
do homage at the foot of the throne. They are the maimed
of limb, the blear eyed, the ulcerated. Shakespeare saw a
crowd once like them ; they were, he says, "strangely visited
people, all swol'n and ulcerous, pitiful to the eye, the mere
despair of surgery." They are come to the King to be
touched for the King's evil, to be cured by being touched.
What a picture this for the artist ; the might and the splen-
dor of majesty on the one hand, the loathsomeness and the
degradation of disease on the other !

Touching for the King's evil was not confined to France.
The numbers subjected to it during the reign of Charles II
were almost incredible. The King had more patients, it was
said, than all the physicians of his realm. The eagerness to
obtain tickets of entry was such that in Evilyn's diary,
March 28, 1G84, it is written: "There was so great a con-
course of people, men, women and children, to be touched
for the evil that six or seven were crushed to death at the

10 THE CAUL.

door. Yet, according to statistics, more people died of scrofula
in this reign than in any other period, probably from neg-
lect of all proper treatment. March 30, 1714, Queen Anne
touched 200 persons, among whom was the celebrated lexi-
cographer, Dr. Samuel Johnson, the most remarkable ex-
ample, perhaps, of the utter failure of the cure. Yet Jeremy
Collier, in his Ecclesiastical History of Great Britain, speak-
ing of the many virtues and miraculous powers of Edward
II, says "that this prince cured the King's evil is beyond
dispute. He not. only cured it, but transmitted the power
of doing so as a hereditary miracle to all his successors. To
dispute this matter of fact," he continues, "is to go the excess
of skepticism, to deny our senses and be incredulous even to
ridiculousness."

This author tells us of a Roman Catholic thus cured by
Queen Elizabeth, who saidj on being asked about it, that "he
was now satisfied by experimental proof that the Pope's
excommunication of her majesty signified nothing, since she
still continued blessed with so miraculous a quality" (Petti-
grew). This was the testimony of a learned man of his day.
Where is there now such a fool as to believe in the value of
a royal touch ?

The Caul

One of the most ridiculous, though perfectly innocent, of
medical superstitions, which is worthy of mention because
it is still cherished by the illiterate everywhere, is connected
with the fragment of membrane sometimes born over a
child's face, commonly known as a caul. This superstition
has existed from the earliest times and the various imaginary
virtues attributed to it have differed with every time and
place. It is mentioned in the fourth century by Aelius
Lampidius in his life of the Emperor Antoninus. Majolus
attributes to the Roman lawyers the belief that the possesion

CONTRIBUTIONS OF PHYSIOLOGY. 11

of a child's caul would make tliem eloquent and triumphant.
It is spoken of by St. Chrysostom. In France it is an old
superstition. Eire ne- coiffl, "to be born with a caul," has
always been considered a favorable omen. In Scotland it is
called the holy hood. It is .stated by Grose, that a person
possessed of a caul, may know the state of health of the
party who was born with it ; if alive and well, it is firm and
crisp ; if dead or sick, relaxed and flaccid. In former days,
the caul was the perquisite of the midwife who often traded
upon the privileges it was supposed to confer upon the
owner as a charm against drowning. As much as $150.00
has been paid for a caul. The London Times, of May 8,
1S48, contained the following: "For sale, a child's caul.
Price six guineas. Apply at the bar of the Tower Shades,
Tower Street, London. The above article, for which fifteen
pounds was originally paid, was afloat with its late owner
thirty years, in all the perils of a seaman's life and the
owner died at last at the place of his birth." A child's caul
was advertised for sale in the Bristol Times and Mirror,
September 30, 1874. The irrepressible Hood seems to have
been fully aware of the popular recognition of its value
which he combats in the tragic event which subsequently
happened to its possessor.

"But still that jolly mariner
Took in no reef at all,
For in his pouch confidingly
He wore a baby's caul."

Contributions of Physiology.

Look with what tenacity the physicians of the empiric
school clung to venesection. Long after they dared not
practise it they persisted in preaching it still. Centuries
upon centuries they put mercury into a man in whatever
disease of the liver, blind to the fact that notwithstanding

12 CONTRIBUTIONS OF PHYSIOLOGY.

its administration for months in specific disease it in no way
influenced the hepatic functions. And now it turns out
that the liver after all was not the organ affected in almost
all the cases. Scarce two teachers of materia medica taught
the same action upon the heart under digitalis. Why ?
Because each gave his own experience. When regular
physiological experimentation was commenced, it was not
long before it was decided that it had only one action in all
cases, namely, to increase the force of the heart's action, to
diminish the frequency of its pulsations and restore its
regular rythm. Let the most prejudiced observer read up
the action ascribed to alcohol in fevers in different works on
practice before the physiologist put it unchangeably down.
Here it is advised to push it to the utmost ; here to refrajn
from it altogether. Each man spoke from his own experi-
ence. Comes the physiologist with his thermometer. Alco-
hol lowers the temperature is the result of his experimenta-
tion, and the indication for its use is established. The
surgeon used to cut and cut out the facial nerve, leave the
face paralysed and deformed for facial neuralgia (tic
douloureux) until the physiologist taught him that the
facial was a nerve of motion, to the trigeminal he must look
in disturbances of sensation. And then he would cut out
this nerve down to its escape from the skull, excise the
ganglion of Meckel, until he was again taught by the physi-
ologist that this ganglion was only a reinforcing organ of
the sympathetic system, and its ablation could in no way
permanently cure the disease.

"The dangerous disease, to which many children have
fallen victims, laryngismus stridulus, although admirably
described by practical physicians, was never properly under-
stood until the functions of the laryngeal nerves were
clearly ascertained and until it had been shown that spas-
modic actions may be excited by irritation of a remote part

CONTRIBUTIONS OF TTIYSIOLOGY. 13

or through a stimulus reflected from the nervous centre. It
is now known that this disease has not its seat in the larynx
where those spasms occur which excite so much alarm for
the fate of the patient; but that it is an irritation of a
distant part, which derives its nerves from the same region
of the cerebro-spinal centres as does the larynx — that the
afferent nerves of that part convey the irritation to the
centre whence it is reflected by certain efferent nerves to the
muscles of the larynx." Do not these remarks bear with
equal propriety upon epilepsy, chorea, hysteria and a host
of kindred affections dependent in many cases upon reflex
stimulus, a factor whose paramount importance is only rec-
ognised since the labors of the physiologists who first pro-
claimed it. How much advanced would we stand to-day in
the management of gynaecological diseases beyond the time
when the bloody issue was treated by touch, as in the New
Testament, were it not for our knowledge of ovulation and
its necessary consequence, as discovered and developed solely
by physiological investigations. And in ophthalmology, that
department which Virchow characterised in a late address
before the British Medical Association as "that branch- of
medical science which has now reached the highest degree
of scientific surety," how sensibly has treatment developed
under the physiological investigations into the functions of
different parts of the eye. Helmholtz, as is well known, and
Grsefe, forsook all other studies to work up the physiology
of vision, and to these two observers, more than all others,
are we indebted for the "scientific surety" which charac-
terises practical ophthalmology. So I might continue for
an hour and yet fail to enumerate the direct contributions
of physiology to practical medicine within the past few
years.

But if I should desire to put physiology in its proper light
I should have to look out beyond the mere technical details

14 CONTRIBUTIONS OF PHYSIOLOGY.

of direct contributions in the immediate treatment of dis-
ease. It would then be my pleasant duty to point out those
investigations undertaken to unlock the mystery of the
causes of disease and their dissemination by parasitic germs.
I should have to linger more than my time upon the influ-
ence of the nervous system upon all the vegetative functions
as well as upon the circulation. I should have to dwell
with that care, which the intense interest of the subject
demands, upon those recent experiments of exposing and
irritating certain parts of the brain in the now partially
successful attempt at a localisation of its functions and upon
those electrical changes observed in a living nerve when
sentient impressions are transmitted through its course, dis-
coveries all of them whose practical importance in the
future no prophecy may now fortell. It would be my
privilege further to reach out into broader regions still. It
is only in our day that the importance of physiology is fully
recognised in a sanitary point of view. "In their appre-
hensions of epidemics, men are beginning to bend before
the shrine of science and to recognise the fact that it is in
a patient, persevering, hopeful applications of the faculties
of investigation, which have been given them, rather than
in any direct interpositions, that they are to look to Provi-
dence for security."

It is physiology which has been the chief agent in raising
medicine from an art into a science. So far as the treat-
ment of disease is concerned, or the recognition of its nature,
we have no other way to arrive at the action of remedies or
lesions of structure than through the portals of physiology.
I might illustrate this fact, besides by the agents already
referred to, in no way more clearly than by allusion to the
really wonderful results following the administration of
ergot and its active principle after its mode of action had
been fully established by the physiologist. And this, too,

THE MODERN PHYSICIAN". 15

when there had been previously such a diversity Of opinion
concerning its action as to practically abolish it from general
use. Pathology is only the physiology of disease.

It is physiology which distinguishes regular medicine
from charlatanry. Together with the other natural sciences
it gives evidence which is positive, immutable. Theories
about fever may be limited only by the number of those
who choose to express an opinion, but there is only one
interpretation to the circulation of the blood, the action of
a nerve, the constitution of a secretion. It is. physiology,
thus, chiefly, which lifts off the mist and the mystery of
dogma and puts medicine on the basis of other natural
sciences, so that it may be proven like them by evidence
before all the cultivated senses. So when physiology be-
comes a perfect science, should that day ever be, there can
no more be quackery in medicine than in machinery. "When
the question of the propriety of introducing homoeopathy
into the

Medical School of Naples

was presented to the faculty a few years ago, the following
characteristic reply was tendered : "The University of
Naples is not a proper field for instruction in homoeopathy,
because the rational medicine which is imparted here, on the
basis of the natural sciences, excludes allopathy, as well as
homoeopathy, or any other absolute system or dogma. The
study of rational medicine is as far removed from the ancient
allopathy, with its blood-letting and purgation, as from the
recent delusion of homoeopathy, with its ridiculous infinitesi-
mal doses and similia similibus medication."

The Modem Physician.

This revolution in the study an.d practice of medicine has not
passed unobserved in the outside world. It has changed the

16 THE MODERN PHYSICIAN.

whole social status of the physician. Even as late as the J 5th
century an apprentice would not be accepted in any of the
mechanical arts unless he could prove that he was not the
child of a butcher, executioner or a bleeder. The following
old time advertisement clipped from a paper of Shakespeare's
day thoroughly establishes the position of the every-day
practitioner at that period: "Wanted. — In a family who
have had bad health, a sober steady person in the capacity
of doctor, surgeon and man mid-wife. He must occasionally
act as butler and dress hair and wigs. He will be required
sometimes to read prayers and to preach a sermon every
Sunday. A good salary will be given." The modern
dramatist, if he would reflect the sentiment of the people,
exhibits the doctor in a role very different from the old
time cunning knave or ignorant charlatan. A moaern
novel is scarcely perfect without a modern medical character.
Witness, more especially, the best works of Bulwer and
George Eliot. The chord so feelingly struck by the master
hand of Lever has responded full and as feelingly to the
magic touches of Dickens and Thackery. The physician is
called, like Haller, to the chief position among the chairs of
state. His profession is recognised by the highest civil
authorities. Said Mr. Gladstone in a recent response : "and
speaking of the body cf the profession, even as an observer
from without, it is impossible for us not to notice the change,
it is impossible for us not to see how far more strongly now
than of old, the medical man of to-day conforms to those
general laws of common sense and prudence, which are, after
all, universal laws of human life in every one of its depart-
ments. It is impossible not to see his greater and more
sustained earnestness of purpose, that elevated sense of
the professional dignity, that desire to make it subservient
to the good of humanity, that general exaltation of his aims
in the exercise of his profession."

WILLIAM HARVEY. 17

And what is it that has thus lifted up the character of
the physician in the eyes of his fellow-men ? It is because
the modern science of medicine is supported by the same
kind of evidence as any other science. Evidence which
may be sifted by instruments of precision, evidence which
is tangible, demonstrable, indisputable. Such evidence i3
plain to the common understanding in whatever pursuit of
life. It is evidence, to repeat the language of the dis-
tinguished statesman just cited, which conforms to those
general laws of common sense, after all, the universal laws
of human life in every one of its departments.

I do not know how I could better exhibit the influence
of the study of physiology than by a very brief narration
of some of the principal incidents in the lives of the two
greatest of physiologists, Harvey and Haller, already
cited. With both physiology wras a life study. Each is
known in medical history as having contributed a discovery
by means of which we are chiefly guided in the treat-
ment of disease; Harvey's, the circulation; Haller' s, the
knowledge that disease depends on lesion of structure or
function.

William Harvey.— 1578-1658.

Harvey was the oldest in a family of nine children. His
parents belonged to the respectable middle class of society,
that class from which has emanated, as is statistically
proven, the greatest number of great men. With the rest
of the family, he had that kind of training, which instils
those virtues in childhood life, obedience and respect to
authority and order, so characteristic of the English race,
and without which excellence can be attained in no pursuit
in life. With these traits, industry. That was all. But
that is always enough. After leaving Cambridge, at the age
of 21, he went to Padua to study under the great Fabricius,

18 WILLIAM HARVEY.

who gave him the first clue to his discovery by show'ng
him the valves in the veins. What were these valves for?
It was no flash of inspiration that answered this question
for Harvey. It was solved, as has been stated, only after
twenty years of patient, earnest toil. It was only the fact
of his reputation as a worker that secured him any recogni-
tion at all at first. But there was a charm in Harvey's
statements that could not fail to win him followers. It was
the extreme modesty which characterises every line. When
he could, he would support the opinions of those who had
preceded him. When the truth forced him to differ, he
did so, but with a delicacy the most sensitive, and with an
array of proof that could leave no doubt of the correctness
of his views. There have been to this day no corrections
to make in Harvey's work, and there never since has been
written a description of the circulation so comprehensive,
so terse, so vivid. He was a worker so indefatigable and
his works were so full of results that he soon acquired
fame. The work of an earnest man is a synonim with fame.
He was made a physician at St. Bartholomew's, a boy but
20 years of age. He was only 37 — that was a youthful age
in his day — when he was appointed professor of anatomy
and surgery, and it was but a few years later that he
became body physician to Charles I. He lived a life of the
greatest simplicity and self-denial; Michael Angelo not
more so. Much of his time he spent in perfect retirement
with one or other of his brothers at their village homes.
He declined the high honor of the presidency of the College
of Physicians, though they succeeded in persuading him to
allow his bust to be cast. At the age of 80, writes Haeser,
the historian, he closed a life which had not been less
glorious by the magnitude of his scientific labors than by
his most rigid sense of justice, his exceeding gentleness
and amiability of character and modesty of manner. "On

ALBERT HALLER. 19

June 3, 1G58, lie died," said Spengel, Our greatest historian,
"but he left a name which is immortal. It is a name which
posterity the most distant will never pronounce without
experiencing a sentiment of veneration and of gratitude.
It will shine with equal lustre with those of Aristotle,
Fallopius and Haller. His industry, his prudence and his
rare modesty, make of his character, eternally, a model, the
most noble, for the naturalists, for the writers of all peoples
and times."

Albert Haller.— -1708-1777.

The most cultivated physician and the greatest naturalist
of his age was Albert Haller, of Berne. His advent upon
the theatre of action is characterised as the illumination of
a meridian sun upon the obscure dawn of day. Haller was
of patrician parents, but it was no misfortune to him, as is
the rule, and his subsequent career in the face of the tempta-
tions besetting wealth affords an illustrious example of the
manner in which money may be made subservient to the
higher purposes of life. A puny, delicate, rachitic boy, he
could not be kept away from books. It is said of him that
up to the age of nine years he had read over two thousand
biographies. When his father died, his education was com-
mitted to a priest who attempted to force his studies in the
direction of theology with the intention of making him
wear the robes. But Haller loved the teachings of nature
better than the wisdom of man, and the time which should
have been devoted to clerical studies was spent among the
flowers. He was only 15 years old, when he commenced the
study of medicine at Tubingen. All the anatomy he could
learn here was from dissections of the dog. The fame of
Boerhaave and Albinus drew him to Leyden. Here he
became such a favorite with his teachers that Albinus would
permit him to dissect on one side of the body while he

20 ALBERT HALLER.

worked on the other. At 19, he graduated and commenced
his travels. He was the student of Douglas, in London, in
whom he inspired such confidence that he made Haller
promise to help him in his investigations into the develop-
ment of bone. The same restless, knowledge seeking spirit
carried him next to Paris, where his enthusiasm is said to
have been kindled to such a pitch under the teachings of
le Dran and Winslow, that he stole a body from the grave
for material upon which to work. He had to leave Paris to
escape punishment and next we find him in Basel, at the
age of twenty, teaching anatomy to the students. In 1736,
he was now 28, he was elected professor of anatomy and
surgery at the newly established university of Gottingen.
Proud of so early a recognition of his talents, he labored for
the success of this institution until students streamed in td
the young college from all parts of Europe. He was now
teaching anatomy, surgery and botany. A regular chair of
physiology had not yet been established. Besides these
labors, he kept up his work in natural history, wrote a great
number of literary papers and occupied what leisure was
still left in composing poetry. At the age of 45 he was so
completely broken down that he had to retire. from all active
duties. We form some idea of his "iron industry, his almost
incredible memory, his profound culture in all the branches
of human knowledge" by the story which has come down to
us that no one of his Gottingen colleagues ever ventured to
visit him without a formal preparation upon the theme to
be made the subject of conversation. He is said to have
written 12,000 reviews! And yet he never left a letter
unanswered. According to all testimony, there was never in
medicine a laborer so untiring. Rudolphi naively remarks
in the preface to his own work on physiology : "If you should
ask all the authors of works on physiology, which book they
considered the best, it could not be thought strange if each

CHARACTERISTICS OF PHYSIOLOGISTS. 21

one would reply, his own. But if you should go further
and ask each one what book he considered next best, I am
convinced that every one without exception would name
Haller's. And surely," Rudolphi continues, "what seems
to all the second best must be in reality the first."

Besides this, his greatest work, Haller was the author of
three distinct bibliographies, of anatomy, surgery and prac-
tical medicine, which have been characterised as "monu-
ments of his incredible literary activity, which stand isolated
in medical literature, and will remain for all time as inex-
haustible sources of information to the medical historian."
Colin, in his Comparative Physiology, called Haller "Uhomme
desfaits, Vhomme de V observation et des experiences ; son oeuvre
est le point de depart de toute la physiologie moderne. Cruveil-
hier spoke of it as "full of discoveries." His original in-
vestigations were so numerous and so valuable, as to justly
entitle him to the place assigned him by posterity as the
"Founder of Modern Physiology." The latter part of his
life he spent at Berne in the exercise of the highest civic
powers in the state, though even here he found leisure to
prosecute his favorite scientific and literary pursuits. The
sculpture on the pillar of fame in history has chiseled his
name beside that of Aristotle and Goethe and Humboldt.

Characteristics of Physiologists.

And what then were the characteristics of these two great
physiologists? They were cautious men. Harvey proved
his study twenty years before he preached it. Haller made
109 experiments before he published his discovery of the
independent irritability of muscle. They were truthful
men. The bitter opposition of their contemporaries, the
experimentation of all posterity, have never shaken the facts
they advanced. They were simple men ; in all their tastes
and habits ; among other things it is recorded of both, they

22 CHARACTERISTICS OF PHYSIOLOGISTS.

were men of gentle deportment. Above all, they were
working men. And if the question were asked as to the
influence of the study of physiology on the character of the
physician, there could be no more fitting answer than a
reference to the lives of men who have drifted into it as a
life study because of their natural adaptability to it.

One point more. Physiology offers to the physician a
present refuge in time of trial. The vicissitudes of practice,
the rancor of rivals, the unceasing combat against prejudice
and ignorance and superstition make life a burden at times
even where envy marks it a great success. It is in dark
hours like these, and who but knows them, that the physi-
cian may turn to the study of physiology. No man of the
world, no man of other profession than natural science, may
ever know or be able to understand the peace, in the way of
fresh inspiration for future work, which nature offers at
the foot of her altars. The chief reward of every kind of
mental work — higher than either wealth or fame— is its
effect upon the character. The study of medicine is pe-
culiarly excellent in developing the mental faculties. Hav-
ing elements in it belonging to both literature and science — ■
the bride and her spouse in modern education — it most
happily blends the virtues and balances the faults, pertain-
ing to a purely literary or a purely scientific pursuit.

I should fall short of the high purpose of our convo-
cation, to-night, should I fail to impress upon you clearly
the trial which science demands at your hands before she will
adorn you with the stamp of her nobility. It is the trial
of work, the chief characteristic, as you have seen, in the
lives of our eminent men ; work with the sacrifice of self ;
work which is only stimulated to higher efforts by the
achievements of others ; work with something, at least, of
that feeling in the breast of Themistocles— a poor illegiti-
mate boy— Euler of AtherTs he became— who was alone

THE CONSERVATION OF FORCE. 23

sorrowful and distressed amidst the general rejoicing over
the great victory at Marathon. And when they asked him
why his eyes were red with weeping and why he walked
the streets with disheveled hair, he made them that reply
which foretold his future success : "It was the trophies of
Miltiades that would not let him sleep."

LECTURE II.
THE CONSERVATION OF FOECE.

CONTENTS.

The Alphabet of Science — Indestructibility of Matter— No Matter with-
out Force — Solar Origin of Heat of Coal— Correlation of Forces —
Machinery, a Means of Changing Force— Clocks, Water-Wheels,
Winds, Windmills and Steam Engines— The Equivalence of the
Forces — The Conservatory of Arts and Trades— Motion from Heat —
Motion from Electricity— The Electric Light— The Sun as the Source
of Power— Source of Solar Force— The Nebular Hypothesis— The
Channel of Mt. Pilatus— The Perpetuity of Force— Physiological
Force — Excretions, the Products of Combustion— Animal Bodies as
Machines— The Force Value of Foods— Physiological, Correlative
with Physical Force.

Within the past quarter of a century has been generally
promulgated one of those fundamental principles or laws in
natural science which, like that of gravitation or of ter-
restrial revolution, marks a most memorable epoch in its
history. What especially distinguishes this law and lifts it
to a plane above all other laws of nature, is the fact that it
spans, in its giant grasp, every order of existence. It
reduces to shape and order the primitive chaos of the uni-
verse, governs the movements of the heavenly bodies thus
created, generates the various forms of the mighty forces
about us, and, while engaged in this stupendous work, con-

24 INDESTRUCTIBILITY OF MATTER.

cerns itself no less with the insignificant phenomena of life
upon our insignificant globe ; swinging systems of planets
in their spheres, upon the one hand, and, on the other,
springing flowers from the bosom of the earth. I need
hardly say that this law, which has been announced as the
primal law of all science, and which has been characterised
by Faraday as the highest law in physical science that our
faculties permit us to perceive, is the law of the Conservation
and Correlation of Force. That is, it is the law which has
demonstrated that force, as well as matter, is indestructible,
however much its form may change, and which has proven
that all the forces, light, heat, electricity, motion, etc., may
be converted, the one into the other, quantity for quantity,
in exact equivalents, no force being ever created anew and
no force being ever lost.

We shall study this law to-night more especially in its
bearing upon human life, and shall try to make it plain
that what is known as life, or vital force, is only part of the
general store of force in the universe, borrowed for the time
being from other physical forces and being continually sur-
rendered again in the various phenomena of life, as in heat,
motion, secretion, reproduction, intellection, etc.

Indestructibility of Matter.

It is now more than a century ago that it was known
among men of science that matter is indestructible. When
we speak of the destruction of matter, we refer simply to
the form of the matter. For instance, we say matter is
destroyed by fire. But when we come to analyse the pro-
ducts of combustion, we find in the smoke, the gases and
the ash precisely the same elements as before. We pro-
ceed to weigh these various products in delicate scales to
discover only pounds and ounces and grains, just the same
as before. Fire has only changed the form. So when wa

SOLAR ORIGIX OF HEAT. 25

speak of organic matter suffering destruction by decay, we
refer again simply to the form. The water, the salts, the
gases of decomposition, weigh exactly the same, are in
elementary construction, in every particular, just the same
' as before. Putrefaction has only changed the form.

And so, too, of creation. We justly boast of our manu-
factured products. But no ingenuity of man has ever suc-
ceeded in creating matter anew. Ex nihilo nihil fit. Anni-
hilation of matter, creation of matter are alike impossible
and unknown.

Now it is discovered that there is

No Matter without Force.

The force may not be always apparent, that is, it is not
always in active operation, but we have simply to change
the condition of matter to awaken and make manifest its
silent force. Force in operation is known as actual force ;
that which is silent, at rest, so to speak, or latent, is
known as potential force. The arrow speeding in its flight
or striking its target represents actual force, while the bent
bow, unsprung, represents latent or potential force. The
force in the bow is stored up muscular force to be set free,
it may be at once, or it may be after years. Plants now
living contain recently stored latent or potential force,
while coal fields are vast magazines of force stored up ages
ago.

Solar Origin of Heat.

George Stephenson, the celebrated engineer, long ago con-
ceived the happy idea, as he sat by his hearth, that the light
and heat of the burning coal in his grate originally came
from the sun. This thought, which seemed at the time to
be as visionary as a poet's dream, is now known to be true.
Every one knows that coal is a product of vegetable life.

3

26 SOLAR ORIGIN" OF HEAT.

A fresh fracture often reveals upon its surface the outlines
of stems and branches and leaves with such distinctness as
to enable the botanist to specify the particular plant which
has formed the specimen of coal. Vegetation of all kinds
develops only under the light and heat of the sun. Veget-
able, seeds imbedded in clean sand and moistened with
water containing only mineral matters in solution, germinate
and develop into plants containing a large amount of starch.
The simple process is as follows:

Carbonic Acid Gas. Water. Oxygen. Starch.

C6012 + H10O5-O12 = C6H10O5.

The light and heat of the sun, entering the substance of the
plant, dislodge a certain amount of oxygen gas that the
atoms of the inorganic compounds may rearrange themselves
to form organic matter. Starch is the first organic principle
of the plant. The sugar, cellulose and other ingredients
are easily developed by the addition or change of equivalents
of water. Thus :

Starch. Water. Grape Sugar.

C6H10O5 -f- H20 = CGH1206.

Thus, then, is built up the plant, the tree, vast forests of
which covered the earth in primeval times to become sub-
sequently submerged and converted into coal. In burning
coal we simply release from it the locked up heat of the
sun. The heat and light we enjoy to-night came down
from the sun thousands of years before man put in his pres-
ence upon earth.

No force is ever lost. It may be changed as to its direc-
tion or changed as to its character, but in some form or
other it perpetually reappears. So all the affections or con-
ditions of matter, heat, light, electricity, chemical affinity,
motion, etc., are mutually convertible. Neither can be
said, strictly speaking, to be the cause of the other, but

MACHINERY A MEANS OF CHANGING FORCE. 27

either may be converted into the other : "it being an irre-
sistible inference from observed phenomena that a force
caunot originate otherwise than by devolution from some
preexisting force." It is, therefore, not right to say that
any one force is the cause of all the rest. One writer, for
instance, claims electricity as the primal cause ; another,
chemical action ; a third, heat ; but the true expression of
the fact is, that each mode of force is capable of producing
the others, and that any one of them can be produced by
any other.

Machinery a Means of Changing Force.

"We may best exemplify the conversion and correlation
of force by the transmutations which take place in various
kinds of machinery. In fact, machinery is only a means
of effecting change in the form of force. Thus in
our clocks, the wheels which sweep the hands around the
dial plates are revolved by sinking weights. When the
weights reach the floor of the clock the wheels cease to
move. In other wrords, the force of gravity ceases to act.
We must first raise the weights, or, in the case of a watch,
give tension to the springs, before the wheels will run. This
is accomplished in the winding up. The individual wrho
winds the clock simply transfers power from his muscular
force and precisely so much as is thus transferred is again
surrendered in the ensuing twenty-four hours. The wheel
work of the clock, in measuring out time, creates or exhibits,
therefore, no new force ; it simply distributes a borrowed
force over a longer period of time. The borrowed force
is that of the muscle, which receives it, in turn, from food
containing, latent, the original force from the sun.

We stand in admiration before the majestic revolutions
of a gigantic water wheel, whose force is distantly conducted
to intricate machinery, constructed to minister to the wants

28 THE EQUIVALENCE OF THE FORCES.

of man. Broad belts here and there take off some of the
force for widely different purpose. The antecedent force is
gravitation, which causes the fall of the water. The force
behind gravitation was that which lifted the water to its
higher level. What is this force but the heat of the sun
which has raised the vapor of the sea to the clouds, whence
it has fallen in rain, to form brooks and rivulets, ever
widening streams, the force of whose fall (gravity) may be
used in running mills.

The swiftly sailing vessels cleaving the breast of the
waters under the resistless force of the wind is no less indebted
to the heat of the sun, the unequal distribution of which
creates the currents of air and the tides. It is the same
force of the wind, produced by precisely the same cause,
which, by means of windmills, lifts whole lakes of water
from inundated lands.

The most powerful, and the most widely varied, of all
our machines, the steam engine, is just as distinctly, though
not so directly, driven by the heat of the sun. For, first
of all, we make use of artificial heat. This heat is the
result of chemical force, the union of oxygen and carbon,
i. e., coal, which contains in it, latent, the original heat of
the sun. This chemical force produces heat, which is con-
verted into motion, which is, in turn, again converted into
heat at the axles of the wheels. A locomotive has there-
fore been likened to a kind of distilling apparatus, which
takes heat into its big retort, the boiler, converts it into
motion and reconverts the motion into heat at the axles of
the wheels.

The Equivalence of the Forces.

What especially contributed to establish the doctrine of
the conservation of force, was not so much the discovery that
one force could be converted into another, but that one

CONSERVATOIRE DES ARTS ET DES METIERS. 29

force, or one form of force, could be converted into another,
quantity for quantity, in exact equivalents. Though the
constancy of the forces was first formally announced by
Grove before the London Institution in 1842, it did not
receive general acceptance until Mayer and Ilelmholtz, of
Germany, and more especially Joule, cf England, had
succeeded in establishing the equivalents of various kinds
of force, that is, the amount of one kind, or form of force,
necessary to produce a certain amount of another kind of
force. The correlation, or convertibility of force, is thus
based upon the conclusion that the whole amount of force
in the entire universe is always the same. It may change
its form continually, but it may never change its total
sum. Joule first discovered the equivalent of heat to
mechanical force. The quantity of heat sufficient to raise
the temperature of a pound of water one degree in tempera-
ture would, when properly applied, raise a pound of water
772 feet high. One degree of heat is, therefore, equivalent
to the mechanical force represented in an elevation of 772
feet. This constant relation between heat and mechanical
force has been confirmed in the most varied manner and
the law thus established has proven of the highest im-
portance in practical adaptation to mechanics.

As every form of steam engine is an illustration of the
convertibility of heat into motion, it would seem needless
to cite further proof, but I may not refrain from mention-
ing the curious application of the law recorded by Liebig in
his article on the Connection and Equivalence of Forces in
the case of the

Conservatoire des Arts ct des Metiers,

in Paris. In this building, which was formerly a convent,
the nave of the church was converted into a museum for
industrial products, machines and implements. In its arch,

30 CONVERSION OF MOTION INTO HEAT.

traversing its whole length, appeared a crack, which
gradually increased to the width of several inches and
permitted the passage of rain and snow. There were,
doubtless, not wanting individuals at this time who looked
upon this threatened destruction of the building as a sign of
Divine vengeance for its desecration. The opening could have
been easily closed by stone and lime, but the further
yielding of the side walls would not have been thus
prevented. The whole building was on the point of being
pulled down when a natural philosopher appeared on the
scene and proposed a plan which finally saved the building.
A number of strong iron rods were firmly fixed at one end
to a side wall of the nave and after passing through the
opposite wall were provided on the outside with large nuts
which were screwed up tightly to the wall. The nuts were
now tight, but no force was sufficient to move the walls
a line. So then the rods were heated with burning straw,
whereupon they extended in length. The nuts were thus
removed several inches from the wall and were now again
screwed up further on to the thread and tight to the wall. The
rods, on cooling, contracted with enormous force and made
the side walls approach. By repeating this operation the
crack entirely disappeared. The building, with its retaining
rods, is still in existence, a monument to the triumph of a
natural philosopher over the supposed act of vengeance of an
offended Deity.

Even the savages knew how to transform

Motion into Heat

by the friction of two pieces of wood or by striking a flint.
A skillful blacksmith can render an iron rod red hot by
hammering. The axles of our carriages have to be greased
to lessen the heat of friction. In some factories where a
surplus of water-power is at hand, this surplus is applied to

MOTION FROM ELECTRICITY. 31

cause a strong iron plate to revolve swiftly upon another,
so that they become strongly heated by the friction. The
heat so obtained warms the room and thus is secured a stove
without the expense of fuel.
An example of

Motion from Electricity

we have proclaimed from our watch towers every day at
noon, or on the occasion of every fire. Electricity is con-
verted into the motion of the hammer which falls upon the
bell. This electricity itself is the product of chemical action,
that between zinc and acids at work in a few glass cups.
Almost any chemical action, as the oxidation of metals, or
the burning of combustibles, the combination of oxygen
and hydrogen, develops electricity. There is little doubt
that the time will soon come when we will be able to realise
as electricity the whole of the chemical force, wrhich is active
in the combustion of cheap and abundant fuel, such as coal
and wood and fat, and thus "secure a mechanical power in
every respect superior to its applicability to the steam
engine."

Even now we convert

Electricity into Light,

whose brilliance over that from every other artificial source
is a promise of the power yve shall one day possess in every
field of mechanics. Let us trace up the transformations of
force now necessary to secure a powerful electric light. First,
light, the result of electricity, produced by magnetism, in
turn developed by the mechanical force of steam, which
force is a transformed chemical force evolved in the com-
bustion of fuel, containing in it, latent, the original light of
the sun.
In every case we finally block up at the sun.

32 THE SUN AS THE ULTIMATE SOURCE OF FORCE.

The Sun is the Ultimate Source

of all the force manifest upon the earth. With the excep-
tion of the tidal force, partly caused by the attraction of the
moon and which, though in some isolated cases it is utilised
to run a few mills, must, nevertheless, be regarded as the
earth's greatest foe, because it is insidiously checking up the
velocity of our rotation, with the inevitable effect of finally
plunging us into the sun, with this exception, all terrestrial
force emanates from the sun. But the sun is so vast, its
resources are so enormous, that it can feed our whole plane-
tary system and still irradiate infinite heat into interstellar
space. The surface of the sun measures 115,000 millions of
square miles and its mass is 350.000 times greater than that
of the earth. The amount of heat aid light emanating
from the sun is sufficient to account for all the force of
whatever form, manifest upon the earth. According to the
pyrheliometric measurements of Pouillet, three or four
•equivalents of heat are received upon every square foot of
the earth under perpendicular rays of the sun. The amount
received daily is equivalent to that engendered in the con-
sumption of five billions tons of stone coal, which is again
equal to sixty-six billions horse-power every hour. If the
entire quantity of solar heat received in a year were uni-
formly distributed over the whole surface of the earth, it
would suffice to melt a universal layer of ice one hundred
feet thick or bring from the freezing to the boiling point an
ocean covering the earth to the depth of fifteen miles. In
every second of time the sun irradiates into space as much
heat as would result from the combustion of eleven thousand
mx hundred billions of tons of stone coal. We are told as
an easily remembered relation, that each portion of the sun's
8U rfacc, as large as our earth, emits as much heat, per second,
as would result from the combustion of a billion tons of coal,

ORIGIN OF THE FORCES ITSt THE SUN. 33

whence it is calculated that if its whole mass consisted of
coal and could burn right out to the last ton, maintaining
till then the present rate of emission, the supply would last
five thousand years. The small pencil of rays which the
earth intercepts at a distance of ninety-three millions of
miles is only the one-twenty-three-hundred-millionth part
of all the heat irradiated from the sun. This heat at the
surface of the sun is so intense as to volatilise iron and other
metals, which we are unable by any known method of
application to reduce to a gaseous state upon the earth.
The enormous quantity and intensity of heat from the sun
can only be fully comprehended by some familiar illustra-
tion of its magnitude. As Helmholtz has put it : "Its diame-
ter is so great that if you suppose the earth to be put into
the centre of the sun, the sun itself being like a hollow
sphere, and the moon going about the earth at its distance
from it of 238,000 miles, there would still be a space of
more than 200,000 miles around the orbit of the moon, lying
all interior to the surface of the sun." The heat and light
from such a vast source of power are thus infinitely more
than sufficient to account for every form of force upon
earth without the necessity of any local genesis.

But unde^ the doctrine of the conservation of force we
may not stop at the sun. What then is the

Source and Origin of the Forces in the Sun?

The original signification of physiology, a description of
nature, permits us, without too great migration from our
proper studies, to consider, for a moment, the workings of
nature in its grandest fields, in the construction and move-
ments of the heavenly bodies. I avail myself here, in the
main, of the clear and concise description of Helmholtz, in
his paper on the Interaction of the Natural Forces, taking

34 COMMENCEMENT OF THE PLANETARY SYSTEM.

the liberty, simply, of condensation and omission to bring
the subject within the limits of our time.

A number of singular peculiarities in the structure of our
planetary system indicates that it was once a connected mass
with a uniform motion of rotation. Without such an
assumption, it is impossible to explain why all the planets
move in the same direction around the sun, why they all
rotate in the same direction around their axes, why the
planes of their orbits and those of their satellites and rings
all nearly coincide, why all their orbits differ but little from
circles, and much besides. From these remaining indica-
tions of a former state, astronomers have shaped an hypo-
thesis, regarding the formation of our planetary system,
which althougn from the nature of the case it must ever
remain an hypothesis, still in its special traits is so well
supported by analogy, that it certainly deserves our atten-
tion. No other hypothesis has ever so well explained the
facts. It was Kant, first, who, penetrating the fundamental
ideas of Newton, seized the theory that the same attractive
force of all ponderable matter, which now supports the
motion of the planets, must also, in ancient times, have
been able to form from matter loosely scattered in space
the planetary system. Afterwards, and independent of
Kant, Laplace, the great astronomer, laid hold of the same
thought and gave it the support of his fame.

The commencement of our planetary system was thus an

Immense Nebulous 3Iass,

which filled the portion of space now occupied by our
system far beyond the limits of Neptune, our most distant
planet. Even now we see similar masses in the distant
regions of the firmament, as patches of nebulse and nebulous
stars ; and within our system, comets, the zodiacal light,
the corona of the sun during a total eclipse, exhibit rem-

COMMENCEMENT OF THE PLANETARY SYSTEM. 35

nants of a nebulous substance, which is so thin that the
light of the stars passes through it undiminished and un-
bent. If we calculate the density of the mass of our plane-
tary system at the time when it was a nebulous sphere,
reaching out to the path of the outmost planet, we find that
it would require several cubit miles of such matter to weigh
a single grain.

The general attractive force of all matter must, however,
impel these masses to approach each other and to condense
so that the nebulous sphere became incessantly smaller, by
which, according to mechanical laws, a motion of rotation,
originally slow, would gradually become quicker and quicker.
The enormous centrifugal force thus developed, acting most
energetically, of course, upon the equator of the nebulous
sphere, would swing off masses from time to time, which,
separating from the main mass, would form themselves into
single planets, or, similar to the great original sphere, into
planets with satellites and rings, until finally the principal
mass left condensed itself into the sun. When the nebu-
lous chaos first separated itself from other fixed star masses,
it must not only have contained all kinds of matter which
was to constitute the future planetary system, but also, in
accordance with our new law, the whole store of force with
which we have since become acquainted. Then, too, an
immense dower of force was bequeathed in the entire or
partial arrest of the general attraction of all the particles
for each other. When through condensation of the masses,
particles came into collision and clung to each other the
force of gravity is lost to reappear as heat.

The store of force yet possessed by our system is also
equivalent to immense quantities of heat. If our earth, whirl-
ing about the sun at the rate of eighteen miles a second, and
whirling on its own axis, in our latitude, at the rate of 110
feet a second, were to be suddenly stopped in its orbit, a

36 HEAT FROM PROCESSES OF CONTRACTION.

calamity not to he feared in the present condition of things,
by such a shock a quantity of heat would be generated
equal to that produced by the combustion of fourteen such
earths of solid coal, that is, the earth would be heated to
11,200 degrees centigrade, in other words, it would be
instantaneously fused and converted into vapor. When it
then fell into the sun, as would of necessity be the case, the
quantity of heat developed by the shock would be just 400
times greater still (Helmholtz).

Here, now, we have something of a clue to the mysterious
origin of the heat of the sun. From time to time a similar
process is repeated upon our earth in the fall upon it of
meteors or meteoric stones deflected from their course about
the sun. It has been calculated that a velocity of 3,000
feet a second would raise a piece of meteoric iron 1000° C.
in temperature, or, in other words, to a vivid red heat.
Now the average velocity of meteors is thirty to forty times
this amount, and we can thus understand why it is that
meteors often burst upon striking the earth with a violent
explosion, or are completely fused to vapor, by the resistance
of the air, before reaching it at all.

But, it is now generally admitted by physicists and
astronomers that the solar heat has had its origin, in the
main, almost wholly in fact, in

Processes of Contraction;

and that it is maintained by such processes. In other words,
the gravitation of the sun's mass has given birth to all, or
very nearly all, the heat which the sun has emitted in the
pa.st and will continue to emit to the end of his career as a
sun. As, however, the heat resulting from this contraction
corresponds to only about twenty million years supply, a
period far short of the known age of the earth, the theory
has been proposed that an immense store of heat was already

CONVERSION OF GRAVITATION INTO HEAT. 37

present in the original nebular mass. The hypothesis most
generally accepted by astronomers at present derives this
original heat from the collision of dark bodies circulating in
space. But we are now being carried too far away from
our special studies in the attempt to follow up the transfor-
mations of matter and force in the remotest history of the
universe. It is sufficient for our purpose to know that the
immense store of force in the sun, like the insignificant store
of the earth, was also derived from some antecedent force ;
and whether this force was the result of meteoric bombard-
ment of the sun, as formerly believed, or of continuing con-
densation of matter, as now maintained, are questions of no
essential difference. The practical result is the conversion of

Gravitation into Heat.

To form even a faint conception of such mighty forces,
we are in constant need of some familiar standard. Such a
basis for estimation is given by Mayer, in his work on
Celestial Dynamics, in the case of the

Gigantic Wooden Channel,

in which tall trunks of trees were allowed to glide down
from the steep and lofty sides of Mount Pilatus into the
plain below. This channel, which was built about forty
years ago by the engineer Rupp, was nine miles in length
and was so nearly perpendicular, that the largest trees were
shot down it, from the top to the bottom of the mountain, in
about two minutes and a half. The momentum possessed
by the trees on their escaping at their journey's end was
sufficiently great to bury their thicker ends in the ground
twenty to twenty-five feet. To prevent the wood getting
too hot and bursting into flames, streams of cold water had
to be let into the channel in various parts of its course.
But this stupendous mechanical process appears infinitely

38 THE PERPETUITY OF MATTER AjStD FORCE.

small when compared with the cosmical processes on the
sun. It is here the mass of the sun which attracts
and, in lieu of the height of Mount Pilatus, we have distances
of thousands upon thousands of miles. The amount of heat
that would be generated by cosmical falls, is at least nine
million times as great.

The Perpetuity of Matter and Force.

Such are the questions that engage us and the conclusions
that face us in studying the operations of the Law of the
Conservation of Force. "Presented rightly to the mind,"
I cite from the eloquent peroration of Mr. Tyndall,
"the discoveries and generalizations of modern science con-
stitute a poem more sublime than has ever yet been
addressed to the intellect and imagination of man. The
natural philosopher of to-day may dwell amid conceptions
that beggar the visions of Dante and Milton. So great and
grand are they, that in the contemplation of them, a certain
force of character is requisite to preserve us from bewilder-
ment." All the energies of our earth, mighty as they
seem to be, are derived from the small pencil of rays it
receives from the sun. Of this store, which represents but
the one-twenty-three-hundred-millionth part of all the heat
irradiated from the sun, but a small fraction is really stored
up in latent force. And in all the lapse of human history,
at least, there has been no diminution in the efflux of solar
force. "Measured by our largest terrestrial standards such a
reservoir is infinite ; but it is our privilege to rise above
these standards and to regard the sun himself as a speck in
infinite extension — a mere drop in the universal sea." We
pass out to regions in space where all our planets are in-
visible and the sun himself is reduced to a point of light.
We may pass again, beyond and beyond, to points where the
places of each successive survey disappear in the limitless

PHYSIOLOGICAL FORCE. 39

regions of space, boundless, because we no sooner assign a
boundary than we must ask, what bounds the boundary.
Everywhere and forever is the same force and matter in the
midst of incessant change. Creation, annihilation still re-
main impossible and unknown. Nebulae may condense into
systems and suns, collisions of suns may reproduce nebula?,
our earth, our whole system, nay, our visible firmament
might, in the figurative language of the Orient, be indeed
rolled up like a scroll and wafted to distant regions of space,
but the matter and the force must forever remain the same ;
secula scculorum, the same.

Physiological Force.

When a weight is lifted by the hand it seems a long way
off to go to the sun for the muscular force necessary to
effect it. Yet the fact is capable of direct proof. All
muscular force, all force of whatever character in the body,
is directly liberated from the food. We have already seen
how the light and heat of the sun become locked up in the
plant and all animal life is directly or indirectly dependent
upon the life of plants. Either the animal feeds upon vegeta-
bles exclusively, as in the case of the herbivon, or it feeds
upon the flesh of these animals and thus indirectly upon
the plant. "The carbonic acid of the air which is
decomposed by the plant, is decomposed solely and
exclusively at the expense of the light of the sun.
Without the sun the reduction can not take place
and an amount of sunlight is consumed exactly equivalent
to the molecular work accomplished." The so-called chemi-
cal rays of sunlight (blue and violet) have a higher affinity
in the green leaves of plants for the carbon of the carbonic
acid gas than has oxygen. The carbonic acid gas is thus
decomposed, the oxygen is set free and the carbon and the
chemical rays of the sun, which thus disappear completely,

40 PHYSIOLOGICAL FORCE.

are locked up in the plant. If the solar rays fall upon a
surface of sand, the sand is heated, but the heat is later
irradiated into the air, but if these rays fall upon a forest,
some of it is retained or invested in the structure of the
trees. "A bundle of cotton ignited bursts into flames and
yields a definite amount of heat ; precisely that amount of
heat was abstracted from the sun in order to form that bit
of cotton. This is a representative case. Every tree, every
plant, every flower, flourishes and blooms by the grace and the
bounty of the sun" (Tyndall).

In the bodies of animals, vegetables are burnt up just as
coal is burnt up in the furnace of the engine and thus is
liberated the force in either case. So much fuel, so much
force, in the case of the engine; so much food, so much
force, in the case of the animal body. The plant is like the
clock wound up but not running. In the animal, the pendu-
lum is swung, the wheels are started and the latent force is
set free. The clock runs down. And as surely as the force
which moves the clock's hands is derived from the arm
which winds the clock, so surely is the force of the muscle
derived from the sun.

The great mass of organised matter in both plants and
animals consists (aside from water) of carbon compounds ;
carbon united with oxygen, hydrogen and nitrogen. These
compounds are built up in plants from inorganic matters
in the earth and air. The carbon is chiefly derived from
the carbonic acid gas in the air. The vast magazines of
carbon stored away in our inexhaustible mines of coal, ex-
tending from the tropics to the poles, were abstracted from
an ancient atmospheric ocean far richer in this gas than the
air about us now. The remaining ingredients, oxygen,
hydrogen and nitrogen, are derived from water and air,
and the ammonia and nitrates constantly present in each.
Compounds of these simple bodies are constructed in the

EXCRETIONS, THE PRODUCTS OF COMBUSTION. 41

protoplasm of nature in the vsame manner as in the labora-
tory of art. In fact, complex organic substances have been
already thus artificially compounded. Wohler first, in 1828,
made urea (CH4 No O) from the cyanate of ammonia and
a number of organic compounds, allantoin, for instance,
and various organic acids have been since artificially
constructed.

Excretions, the Products of Combustion*

The essential difference between organic and inorganic
compounds lies in the fact that the inorganic compounds
are products of oxidation (combustion). They have been
already oxidised, these ashes of nature, and admit of no
further combustion. Organic compounds, on the other
hand, containing little or no oxygen, are still highly
oxidisable (combustible): The phenomena of life ; that is,
the liberation of the latent forces stored up in these com-
pounds ; depend upon the oxidation of these compounds.
"We have as the result of life precisely the same oxidation
products (excretions) from these compounds as after their
more direct combustion. When an animal or a vegetable
body is burned (oxidised), the mass of it is resolved into
the gases of combustion. The carbon unites with oxygen
to become carbonic acid gas (CO>), the hydrogen unites
with oxygen to form water (H20), or with nitrogen to form
ammonia (NH3), while the phosphorus and sulphur (when
present) remain with other inorganic matter in the ash.
Examination of the ash reveals carbon (not escaped in gas),
chlorine, potassium, sodium, calcium, magnesium, iron, etc. ;
the same elements and principles discovered in the various
excretions of the living body.

When the Duke would excite in the mind of Claudio

42 EXCRETIONS, TIIE PRODUCTS OF COMBUSTION".

(Measure for Measure) a contempt of life, lie advises him : —

* * * "Reason thus with life: —

* * * a breath thou art,

(Servile to all the skiey influences),
*****

For thou exist' st on many a thousand grains
That issue out of dust."

The plant-cell, then, absorbs from the earth and air these
inorganic, oxidised compounds, and under the light and
heat of the sun liberates the oxygen and fixes the now
deoxidised compounds in their substance; whereas the
animal cell absorbs (ingests) the deoxidised compounds
and the oxygen with which it burns (oxidises) them, and
thus again reduces them to gases and salts for reabsorption
by the plants. That is, the earth and air feed the plants,
the plants feed the animals, the animals feed the earth and
air. This is the great circle of nutrition in nature. The
carbon of the carbonic acid gas in the air becomes the carbon
of cellulose, starch, sugar, fat, etc., of the plant, which,
in turn, furnishes carbon for the albumen in the blood,
muscle, brain, etc., of the animal, by which it is again
delivered over as carbonic acid to the air, whence it was
derived.

The plant-cell fixes in its body as latent force the light
and heat of the sun, that the animal cell may set it free in
other forms, as in heat, electricity, mechanical work, nerve-
force, etc. But that the animal cell may possess this power,
it must make constant consumption of oxygen gas. In
the body of man, where the liberation of forces meets
itshighest expression, the consumption of oxygen is immense.
A man of average weight inhales, by various avenues,
700-1000 grammes per day, that is 500-700 pounds of
oxygen a year. And as the great bulk of his body is composed
of material already thoroughly oxidised (two-thirds to

THE FORCE VALUE OF FOODS. 43

three-fourths of it is water), it may be readily seen that all
the organic matter of the body would be soon resolved into
gases and ash, were it not for the new matter constantly
furnished by the food. The new matter thus furnished so
nicely balances the loss by oxidation that the body, though
in incessant change, may lose nothing of its weight in years.
And that the atmosphere may also remain the same under
the constant abstraction of oxygen by animal cells, this
gas must be as perpetually furnished by the plants. Thus,
that the 700-1000 grammes of oxygen, appropriated by
each human being in a day, to say nothing of other animals,
may be restored to the air, the plant must decompose
enough water and carbonic acid gas to make 33-40 lbs. of
starch, cellulose, etc., in the same period of time.

Animal Bodies as Machines.

Our bodies come, therefore, to be regarded as machines
for the exhibition of various forms of force. As the steam
engine liberates in other forms the forces stored up in the
fuel, the body sets free in the phenomena of life, the forces
stored up in the food. We are, however, unable as yet to
construct a machine that may liberate force as perfectly as
the human body. Helmholtz has shown that the best steam
engine can convert into motion only one-tenth of the force
of its fuel, the remaining nine-tenths escaping as heat ;
whereas the body of man may transform into mechanical
work as much as one-fifth of the force of his food, the re-
maining four-fifths escaping with the unoxidised, that is,
the unburnt, compounds in the various excretions.

The Force Value of Foods.

The force of the body being thus directly derived from
the food, and the amount of heat being known which the
combustion of any article of food outside the body will

44 COST OF FUEL AND FOOD.

produce, it is easy to compute the force value of the different
kinds of food. Frankland has thus tabulated the force
value of foods and has shown, as might have been antici-
pated, that the most highly combustible articles of food, the
fats, stand at the head of the list in the amount of force that
may be liberated in their digestion. Thus, half a pound of
fat furnishes the same amount of force as one and one-third
pounds of flour, one and one-half pounds of sugar, three
and one-half pounds of lean beef and live pounds of potatoes.
The laboring man gets from his slice of breakfast bacon
more work than the retired merchant, professional man or
epicure can obtain from a table overloaded with other things.
The appetite comes thus to be recognised as a measure of
the capacity for work. A farmer when asked "how he could
afford to pay his laborers so well," replied, that "he could
not afford to pay them less, as less wages meant less food
and less work." Another sat at the table with his men and
wThen he found one of them taking less food he turned him
off, as he at once knew that that individual was shirking his
work. Longet relates that in 1841, some English and French
laborers were engaged in the construction of a railroad from
Paris to Rouen. It was soon discovered that the French
laborers could accomplish only about two-thirds as much
work as the English. It was suspected that this deficiency
of force was due to the deficiency of food. The French
laborers were thereupon supplied with an equal amount of
food and soon were able to accomplish an equal amount of
work. "The muscular strength, the intelligence and com-
mercial industry of a people depend upon the proper use
and right distribution of its food/'

Cost of Fuel and Food.

But if force is more fully set free by the human body than by
a machine, the question becomes pertinent: why not employ

COST OF FUEL AND FOOD 45

human beings for mechanical work rather than machinery.
The answer is very easy ; because of the cost of food in com-
parison with fuel. A steam engine will work all day at a
cost for its fuel of twenty cents ; the food of two horses, the
equivalent of the machine, costs $2.00; and the food of
twenty-four men, required to perform the same work, costs
$10.00. Hence, as Donders has shown, the animal body can
never successfully compete with the steam engine, and "the
worst use to make of a man is to employ him exclusively in
mechanical work, a statement which harmonizes with the
increased introduction of machinery in our advancing
civilization."

If we should allow any humanitarian influence a place
at all in this consideration, we should have to remember also
that if we divert all the force in the body to mechanical
work, there is none left for mental work. The force of the
body is of course pretty much a fixed quantity, just as it is
for a machine, depending largely upon its original construc-
tion, as determined by heredity. We cannot use all the
power of a machine for a special purpose, say to saw a log,
and have enough left to turn a mill-stone. So with very
few exceptions hard muscular workers achieve no eminence
in intellectual life. Stallions whose force is to be used in
reproduction are kept idle in the stalls.

The body of man is built up of cells (protoplasm), which
are, in turn, composed of atoms or molecules, whose arrange-
ment (transmitted by heredity and modified by external
conditions) determines the special action or use. Or, as
Goethe has put it : "Nicht allein das angeborene, auch das
Enoorbene ist der Mensch." (Man is not alone what he
inherits ; he is also what he acquires.) The action of
protoplasm, though sometimes apparently, is never really
spontaneous. The cells are called into action by stimu-
lus, which, so far as we can trace it, always pro-

46 PHYSIOLOGICAL, A PHYSICAL FORCE.

ceeds from without. The various phenomena of life
are principally manifestations of reflex action. In
simple bodies (individual masses of protoplasm) the out-
side stimulus is conveyed from atom to atom, like chemical
force in gunpowder, from grain to grain. In complex
bodies the stimulus is carried along definite trains (nerve-
strands) to special destinations. If a muscle contract, it
contracts in obedience to stimulus carried to it by a motor
nerve. The stimulus conveyed along the nerve has its
development in a nerve-center (ganglion). The stimulus
experienced in the nerve-center is in turn derived from
a sensitive nerve. The sensitive nerve transmits an im-
pression received upon a sensory surface (skin, mucous
membrane, gland, etc.). Even the most complex mani-
festations of the brain fall under the same category. So-
called voluntary movements are only the final responses to
impressions made upon the special senses at the time or in
the past (memory). The highest expressions of the intellect
of man may be resolved into the more perfect transmutations
of outside forces by machinery made more perfect by original
construction (heredity), or made more perfect by labor,
(education).
Thus :

Physiological is Correlative with Physical Force,

or, more literally expressed, is identical with physical
force, and, the matter of our bodies being the same, and the
forces which operate upon it being the same, as in the inorganic
world, the exhibition of life is no more due to an innate
principle, a separate essence, a quid intus, a something
within, than is the registry of time in a clock.

THE ORIGIN AND EVOLUTION OF LIFE. 47

LECTURE III.
THE ORIGIN AND EVOLUTION OF LIFE.

C O NTENTS.

Definitions of Physiology — Ancient Definitions of Life — Modern Defi-
nitions of Life — Difference between Organic and Inorganic Matter
— The Property of Assimilation — Period of Development of Life —
The Theory of Evolution — Palaeontology — The Cataclysms of Cuvier
— The Operation of Existing Causes — The Age of the Earth — The
Evolution of Fossil Forms.

Physiology (ow^f, Aoyog), in our day, has a meaning very
different from the old conception of the term. It is no
longer a "description of nature" in general, according to its
literal origin and primitive significance. The vast collection
of facts in natural science, accumulated since physiology
first was taught, has been classified in appropriate lists, and
relegated to special and separate departments. The range
of physiology in ancient times becomes apparent from the
titles of the works of the oldest authors. Thus, Aristotle
wrote a work entitled Historic!, Partes, Incessus, Motus,
Generatioque Animallum; atque Plantarum natures brevis
descriptio. Aristotle was the first to use the term 61 <j>vcno2.oyoi,
designating as such, Thales, Anaximenes, Heraclitus, Dio-
genes, Empedocles and Anaxagoras, philosophers who were
engaged in the study of the nature of things, their causes
and commencements. Fernel first (1538) limited the term
to the nature of man in health. Boerhaave and Haller used
it in the sense of the use or actions of the various parts of
the body. Synonims of Physiology were the Philosophy of
Living Bodies, Dynamology, Organonomia, Zoonomia,
Biology. Johannes Muller (1833), "who dealt the death
blow to vitalism" in physiology, called it "The Physics of

48 ANCIENT DEFINITIONS OF LIFE.

Organisms," basing it solely upon Anatomy, Chemistry and
Physics.

Physiology, in its modern sense, is limited to the phe-
nomena observed only in living things, and though really
only more closely allied with subjects not especially endowed
with life, it has gradually become disencumbered from
necessary consideration of them. Physiology is, in short,
biology, the science of life.

What, then, is Life?

A satisfactory definition of life in a few words was a want
experienced long before physiology was studied as a separate
branch of knowledge. With the ancients this question was
easily answered. Life to them was a miracle, a supernatural
creation. "Humanity in its infancy, like the infant still
in humanity, was satisfied with a word it could not compre-
hend." Every inexplicable event, from an eclipse to an
epidemic disease, was accepted as a miracle, and further
inquiry was prevented, if not punished, indeed, as a presump-
tion upon the prerogatives of the gods.

Ancient Definitions of Life.

Or, later, definitions of life were evolved from the revel-
ries of metaphysics. Life, said Thales, of Miletus, emanates
from water with every other earthly thing. According to
Pythagoras, the principle of life is heat. Alcmeon thought
that the principle of life was in the blood, but the soul, a
distinct principle, was seated in the brain. The chief ingre-
dient in the manufacture of life for Empedocles was fire,
though water, air and earth, all the elements, entered into
its composition. It was with fire stolen from heaven that
Pygmalion infused the breath of life into his marble statue.
Hippocrates, most wise of all, refrained from any definition
of life, and counseled the study, not of its causes, but of its

ANCIENT DEFINITIONS OF LIFE. 49

manifestations. Plato, the great spiritualist, maintained
that the rational soul, an immaterial essence, was located
in the brain, the irrational, likewise an essence, in the abdo-
men. The body is only the theater in which the soul lives,
and thinks and acts. Aristotle subdivided the soul to such
extent as to localise its parts in every organ, whose functions
the special parts direct. The still popular "animation" of
the heart, stomach, bowels, liver, spleen and kidneys is the
relic of these views. In the reaction which naturally
followed this exaltation of the soul, Epicurus, like Demo-
critus before him, renounced the soul entirely with every
form of immateriality. The body is only an accidental
collocation of atoms, whose aggregation and arrangement
explains the different functions. Galen with his pneuma
again restored the soul as the principle of life. It was
developed in the ventricles of the brain, and lodged in the"
arteries, the air or pneuma carriers, whence they have their
name. But with Galen came again the reinstatement of
observation, as recommended by Hippocrates, and the first
establishment of experiment. Galen is thus justly looked
upon as the father and the founder of scientific physiology.
Unfortunately, his example had no followers. "Fireside and
writing-desk theories" — easier paths to notoriety — soon sup-
planted bed-side observations and experimental studies, one'
after another triumphing in turn, until everything was lost
in the succeeding darkness of the middle ages. "The field
of physiology illuminated for a moment by the genius of
Galen was then enshrouded in twelve centuries of gloom."

After the long night of ignorance and superstition broke
the dawn of the day which is still upon us in glimmers of
light from the natural sciences. From the still smouldering
embers of alchemy and astrology — as Christianity- upon the
altars of the unknown gods — -were fanned the flames of modern
chemistry, physics, and the. other natural sciences, under

5

50 MODERN DEFINITIONS OF LIFE.

the light of which were read new interpretations of the prin-
ciple of life. Paracelsus, Van Helmont and Sylvius, could
see in its most complicated phenomena nothing but effects
of combinations in chemistry. Descartes introduced the
new science of mechanics. "The body had been an alembic ;
now it was a machine. The principles of gravity, mechanics
and hydrostatics served to explain the phenomena of the
senses, the movements of organs, the exercise of all the
functions, and even the acts of intelligence" (Longet).

Again, there was reaction toward a vital as distinct from
physical force. Haller, who was second only to Harvey,
for having revived anew the long neglected studies by direct
observation and experiment in lieu of surmise and specula-
tion, discovered the inherent "irritability" in various tissues,
a property innate to the tissue itself, and characteristic of
living matter.

Modern Definitions of Life.

The definition of life in our own day has been mostly a
play upon words. Bichat says "life is the sum total of the
functions which resist death." Lawrence declares it to be
"an assemblage of all the functions or purposes of organised
bodies, and the general result of their exercise." Lewes
defines life as "a series of definite and successive changes
without destruction of identity." Duges calls it "the special
activity of organized bodies," Beclard, "organisation in
action," and Spencer, "the coordination of action." Truly, it
might be said of all these phrases, they are only idle repe-
titions of "life is life."

Thus, to define physiology as the science of life, is one
thing; but to define life, the subject of which it treats,
is another. One might almost say that the definition of
life is a rock surrounded with shipwrecked attempts. It
is no answer whatever to say that life is a creation.

ORGANIC AND INORGANIC MATTER. 51

Such an assertion may satisfy the wants of the emotions,
but it will in no way appease the demands of the intellect,
trained by cultivation in physical science to entirely ignore
unnatural explanations for natural events. Equally empty
and evasive in the pcriphrase that life is the result of all its
phenomena.

Difference between Organic and Inorganic Matter.

May we succeed better, perhaps, with the understanding
of life by a comparison between matter endowed with it,
and that which is not ? Automata have been made to
simulate every visible manifestation of life. Vaucanson's
duck could walk, talk, i. e., utter sounds (Faber's machine
could talk), eat, digest food, and even void per anum
indigestible residue. Yet this automaton was wholly built
up of wheels and springs, retorts and tubes, mechanical
and chemical devices, a cunning contrivance to nearly
realise the fanciful conception of Frankenstein. In what
respect does such a finished piece of mechanism differ from
an organism, a really living thing ?

It has been said that the activity of an organism is innate,
while that of a mechanism is accidental. An animal lives,
moves, and has its being of itself, while a machine, steam-
engine or watch must be supplied with fuel or wound up
before its activity is shown.

But an organism is no more capable of living without
food, than a machine of running without fuel. The food
is fuel in a literal sense, and it is the combustion of the food
in the body of man, as it is the combustion of fuel in the
furnace of the engine, that develops the force in either
case.

Again, it has been said that activity of some kind or other
is essential to the organism, but unessential to the mechanism ;
that is, if the organism ceases to act, it perishes and is lost,

52 THE PROPERTY OF ASSIMILATION.

whereas an engine remains an engine, or a watch remains
a watch, even though not set in motion for years. But we
know many organisms that have ceased to show any signs
of life for years and yet still exist as such. Small wheel-
like animals, tardigrades, rotifers, etc., may be completely
dried up and kept as lifeless particles for years, to be re-
stored with every manifestation of life, swimming as actively
as before, on being put again in water. Frogs and fishes,
low in the scale, have been frozen hard into inanimate bodies
and again thawed into life. Seeds from the tombs of
mummies have been made to germinate and bear fruit
after the desiccation of a thousand years.

Nor can the much-vaunted power of reproduction be
looked upon as a criterion of living things. The power of
reproduction is present only at a certain phase of life in all
animals and plants, and yet at every period are they none
the less alive. Besides, many living things are sterile
throughout life, as the workers among bees, the soldiers of
ants, hybrids among horses, etc.

Nor, again, may it even be maintained that every
living thing is descended from a parent like itself; for
many species of animals and plants now upon the earth
differ so entirely from ancestral forms as to have been long
regarded as entirely different species. A skilled zoologist is
required to trace the resemblance between fossil and existent
forms.

The Property of Assimilation.

Nevertheless, observes Briicke, who has so clearly estab-
lished these refutations of long accepted views, we do possess
a difference, which enables us to separate living from lifeless
matter. Organisms have the property, with which no
mechanism of any kind has ever been endowed, of taking
up foreign matter and transforming it into their own sub-

THE PROPERTY OF ASSIMILATION. 53

stance ; and the organism grows at the expense of the
substance thus acquired. This is the property of assimila-
tion. "It pertains to every organism, so long as it is an
organism, and must pertain to every organism, because
upon it is based its whole organic life." But if we contrast
the growth of an organism with the growth of inorganic
matter we may not make this difference so distinct. For,
in the first place, we observe that the elements which go to
form an organism are not different from those that constitute
inorganic matter. The carbon, hydrogen, oxygen and
nitrogen of living matter are precisely the same carbon,
hydrogen, etc., in the inorganic world. A simple monad,
a shapeless mass of protoplasm, scarcely contains as many
elements as a piece of common feldspar. That either
should increase in size, it must be placed in a medium con-
taining matter like itself, or that may be cjianged into matter
like itself. In the slow evaporation of the solution of a salt,
the formation of crystals develops. Each crystal particle
grows by addition to its surface. In the growth of an
organism the addition is effected from within. So far as
growth is concerned the essential difference between the two
is merely one of density. Organisms are of soft consistence,
hence are penetrable to nutrient matter. Inorganic matter,
from its nature, is hard and dense, impenetrable from with-
out. Growth may only take place on its surface, but it is
here, as in the organism, always at the expense of the new
material. It is true that in the organism the new material
is subjected to chemical change, a new arrangement of its
atoms resulting from its absorption and assimilation, but
this change is due to the fact that carbon, the principal
elementary ingredient of organic bodies, has such multi-
tudinous and varied relations with all the other elements.
In other words, the various manifestations of life, in its
simplest forms at least, admit of explanation on physical

54 PERIOD OF DEVELOPMENT OF LIFE.

grounds alone ; and, so far as growth and reproduction are
concerned, it is no more necessary to invoke the phantom of
a mystic vital force in their comprehension, than in the
explanation of the form or formation of a crystal in the
inorganic world.

Whatever theory we may adopt as to the nature of life,
there is no longer any doubt as to the

Period of its Development upon our Earth,

that is, it is positively known that life did not appear
coeval with the dissipation of the chaotic confusion which
marks the first epoch in every theory of creation. Ages
must have lapsed before the necessary conditions of life
could have developed.

Two theories prevail at present in the civilized world
regarding the firs&,creation of life ; the so-called miraculous
and non-miraculous theories. These theories are more
euphemistically designated the teleological and mechanical
theories ; teleological {rzloc^ end and 7.oyoq, discourse) because
evincing design, according to human conception of the term ;
and mechanical in the sense of being explicable by the action
of natural laws in continuous operation. The miraculous is the
supernatural theory as revealed in the first book of Genesis.
Because it has received its finest exposition in our day at
the hands of the great English poet, Milton, this theory is
often called the Miltonic theory. It is depicted in the
Bible with the solemn cadence, the metaphor and poetic
imagery, the "inspiration," characteristic of the Orient. In
its regular sequence of chaos, darkness, absence of form and
life, then lir^ht, water, vegetation, aquatic life, land life,
and, last of all, man, it is in perfect harmony with the natural
theory of creation. But, in its disposition of the earth as
the center of the universe, and of man as the center of all
life, it is directly opposed to all the facts of astronomy,

PERIOD OF DEVELOPMENT OF LIFE. 55

geology and biology. The earth we know to be but an
atom in the illimitable expanse of space and we have
reason to consider man but as an accident of conditions
upon its surface prevailing at his time.

The non-miraculous is the natural theory of creation.
This theory in the first place repudiates every idea of crea-
tion in the strict sense of the term. Such a thing as the
creation of a new substance is impossible and unknown.
The matter of which our earth consists has existed and will
exist forever. It may become subject to as many changes
in future ages as it has undergone in the past; it may,
ultimately, even lose its separate existence and identity by
fusion with other globe's of matter and return to a former
nebulous state, but the matter of its present composition
must remain, in essence, forever the same.

"Dinanzi a me non fur cose create,
Se non eterne, ed io eterno duro."

As it is imperishable, it may not have been created.
In its organic form it may suffer decomposition but,
as we have seen, the water, the gases, the "dust," into
which it is resolved, is the same matter in its elements as
before. It has only changed its form. The smoke and ashes
of matter consumed by fire, weigh exactly as much, and are
the same elements as before. Creation under the natural
theory refers not to substance, but to form.

Facts in the natural sciences, which it is not our prov-
ince to repeat, enable us to trace back the past history of
our earth, through successive changes of form, to a mass of
molten matter, irradiating its heat into space, until its ex-
terior was enveloped in a more or less solid crust. The sub-
sequent condensation of steam, into which its water had
been forced by heat, let the rain fall upon the surface until
it was wholly covered with water. The surging of the mol-

56 THE THEORY OF EVOLUTION.

ten interior lifted land above the waters in islands, conti-
nents and mountain chains. Then, when the heat had been
sufficiently reduced, when water was present in quantity,
when an atmosphere (though not the air we are breathing
now) floated above the waters, then — all the conditions
being present — life was developed in its lowest forms, as
inevitably as the heat was irradiated, or the steam condensed,
or the minerals crystallised into special forms, or as inevitably
as any physical law.

The Theory of Evolution.

That higher and higher forms of life were successively
developed from lower forms, is now abundantly proven by
facts in palaeontology, comparative anatomy and embryology,
as well as by direct observation of the effects of natural and
artificial selection.

Palceontology , the Science of Petrifactions,

or of fossils, furnishes what may be now called indisputable
proof of the gradual evolution of higher forms of life. "The
organisms buried in the most ancient geological strata must
be looked upon as the ancestors from which the rich
diversity of forms of the present creation have originated
by continued generation and by accommodation to pro-
gressive and very different conditions of life" (Carus). The
different strata of the earth, successively deposited at differ-
ent epochs of time, may be thus regarded as so many shelves,
each filled with specimens of synchronous creation. Of the
vertebrate animals, for example, we encounter first fish, then
amphibious animals, then reptiles, birds and mammals.

The explanations offered to account for the existence of
fossils on any other theory than that of evolution are very
curious. It was believed, for instance, that fossils were
models in clay or mineral matter of subsequently improved

THE SCIENCE OF PETRIFACTIONS. LI

creations in organic life. According to others, petrifactions
resulted from the influence of the stars upon the interior of
the earth. "Sports of nature," they were playfully called.
Since we have become acquainted with the vast denudations
effected by the action of the air and falling and running
water, we can readily understand how forms of life become
gradually encrusted with sand and mud, and remain en-
tombed for all time, as indestructible as the subjects and
objects in Pompeii and Herculaneum while still enveloped
in ashes and lava.

Though the animal nature of fossils was recognised by
some of the ancient Greek philosophers, notably by Xeno-
phanes, of Colophon, as also by Aristotle, and though even
the manner of their petrifaction seems to have been under-
stood by that most versatile genius of the fifteenth century,
Leonardo da Vinci, it was not until the beginning of the
present century that their regular order of deposit began to
be observed, so that laws could be deduced to entitle palaeon-
tology to a distinct place amongst the exact sciences. AVe
owe our first definite knowledge of the deposition of these
ancient forms cf life to the great natural philosopher of
France, George Cuvier. This observer discovered that the
fossils deposited last, that is, those nearest the surface in
undisturbed strata, most closely resembled the forms of life
now existing upon earth, whereas those deposited first, in
the deeper strata, differed most widely from living forms.
Unfortunately, Cuvier wasnot able from this most suggestive
discovery to proclaim the gradational development of forms
of life, and thus anticipate for himself and his time the
honor of the discovery of the theory of descent. The differ-
ences in the forms of life encountered in different strata, he
believed to be inherent, and to have been imprinted from
their birth. In other words, he believed that each new strata
represented an entirely new creation of all the forms of life.

58 THE CATACLYSMS OF CUVIEE.

The Cataclysms of Cuvier.

To account for such extraordinary phenomena as the ex-
tinction of all existing, species and the creation of new, he
invented the theory of the cataclysms, sweeping revolutions
or mighty casualties of nature, which at stated periods
suddenly convulsed the earth, overwhelmed every form of
life, and changed to chaotic confusion the whole face of the
globe. With the restoration of order came new forms of
life, different from their predecessors, to again take possesion,
until they, too, in turn succumbed in the general crash of
another grand disaster.

These unnatural cataclysms of Cuvier prevailed uncontra-
dicted during the first quarter of our century, completely
paralysing any hope of progress in biological studies, by not
only recognising multiple creations and destructions in the
past, but providing also for new ones in the future. Any
connected history of development under such an hypothesis
was, of course, impossible.

Closer observations, however, in physical geography began
to develop the fact that changes were continually taking
place in the level of different regions, and in the disposition
of land and water. Mr. Croll and Mr. Geike concluded from
the results of their investigations that the whole terrestrial
surface is denuded at the rate of one foot in six thousand
years. "At this rate, one foot in six thousand years, ten feet
in sixty thousand years, one hundred feet in six hundred
thousand years and one thousand feet in six million years,
the Mississippi river would not require more than about
four million five hundred thousand years to wear away the
whole of the North American continent, if its mean height
is correctly estimated by Humboldt at seven hundred
and forty-eight feet." The potency of falling water in
degrading the higher surfaces — a potency which, if un-
checked, would thus reduce the whole face of the earth to a

THE GREAT AGE OF THE EARTH. 59

common level in a few million years — is being continually
counteracted by the elevating influence of the molten
interior of our globe. The coast of Sweden, for example, is
observed to be continuously rising, while that of Holland is
continuously sinking. So constant, indeed, must be the
labor of man, in lifting off the water from the coasts of
Holland as to have given rise to the saying there, that "God
made the sea, and man, the shore." The west coast of South
America has been lifted up perceptibly within the history
of man, while the east coast has sunk in the same way in
the same space of time. It was the observation of such
alterations that led the eminent geologist, Robert Lyell, of
England, to the conviction that all the changes which have
heretofore taken place in the physical geography of the
earth were the

Results of Existing Causes,

that is, those still in operation. "The rivers and the rocks,
the seas and the continents have been changed in all their
parts; but the laws which direct those changes and the
rules to which they are subject have remained invariably
the same" (Playfair). We may explain all the phenomena
of nature, said Generelli, in his address to the Academy at
Cimento, "senza violenze, senza finzioni, senza supposti, senza
miracoli" (without violence, without fictions, without hy-
potheses, without miracles). These changes, which may be
very slight — a line or an inch — in the life of man, or, indeed,
of mankind, assume sufficient magnitude in the untold ages
of the past to account for the loftiest peaks of mountains or
the greatest depths of the sea.

The Great Age of the Earth

is now attested by a multitude of facts. Geologists
claim to have positive evidence that for at least ninety

60 THE GREAT AGE OF THE EARTH.

millions of years, rain must have fallen upon its surface
to effect the present degree of denudation. The formation
of coal and of coral, of stalactites and stalagmites, furnish in-
disputable evidence of the lapse of ages upon ages of time.
"Men are in the habit of measuring the greatness and the
wisdom of the universe by the duration and the profit
which it promises to their own race ; but the past history
of the earth already shows what an insignificant moment
the duration of the existence of our race upon it constitutes.
A Nineveh vessel, a Eoman sword awakens in us the con-
ception of gray antiquity. What the museums of Europe
show of the remains of Egypt and Assyria we gaze upon
with silent astonishment, and despair of being able to carry
our thoughts back to a period so remote. Still must the
human race have existed for ages and multiplied itself
before the pyramids of Nineuch could have been erected.
We estimate the duration of human history at 6000 years;
but immeasurable as this time may appear to us, what is it
in comparison with the time during which the earth carried
successive series of rank plants and mighty animals and no
men ; during which in our neighborhood the amber tree
bloomed and dropped its costly gum on the earth and in
the sea ; when in Siberia, Europe and North America groves
of tropical palms flourished; where gigantic lizards, and
after them elephants, whose mighty remains we still find
buried in the earth, found a home ? * * * * And the
time during which the earth generated organic beings is
again small when we compare it with the ages during which
the world was a ball of fused rocks. For the duration of its
cooling from 2000° to 200° centigrade, the experiments of
Bishop upon basalt show about 350 millions of years necessary.
And with regard to the time during which the first nebulous
mass condensed into our planetary system our most daring
conjectures must cease. The history of man, therefore, ia

GItADATIONAL EVOLUTION OF FORM. 61

but a short ripple in the ocean of time" (Helmholtz).

It is only necessary to appreciate the great age of the earth to
understand the might of the slow and silent changes in per-
petual operation, and to realise the truth of the remark that
"changes which are rare in time are frequent in eternity."

It was this revalation of the order, instead of disorder,
observed in the history of the development of the inorganic
world that enabled palaeontologists to disclose in fossils the

Gradational Evolution of Forms of Life.

It is only within the past twenty years that proof of this
fact has received its highest confirmation in the accumula-
tion of evidence of the existence of man in ages antedating
any historical record. It may be stated as now beyond
question that "not only man, but, what is more to the pur-
pose, intelligent man, existed at times when the whole
physical conformation of the country was totally different
from that which characterises it now." And the fact itself
that the difference is so slight between the most ancient
remains of human forms as yet discovered — the celebrated
Neanderthal skull for instance — and the forms now upon
the surface of the earth, is most conclusive evidence of the
time required to effect any very great change in the physical
conformation and constitution of our earth. The horse,
which now exists is the same in all essential regards as the
horse of .the period of time referred to, but is a very different
animal from the horse of a much more ancient period. It
was the recognition of the eras of time necessary to effect
radical changes in the structure of animal forms under the
slow agencies of natural selection that forced upon scientists
the conviction that no series of sudden catastrophes or
convulsions have marked or marred the even course of
nature. As Mr. Huxley has remarked : "Catastrophic
palaeontologists are now practically extinct." It may

62 GRADATION AL EVOLUTION OF FORM.

not be said, indeed, that our record is in all respects
complete. When we consider the disturbing eleva-
tions and depressions to which all parts of the earth have
been repeatedly subjected, the yery small extent of surface
as yet explored — not the one-thousandth part of the whole
— the metamorphic changes which heat has induced in the
lowest strata of rock, and when we recall the perishability
of intermediate forms, and of all except the hardest parts of
all forms, we cease to wonder at the "missing links." Many
of the specimens still preserved are in sadly mutilated
state, like the wounded in the broken ranks at the roll
call after battle. But the losses are compensated in some
degree by the skill of the interpreters. Some of you are
doubtless familiar with the story of Zadig in the Eomances
of Voltaire. He was a youth who had "chiefly studied the
properties of plants and animals, and soon acquired a sagacity
that made him discover a thousand differences, when other
men see nothing but uniformity." The light and long
furrows impressed upon the sand between the marks of the
paws, revealed to him that the animal escaped was a bitch
recently whelped ; other side traces told of the hanging ears
of a spaniel, and the slighter impression of one of the paws
showed that the animal was a little lame. Thus also he was
able to divine the height of a runaway horse, the length of
his tail, the character of his shoes and bit, in a manner to
astound his questioners, and, as has often happened since,
under similar circumstances, to render him liable to persecu-
tion for sorcery. But how much more incredible and incom-
prehensible to the unlearned is the more definite and extensive
knowledge afforded by a footprint to the palaeontologist or com-
parative anatomist? "Whoso sees merely the print of a cleft
foot," wrote Cuvier, "may conclude that the animal which
left this impression ruminated, and this conclusion is as
certain as any other in physics or morals. This footprint

GRADATIONAL EVOLUTION OF FORM. 63

alone yields to him who observes it, the form of the teeth,
the form of the jaws, the form of the vertebra?, the forms
of all the bones of the legs, of the thighs, of the shoulders
and of the pelvis of the animal which has passed by ; it is
a surer mark than all those of Zadig." A fossil fragment
of a lower jaw directly attached to a piece of skull would
enable the palaeontologist as positively to assert that the
animal of which the fragment was part had two occipital
condyles with an ossified basi-occipital bone, had also red
corpuscles in its blood and breasts to suckle its young.

Thus the excavation of a few fossil bones of the leg in
our country completed the line of descent of the horse, the
discovery of a couple of small back teeth (of a predatory
marsupial) in the Trias formation established the existence
of mammals at that early period of time, and the im-
perfect impression from the Jura of a fossil bird (the
archseopteryx) with a lizard's tail confirmed the con-
jecture previously made that birds were developed from
lizards. Thus from a fragment of bone or a tooth, from a
feather or a footprint, has been deciphered, as from ancient
hieroglyphics, the gradational development of animal life.

For my part, said Mr. Darwin, in speaking of the imper-
fection of the geological record, for my part, following out
Ly ell's metaphor, I look at the geological record as a history
of the world imperfectly kept and written in a changing
dialect ; of this history we possess the latest volume alone,
relating only to two or three countries. Of this volume,
only here and there a short chapter has been preserved , and
of each page, only here and there a few lines. Each word
of the slowly changing language, more or less different in the
successive chapters, may represent the forms of life which are
entombed in our consecutive formations and which falsely ap-
pear to us to have been abruptly introduced. On this view the
difficulties discussed are greatly diminished or even disappear.

64 THE EVOLUTION OF FORMS OF LIFE.

LECTURE IV.

THE EVOLUTION OF FORMS OF LIFE.

CONTENTS.

Comparative Anatomy— Of the Eye and the Ear— Order of Develop-
ment—Jean Lamarck — Wilhelm von Goethe— The Intermaxillary
Process— Erasmus Darwin— Anatomical Resemblances— The Hand
and its Homologues— Comparative Embryology— Ernst Haeckel—
The Rudimentary Organs— Bone Rudiments— Muscle Rudiments —
Rudiments from the Digestive System— Other Rudiments— Explana-
tions of Rudiments.

To-day we approach the development of life from the
standpoint of

Comparative Anatomy.

The most striking feature in a general survey of the forms
of life is their almost infinite diversity. The mind is fairly
confused in its attempt to review the vast procession of ani-
mated beings in constant defile about us, having nothing
more in common, apparently, than motion or growth, repro-
duction or assimilation, the grosser phenomena of life.
Humboldt estimated, many years ago, that there were 56,000
species of plants and 51,700 species of animals. We know
now that species are numberless because they are mutable.
It is comparative anatomy alone that reveals to us the simi-
larity of structure pre vading all these forms, notwithstanding
their great diversity in external appearance. By the study
of comparative anatomy we are thus enabled to group the
forms of life into species, genera and tribes, to single out
elements or types of structure from which all the various
forms are modeled, however much they vary to superficial
inspection, and to trace the points of resemblance to and

Fig. i. — Man, iv weeks. Fig. 2. — Dog, iv weeks.

Fig. 5. — Ccecum and vermi-
form appendix, c, small in-
testine, e, large intestine. </,
ileo-ccecal valve, c, orifice,
and b, termination of vermi-
form appendix, (p. 80)

Fig. 6. — Eve. a. plica semi-
lunaris, rudimentary nictitat-
ing membrane, (p. 80)

Fig. 3. — Chick, iv days. Fig. 4. — Tortoise, iv weeks.

THE VERTEBRATE FCETUS. (p. 74.)

Fig. 7. — Pelvis, o, coccyx, rudimentary cau- Fig. 8.— Ear. b, extrinsic, and a. , intrin-
dal extremity. (,p. 78) sic (rudimentary) muscles, r, position of

point of ear turned in. (p. 81)

RUDIMENTARY ORGANS.

THE ORGAN OF VISION. 65

divarication from the archetypal plan. Cuvier has happily
compared the examination of the comparative anatomy of
an organ, in its gradation from its simplest to its most com-
plex state, to an experiment which consists in removing
successive portions of the organ, with a view to determine
its most essential and important part. In the animal series
we see this experiment performed by the hand of nature,
without those disturbances which mechanical violence must
inevitably produce. We thus learn from comparative
anatomy, that the vestibule is the fundamental part of the
organ of hearing ; and that the other portions, the semi-
circular canals, the cochlea, the tympanum and its contents,
are so many additions made successively to it, according as
the increasing perceptive powers of the animals rendered a
more delicate acoustic organ necessary.

Comparative anatomy thus discloses the development and
differentiation of all the various organs, from the most
simple elementary forms to the most finished and compli-
cated structure, and at the same time reveals the regular
order of addition o'f parts on the road to gradual perfection.

We might select, for example, the complex and composite
structure of the

Organ of Vision,

wdiich, if regarded only in its nearly perfected state, as in
man or birds, would seem to have required separate and
independent creation in the body in which it is found. But
comparative anatomy, in tracing down the structure of the
eye, shows us the gradual reduction of parts and brings us
at last to the simplest possible arrangement of cells which
could serve for visual purpose.

Thus, lowest in the scale of living beings, among the
protozoa, we find simply a collection of pigment cells, with-
out any nervous structure whatever, resting upon sensitive

66 JEAN LAMARCK.

protoplasm. In star-fishes the pigment cells are depressed
and the cavities filled with gelatinous matter to constitute
primitive lenses and to effect the first concentration of light.
In articulate animals an optic nerve is coated with pigment
sometimes arranged in the form of a pupil. In insects are
superadded numerous facets, each a distinct lens to converge
the rays of light upon the sensitive nerve filaments beneath.
In the lowest vertebrate animal, the lancelet, we start with
"a little sack of transparent skin, furnished with a nerve
and lined with pigment, but destitute of any other appa-
ratus." As we ascend the scale of vertebrata we successively
encounter the more or less developed crystalline lens, the
vitreous and aqueous bodies (additional lenses), the retina
with rods or cones, or both, and, finally, the accessory appa-
ratus of muscles and lids and lashes, glands for the manu-
facture of lubricating oil and tears, and tubes to convey
away superfluous fluids.

What is true in this way of organs in the body is true of
the whole body, that is of the position it occupies in the
animal scale. We may observe in the study of comparative
anatomy, the

Order of Succession

of different animals in a progressive and uninterrupted chain.
In the vertebrate animals, for instance, we see this succession
maintained from fishes to amphibia, reptiles, birds and mam-
mals, and from the lower to the higher orders of each class.
Comparative anatomy pays its highest tribute to biology
in displaying the general unity of structure in the various
forms of life. We owe the first definite exposition of this
principle to the distinguished French philosopher,

Jean Lamarck.

In the earliest years of the present century Lamarck pub-
lished in Paris his Zoological Philosophy, which was accord-

JEAN LAMARCK. 67

ing to its title "an exposition of the natural history of ani-
mals showing the diversity of their organization and faculties
the physical causes which maintain them in life, give rise to
the movements they may execute and endow them with
sentiment and intelligence." Lamarck first propounded the
theory of descent in his Natural History of Invertebrated
Animals — 1815 — 1822. In this work he maintained that
"the systematic divisions of classes, orders, families, genera
and species, as well as their designations, are the arbitrary
and artificial productions of man. The kinds or species of
organisms are of unequal age, developed one after another
and show only a relative and temporary persistence. * * *
The differences in the conditions of life have a modifying
influence on the organization, the general form and the parts
of animals, and so has the use and disuse of organs. In the
first beginning, only the very simplest and lowest animals
and plants came into existence; those of a more complex
organization only at a later period. The cause of the earth's
development and that of its organic inhabitants, was con-
tinuous, not interrupted by violent revolutions. Life is
purely a physical phenomenon. All the phenomena of life
depend on mechanical, physical and chemical causes, which
are inherent in the nature of matter itself." Lamarck
is therefore justly regarded as the originator of the
theory of evolution or the doctrine of descent. His views
excited, however, but little attention at the time of
publication. Lamarck had no idea of the struggle for
existence entailed by numbers and the survival of the
fittest, the key notes in the comprehension of the doc-
trine of descent; still for having proposed the theory
and backed it with proof from comparative anatomy,
Lamarck must always be regarded as the pioneer in this
great discovery.

Almost about the same time, the doctrine of unity of

6$ WILHELM WOLFGANG VON GOETHE,

structure was occupying the attention of the greatest intel-
lect in Germany,

Wilhelm Wolfgang von Goethe.

We are all fully familiar with the literary achievements of
Goethe, whom we are accustomed to regard as second only
to Shakespeare as a delineator of human feelings and pas-
sions, but few of us are aware that he far surpassed Shake-
speare in his deeper and more subtile conceptions of the
secrets of nature — the result of higher culture in the physical
sciences of his day. In his persistent search after a type of
structure in the vegetable world he had already hit upon
the leaf — and would have reached the cell, no doubt, had
the microscope been in general use — when he directed his
attention to the study of animal life. From his investiga-
tion into the structure of insects he was able to announce
the ring, a succession of which, from the head to the tail,
constitutes the whole body, to be the fundamental principle,
modified only to form the various parts of the animal.
What the leaf was to the plant, was the ring to the insect.
So the vertebra is the starting point or ground principle for
the vertebrate animal. But for a long time the bones of the
cranium confused him. They seemed so entirely different
from all other osteological forms in the body "as to trans-
port him," as he said when attempting to deduce them from
vertebrae, "into a sort of frenzy." A bleached sheep's skull
picked up in the Jewish cemetery at Venice,during one of these
perturbed meanderings, revealed to him as in a flash of in-
spiration the derivation of the cranium from the vertebral
bones. Though this view has since undergone much modi-
fication, it was of the highest value in its day in concen-
trating the attention of the scientific world upon the funda-
mental principles underlying all animal structure. There
remains still another discovery of Goethe, worthy of especial

THE INTER-MAXILLARY PROCESS. 69

mention in this connection, a genuine discovery, which no
later developments may ever confute. It is to Goethe that
we owe the discovery in man of the so-called mid jawbone,

The Inter- Maxillary Process,

supporting the upper incisor teeth, found constantly in most
lower animals in the class of mammals, but up to the time
of Goethe, never detected in man. "The strange case now
occurred," wrote Goethe, "that the distinction between apes
and men was made by ascribing an inter-maxillary bone to
the former and none to the latter ; but as this part is mainly
remarkable because the upper incisor teeth are set in it, it
was inconceivable how man should have the incisor teeth
and lack the bone." Goethe therefore determined that man
must possess the inter-maxillary bone and began his search
for it in every skull that came in his way. After examin-
ing a great number of skulls he found it at last an inde-
pendent bone. Every skull possesses it, but as age advances
it unites with the superior maxilla so closely that even
the line of union, like that of the halves of the frontal
bones, is completely lost to view. During the whole of
foetal life it may be readily demonstrated in every case,
often too in early infancy it remains still isolated except by
membranous connection, but only as the greatest rarity may
it be observed in later life. Goethe was so fortunate as to
encounter such an unanchylosed specimen and thus could
forge another link in the chain of evidence for the theory of
descent. "Thus much," said Goethe in summing up his
views on animal life, "thus much, then, we have gained,
that we may assert -without hesitation that all the more
perfect organic natures, such as fishes, amphibious animals,
birds, mammals, and man at the head of the last, were all
formed upon one original type, which only varies more or
less in parts, which are none the less permanent, and still

70 ERASMUS DARWIN.

daily changes and modifies its form by propagation." No
one has so tersely expressed the power of adaptation or
adjustment to external circumstances as Goethe when he
said "the animal is formed by circumstances for circum-
stances."

This same thought had, however, already found expression
in a different tongue in a different part of the civilized world.

Erasmus Darwin,

the grandfather of the author still living, whose name is
now known everywhere, had arrived at the same conclusions
without any knowledge of the labors of Goethe or Lamarck.
The doctrine of descent "pervaded the air," one might say,
on observing its almost simultaneous enunciation in Ger-
many, England and France. Erasmus Darwin published
his Zoonomia in 1795, already recognizing at this early
period the changing structure of animal life under changing
external conditions.

Such is, in brief, the early history of the filiation theory
in its relation to comparative anatomy. When we come
now to observe for ourselves the

Anatomical Resemblance

between man and the lower animals, we are struck with
amazement that their relationship was not noticed long
before. The whole structure of the skeleton is glaringly
similar among all the vertebrate animals. Confining our-
selves to the highest types, we observe such close resem-
blance between the bones of man and anthropoid apes as to
require intimate knowledge of comparative anatomy to
declare which is which. The same remark might be made
of all the internal organs. The difference between the brain
of man and apes is much less, said Vulpian, than between
that of apes and the quadrumana just below them. We

ANATOMICAL RESEMBLANCES. 71

find, indeed, less difference in bodily structure and mental
faculties between higher and lower apes than between higher
and lower species or races of man. The refinements of
chemistry and spectroscopy have not been able to differenti-
ate the blood of man from that of lower animals. The
microscope refuses to note a distinguishing point between
the blood corpuscles of man and the dog. Finer evidence
even than this, the same medicines, and the same diseases
produce the same effects. Post-mortem sections reveal to us
the same lesions of structure in apoplexies, phthises, hepatic
diseases, brain affections, etc., common to all the higher
forms of life. "Many kinds of monkeys," Mr. Darwin re-
lates, "have a strong taste for tea, coffee and spirituous
liquors ; they will also, as I have myself seen, smoke tobacco
with pleasure." The same author quotes from Brehm the
assertion, that the natives of northeastern Africa catch the
wild baboons by exposing vessels with strong beer, by which
they are made drunk. They suffer also the same scourges for
these pleasant vices, for monkeykind endure "katzenjammer"
on the next morning in common with mankind. But Brehm
tells the story of an American monkey who after getting
drunk on brandy, would never touch it again, and thus was
wiser than many men. The taste nerves and the whole
nervous system, therefore, is the same in the monkey as in
man. Carl Vogt concludes from his numerous investigations
that there is no doubt whatever that, according to the
fundamental part of the brain, man, belongs to the ape.
On comparing, says Gratiolet, a series of human and simian
brains, we are immediately struck with the analogy
exhibited in the cerebral forms in all these creatures. The
convoluted brain of man resembles the smooth brain of the
ouistitis in the characteristics of a rudimentary olfactory
bulb ; a posterior lobe, which entirely covers the cerebellum ;
a perfectly marked Sylvian fissure, and a posterior cornu

72 THE HAND AND ITS HOMOLOGUES.

in the lateral ventricle of the brain. And he might have
added, adds Vogt, the existence of a central or intermediate
lobe which occurs in all apes. "Thus there is a cerebral
form peculiar to man and ape ; and so in the cerebral
convolutions, wherever they appear, there is a general unity
of arrangement — a plan, the type of which is common
to all these creatures" (Gratiolet). "But," Bischoff persists,
"there is no time when we may not differentiate the brain of
a monkey from that of a man." "True," replies Mr. Darwin,
"else a monkey would be a man." The difference is only
difference in degree. As long ago observed by Wundt, ani-
mals are creatures whose intelligence differs from men only
by the degree of development. There exists between men
and brutes (mutes is a better word), no wider gulf than is
to be found within the animal kingdom itself. All animated
organisms form a chain of connected beings without an
interval. It is only "an antiquated psychology, with its
great variety of mental faculties, which draws here and
there lines of demarcation."

Man belongs to the division of vertebrates, the class
of mammifera and the order of apes. But it is known that
man did not descend from any of the existing anthropoid
apes. No naturalist now maintains this view. Man is
known to have descended from acatarrhine ape with pointed
ears, a hairy skin, a caudal extremity, arboreal in habit, an
ancestral form, common to man and to existing apes. Nearly
ten years ago, Dr. Barrago Francesco published a work,
bearing in Italian the title, "Man made in the image of God,
was also made in the image of the ape."

The Hand and its Homologues.

Perhaps no part of the body will furnish a more satis-
factory demonstration of the unity of structure, notwith-
standing the difference of external form, than the termination

COMPARATIVE EMBRYOLOGY. 73

of the upper extremity, the hand in man or its homologue
in lower animals. If Ave compare in this way the hand of man
with that of the gorilla and orang, with the forepaw of the
dog, the flipper of the seal and dolphin, the wing of the bat,
the shovel foot of the mole and the forefoot of the duck-bill,
we shall find them to be composed of exactly the same bones,
arranged in exactly the same order, with exactly the same
connections. The breadth and thickness of the thumb in
the gorilla, so much approach that of man, that, as Mr.
Huxley justly observes, there is more dissimilarity between
the hand of the orang, which has one bone more in the carpus,
and that of the gorilla, than between the hand of the gorilla
and that of man. Indeed, the hand of man, the highest of
mammals, more closely resembles the fore extremity of the
duck-bill, the lowest of mammals, than any of the intervening
types. As with the hand, so it is with every other member
or organ in the body, the similarity of fundamental struc-
ture betrays the kinship, the inheritance from the common
ancestral type

Comparative Embryology.

But, comparative anatomy only sheds its full illumination
over the field of biology when its light is turned upon every
stage and phase of life. Hitherto it is only adult or mature
forms that have been thought worthy of any consideration.
In quite recent years undiscovered treasure has been dis-
closed in embryonic life, a phase of existence almost wholly
ignored, or at least studied only by the privileged few.
What makes comparative embryology especially profitable
in the study of the development of forms of life, is the fact
that changes of structure occur in the embryo with such
very great rapidity. The transformations of maturer
types, which geological ages required to effect under the
slow agencies of natural selection, are run through in the

7

74 COMPARATIVE EMBRYOLOGY.

foetus in a few weeks or months. Thus we may observe,
at different stages of foetal life, phases of development
and evolution, for whose recognition in mature forms
we must appeal to the faulty records of the prim-
aeval world. It is in the respect of its completeness,
thus, that the evidence furnished by embryology is so much
superior to that of palaeontology. And for this evidence it
may be claimed with equal truth that it has not been
"tampered with by the hand of man."

Although the main facts in our present knowledge of
embryology had been divulged as long as a century and a
half ago by the eminent German naturalist, Caspar Wolff,
and although the full history of embryonic development of
animals had been exhaustively studied by Pander and Bar
within the first quarter of this century, yet it was not until
the present decade, our own day, as it were, that we have
become familiar, through the labors of

Ernst Haechel, of Jena,

with the developmental phenomena of foetal life, and their
significance in comparative anatomy. Haeckel conceived
the happy idea of placing accurate representations of the
foetus of different animals, including man, in parallel columns
that their resemblance, one might almost say, identity of
form and structure, should be apparent at a glance. No one
may look upon these representations of the foetus of man,
the dog, the chicken and the tortoise, with an unprejudiced
eye, and fail to be convinced of their unity of structure.
The general conformation, the position of the upper and
lower extremities, are the same in every foetus; the various
vesicles of the brain are alike present in each ; the organs
of the senses and the viscera are similarly located and dis-
posed ; and each has a caudal termination projecting between
the lower extremities.

COMPARATIVE EMBRYOLOGY. 75

Perhaps the most striking feature common to every foetus
is the row of branchial clefts ou the under and lateral sur-
face of the neck. The human foetus presents these fissures
as distinctly as every other. But it is only in the fish that
these clefts persist to become developed into the gill arches
supporting the leaves formed by the ramifying pulmonary
vessels, "the fishes ears," properly, its lungs. The gill
arches of the human and most other vertebrate foetus are
subsequently absorbed in the formation of the jaw and organ
of hearing, but their existence at an early period of embryo
life is incomprehensible in any other light than that of con-
struction upon the same fundamental plan. At a still
earlier period in the life of the human foetus, the arteries
run in arches to these branchial clefts and some time after
the superfluous arches have shriveled away, the branchial
clefts still remain as landmarks of their former place. The
arch of the aorta, and the arches of the subclavian arteries,
are the last relics of the vascular arches of earlier dates.

In the human foetus, as in that of all vertebrate animals,
the heart is at first only a dilatation of the aorta, a simple,
spindle-shaped, pulsatile vessel without septa or valves.
The human foetus has also, in common with the rest, a pair
of Wolffian bodies, in lieu of kidneys, and its excreta, like
the rest, are voided through a cloacum. The convolutions
of the brain of the human foetus at the seventh month
nearly exactly correspond to those of the adult baboon.
Mr. Huxley makes the remark, that it is only "quite in the
later stages of development that the young human being
presents marked differences from the young ape, while the
latter departs as much from the dog in its developments as
man does. Startling as this last assertion may appear to be,
it is demonstrably true."

Embryology reveals to us the significance of organs and
structures like the Wolffian body and ductus venosus, or

76 COMPARATIVE EMBRYOLOGY.

urachus, etc., and at the same time reconciles otherwise dis-
cordant features in comparative anatomy. The develop-
ment and formation of the lower extremity may serve as an
example. The similarity of structure of the upper extremity
among all vertebrate animals has already been mentioned.
It is easy to recognize the same bones, in the same order,
arrangement and connection, etc. But in the lower ex-
tremity this harmony is apparently not observed. Thus,
in the leg of the bird, we may observe the femur, below it
the tibia, but in place of the tarsus and metatarsus, there is
only a single bone to which the phalanges are attached.
Here is a gross dissimilarity which strongly militates against
the unity of structure. If we turn, however, to the develop-
ment of the bird in the egg, the dissimilarity is dissipated
at once. For we find in the f cetal bird, first the femur, then
the tibia, below it two bones to constitute the tarsus, and
below these two short, thick bones, and parallel with each
other, are three or four long, slender metatarsal bones to
which are appended the phalanges. The upper tarsal bone
subsequently coalesces with the femur, the lower with the
tibia, the metatarsal coalesce with each other to form one,
and thus is the leg, as well as the wing of the bird, shown to
be constructed from the same fundamental form. "In
short, the history of development," as Oscar Schmidt ob-
serves, "which describes the gradual formation of the organ-
ism, is at every step a beacon to comparative anatomy."

While we are considering the lower extremity, I may call
your attention to the fact that Carl Vogt has shown the
foot of the gorilla to be more anthopoid than that of any
other ape, and the foot of the negro more ape-like than that
of the white man. The bones of the tarsus in the gorilla
exactly resemble those in the negro ; the ape has the same
broad, flat, low heel ; the large toe is thicker and longer
than in the other apes, but the toes, on the whole, are

THE RUDIMENTARY ORGANS. 77

longer, more moveable and the thumb more opposable.
"The posterior limbs of the gorilla," says Huxley, "terminate
in a real foot, with a moveable great toe. It is a prehensile
foot, if you like, but no hand, a foot which differs from that
of man, not in any fundamental character, but in mere pro-
portions, in the degree of mobility and in the secondary
arrangement of its parts."

The Rudimentary Organs.

Comparative anatomy, again, furnishes a lucid interpreta-
tion of the significance of those obscure structures in the
body known as the rudimentary organs. As animals be-
came subjected to different external conditions in the vary-
ing history of the earth, new organs originated from time to
time, or what was most frequent, simple structures became
more and more perfected until entirely different varieties
had been formed. These peculiarities of structure were, of
course, continually transmitted by heredity. But as the
surrounding conditions continued to change, the adjustment
or adaptation to these conditions, necessary to secure the ex-
istence and propagation of the species, would lead to the
gradual sacrifice or reduction of organs, or parts, until at
last they would be present in a body, if present at all, in at-
rophied or merely rudimentary form. Such rudiments or
traces of structures which continue to be highly developed
among lower animals, everywhere abound in the body of
man. Indeed, no system of organs in the body of man is
free from structures thus reduced by disuse, and like ex-
amples are encountered throughout the animal and vegetable
kingdom.

The wings of animals which have lost the power of flight
are examples of rudimentary organs. In the ostrich, the
emeu and cassowary, the legs have gradually become enorm-
ously developed, because flight was unnecessary on account

78 BONE RUDIMENTS.

of the absence of beasts of prey, consequently the wings
have become gradually reduced by disuse.

The atrophied lung of serpents and lizards and the aborted
ovary of birds are also examples of rudimentary organs.
The slender length of the body of the snake leaving no room
for the pair of lungs to which it is entitled, the one under-
goes atrophy and the other compensates for its loss by its
elongation. So the right ovary is aborted in birds as a
superfluous encumbrance in weight. Teeth which never cut
through to appear, as those in the embryo of the whale and
ox, eyes which do not see, as those in moles and under-
ground mice, cave beetles and crabs, etc., the hind leg bones
of whales and boas, which never develop, are additional ex-
amples of rudimentary organs.

Bone Rudiments.

When we come to the body of man, we encounter, as has
been said, rudimentary structures in every system of organs.
Perhaps the most striking example in the bony skeleton is
the coccyx, the rudimentary tail. The individual bones of
the coccyx are each but traces of whole vertebree as they
are composed of the defective central bone, without any of
the characteristic processes. Occasional monstrosities ex-
hibit the coccyx of unusual length. "It is in monstrosities,"
it has been said, "that Nature reveals her secrets." A
distinct rudimentary structure is sometimes found at
the lower extremity of the humerus. It is a small
hook-like process of bone projecting downwards towards
the inner condyle, with which it is sometimes connected
by a band of fibrous ligament. It corresponds to the
supra-condyloid foramen of feline animals, transmitting
the brachial artery and often the median nerve and
protecting them from compression during the contrac-
tion of muscles in seizing and holding prey. This rudi-

MUSCLE RUDIMENTS. 79

mentary process of bone, though present in only about one
per cent., of recent skeletons, is much more commonly met
in ancient specimens ; thus Dupont found thirty per cent.
of humeri perforated in the caves of the valley of the
Lesse, belonging to the Eeindeer period.

Muscle Rudiments.

The muscular system is peculiarly rich in rudimentary
structures. Remnants of the panniculus camosus, the great
surface muscle of the horse, are met in the platysma
myoides, the surface muscle of the neck, and in fasciculi in
the axillae and near the scapulae, as also in the superficial
muscles of the scalp so markedly developed still in some
people. The extrinsic muscles of the ear are typical rudi-
mentary structures. These muscles are highly developed
among wild animals and give the external ear its quick
motion in different directions to catch the faintest sounds.
As the animals became domesticated and the danger less-
ened, the muscles gradually atrophied. Many dogs and
rabbits, the latter the most timid of all animals, have thus
in security lost the power to "prick up" the ears, which have
become in time long and loose appendages. Though careful
dissection will reveal traces of these muscles in man, their
power is lost except in rare cases. The intrinsic muscles of
the ear have become more rudimentary still, and the ability
to move parts of the auricle upon each other is entirely lost.
The rudimentary muscles about the coccyx, the relics of the
powerful muscles of the tail in the lower animals, are
worthy of mention in concluding the examples from the
muscular system.

Rudiments from the Digestive System.

The digestive system furnishes two notable rudimentary
structures. One is the wisdom tooth. On account of the

80 RUDIMENTARY ORGANS.

softer character of the food in civilized life, less mastication
is required, consequently the length of the jaws is being re-
duced and room is scarcely afforded for all the last molar
teeth. The very last is the last to appear and the first to
fall. It has now but two fangs, whereas in ancient skeletons
it possesses three, the number normal to molar teeth. It is
the most caducous of all teeth and is slowly becoming rudi-
mentary. The absence and not the presence therefore of
the last molar tooth will have to be regarded as the sign of
"wisdom." The other example from the digestive system is
the vermiform appendix. The preparation of the food has
become such a science as to limit the period of digestion in
the body. It might, indeed, be said that the food is largely
digested by the cuisine before its ingestion into the body.
Consequently much of the capacity of the alimentary canal
has .become superfluous; The head of the large intestine,
which forms almost an additional stomach in the gramnivora,
and is three times the length of the whole body in the mar-
supial koala, is very much reduced in the carnivora, whose
food contains but little indigestible matter, and is greatly
reduced in the omnivora, as in man. The vermiform
appendix is the shriveled remnant of the great coecal recep-
taculum of the lower animals. In the orang-outang it is
still a long convoluted tube, but in man it is reduced to the
size of a quill three or four inches in length, mostly blocked
with mucus. It is often entirely absent.

Other Rudiments.

From the nervous system the most striking rudimentary
organ is the filum terminale of the spinal cord, the continu-
ation downwards of the envelops of the cord to the extremity
of the coccyx, the relic of the prolonged cord of the lower
animals.

The short hairs over the whole surface of the body and

RUDIMENTARY ORGANS. 81

tlio lanugo or wool of the foetus over the whole surface, ex-
cept the palms of the hands and soles of the feet, where it is
absent in most of the lower animals, are clearly rudiments
of the universal hairy coat of these animals. Occasionally
a 'reversion' is encountered in the birth of an Esau with a
hairy coat.

The eye and the ear each possess a rudimentary structure
of curious interest. At the nasal angle of each eye is a
small, semi-lunar fold of mucous membrane, the plica semi-
lunaris, which is clearly a rudiment of the nictitating mem-
brane, the third or inner eye-lid in mammals, birds and rep-
tiles. In these animals the nictitating membrane is fur-
nished with a muscle to secure its extension across the entire
globe of the eye, in protection of the retina from too great
light. Sufficient protection is afforded in man by the
more highly developed lashes, lids and iris, and the nictitat-
ing membrane has become reduced to an insignificant frag-
ment.

At a point about at the junction of the upper and middle
third of the helix of the external ear there may be commonly
seen a small blunt point projecting towards the antihelix.
Mr. Darwin had his attention directed to this projection by
a celebrated English sculptor, and he docs not hesitate to
interpret it as the "point of the ear" turned in, the vestige of
formerly pointed ears in the primal races of man. "In
many monkeys," he says, "which do not stand as high in the
order as baboons and some species of macacus, the upper
portion of the ear is slightly pointed and the margin is not
at all folded inwards ; but if the margin were to be thus
folded, a slight point would necessarily project inward and
probably a little outward." Whether this point be so re-
garded or not, it is pretty generally accepted that the whole
external ear, the auricle, having become an immobile shell,
hence useless, should be considered as a true rudimentary

82 EXPLANATIONS OF RUDIMENTS.

structure. When all its involutions are filled with wax so
as to make its internal aspect a plane surface, or when it is
entirely removed, as by accident or operation, the sense of
hearing is in no way impaired.

Explanations of Rudiments.

The explanations offered to account for these rudimentary
structures in man on any other theory than that of inherit-
ance from a common type and reduction by disuse, are as
irrational and ridiculous as those to account for the existence
of fossils, and serve simply to show "the embarrassment and
distress which their presence has occasioned." It was
claimed, for instance, that they were furnished to animals
having no use for them to sustain the general plan of crea-
tion, or for the sake of symmetry, "just as doctors in the
army and navy are made to wear small and useless swords
to be in keeping with the officers of the line." But the en-
dowment of the highest animals in the scale with organs
which are not only useless, but sometimes absolutely injuri-
ous (deaths have occurred from impaction of the vermiform
appendix with fruit-seeds and stones), would notseem to be
in keeping with a very high design or order of creation.
This explanation, therefore, is sufficiently ridiculous, but
another offered by an eminent physiologist reaches the very
climax of absurdity. It is claimed for these rudimentary
organs that they serve to excrete matter that is useless or
injurious to the system !

Mr. Lyell says, in his Principles of Geology, that he asked
Lamarck in the year 1867, when he was in his 84th year, by
what facts and reasonings he had been led to entertain his
views, "and he told me that he owed his convictions to the
lectures of Geoffroy St. Hilaire, to which he had listened in
the early part of this century at Paris. That great zoologist,
he said, never lost an opportunity, when he spoke of the

EXPLANATION OF RUDIMENTS. 83

rudimentary organs found in so many animals, of pointing
out their bearing on the theory of transmutation. Accord-
ing to him, they were clearly the relics of parts which had
been serviceable in some remote ancestor and had been re-
duced in size by disuse, and he rejected the idea as puerile
that useless organs had been created for the sake of
uniformity of plan." In truth, there is absolutely no scien-
tific explanation for these rudimentary structures other
than that of inheritance from a common ancestral form and
gradual suppression by disuse, because of subjection to con-
ditions, in which they are no longer of avail.

We have dwelt at length upon the most marked examples
of these strange traces, without having by any means ex-
hausted the list, because of their peculiar significance in the
interpretation of the development of life. What the germ
is to the future, is the relic to the past. Eudiments are like
the blocks of ancient temples incorporated into the modern
edifices which have taken their place. But they differ from
them in being of no use. They are fragments of the crumb-
ling columns of antiquity.

No testimony is more convincing of man s place in nature
than that so speakingly furnished by these rudimentary
structures. For, as Mr. Darwin has eloquently expressed
it, (I take the liberty to interpolate a single line), by
them we see that man with all his noble qualities, with
sympathy that feels for the most abject, with benevo-
lence which extends not only to his fellow-man, but to the
humblest living thing on earth, with an imagination that
outrivals and mocks for expression his marvelous gift of
speech, with a God-like intellect which has penetrated to the
structure and movements of the heavenly bodies— man,
with all these exalted powers — still bears indelible, in every
organ of his frame, the stamp of his lowly birth.

84 THE EVOLUTION OF FORMS OF LIFE.

LECTURE V.

THE EVOLUTION OF FOEMS OF LIFE.

CONTENTS.

The Law of Inheritability — Transmission of Acquired Defects — Homo-
chronous Transmission — Atavism — The Physics of Reproduction-
Adaptation to External Conditions — Difficulty of Classification — Arti-
ficial Selection — The Struggle for Existence — Natural Selection —
Protective Colors — Warning Colors — Sexual Selection — Complications
in Natural Selection — Preservation of the Individual and of the Race
— General Summary.

In concluding our consideration of the evolution of life
we have to-day to study the forces or laws which preserve,
perfect and diversify its forms. I desire to state, at the
start, that though I shall quote from very many authorities,
I am indebted for many of the facts which I shall present
you to-day, to the publications of Darwin, and for most of
them to the Naturliche jSchopfung , s-geschichte (History of
Creation) of Haeckel, a work so complete and comprehen-
sive, as to have elicited from Mr. Darwin the statement, in
the preface to his Descent of Man, "If this work had appeared
before my essay had been written, I should probably never
have completed it." I am led to present you this aspect of
,the subject simply to complete the evidence for evolution
with its most important proof.

The overshadowing law which insures the perpetuity
of form is that of

Inheritability.

That "like begets like" is a proverb in every language.
The law of inheritance is so universally recognized and
acknowledged as to be accepted as a matter of course. It is

THE PERPETUATION OF FORM. 85

the breach and not the observance of the law which makes
it the subject of comment. The birth of a child with webbed
or supernumerary fingers or toes calls up the history of the
remote ancestry in its explanation. The cohesion of the
family, which is the safeguard of the state and nation, rests
upon the acceptance of the principle of heredity. The law
of heredity, if we may be allowed to coin the word, secures
to the offspring not only the reproduction of the general
form of the parent, but also the exact repetition of every
physical and mental feature, characteristic of the parent.
There were families in Rome which received from the shape
of the nose or lips the titles of the nasones, labeones, buccones,
etc. Aquiline noses are still transmitted among the posterity
of the Bourbons. The Hapsburg (Austria) lip is a pecu-
liarity worthy of mention in this connection. The Prussian
kings are noted for their stature. Obesity, color, tempera-
ment, longevity, are all strictly transmitted by heredity.
Vices of conformation, deformities, diseases, are alike re-
produced in the offspring ; moles, freckles, tumors, appear
in the offspring in exactly the same spots as in the parents.
The ancestral history is carefully examined by the physician
in establishing his diagnosis of disease. Affections of the
respiratory organs, e. g., tuberculosis; of the glands, scrofula;
of the nervous system, epilepsy, are especially liable to be
propagated in the offspring. Traits of mind are transmitted
with equal fidelity. The family of Miltiades furnished
heroes, of Pericles politicians. In the family of Bach there
were no less than twenty-two musicians. For a generation
the name of Graefe was venerated in medicine in Berlin,
and in Boston generations of Warrens have been distinguished
physicians. So for generations the Eothschilds have
been renowned for a special talent in the acquisition
of wealth. The horrible cruelties of the Borgias are
counterbalanced in some degree, to the credit of Italy,

§6 TRANSMISSION OF ACQUIRED DEFECTS.

by the refinement and culture of the Florentine Medici.
It is hardly necessary to state that the law of transmission
holds with equal force throughout the animal and vegetable
kingdoms. Albinoes, i. e., animals devoid of color, have
been propagated as a separate species among rabbits and
mice, as well as among men. Paraguay is noted for a special
race of hornless oxen, bred from a bull born in 1770 without
horns. The harmless character of the animal made it the
subject of special selection in breeding, until a whole race
was thus obtained. The well-known case of the otter sheep
in our own country is a good illustration of the force of
heredity. A Massachusetts farmer discovered one day
among his flock an individual sheep "with a surprisingly
long body and short and crooked legs." It occurred to the
farmer that this development would be advantageous in
rendering leaping impossible and thus checking depreda-
tions upon a neighbor's property. He forthwith bred from
this individual with the desired result, and his neighbors
following his example, the sheep of Massachusetts soon
became noted for their staid decorum and profound respect
for others' lands.

Transmission of Acquired Defects.

Even acquired defects are sometimes transmitted. Thus
Brown-Sequard produced epilepsy in some guinea-pigs by
injuring certain parts of their brains, and this artifically-
induced epilepsy appeared spontaneously in all the offspring
of the diseased animals. Haeckel states that a race of
tailless dogs was once propagated by persistently cutting off
the tails of both sexes of the dog for several generations.
The same author narrates that a few years ago, on an estate
near Jena, a bull had his tail wrenched off by the careless
slamming of a stable door, and "all the calves begotten of
this bull were born without a tail."

ATAVISM. 87

Ilomochronous Transmission.

So strong is the force of heredity, that diseases and defects
are not only transmitted, but they are transmitted homo-
chronously, that is, to appear in the offspring at the same
age in which they were manifested in the parents. Diseases
of the lungs, liver and brain occur in the child at the same
period of life as in the parent before it.

Atavism.

But under the laws of heredity the offspring may resemble
not so much its parents as its grandparents, or ancestry
even more remote. This is the phenomenon of atavism, as
it is called. How many peculiarities or eccentricities might
we not be able to explain, if we could only sum up all the
atoms of being that have come down to us from the bodies
of our ancestors in regular line. Oliver Wendell Holmes
bases several of the best characters in his novels upon the
influence of heredity as far back as can be traced. We ob-
serve this phenomenon of atavism in the everyday history
of some of the lower animals and plants. The planarian
worms, for instance, as well as the ferns and mosses, beget
forms entirely different from themselves, and it is only in
the offspring of these different forms that the image of the
first parents is reproduced. This alternation of generation
was first remarked by the poet Chamisso, during his voyage
around the world in 1819, in the case of the salpae, small
transparent structures, which float like particles of glass on
the surface of the sea. In studying the habits and life
history of these animals, Chamisso observed that the parent
form, which has an eye of crescent or horseshoe-shape, pro-
duces offspring with cone-shaped eyes, but in the offspring of
the offspring, the grand-children, so to speak, the original
eye of horseshoe-shape reappears. Among other animals a

88 THE PHYSICS OF HEPKODUCTION.

still greater number of alternations manifests. The sea
buoys, for instance, skip over three generations, and plant
lice ten or twelve, before the original form reappears.
£'trange as this alternation of form seems at first, it is really
not more strange than the different phases of development
at different ages in the life of every animal and plant, and
it is in this light, therefore, of successive phases of develop-
ment, that we may regard these various alternative forms.
We shall have later explanation for the fact so often ob-
served in man, and even more frequently among the lower
animals, that individuals are occasionally born which repro-
duce in form and character some ancient ancestor, or a
type so remote as to have become almost extinct. Horses,
for instance, occasionally show such reversions to the zebra
or quagga in stripes across the shoulders or along the spinal
column, and puppies and heifers are sometimes born which
revert in form to types long extinct.

Thus, then, is evidenced the force of heredity. It appears
at first a great and incomprehensible mystery, "the mystery
of mysteries" once it was called. The exact reproduction
of form and feature, vice and virtue, disease and deformity
from structures — the sperm and germ cells — beyond the
power of vision with the naked eye, would seem a problem
beyond the limits of human analysis. "If the naturalist,"
said Virchow, "cared to follow the custom of historians and
metaphysicians in clothing phenomena, which are in their
way unique, with the hollow pomp of ponderous and sound-
ing words, here would be his opportunity."

The Physics of Reproduction.

But a close observation of the method of reproduction
among the lowest forms of life reveals an entirely material
process, cognizable to the human mind. That is, it is not
necessary in its comprehension to take refuge under a

THE PHYSICS OF EEPPODTJCTIOxT. 89

"miracle." The process of reproduction is a growth beyond
the natural limit of size. In the amoeba, for instance, a
simple, irregular, gelatinous, mass of protoplasm, reproduc-
tion is effected by the separation from the parent of a pro-
truded particle of protoplasm, containing atoms or molecules
of structure exactly like the main mass. The reproduction
or proliferation of cells in a more complex body is the same
process of separation, mostly by division, of part of the
protoplasm from the rest. In the highest animal, man, the
offspring, the new body, is developed from cells originally
derived from each parent. The ovum is as much a part of
the maternal, and the spermatozoids of the paternal, organ-
ism, as the eye or any other organ, and the entire body of
the child is only an aggregate of cells multiplied and
differentiated from the simple cells of the ovum and
spermatozoid. The child must resemble its parent because
it is of its parent a part. It must resemble it just as a piece
of coal detached from a mass must resemble the original
mass. "The child, strictly speaking, does not grow into the
man, but includes germs, derived from its parents, which
slowly and successively become developed and form the
man." Some of these germs, however, may have descended
from an ancestor more remote, and lain dormant in the
immediate parent, to become developed, under conditions,
inexplicable as yet, only in the child. The phenomenon of
reversion, or atavism, as it is technically called, thus ceases
to be mysterious. We are informed by those who have
made the size of molecules or ultimate atoms the subject of
special study, that the minute ovum dl0~i2o °f an ^oh
diameter), may contain as many as five thousand billions
gemmules. Mr. Sorby states that the number of mole-
cules in the germinal vesicle (granting that this con-
stituent of the ovum is the only essential structure) of the
mammalian ovum, is such that if one molecule were to be

8

90 ADAPTATION TO CONDITIONS.

lost in every second of time, the whole would not be ex-
hausted in seventeen years. Surely here are sufficient
particles, as Mr. Thompson puts it, "for all the require-
ments of the most exacting biologist." In the reproduction
of man the gemmules from both parents blend to produce
the child. The question then is not; does the child resem-
ble its parent; but which parent does it resemble most?
Said Goethe :

"Von Vater habc ich die Statur, des Lebens ernstes Fiihren;
Von Miitterchen die Frohnatur und Lust zu fabuliren."

(From my father is my stature and earnestness of mien;
From my mother is my joyousnessand love of romance keen.)

The force or law, therefore, which secures the perpetuation
of forms of life is the force or law of heredity.

We take up now the force or law which produces their
variation. This force is that of

Adaptation or Adjustment

to the surrounding conditions, as effected m slight degree,
comparatively speaking, by artificial, and in high degree,
through the inconceivable ages of the past, by natural selec«
tion.

The proofs of the evolution of forms of life, and their
variation from each other, based upon the action of artificial
and natural selection, are the most convincing of all. From
an historical standpoint, they are also the most interesting,
as having been the means of securing the adoption of the
theory of descent. If we had observed the proper chrono-
logical order in exhibiting the facts bearing upon this sub-
ject, according to the period of their disclosure, we should
have first discussed the action of artificial and natural selec-
tion. Lamarck had propounded the theory of evolution,
it is true, but his views were regarded as visionary, until

CHARLES ROBERT DARWIN. 91

proofs were advanced by a later observer, establishing it
almost beyond dispute. It is almost unnecessary to state
at this stage of general information on this subject, that the
name of this later observer is

Charles Robert Darwin.

The conclusions reached by the investigations of Mr. Darwin
mark an epoch in biology as distinct as those of Galileo in
astronomy, or of Newton in physics. Like these most dis-
tinguished men, Darwin disclosed not a single discovery or
isolated fact, but a great underlying principle, more far-
reaching, however, in its conclusions and influential in its
effects in relation to the position and prospects of mankind,
than any preceding revelation in the history of science. The
train of thought and study which led to these conclusions,
he has himself described in a letter to Haeckel, October 8,
1364, from which is the following extract : "But for some
years I could not conceive how each form became so excel-
lently adapted to its habits of life. I then began systemati-
cally to study domestic productions, and after a time saw
clearly that man's selective power was the most important
agent. I was prepared, from having studied the habits of
animals, to appreciate the struggle for existence, and my
work in geology gave me some idea of the lapse of past time.
Therefore, when I happened to read 'Malthus on Popula-
tion,' the idea of natural selection flashed upon me."

"Some few, whose lamp shone brighter have been led
From cause to cause to nature's secret head
And found that one fixed principle must be." Dryden.

Difficulty of Classification.

Darwin had hitherto always entertained the view, in com-
mon with all naturalists, that all species of animals were
separately and independently created, and were consequently

92 ARTIFICIAL SELECTION.

immutable in form. But, to say nothing of any other objec-
tion to this view, there remained always the insurmountable
difficulty and disagreement as to classification. If species
were separate and immutable, classification should have
been simple and easy. Special features should have readily
marked special varieties. The truth was, however, that no
two zoologists or botanists agreed in their divisions. We
might take as an example one of the commonest European
plants, the Hieracium. Some 300 species of this plant were
recognized in Germany, but the botanist Fries only ad-
mitted 10G, Koch but 52, and others only 20. The same
difference is met with in the case of the brambles. One
botanist claims 100 different species, another 50, and a third
groups them all into 5 or 6. In zoology there is as much
disagreement. Thus Bechstein distinguishes 3G7 species of
German birds, Keichenbach 379, Mayer and Wolff 406, while
Brehm is able to find special characteristics for no less than
900 species. From such gross disparities in classification, it
is plain to see that the specific differences assumed must
have been largely arbitrary. On the theory of adjustment
or adaptation to different surrounding conditions, the
varieties of species are easily understood. The habits of life
determine the species, and as these habits must change with
the continual changes of the external conditions, the muta-
tions of form, "the species," are limitless.

Artificial Selection.

It was the radical changes that man was able to effect in
the domesticated animals and plants which gave Mr. Darwin
the clue through the labyrinth of the different species. It
might be said that we make new species ourselves every day
in the cultivation, i. e. domestication, of wild animals and
plants. We cripple the wings of ducks and fowls, and re-
duce to rudiments the car muscles of rabbits and dogs, by

ARTIFICIAL SELECTION. 93

simply removing them to places of security. Captivity
nearly entirely arrests reproduction in elephants, bears and
monkeys, or changes its whole character. The common ring
snake, for instance, lays eggs which are not hatched out for
three weeks, but if the snake be confined in a cage it does
not lay eggs at all, but retains them in the body until
development is complete. The very radical change from an
oviparous to a viviparous animal is thus artificially produced.
A gardner can produce any colored flower almost at will,
alter the leaf or stem, dwarf or develop any peculiarity, by
changing the external conditions.

Perhaps the pigeon-breeders make the most abundant
and most striking experiments in the modification of form.
The art of piegon-breeding is said to be very ancient. The
Egyptians engaged in it 3000 years before Christ, and the
Romans m the days of the Emperors had already commenced
to record the pedigree of certain species, as the Arabs that
of their horses, or aristocrats among men that of themselves.
The court of Abder Khan in Asia, possessed in the year
1600 more than 20,000 pigeons. Inter-breeding and cross-
breeding, subjection to different kinds of food, to different
climates, to the multitudious differences embraced under
the general term surrounding conditions, have, in the course
of centuries, produced more than 150 varieties of pigeons,
each one of which is so distinct from the other as to have
been regarded as a separate species. Among the most
marked varieties or species, we may mention the fan-tailed
pigeon, in which the number of tail feathers has been
increased from ten or twelve, to thirty or forty, the pouter
which is endowed with an enormous crop distensible with
air, pigeons with periwigs, or with peculiar, often grotesque
transformations of the beak and feet, pigeons with singular
habits, as carriers, or, most remarkable of all, as tumblers.

The alterations thus artificially effected may extend

94 THE STRUGGLE FOR EXISTENCE.

even to the skeleton, so that the shape or number of
its most essential bones may be modified in a high degree.
Thus John Sebright, a celebrated London pigeon fancier,
absolutely maintained that he could produce in pigeons
any variety of external form in one year, and any change
in the bones in five years. And yet all these varieties, thus
artificially or naturally produced, are now known to be
descended from the primary wild blue rock pigeon. Chickens
have been produced by artificial selection with beaks so
short as to be incapable of fracturing and escaping from
the shell.

The same deviations of form have been noticed in all the
domesticated animals. The numerous varieties or species
of rabbits are all derived from the common gray rabbit,
the various species of horse from the zebra or quagga ; in
short, all domesticated animals, and plants may be now
readily traced back to primitive types, to which they
naturally revert again, if allowed to run or grow wild.
. Having observed thus the radical changes of form which
man is able to produce, Mr. Darwin undertook to discover
some force or cause in nature which might effect the same
changes. Here it was that the thought ''flashed" upon him,
after a perusal of Malthus' work, of the

Struggle for Existence

entailed by numbers, and the survival of the individual or
individuals most favored in some peculiarity, best adapted
to the surrounding conditions.

The explanation of the varieties in the forms of life,
by means of natural causes, hinges upon the really appall-
ing numbers of each species produced. Linnaeus calculated
that if an annual plant produced only two seeds (and there
is not one which produces so few) it would yield in twenty
years a million of individuals. Darwin has shown us of

THE STRUGGLE FOR EXISTENCE. 95

elephants, which are the slowest of all animals to increase,
that in 750 years, the descendants of a single pair would
amount to nineteen millions of individuals, that is, suppos-
ing that every elephant, during its period of fertility (from
the 80th to the 90th year), produced only three pairs of
young, and survived itself to its hundredth year. If we go
down much lower in the scale of animal life, go down to
the microscopic infusoria, we find there numbers which
absolutely daze us with their magnitude. Thus, Davaine
has calculated that a single bacterium particle would, in
the course of twenty-four hours, become the parent of 409G
such particles, in forty-eight hours, to over 16,700 such
particles, and between the sixtieth and sixty-second hours,
their numbers attain to one to seventy-one trillions. The
swiftness of manifestation and virulence of expression of
the contagious diseases, supposed to depend upon the
presence of such particles in the blood, corresponds thus to
the marvelous fecundity of the parent germs. If each spore
of one species only of the higher fungi germinated and
reproduced its parent, the children would, in the first
generation, and in the course of a very few days, form a
carpet all over the earth. The increase in the number of
human beings — without any hinderance — would double
the total every twenty-five years. In every century the whole
number wTould increase sixteen fold. "The population of
the United States alone would require, unchecked, but 650
years to cover the whole terraqueous globe so thickly, that
four men would have to stand on each square yard of
surface."

But even this number of births conveys only a faint idea
of the numbers of ova, which never develop at all. Every
joint of the tape- worm, for instance, contains thousands of
eggs, which, fortunately for mankind, fail to find conditions
for development. The number of ova in the human being

96 NATTJKAL SELECTION".

is no less marvelous. The recent investigations of Sappey,
respecting the number of ova developed and undeveloped
in the human female, show that they exist, at the period of
full adolescence, to the number of nearly seven hundred
thousand. Even the more temperate estimate of Henle
puts the original number of ova at not less than 36,000 for
each ovary.

Millions, billions, trillions of living eggs are lost in
animal life ; here and there one is born : and of the millions
born, here and there one survives. Among the survivors,
competition begins at once for the limited means of sub-
sistence. "Every organism struggles from the commence-
ment of its life with a host of enemies. It struggles against
animals which feed on it, for which it is the natural food ;
it struggles against animals of prey and parasites, it struggles
against all kinds of inorganic influences, against heat and
cold, against the weather, and above all, and most bitterly
of all, against organisms most like itself." Whichever
individual among animals and plants has some advantage,
will be the individual to live, thrive, and propagate its kind.
This constitutes what is known as

Natural Selection.

Here comes, for instance, a summer of unusual drought.
Thousands of plants perish for want of water ; a few happen
to have hairy leaves. The hairs on the leaves are hygrcn
scopic. They furnish a larger surface for the absorption of
water, so the hairy plants survive the drought, and propa-
gate their kind. Next summer, most of the plants have
hairy leaves. Island insects are wingless, or have wings re-
duced to almost rudimentary state, while the same species
on continents have fully developed wings. Wings are a
great disadvantage to island insects, because, in soaring
aloft, they are swept out to sea and drown. The insects

NATURAL SELECTION. 97

having the wings least developed are, on islands, the favored
of nature to survive and propagate their kind. Natural
causes thus easily explain the perfect adaptation of struc-
ture to conditions without resort to supernatural design*

Protective Colors.

Another example of natural selection is the coloring of
the various animals. Some of these colors are distinctly
protective. These animals resemble in hue surrounding
inanimate objects. Arctic animals, bears, etc., are white
like the ice and snow. In summer, when the snow vanishes,
they too change color to resemble the gray or black earth.
Desert animals, foxes, gazelles, lions, are sandy or fawn-
colored. The birds and insects of the tropical forests are
green ; butterflies are variegated like the flowers ; fishes,
molluscs, etc., are colorless, or are scarcely distinguished in
the sea. Through the crystalline bodies of many fishes and
pelagic animals, the words on a printed page may be dis-
tinctly read. Eeptiles are spotted and striped and scaled
like the bark of trees, or reeds, or leafy soil upon which they
crawl. These colors conceal the animals from their foes, or
enable them to creep unobserved upon their prey, and the
individual whose color most nearly resembles his surround-
ings is the favored of nature to survive and propagate his
kind.

Warning Colors.

r

Other colors, Mr. Wallace has shown us, are warning
signals. Certain butterflies and frogs are large and vividly
colored. They fly slowly. It is to their advantage to be
seen, because they are unfit for food, their juices having a
disgusting odor and taste to birds and beasts of prey. Bees
and wasps, stinging animals, are often thus distinctly colored
to their safety. Mr. Belt tells us that in Nicaragua, there is a

98 SEXUAL SELECTION".

frog which is very abundant, which hops about in the day
time, which never hides himself, and which is gorgeously
colored with red and blue. Frogs are usually green, brown,
or earth-colored, feed mostly at night, and are all eaten by
snakes and birds. Mr. Belt was convinced, therefore, that
this colored frog was uneatable. He took one home and
threw it to his ducks and fowls; "but all refused to touch
it, except one young duck, which took the frog into its
mouth, but dropped it directly, and went about jerking its
head as if trying to get rid of something nasty."

Sexual Selection.

Natural selection again comes into play in the difference
that exists between the two sexes of all animals. In nearly
all cases, the male animal is the larger and more beautiful.
It has weapons of offense, tusks, spurs, antlers, teeth, etc. ;
and of defense, manes to protect the vessels of the neck,
skin coverings, etc., in its combats with rivals to secure
possession of the female. Locked skeletons of stags are
sometimes found in the depth of forests, so many monu-
ments of such battle-fields. The choice of the female falls
upon "the most vigorous, defiant, and mettlesome male,"
and these peculiarities are transmitted to the offspring, or
she selects the male endowed with the richest ornaments in
plumage, or hue, or is attracted to the most melodious
voice, or sound, as in the case of singing birds, crickets,
locusts, etc. Prof. Weismann has recently shown that fresh
water fleas are brilliantly colored with patches of scarlet
and blue as charms for the opposite sex, and that the masks
with staring eyes upon the feeble caterpillar's back are
"startling" or "terrifying" colors (schreclcfarben) "that he
may enjoy the privileges so usually gained by the ass in the
lion's skin." The choice in pairing resulting from the ex-
hibition of these attractions, offered by the courting sex,

SEXUAL SELECTION. 99

constitutes what is technically styled sexual selection. "We
have no time to fully consider the multiform manifesta-
tions of sexual selection. You may recall, perhaps, the
curious example mentioned by Tom Moore, in his "Loves
of the Angels" :

"For well I know the luster shed
From cherub wings when proudliest spread,
"Was in its nature lambent, pure
And innocent, as is the light
The glow-worm hangs out to allure
Her mate to her queen bower at night."

The rattle of the rattlesnake is also such a call, and not a
means of "striking terror," and thus causing its natural
food to escape. "What an idiotic idea, this last, that an
animal should chase away its own food !

It need scarcely be said that all these actions of natural
and sexual selections are just as marked in man as in the
lower animals. The male captured the female, vi et armis,
in the middle ages, just as now in savage life. The strongest
won. Nearly all the more modern duels concern the posses-
sion of an individual among the fair sex. Charm of face
and form, of voice and dress, are just as potent in man as
in the lower animals. The top-knots and hirsute append-
ages of the monkey find their analogues in the tonsorial
decorations of man. The female bower-bird is no less
attracted by the decorations in the way of shells and
feathers and colored stones, with which the male bestrews
his nest, than is the female of man by a solid bank account,
and a three-story front. But there are, in continual opera-
tion among the sexes, other higher influences than mere
personal attractions, superiorities of mind and character,
the conjunctions of which secure to the human race a ten-
dency towards gradual perfection.

100 COMPLICATIONS IN NATURAL SELECTION.

Complications in Natural Selection.

The laws of natural selection do not always work, how-
ever, in such plain and simple channels. The most compli-
cated conditions and relations sometimes manifest, render-
ing the tracing of the action of natural selection exceedingly
difficult.

Thus, there are small coral islands, whose inhabitants live
almost entirely upon the fruit of a species of palm. The
fructification of this palm is exclusively effected by insects,
which, in feeding upon the flower, bring the pollen
grains into contact with the ova. The existence of these
useful insects is endangered by insect-eating birds, which
are, in turn, pursued by birds of prey. The birds of prey,
however, often succumb to the attack of a small parasitical
mite, which develops in millons in their feathers. This
small dangerous parasite again may be killed by parasitical
moulds. So moulds, birds of prey and insects, favor the
prosperity of the palm, and consequently of man; while
the parasite, insect-eating birds, etc., put them both in
danger of extermination. I cite another case almost literally
as given by Haeckel. Paraguay is noted for the fact that
it contains no wild cattle of any kind. All the countries
around Paraguay abound in wild cattle, but there are none
in this country but the domesticated cattle. This is due to
the fact that there is an insect in Paraguay which lays its
eggs in the umbilical cord of the young animals, and finally
destroys the animal altogether, If some animal should arise
which should prey upon this insect, wild cattle would be
again seen on the plains of Paraguay. As these animals
would consume some of the fauna and flora of the country,
it is easy to see how its botany might be entirely changed,
and in the course of this change, the human population
would have to alter.

COMPLICATIONS IX NATURAL SELECTION. 101

Mr. Darwin's graphic description of the relation between
cats and red clover is always quoted in this connection.

The red clover of England, which forms the very Lest
fodder for cattle, requires the visit of humming "bees to ob-
tain the formation of seeds. These insects, while sucking
the honey from the bottom of the flower, bring the pollen
in contact with the stigma, and thus cause the fructification
of the flower, which never takes place without it. Red
clover which is not visited by humming bees, does not yield
a single seed. Now the number of bees is determined by
the number of their enemies, the most destructive of which
are the field mice. The more the field mice predominate,
the less the clover is fructified. The number of field mice
again depends upon the number of their, enemies, which
here, as everywhere, are chiefly cats. Hence, in the number
of villages and towns wThere many cats are kept there are
plenty of bees and plenty of red clover.

Now, as the cattle which feed on the red clover furnish
the best roast beef in the world, and as it has been conclu-
sively established that superiority of food determines, in
great degree, superiority of body and mind, and hence
superiority among nations, it is an easy inference to ascribe
this superiority, with Carl Yogt, to the influence of the cats
which kill the mice, which kill the bees, etc. ; much in the
order of the house that Jack built. Mr. Huxley, indeed, is
unwilling to stop here, as he traces back the chain of causes
to those who cherish cats, the elderly unmarried ladies, to
whom due homage should be paid for having secured the
wealth and prosperity of the great English nation.

A striking example of a radical change effected in plant
life by a complicated natural selection is related by Francis
Darwin, in his account of the analogies between animals
and plants. The bright colors and sweet smells of flowers
are, as is now well known, only allurements held out to in-

102 PRESERVATION OF INDIVIDUAL AND OE RACE.

sects to entice them to carry the fertilising pollen from one
flower to another. But there is a wild cabhage-like plant in
Kerguelen's land, which alone of the enormous order of the
Cruciferse, is fertilised by the wind. The change in the life
history of this plant, which makes it such an exception, de-
pends upon the fact that the insects in Kerguelen's land are
wingless, and are therefore bad distributors of pollen. The
insects are wingless, because the winged insects have been
blown out to sea and drowned. "Thus the pollen of the
cabbage has to learn to fly, because the insects will not fly
for it."

I quote one further simpler instance of the action of
natural selection, because it contains in itself alone the ex-
planation of the action of natural selection in its widest sense.

Some sailors once let loose upon an isolated uninhabited
island in the Pacific Ocean a couple (male and female) of pigs.
They had, an excess of these animals on board, and they
turned them out to breed, perchance, for future ship-
wrecked mariners. The pigs found upon the island an
abundance of food, and no enemies. They bred with char-
acteristic fecundity, until the island fairly swarmed with
pigs. Subsequently, other sailors put upon the island a
couple of dogs. The pigs became the food for the dogs.
The dogs multiplied, and the pigs decreased. Finally all
the pigs were destroyed, and then, of course, starvation
killed the dogs. But during the long periods of super-
abundance, abundance, and want of food, various modifica-.
tions ensued in the forms of both animals, making at
different times, species very different from those first intro-
duced.

Preservation of the Individual and of the Race.

Here operated upon this isolated island in the Pacific
Ocean the two great causes, everywhere at work, one of

GENERAL SUMMARY. 103

which insures the perpetuity of form, at least for a long
time, while' the other insures its mutation. Of these two
great causes, one is the instinct which secures the preserva-
tion of the species, viz., that of reproduction and the other
is the instinct which secures the preservation of the indi-
vidual, viz., hunger.
So said Schiller long ago :

Einstweilen bis den Bau der Welt;
Philosophic zusammenha.lt,
Erhalt sich ihr Getriebe,
Durch Hunger und durch Liebe.

Which I have ventured to translate very liberally :

"Until the earth is all explained,
Without call on power above,
Its working's still will be sustained
By Hunger and by Love."

I present you, thus, in this series of lectures, the barest out-
lines of the state of existing knowledge concerning the
origin and evolution of life, as explained by natural causes.
We have considered the subject from the standpoints of
palaeontology, comparative anatomy, and natural selection
only. Of these fields, wTe have had time to take only
bird's-eye views. The proofs offered by philology, the study
of languages, and chorography, the geographical distribution
of animals, are no less clear and convincing. But these
studies are entirely out of our special province. I refer you
to the now familiar works of Mr. Darwin, of Mr. Wallace —
whose discoveries really forced upon Mr. Darwin the publi-
cation of his own views, prematurely, as he then believed —
of Haeckel, Schleicher, Geiger, Steinthal, and the recent
epitome by Oscar Schmidt, for a full and complete state-
ment of all the evidence. Evidence which may now be
likened to an arch, composed of many pieces, with palaeon-

104 ' GENERAL SUMMARY.

tology and comparative anatomy as foundation stones at
either end, and natural selection as the key-stone in its
center.

I do not know how I may better close this part of our
subject, now, than by repeating, with very slight modifica-
tion, the recapitulation of Mr. Darwin at the close of his
first and greatest work, the "Origin of Species." It is to
his genius that we owe the whole elaboration and proof of
the "Theory of Descent," as first advanced by Lamarck in
1809, as it is to his marvelous collection of facts, his clear-
ness of statement, and his candor, that is due its general
adoption in every field of science to-day :

It is interesting to contemplate a tangled bank, clothed
with many plants of many kinds, with birds singing in the
bushes, insects flitting among the flowers, and worms crawl-
ing upon the bosom of the great mother earth. It is inter-
esting to contemplate all these things, and to reflect that
these elaborately constructed forms, so different from each
other, yet so dependent upon each other, have all been pro-
duced by laws continually acting around us. The laws of
growth and reproduction ; a ratio of increase so high as to
lead to a struggle for life, as a consequence to natural selec-
tion, and the slow but certain improvement of forms. Thus,
from the war of nature, from famine, and from death, the
most exalted object which we are capable of conceiving,
namely, the production of the higher animals, directly and
inevitably follows. There is a grandeur in this view of life,
with its several powers, having been originally breathed
by the Creator into a few forms, or into one ; and in that,
whilst this planet has gone cycling on, according to a fixed
lav/ of gravity — from so simple a beginning — endless forms,
most beautiful, most varied, and most wonderful, have
been, and are being evolved.

Fig. 9.— The

Amoeba.

(p. 114)

Fig. 10. — The Ovnm,
a typical cell, a, cell Fig. ii.-Seg- Fig. I2.-Furth- sSgeSk)n " c?S

wall. 4, cell contents mentation of er process of seg- segmentation. «, ecu
or protoplasm, c, nu- the cell, a, cell mentation, a, cell wall. b, subdivided
cleus and nucleolus, wall, b, subdi- wall, b, subdivid- ceils,
(pp. 109-113) vided cell ed cells, the low-

showing divi- est of which

sion of nucle- shows a subdi-

olus. (p. 144) vided nucleus.

Fig. 14. — Section of skin of chameleon
showing pigment cellsm retracted (active)
state, (p. 117)

Fig1. 15.— The same showing pigment
cells in protruded (relaxed) state, (p. 117)

Fig. 16. — Penetration of ovum (without
wall) by the spermatozoid. a, spermatozoid.
b, enveloping mucus. £, yolk or protoplasm,
(p. 124)

Fig. 17. — The same. Further process of
penetration, a, spermatozoid. £} space in
mucus left by retreating yolk. cy mucus.
d, yolk. (p. 124)

Fig. 18. — The impregnated
ovum, a, zonapellucida (wall).
b, sperm nucleus, c, nucleus
of the ovum. (p. 125)

Fig. 19.— The impregnated Fig. 20.— The ovum at full
ovum, a, the nucleus result- maturity, c, the micropcle. by
ing from the fusion of the the zona pellucida (wall) show-
sperm and germ nucleus. 6, ing the pore canals (striae). £,
the cell wall. (p. 125) the seminal cord. </, the germ-

inal vesicle (nucleus of the
ovum), (p. 125)

THE CELL AND ITS REPRODUCTION.

PROTOPLASM AND ITS PROPERTIES. 105

LECTURE VI.
PROTOPLASM AND ITS PROPERTIES.

CONTENTS.

The History of Histology — The Invention and Use of the Microscope
. — The Discovery and Doctrine of The Cell — Derivation and Im-
port of The Cell— The Cell Wall— The Nucleus and Nucleolus— The
Cell Contents or Protoplasm — The Amceba — The Properties of Proto-
plasm— Motion — The Color Changes of the Chameleon — Ciliary Mo-
tion— Motion of Other Cells — Molecular Motion — Molecular Changes
in the Ovum — Parthenogenesis — Motion as the Essence of Repro-
duction

We have already seen that different machinery or appa-
ratus is required to effect the various changes of matter aud
force. We convert chemical force or affinity into galvanism
in galvanic cups, magnetism into electricity with iron bars
and wires, heat into motion with boilers, cylinders and
pistons, etc. That physical may be converted into physi-
ological force there is requisite animal or vegetable matter.
In our day, we name this matter or apparatus protoplasm.
In complicated arrangement we say the protoplasm consti-
tutes an organism. In the study of physiology we are
engaged with the construction of the organism (instrument)
which sets the force free, with the mode of action by which
it is changed to other forms, and with the various forms
under which it reappears.

As there can be no force without matter, there can be no
knowledge of action without knowledge of construction.

Our knowledge of the

Construction of the Body
from an historical standpoint naturally falls under two

106 INTENTION AND USE OF THE MICROSCOPE.

divisions, that acquired before the discovery of the micro-
scope and that acquired since.

The older anatomists and physiologists made us acquainted
with everything that could be seen with the naked eye.
They described the position and relations of all the organs
of the body, defined what we now consider the grosser
characteristics of the various tissues and established their
general properties. The older anatomists and physiologists
drew what we might call the general outlines of all the
structures of the body, and with a fidelity which is the
highest tribute to their diligence and skill. We read with
astonishment the accurate descriptions of Vesalius and
Fallopius, of Soemmering and Bichat, and with admiration
the ingenious experiments of Harvey and De Graaf. But
the older anatomists and physiologists could not penetrate
to the minute construction of the tissues. Histology in tlje
true sense of the term, was a sealed and unopened volume.
It was only with the invention of the microscope, more
especially with its perfection, that such studies became
possible.

The Invention and Use of the Microscope.

The honor of this invention is claimed by the French,
the Italians and the Dutch. The truth is, however, that
lenses were in use, as such, in ancient times. Aristophanes
informs us that globules of glass, known as "burning spheres,"
were sold by the grocers of Athens. It is hardly possible to
imagine that the magnifying power of these spheres could
have escaped observation ; indeed, we read in Seneca among
the "Natural Questions" the following statement in proof.
"However small and obscure the writing may be, it appears
larger and clearer when viewed through a globule of glass
filled with water." So-callecl "water microscopes," consisting
simply of a drop of water attached to the end of a bras3

INVENTION AND USE OF THE MICROSCOPE. 107

wire, were still in common use at the beginning of the 17th
century. We have evidence of the ancient use of lenses
for magnification in the engraving of characters and letters
too small to be visible to the naked eye. We would
be hardly prepared to admit that vision was keener centuries
ago than now, so that we must believe the eye to have been
aided with the lens. Thus Cicero speaks of an Iliad of
Homer small enough to have been enclosed in a nutshell,
and Pliny mentions that Myrmecides "executed in ivory a
square figure which a fly covered with its wings." In fact,
veritable lenses have been exhumed from Nineveh and
Herculaneum.

The microscope, thus, like every other invention, was in
no sense a sudden discovery. It reached from time to time
a process of development, to then fall into oblivion for
years, or for centuries, and be again revived with improve-
ments to give it new impulse in its gradual evolution.

The first individual to give the microscope permanent
place among the acquisitions to the study of nature was
Zacharias Janssens, a celebrated optician in Holland
(1590). As every discovery in every field of science sooner or
later comes to be utilised in the study of medicine, it is not
surprising to learn that scarcely 25 years had elapsed before
Italian and Dutch anatomists (Malpighi and Leeuwenhoek,
1G28-1723), were busy with the microscope in the study of
the human body. Though the instruments then in use
were exceedingly clumsy and defective, it was with their
aid that the most remarkable phenomena in nature were dis-
closed. The last link in the chain of evidence establishing
the circulation of the blood was only completed with the
discovery of the blood corpuscles and capillary net work by
Malpighi ; whose name is still transmitted with histological
elements in the kidneys and spleen ; and the essential
element of the semen — to select only the most striking ex-

108 DISCOVERY AND DOCTRINE OF THE CELL.

amples — the spermatozoids were first described by Leeuwen-
hoek, to whom they had been shown by one of his students,
Von Hamm, in 1677.

But the revelations of the microscope, at this period in its
history, were, as Frey remarks, "more in keeping with the
curiosity loving spirit of the times, than with any definite
principle or basis of. investigation." Penetration to funda-
mental structure was still impossible, until the study of
histology had received fresh impetus in steps towards the
perfection of the microscope, taken first by Dutch and
German opticians, Van Deyl and Fraunhofer, in the first
decade of the present century. The simple lense3 of
Malpighi and Leeuwenhoek were now speedily duplicated
many times, combinations of different lenses, of different
kinds of glasS) were soon arranged to obviate aberrations of
sphericity and chromatism, and "the clumsy and deceptive
implement of the last century was transformed into the
elegant and accurate instrument of the present day."

The Discovery and Doctrine of The Cell.

Now, then, for the first time, was rendered possible a pene-
tration to the minute construction of the various tissues.
A host of observers were soon engaged in histological study,
Miiller, Purkinje, Wagner, Valentin, Henle, among the
pioneers, and one distinguished above all the rest, "not only
on account of his own researches, but also on account of his
collocation and arrangement of the discoveries of others,
and his deductions thence of general laws, which are to be
regarded as the foundations of modern histology" (Tizzoni).
The "cell doctrine," as established by C. Th. Schwann
(1838), marks the first great epoch in the modern science of
histology.

According to this doctrine, as subsequently elaborated
more especially by lleichert, Kolliker and Virchow, every

SHAPE AND SIZE OE CELLS- 109

tissue and organ of every, living thing, plant or animal, is
built up of an aggregate of cells, or the products of cells.
An organ, the whole organism, is an union of cells, just as a
state or association is an assemblage of individuals. "The
greatest discovery of the microscope is not, as might at first
appear, the revelation of a new world of microscopic life ;
it is the discovery of the simple, elementary structure of the
human body, and of every organised body in nature ; it is
the astonishing discovery that every living thing, from man
to the invisible insect, from the oak to the infusoria, how-
ever different their apparent natures, are constructed upon
one plan, from one and the same elementary form" (Banke).

Shape and Size of Cells.

^ A typical cell is a spheroidal body, consisting of an
envelop (or cell wall), of so-called cell contents (protoplasm,
bioplasm, cytoplasm, sarcode, etc.), including a smaller
eccentrically situated spheroidal mass, the nucleus, which
in turn includes one or more still smaller particles, nucleoli. v

Such a cell is the ovum, or primordial cell, from which
every organised body develops. The various parts of the
ovum have, however, been dignified with special names.
Thus the translucent wall is the zona pellucida, the contents
form the yolk, the nucleus is called the germinal vesicle, and
the nucleolus is the germinal spot. The ovum differs from
all other cells in the body of man in being visible to the
naked eye. It is the largest cell in the body, measuring

* tto °£ an inck (0.21 mm.) in diameter. Hence, in describ-
ing the size of cells, the ovum is put at one extreme, while
at the other is placed the red blood corpuscle, with a

^ diameter of -gJ^ of an inch (0.0077 mm). Cells vary in
size between these extremes. There is full as great variety
in shape. Fat cells are rounded, liver cells polygonal,
epithelial cells fiat or cylindrical, muscle cells fusiform, con-

110 IMPORT OF THE CELL.

nective tissue cells filiform, while bone cells, with their
radiating canaliculi, and nerve cells, with their numerous
poles and bright nuclei, present very peculiar, stellate or
even fantastic shapes.

The whole body is thus reduced to cells of definite size
and shape. * We obtain, thus, the ultimate elements of organ-
isation, v '"'The cell theory in physiology corresponds to the
atom theory in physics, but cells have the advantage over
atoms, of being visible and available" (Kiiss).

The question now arises which of the constituents of the
cell, the wall, the contents, the nucleus, or the nucleolus, is
the most essential element ?

Derivation and Import of the Term.

It should be remarked first that the term "cell" has now
a very different significance from its first use. The dis-'
covery of Schwann in histology was really based upon the
discovery of Schleiden in botany, that sections of young
plants under the microscope presented the appearance of
the cells of the honeycomb. Schwann observed that
epithelial cells present the same appearance, hence, the title
of his work, the Uebereinstimmung , etc., the similarity or
Identity in construction of animals and plants, and hence,
the term cells. The first intimation of the cellular struc-
ture of animal tissue was that of Johannes Miiller, who
showed that the chorda dorsalis of the fish consists of closely
apposed cells with peculiar walls. Miiller also first distin-
guished nuclei in the analogous cells of the chorda dorsalis
of the frog. Besides the interest which attaches to this
structure as the primitive vertebral column, the chorda
dorsalis has also the additional historical interest of having
been the tissue in which "the cell" was discovered.

If the tail of a dead tad-pole, after having been for 24
hours in water, be cut through at its point of origin and the

THE CELL WALL. HI

chorda dorsalis expressed by gentle pressure from the head
downwards, suitable particles of it may be examined under
the microscope (best with a 6 per cent, solution of common
salt). The cells appear of irregular polygonal form, those
from the middle of the chord larger, those from the
periphery smaller (Gescheidlen). We have now the picture
first seen by Schwann. The likeness to the cells of the
honeycomb or to vegetable cells is exact. Tt was a subse-
quent elaboration of this disclosure at the hands of a num-
ber of observers, the discovery that all the organs and
tissues are constructed upon the same plan, so that the cell
in modern histology means more than mere form or shape ;
it means the ground plan, the origin and individuality, the
ultimate anatomical element, the chemical laboratory, and
the physical and" physiological centre in which all the
phenomena of life are evolved. *"

The Cell Wall

As to the relative importance of the various constituents
of the cell, it is known (Bergmann, Bischoff, Kolliker) that
the embryonal stage of certain animals exhibits cells com-
posed of nucleated contents entirely deprived of a wrall.
Moreover there are animals, whose whole life is comprised
within the narrow circle of a single cell, consisting simply
of a homogeneous mass of contractile substance, without
either nucleus or wall. Again, there are forms of life, con-
sisting of multiple cells or aggregations of matter, sponges,
radiolarice, etc., devoid of wall and nucleus. So Max
Schultze and Lionel Beale regard the wall as an addition,
rather than as a necessary constituent of the cell. Accord-
ing to Schultze, the subsequent formation of the cell wall
indicates a limitation in the life of the cell, i. e., it is a sign
of decrepitude, while Beale regards the wall as a product
of the cell, the formed material, in distinction to the form-

112 THE NUCLEUS AND NUCLEOLUS.

ing, or germinal matter, the protoplasm. Kolliker looks
upon the cell wall as the sign rather of full development
and maturity. The cell wall, more dense and firm than the
.remaining constituents, is the protecting envelop of the
more delicate structure within, and at the same time regu-
lates diffusion between its contents and circumambient
media.

Diffusion is effected through the cell wall, when homo-
geneous in structure, by simple absorption or osmosis, but is
more directly effected in some cases through minute canals,
which may be seen in transparent cells as fine rines or
striae traversing its entire thickness. Thus Virchow men-
tions having seen fat globules penetrating from the intes-
tinal canal through the wall of the cells which cover the
lacteals, and Lowe describes in detail the penetration by the
spermatozoid of the zona pellucida (wall) of the ovum
through one large opening, the micropyle, or through one
of the numerous finer canals in the rest of the wall.

The Nucleus and Nucleolus.

The nucleus is the smaller, separated body, of various
size and shape, usually somewhat eccentrically situated in
the protoplasm which composes the body of the cell. It
may be recognised, as a rule, by its comparative opacity, and
is made more visible under the microscope by the addition
of various chemical reagents, dilute acids, etc.

The essential value of the nucleus, according to Kolliker,
who takes a middle ground between the older advocates of
the cell with all its parts, and the more modern advocates of
the protoplasm theory, is "to secure to the protoplasm a
definite form and function, and more especially to officiate
as its proper organ of reproduction." The ovum, or
primordial cell loses its nucleus, as one of the first signs of
development, while the new nucleus, developed later in the

THE CELL CONTENTS OR PROTOPLASM. 113

egg, is an entirely new formation. As to the spermatozoid,
it is wholly and exclusively composed of the nucleus of a
cell, the remaining constituents of which have been left be-
hind it in the seminal ducts.

The nucleolus is the still more minute body disposed to-
wards the nucleus and acting for it the same part as the
nucleus towards the entire cell. Both of these bodies are
to be regarded as masses of protoplasm differentiated from
the main mass or developing within the main mass as the
youngest or latest additions of matter. When staining
matters, carmine, aniline, etc.,. are brought into contact
with the entire cell, the newest matter is deepest stained.
The cell wall and the protoplasm just about it are not stained
at all.

The Cell Contents or Protoplasm.

If, then, the cell wall be relegated chiefly to a protective
office, and the nucleus (with its contents) to the function
chiefly of reproduction, it is in the cell contents, the proto-
plasm, that we must locate the remaining essential pro-
cesses in the life of the cell. The lowest forms of life con-
sist of protoplasm alone, protoplasm in shapeless mass,
without nucleus or wall. Such are the vast masses of
gelatinous matter (deep sea ooze) endowed with motion,
assimilation, reproduction, etc., which have been dredged
(Huxley, Thompson, 1868) from the bottom of the North
Atlantic Ocean, at depths varying from 5,000 to 25,000
feet. Much doubt has been cast upon the nature of this so-
called Bathybius ( Urschleim), by the fact that deep ooze
has been dredged from other seas not endowed with these
phenomena, but the later observations of Bessels (1873)
confirm the existence, at the bottom of certain seas, of
masses of pure protoplasm, "very sticky, mesh-like struc-
tures, with perfect amoeboid movements," which "took up

10

114 THE AMCE3A.

particles of carmine and other foreign substances" and
which "showed active motion of the nuclei."

The Amoeba.

Of the isolated masses of protoplasm, the best known ex-
ample is the amoeba. Towards the close of the last century,
O. F. Muller gave the name of Proteus to certain forms of
infusoria observed to be in ceaseless motion, and M. Borg
de St. Vincent called one of these forms (the proteus
diffluens), "Amiba" a name subsequently changed by
Ehrenberg, to harmonise it with his etymology, to Amoeba"
(Milne Edwards). Amoebae are masses of protoplasm which,
as a rule, have nuclei but no walls, but since Max Schultze
discovered in the Adriatic sea a non-nucleated amoeba (the
amoeba porrecta) this low form of life has been selected from
among all the rest as a basis for physiological study.

The physiologist has here, and in similar structures, a case
"in which those vital operations which he is elsewhere
accustomed to see carried on by an elaborate apparatus, are
performed without any special instruments whatever ; a
little particle of apparently homogeneous jelly changing
itself into a greater variety of forms than the fabled Proteus,
laying hold of its food without members, swallowing it with-
out a mouth, digesting it without a stomach, appropriating
its nutritious material without absorbent vessels or a circu-
lating system, moving from place to place without muscles,
feeling (if it has any power to do so) without norves, propa-
gating itself without genital apparatus. And not only this,
but in many instances forming shelly coverings of a sym-
metry and complexity not surpassed by those of any
testaceous animals" (Carpenter).

The best examples of protoplasm devoid of walls or nucleus
are the so-called myxomycetes, fungi found in abundance
on decomposing vegetable matter, moist flower pots, bark

THE PROPERTIES OF PROTOPLASM. 115

of trees after a rain, etc. The best examples of protoplasm
with wall but without nucleus are the hyphens, fungi found
on fruits, bread, etc., kept in a warm wet place. The largest
specimens are obtained from the surface of manure spread
on bricks and kept in moist places. Amoebae are the best
examples of protoplasm with nuclei but without walls.
These animalcules are found in myriads in stagnant wTater
exposed to a hot sun. Some forms of amoebae are, as we
have seen, also devoid of nuclei. The mammalian ovum
exhibits the typical isolated cell with all its parts, nucleus,
contents and wall. It may be readily expressed from the
ovary after puncture of the Graafian follicle.

The protoplasm (-pu-og, first, tz/mcgu, I form), or cell con-
tents, constitutes, thus, the essential element of the cell, while
the wall and the nucleus are to be regarded as additions of
structure in cells, or masses of protoplasm, differentiated
for special purposes or for higher grade of development.
The perfect cell, that universally present in the construc-
tion of all the organs of animals and plants, so highly de-
veloped as to possess organs, consists of contents, wall and
nucleus, so that the cell with all its parts must still be re-
garded as the ultimate physiological element in the body
of man.

The Properties of Protoplasm.

In studying the phenomena of life, we have, therefore, to
consider the properties of protoplasm as observed in the
forms of life consisting only of single and simple masses of
protoplasm, and as likewise observed in more complex struc-
tures composed of myriads of masses (cells), each individual,
independent, and in a sense isolated, yet all connected and
brought into harmonious action by common fluids (blood,
lymph, etc.), in which tjhey are continuously bathed, and

116 SHE PROPERTY OF MOTION".

by "facile threads of communication," nerves, bonds and
links of association.

We observe, then, first, as the most striking endowment of
protoplasm,

The Property of Motion.

Sarcode (aapij, flesh) was used by Dujardin (1S35) as a
synonym of protoplasm, because it implied the property of
motion as observed in muscle tissue. This motion may bo
partial, manifesting itself simply as a protrusion and subse-
quent retraction of some portion of the substance, or it may,
in detached and isolated masses, be general, effecting the
locomotion of the entire mass. The amoeba, for instance,
the individual mass of protoplasm, extends from its sub-
stance prolongations to encircle some foreign body, the
nutritive principle of which it absorbs and incorporates, to
then release itself or flow away from the indigestible residue.
A very distinguished botanist was once deceived into the
belief that a starch granule had become converted into
living protoplasm by observing the disappearance of the
granule and its substitution by a moving mass of matter ;
the apparent substitution being only an envelopment of the
granule, for the time being, by a living amoeba in its vicinity.
The white blood corpuscle may thus gradually protrude
itself through interstices in the capillary wall to effect
migration to distant parts.

In the early life of all cells (the embryonal stage of com-
plex structures), the property of motion is always manifest,
but as the cell matures or becomes senescent, it loses this
property in most cases ; it becomes quiescent and exhibits
its activity only in other ways.

Individual masses of protoplasm being invisible to the
naked eye it is only possible to study their motion under
the microscope, but the general motion effected by aggregate

COLOR CHANGES IN THE CHAMELEON. 117

masses is apparent in the contractility of muscles, locomo-
tion of members, etc. We have in the color changes assumed
by various fishes and frog3 handsome illustrations of the
motion of cells. The change of color is effected by changes
of shape in cutaneous pigment cells. The colored masses of
protoplasm, (pigment cells) approach to or withdraw them-
selves from the surface and thus vary the color of the ani-
mal. If the pigment cells move uniformly in the skin, the
animal is uniformly varied in color. If only some of the
cells move, the animal appears spotted or striped or ringed,
etc.

The Color Changes of the Chameleon.

The chameleon is so universally known for its change-
ability as to have had its name used ever since Tertullian as
an epithet to express sycophancy and vacillation of purpose.
Prior says: —

"As the chameleon which is known
To have no colours of his own
But borrows from his neighbor's hue
His white or black, his green or blue.'"

And Dryden perpetuates this and a greater fallacy in the
lines : —

"The thin chameleon fed with air receives
The colour of the thing to which he cleaves."

But the chameleon is not so changeable as has been repre-
sented. It is not able to assume any color whatever, nor is
it able to take on the color of every object upon which it
may rest. Basking in the sun it may appear blue, green or
red, according to the incidence of the light, or it may appear
dark, black or iridescent, As different chameleons differ in
the natural color of the unpigmented part of the skin, an
individual may be white or yellow. Moreover it may show

118 COLOR CIIAXGES IX THE CHAMELEON.

gray and brown. All these colors it may exhibit, but it
may not exhibit all colors. The change of color in the
chameleon is due to the presence in the skin of pigment
cells having prolongations which, under nervous influence,
may penetrate the interstices of the superjacent layer of
unpigmented skin tissue, and spread out to cover the surface
wholly or in part. The physical laws regulating the re-
flection, absorption and interference of rays of light in
different media fully explain the different colors the animal
may assume. What especially interests us in this connection
is the property of motion with which the pigment cells are
endowed, and which enables them, in obedience to stimulus
from the nervous system, to assume different shapes and
positions with reference to the super and circumjacent skin
tissue and subjacent blood-vessels. When a chameleon is
poisoned with strychnia it becomes uniformly light in
color from a complete retraction (tetanus) of the pig-
ment cells. This retraction represents the active con-
dition of the cells. When the animal is sick, it is
spotted, some of the cells being retracted, others pro-
truded. Section of individual nerves of the skin produces
the same effect, corresponding cells being passively protruded
(paralysed). The black spots now show dendritic prolonga-
tions. Section of a series of nerves produces a black stripe.
A mechanical, chemical (turpentine) or electric irritant
applied to the skin induces a retraction of the cells, and
thus gives rise to a light or yellow color at the surface of
irritation. The cells relax and spread themselves out
(passively) under the light and heat of the sun, hence, the
animal under such conditions is dark or black. In dark-
ness the cells are actively retracted, hence, the animal is pale.
If parts of the body be protected from the sun, as by bands
of varnish, these parts remain light, while the rest of the
body is dark. Psychical influences likewise affect its color.

CILIARY MOTION. 119

In the passive state it is uniform in hue ; excited after
food, in strife, etc., it is variously tinted. Thus "so far
from being a symbol of falsehood, the chameleon is rather
a symbol of frankness, as every emotion is depicted upon
its surface" (Briicke).

But the motion of pigment cells is not independent.
It is directly under the control of the nervous system.
The motion of muscular tissue, though inherent in the
muscle protoplasm itself is evoked by the nervous system.
Of course, in speaking of independent motion, it is not for
a moment intended to imply a spontaneous motion. It is
simply meant that we are ignorant as yet of the external
influences which induce the motion. As Strieker has
observed, we no longer term the movements of striated
muscle spontaneous, because we know the external influences
or stimuli through which it can be excited. "And so, also,
there can be no doubt that as soon as we have acquired
a knowledge of all the external influences by which
movements in protoplasm can be induced, we shall cease to
term them spontaneous. Thus, in stating that protoplasm
is capable of active or vital (spontaneous) movements, we
have by no means admitted the existence of an immaterial
force" (Strieker). The best example of protoplasmic motion
entirely independent of the nerves, is that exhibited in the
undulations of the ciliary processes upon the surface of cer-
tain epithelial cells.

Ciliary Motion.

Ciliated epithelial cells are cylindrical, conoidal or goblet
shaped masses of protoplasm, from whose upper free surface
protrudes a thicket (not simply a few, as always represented)
of fine, hair like, processes, the cilia. Such structures have
long been recognised in certain infusoria, for which they
furnish means for locomotion, prehension of food, and

120 CILIARY MOTION.

for which, also, by creating currents, they minister directly
to respiration. Purkinje and Valentin discovered their
existence in vertebrate animals and in man. Such cells
line the entire respiratory tract from the nasal cavities,
except the space within the anterior nares, down to the
finest bronchioles (but not the air cells). Ciliated cells
tapestry also the cavities accessory to the nasal, the antrum
of Ilighmore, the frontal sinus, etc., the Eustachian tube,
and for the most part, the cavity of the drum of the ear.
A tract of epithelial cells is also found in the epidydimus,
the efferent ducts of the testicles, and in the female, in the
parovarium, the Fallopian tubes, and the body of the
uterus, extending into the uticular glands. Ciliated cells,
though much smaller and more delicate, occur also in the
various cavities of the nervous system ; in the lateral
ventricles, the floor of the fourth ventricle, and the cerftral
canal of the spinal cord.

The cilia (cilium, an eyelash), are for the most part sabre
shaped, with a broad attached base and a free pointed
extremity. They are implanted directly into the protoplasm
(the cell), of which they are part, and not inserted into a
membrane or an upper distinct layer of protoplasm as once
believed. At rest they are slightly inclined, mostly towards
the exterior of the tube or cavity in which they are found.
In motion they strike with their broad or flat surface and
return, like oars in skillful hands, by feathering the edge,
to nearly, but not quite, a perpendicular position. The
stroke is the result of an active contraction (motion) of the
protoplasm while the less quick return is due to a simple
passive elasticity. But the cilium in its stroke is not
passively moved by the contracting protoplasm. On the
contrary, it is the cilium itself which is endowed with the
contractility, and the cell when free (as in the detached
masses found in the secretion of coryza), is passively

CONDITIONS INFLUENCING CILIARY MOTION. 121

moved about by its vibratile cilia. This contraction and
relaxation is exceedingly rapid, too rapid, indeed, to be
individually visible. Cilia move in the frog at the rate of
twelve times in the second, and in warm blooded animals
much faster. It is only when contractility has become
partially exhausted that individual motion may be observed.
In molluscs, where the cilia are of very great size, their
motion produces undulations which may be seen in its
totality as glittering waves even by the naked eye. The
motion of tracts of cilia has been not inaptly compared to
the undulations of a field of grain agitated by the wind,
or to the glistening of a river in the sun.

Conditions Influencing Ciliary Motion.

Cilia are entirely independent of the nervous system.
Section or stimulation of- nerves produces upon them no
effect. They contract when removed from the body, and
survive somatic death for hours, even nine hours in the
frog. Nevertheless ciliary motion in life is not irregular ;
all the cilia in a given "tract move in a definite direction,
and produce definite currents in the circumambient fluids.
It is for this reason that particles of mucus or other for-
eign bodies are propelled upon the surface, tossed from
place to place, towards the exterior. The force of cilia is
really astonishing. Particles of coal dust suspended over
them by means of a drawn thread of sealing wax are lifted
and pushed on at the rate of -^^ of an inch per second.
It was by means of such an experiment that Kistiackowsky
was able to prove that induced currents of electricity
stimulated the cilia, contrary to opinions expressed hitherto,
to greater activity, or renewed it after a period of quies-
cence. Heat quickens, cold retards their motion. The
activity of the movements of protoplasm in general is
greatest at about 100° F. (38° C). At 32° F. (0° C), they

122 MOTION OF OTHER CELLS.

become extremely sluggish, or ceases altogether. The ova
of trout, however, uudergo segmentation perfectly in iced
water, whilst they soon cease to move at ordinary tempera-
tures. Dilute alkalies act as ^direct stimulants to ciliary
motion, partly by simply diluting the thickening mucus in
which they float and partly by increasing oxidation. Chlo-
roform suspends their activity, or in excess disorganises and
destroys the cells.

Ciliated epithelial cells are best obtained for study by
scraping the roof of the mouth or the pharynx of the frog.
A few cells may be detached in man by inserting a feather
into the upper cavities of the nose. The largest cilia are
found in the molluscs, in the so-called beard of the oyster or
clam. Tracts of cells are secured by dissecting off parts of
the pharyngeal mucous membrane of the frog. Calliburces
constructed a very elegant apparatus to cause cilia in motion
to strike upon and revolve a glass cylinder and thus record
their own velocity of movement. Bowditch exhibited this
motion more simply and effectually by cutting through the
body of a frog just below its anterior extremities, after
destruction of the spinal cord, and passing a glass rod
through the oesophagus. The body of the frog is gradually
pushed along the rod by the motion of the oesophageal cilia.
The front part of the jaws should be cut away to prevent
too great friction, and the rod should be dipped in salt water
to secure the best action of the cilia. If the oesophagus
alone be slipped over the tube the motion will be much
more apparent.

Motion of Other Cells.

A spermatozoid is a detached ciliated cell ; the whip-lash
tail is the cilum and the head is the nucleus of the cell.
The spermatozoid, all moving protoplasm, indeed, is affected

MOLECULAR MOVEMENTS,, 123

in like manner with ciliated epithelium by the various
agents mentioned.

Motion has been studied also in the lymph and pus cor-
puscles, in cartilage and in connective tissue cells. Certain
corneal corpuscles have been observed by Recklinghausen
to penetrate tissue interstices and wander about, like the
white blood corpuscles, to considerable distances. It is by
means of motion of this kind that young cells may arrange
themselves in position in the original construction of the
various tissues and organs

But the motion of the highest physiological interest in
this connection is that which takes place in the interior of
the cell itself. Such movements are known as

Molecular Movements,

because they consist of agitations, tremblings or rotations
of the fine granules in the protoplasmic mass. These
movements are not to be confounded with those exhibited
by inorganic bodies floating free in fine particles, the
movement described by Brown, and known as the Brunonian
movements, for in the case of the inorganic body the
movements are oscillatory or merely passive folio wings of
the currents in the fluids. Protoplasmic molecular move-
ment is active and translative from place to place. It may be
seen to advantage in the cells of the salivary glands, in living
blood corpuscles (white) or in pus corpuscles when water is
added to the fluid in which they float. These movements cease
only with the death of the cell. A stroke of electricity
which kills the cell stops the granular movement at once,
proof that it is in no sense a passive phenomenon. The hair
of the stinging nettle exhibits protoplasmic molecular move-
ment even more clearly than any animal structure. Such a
hair consists of one elongated cell filled with intra-cellular
fluid ; its transparent wall being lined with soft protoplasm.

124 MOLECULAR CHANGES IN THE OVUM.

The molecules or granules in the protoplasm not only trem-
ble like the salivary corpuscles, but they actually circulate
in a regular stream. The protoplasm itself undulates in
different directions. A shock from a magnetic electro-
motor apparatus arrests the regular system of waves, and
suddenly projects the protoplasm in promontories into the
intra-cellular space. During this attack, so to speak, the
molecular motion ceases, to recur only when the protoplasm
resumes its normal motion.

Molecular Changes in the Ovum.

The ovum, or primordial cell, is, however, here again, the
best object for study of this kind of motion. The ovum in
both plants and animals is the continual seat of molecular
motions of the most active as well as curious character. In
its development the nucleus of the ovum first becomes
elongated, spindle-shaped and covered with fine threads or
hairs. The granules of the protoplasm now move about to
arrange themselves in regular lines irradiating from the
ends of the nucleus and finally the whole protoplasm splits
in two, forming two cells, a smaller, so-called cemetery-cell,
containing the products of excretion, which entirely disap-
pears, and a larger formative cell which contains all the
elements essential to the formation of the new being. In
ova without special walls, enveloped only in the mucus
from the maternal genital canals, a single spermatozoid, out
of the 70-80 upon the surface of the enveloping mucus, pene-
trates the mucus to reach the yolk. "At the moment when
this penetration is effected, the yolk, which had hitherto
presented a uniform arched surface, suddenly projects an
elevation towards the head of the spermatozoid, seizes it,
surrounds it and draws it with a celerity which almost
escapes vision, into the interior of the egg." The tail of the
spermatozoid now disappears by solution in the yolk proto-

MOLECULAR CHANGES IN THE OVUM. 125

plasm, and the head gradually travels towards the nucleus
of the ovum. So soon as contact is effected the two bodies
roll about each other several times and then fuse together
to become the new nucleus of the ovum. Hereupon ensues
the division and subdivision of the new nucleus, until the
whole ovum has undergone the process of segmentation into
daughter cells, which arrange themselves into three layers,
the blastodermic layers, containing the elements of construc-
tion of the whole body. In ova provided with a distinct
wall (zona pellucida) there may be usually detected some-
where in the wall a large opening, the micropyle, for the
entrance of the spermatozoid. The cell wall is often pene-
trated, besides, by very fine radiating canals, in every one of
which is a thorn-like protrusion of the yolk stopping up the
canals, like bottle stoppers, to prevent the entrance of fluids
in which all ova float. A cord or track of clear protoplasm,
the so-called seminal cord, passes from the micropyle to the
nucleus of the ovum, as a road along which the spermatozoid
may pass to the nucleus of the ovum.

Now the most serious accident that can befall an ovum is
the accidental penetration of more than one spermatozoid.
Malformations and double monstrosities always occur after
such accidents. But the ovum is protected against these
accidents by a provision which is as curious as effective, and,
as a striking exemplification of molecular motion, is worthy
of mention here. In the naked (wall-less) cells, at the
moment when the hillock of yolk has seized upon the first
penetrated spermatozoid, "a fine, delicate, but very resistent
membrane immediately — so quickly as to be invisible to
the eye. in its stages of formation, a kind, therefore, of
chemical deposit — covers over the whole surface of the
yolk," to effectually bar the passage of further spermato-
zoids. In ova with walls, a number of spermatozoids are
seen gliding, head first, about the surface of the wall.

126 MOTION THE ESSENCE OF REPRODUCTION.

Finally, one succeeds in reaching the micropyle. "So soon
as this happens, the seminal cord is at once torn away from
the micropyle and the thorn-like protrusions of the yolk are
at once withdrawn from the radiating canals in the zona
pellucida, whereupon water streams into the radiating
canals and through the open micropyle, to spread out
between the surface of the yolk and the zona pellucida.
The zona pellucida (cell wall) is thus lifted' away from the
yolk (cell contents) and thrown into irregular folds to
oppose an insurmountable obstacle to the penetration of
even a second spermatozoid" (Lowe).

The motion of the molecules in the ovum is the cause of
its development. That is, motion is the

Essence of Reproduction.

The assistance of the male element is not by any means a
necessity in reproduction. In many animals, notably in in-
sects, continued progeny (ten to twelve generations) is pro-
duced without copulation. Generation of this kind,
partheno -genesis, or virgin generation, instead of being a
mysterious exception, is the rule in all animals up to a cer-
tain grade of development. Bischoff found that all the first
stages of development, disappearance of the germinal
vesicle, appearance of the new nucleus in the interior of the
yolk, condensation and volume reduction of the yolk, move-
ment phenomena in the yolk, finally even the first stages of
segmentation, all these changes occur in eggs which have
never been impregnated, and in eggs which are never
impregnated at all, but which have been discharged from
the ovary simply on account of their maturation. Moquin
Tandon has seen the process of segmentation of the yolk in
unimpregnated frog's eggs, and Van Beneden has shown
that the first phases of development in the rabbit are
entirely independent of impregnation. These changes are

PARTHENOGENESIS 127

not dependent, therefore, upon the formal union and copu-
lation of a sperm and germ cell, nor upon any chemical or
dynamical effect of the spermatozoids, for they occur with-
out the presence of spermatozoids at all. They depend
upon the motion inherent in the molecules of the ovum
itself. But, in the rule, we observe that the intensity of this
motion is not sufficiently great to lead to further develop-
ment and production of form. It must receive additional
force, and probably also a definite direction, in order that
the further movements of development, those requisite to
the complete construction of the embryo, may ensue. The
egg receives this further addition, strength and direction of
motion from the spermatozoids, whose individual mass
movement is proof that the matter of their composition is
also in the condition of intense activity. Bischoff in
making this statement concludes : "we possess nowhere else
such a perfect insight into the cause of organic movements as
here, and the view which this insight gives will be as satis-
factory to the reasoning mind as every other application of
the law of the conservation of force."

The case of the bee affords a striking confirmation of the
fact that development up to a certain grade is possible
without copulation, while more perfect development re-
quires assistance. Thus the queen, bee in captivity or isola-
tion continues to breed drones (males) almost indefinitely,
and under conditions which preclude the idea of any utilisa-
tion of sperm stored up in the past, while the produc-
tion of workers (females) only ensues after copulation. In
fact, the observations of Leuckart and Siebold prove that
spermatozoids are always found about the micropyle of the
ova of females, and never about the ova of males. But
among'the sack bearing insects (psychides) the sex is reversed,
that is, the production of males requires copulation ( Wundt).

The essence of reproduction, therefore, so far as may be

128 THE CIIEMISTTIY OF PROTOPLASM.

comprehended by the limited understanding of man, is a
transmission of motion, as the remaining manifestations of
protoplasm (the various phenomena of life), are transmuta-
tions of some physical force.

LECTUKE VII.

PROTOPLASM AND ITS PROPERTIES.

CONTENTS.

The Chemistry of Organic Matter— The Ultimate Elements— The
Proximate Principles — Albumen and its Products — The Chemistry
of the Cell — Absorption and Assimilation — Metabolism — Oxidation
Processes — Oxidation in the Ovum — Oxidation in Muscle — Oxidation
in the Blood — Oxidation in Nerve Tissue — The Quantity of Oxygen
in the Body — The Genesis of Protoplasm — Spontaneous Generation—
Omne Yivum ex Ovo — Reproduction and Nutrition — Modes of Cell
Genesis — Death of Cells — Recapitulation — Classifications of the
Tissues.

We have already regarded the matter of the body, the
protoplasm, from an anatomical stand-point and before con-
tinuing the study of its properties we shall have to survey
it from a chemical point of view.

What seems especially striking in the

Chemical Analysis of Organic Matter

is the simplicity of its elementary construction. The num-
ber of elements entering into its composition we discover to
be extremely small. Of the sixty-four ultimate elements
into which the matter of our earth may be resolved but four
take any prominent part in the manufacture, so to speak,
of purely organic matter. These are carbon, which is absent

THE ritOXIMATE miNCirLES. 129

in no organic body, and oxygen, hydrogen and nitrogen.
But in the construction of the more complex animal and
vegetable bodies we encounter also seven other elements,
viz., sulphur, phosphorus and iron, as elements most widely
diffused, and chlorine, potassium, sodium and calcium as
elements most rarely met. The first four mentioned ele-
ments, carbon, oxygen, hydrogen and nitrogen, are the
essential elements; the rest are said to be incidental ele-
ments. I have here before me a glass of water. I drop into
it a small piece of coal. We have now in this glass hy-
drogen and oxygen in the water, nitrogen (with oxygen) in
the air and carbon in the coal, all the essential elements,
and in some cases the only elements, entering into the com-
position of organic matter.

The Proximate Principles.

But no familiarity with the characters or properties of
these ultimate elements may acquaint us with the properties
of their compounds, the results of their combinations, the
so-called proximate principles, as they are encountered in
the body. No knowledge, for instance, of the peculiarities
and characteristics of chlorine, a heavy, greenish-colored
gas, with bleaching properties, or of sodium, a whitish
mineral which burns upon the surface of water, would in-
form us as to the properties and characteristics of the
chloride of sodium (common salt), a substance as different
from either of the elements of which it is composed as they
are from each other. In the study of the structure of the
body from a chemical point of view, it is the combinations
of the elements, and not the elements themselves, with
which we have to deal ; the proximate principles, and not
the ultimate elements, present the peculiarities pertaining
to living things.

There are organic compounds which consist of but two of

130 ALBUMEN AND ITS PRODUCTS.

these ultimate elements, but the great majority of them are
made up of three, viz : carbon, hydrogen and oxygen. These
carbo-hydrates owe their name to the fact that they are
composed of, besides carbon, hydrogen and oxygen, in the
proportion to form water. Starch and the various sugars,
so easily mutually convertible by the addition or abstraction
of water, are examples of the carbo-hydrates. The closely
allied fats have an excess of hydrogen, so that all these sub-
stances are often grouped under the head of the hydro-
carbonaceous compounds.

Another group of organic matters contains, in addition
to the three elements mentioned, nitrogen. They are, there-
fore, known as the nitrogenous in distinction to the non-
nitrogenous principles. To this group belong the complex
products, the albumenoids (including haemoglobin and
vitellin), which also contain sulphur, phosphorus or iron.
The white of egg is a typical albumenoid substance.

Chemical analysis of the body discloses, besides these two
classes of principles, the nitrogenous and non-nitrogenous, a
third group of inorganic or mineral principles, as water,
common salt, phosphate of lime, etc., contributing to the
formation of tissues and juices of every character and con-
sistence.

Albumen and its Products.

The chief constituent of protoplasm is albumen in some
one or other of its numerous forms. Albumen with water
in considerable amount, mineral matters and fat, these are
the substances which compose the animal cell. Protoplasm
is thus a peculiar albuminous compound, tough and viscid
before undergoing subsequent change, which coagulates
under heat (or at the death of the cell, as in rigor mortis),
and which is swollen up or gelatinised, but is not dissolved,
by the action of water.

THE CHEMISTRY OF THE CELL. 131

It is a humiliating confession to have to make, but it is
true, as Frey remarks: "This is about all we know, at pres-
ent, of this important compound, protoplasm."

We recognize in albumen, in some of its forms, the funda-
mental substance in the composition of protoplasm. In the
lowest forms of life, at all times, and in the higher forms in
the embryonic stage, albumenoid (protein) bodies are uni-
versally present. But as development advances in the more
complex forms the differentiation of individual masses of
protoplasm into separate tissues and organs is characterized
by a change of the protein bodies into some of their more
permanent derivatives, as chondrin, elasticin, etc. What
especially characterizes the albumenoid bodies is their insta-
bility of structure, that is, the readiness with which they
may be broken up into new compounds. In this decomposi-
tion, the force latent in the albumen is translated into active
forms with the development of various decomposition pro-
ducts wThich escape in the secretions. Such products are
urea, leucin, tyrosin, creatin, creatinin, glycogen, peptones,
and ferments. Some of these products, glycogen, peptones,
etc., are true secretions, having further purpose to subserve
in the body ; others, urea, creatin, creatinin, are veritable
excretions, effete matters of no further use. Very grossly
considered, the first mentioned useful products correspond
to the steam of the engine; they are the agents of force ;
while the seqond class of useless products are the ashes and
smoke ; they* must escape from the body, as their accumula-
tion in it extinguishes the processes of life.

The Chemistry of the Cell.

The protoplasm (or cell contents) is thus composed of
albumen in some of its forms, of water, of mineral matter
and of fat. The outside or cortical layer of protoplasm
(the cell), when such a layer is present, differs from the

132 ABSORPTION AND ASSIMILATION.

inner substance in its greater density. The albumen is here
converted (differentiated) into elasticin, which, as its name
implies, is more resistant and elastic, and hence is better
qualified to serve as a protection to, and to regulate diffusion
for, the more delicate protoplasm inclosed.

The nucleus of the cell, again, may also be differentiated
into a wall and more fluid contents chemically somewhat
different, in turn, from the wall and contents of the main
cell. Thus minute granules are readily precipitated in the
nuclear contents by the addition of alcohol and acids, while
the wall of the cell differs from that of the nucleus by the
greater solubility of the former in alkalies. The nucleolus,
from its high refracting properties, is supposed to consist
largely of fat.

With this glance at the chemical constitution of the cell
we are better prepared to continue the study of its properties.

Absorption and Assimilation.

Cells have the power to absorb, assimilate or store up
material from without, to elaborate or transform the ma-
terial thus absorbed, and to filter out, excrete or eject
material from within.

In the ordinary growth and nutrition of the cell new
matter passes by penetration, imbibition or osmosis, directly
into the substance of the cell. The whole collection of cells
constituting the body may be roughly compared to a sponge
soaked in nutrient fluids. These fluids penetrate the wall,
and thus constantly contribute to the cell new material.
Just as every plant absorbs from the earth the particular
salts essential to its growth, does each cell drink up from its
earth, the blood and the part of the body in which it is
found, the particular elements essential to its growth and
work. The cell in this way feeds itself, absorbing with
what seems a selective agency (chemical affinity) the ma-

TROCESSES OF OXIDATION. 133

terial upon which it can live and work, and with some dis-
crimination refusing to absorb useless and innutritious
matter. The new matter may then be transformed into the
protoplasm of the cell (assimilated), or it may be stored up
for other use in its work. Thus the protoplasm grows, im-
perceptibly increases in size, or fills itself with foreign
bodies (blood corpuscles, fat cells, coloring matters), which
may be seen entire or in fragments in the body of the cell.

The Metabolism of the Cell.

The transformation of matter (metabolism) in the in-
terior of the cell, is the highest physiological endowment
of protoplasm. In this process, chemical changes, to large
degree inscrutable as yet, are incessantly at work. Muscle-
cells and nerve-cells elaborate in this way their irrita-
bility and other properties which endow them with their
peculiar physiological dignity as the master-tissues of the
body. Gland-cells manufacture ferments ; as the gastric
epithelium, pepsin, the pancreas, pancreatin, or new com-
pounds, as the mammary cells, milk sugar, liver cells,
glycogen; from the disintegration and rearrangement of
matters pre-existent in the blood. Lastly, certain masses
of protoplasm (cells) come to be set apart for the pur-
pose simply of filtering out from the blood and eliminating
from the body various products of decomposition and
waste.

The most important factor in effecting these various
metamorphoses is oxygen gas. To great extent the chemi-
cal changes in the cell, the metabolism of the cell, as it is
called, are

Processes of Oxidation.

The various excretions of the animal body are, as we have
seen, for the most part, products of oxidation. Of these

134 OXIDATION IN THE OVUM.

excretions, some, carbonic acid gas and water, are com-
pletely oxidised products, while others, the urates, for in-
stance (but not urea) escape only partly consumed (oxidised)
and must undergo further oxidation outside of the body
before they are resolved into the fully oxidised products,
water, carbonic acid gas, ammonia, etc. These finally
oxidised products thus restore to the earth and air what
was abstracted by the plant.

"See dying vegetables life sustain,
See life dissolving- vegetate again,
All forms that perish other forms supply,
By turns we catch the vital breath and die." Pope.

Oxidation (union with oxygen), so far as we can follow
it, causes the decomposition or splitting up of compound
into simple bodies. Deoxidation (abstraction of oxygen)
causes or attends the rearrangement of simple into com-
pound bodies. The plant (vegetable) cell has the power,
under the light and heat of the sun, to disengage oxygen
and rearrange the atoms of simpler into more compound
bodies. In this way the plant-cell builds up and stores
up these compounds as latent force. The animal cell
(protoplasm) has the power to reduce these compounds,
with the aid of oxygen, and set the latent force free.

Oxygen being thus the principal agent in decomposing
the matter of the animal cell, and setting free the force
which it contains, we may now consider its appropriation
by the various organs somewhat in detail.

Oxidation in the Ovum.

To commence, then, at the beginning of the cell, it is
observed that the ovum breathes. The butt end of the
chicken's egg has a cavity filled with air, which, according
to BischofF, contains, on the average, 23. 5 per cent, (more,
thus, than the atmosphere, which contains but 20 per cent.)
of oxygen gas. This cavity is a reservoir of air for extra

OXIDATION IN MUSCLE. 135

demands. Oxygen continually penetrates the shell of the
egg in greater quantity as the shell grows thinner, in corre-
spondence, thus, with the increasing demands of increasing
development within.

In Baumgartner's artificial hatching experiments, so
conducted that the absorption of oxygen and exhalation
of carbonic acid gas could be accurately measured, it was
observed that the egg gained in twenty days (up to the
time of the escape of the young chicken from its cavity)
26.82 per cent, in weight; a gain attended with the ab-
sorption of 6.29 per cent, of oxygen, and the escape of
8.412 per cent, of carbonic acid gas, and 24.69 per cent,
of water. The volume of the oxygen absorbed from the
air is always greater than that escaping with the carbonic
acid gas, as the oxygen not only contributes to the forma-
tion of carbonic acid gas and water, but is also used in the
formation of other products remaining in the substance of
the egg.

Though there are many recondite chemical processes
continually in operation in the body, most of the changes
connected with the development of force are simple oxi-
dations. The force-material of the body may be said,
therefore, to be represented by oxidisable (organic) com-
binations on the one hand, and by free oxygen on the
other.

The direct absorption of oxygen gas has been observed
by Kuhne, in the case of the ciliated epithelial cells.
The movements of cilia are intimately connected with the
consumption of oxygen. They cease in its absence, and
they cannot be started again without it.

Oxidation in Muscle.

The contraction of muscle protoplasm is as closely con-
nected with the absorption of oxygen, and the excretion

136 OXIDATION IN THE BLOOD.

of carbonic acid gas. But it is not so much the muscle
substance itself that is oxidised in the production of mus-
cular force, as the non-nitrogenous elements of the blood,
circulating through the muscle. For, it has been now
pretty clearly established that the urea, urates, etc., pro-
ducts of the waste of muscle itself, are not increased in
the excretions (urine) in correspondence to muscular ex-
ercise. On the contrary, the increase concerns the car-
bonic acid gas exhaled from the lungs, proof that it is the
carbo-hydrates of the food, and not the nitrogenous mus-
cle itself which serve as fuel for the muscle machinery.
When a muscle is at rest, the blood in its emulgent veins
is red in color, but after contraction its escaping blood
is deoxidised to a blue color, showing that oxygen is used
up in the blood. But oxidation of muscle-substance itself
does take place, in some, though slight, degree. For, aside
from the presence or absence of its products in the urine,
a muscle will continue to give off carbonic acid gas for a
time, even when washed free of blood, or even when
placed in an atmosphere absolutely free from oxygen, as in
hydrogen gas. The production of carbonic acid gas in this
instance depends, of course, upon the presence of oxygen,
stowed away in the muscle previous to the experiment.
The protoplasm of the tissues is everywhere the chief seat
of the processes of oxidation. If a separate muscle, free of
blood, be inclosed in a gas chamber, it will absorb more
oxygen, and give off more carbonic acid gas during con-
traction than during rest. Examination of the blood of the
femoral veins in the frog, after galvanisation of the posterior
extremities, shows an increase in the amount of carbonic
acid gas.

Oxidation in the Blood.

But the blood is also a vast field for the operations of
oxidation. The hamiato-globulin, the albumenoid principle

OXIDATION IN THE BLOOD. 137

of the blood corpuscles, collects it at the lungs, and carries
it in loose combinations for surrender to the various tissues
of the body. Then the blood corpuscles are endowed with
what we might term a magical power of converting oxygen
into ozone. Ozone (nascent oxygen) is a peculiar modification
of oxygen, with much higher oxidising powers than simple
oxygen. The molecule of oxygen being represented by one
O, that of ozone is triplicated. Ozone is 03, so that it has
much wider range of affinity. If a drop of blood be let fall
upon a piece of ozone test paper (made test paper by
having been saturated in tincture of guiacum, and
afterward dried) a deep blue color forms about it. This
is the reaction of ozone. The serum of the blood will
not show it at all (Schmidt). The ozone of the blood
can not be directly established in this way, as it is
at once used up for oxidation purposes. The ozone
thus proven present has been just created by the blood
corpuscles.

The blood, again, very greatly assists the oxidation process
by its alkalinity. All alkalies have this property. Many
organic compounds, not at all affected by oxygen, are at
once attacked in the presence of a free alkali. The organic
acids ingested into the body pass over unchanged into the
urine, or, at most, are oxidised to very slight degree ; but
when they reach the blood in alkaline combinations, they
are at once completely oxidised, and appear as carbonates
in the urine. Gallic and pyrogallic acids, are not oxidised
in the atmosphere, but on the addition of a free alkali,
oxidation occurs so quickly that the solution of pyrogallic
acid can be used in eudiometry, and sugar becomes so
oxidisable in the presence of a free alkali that it will abstract
a part of its oxygen from a metallic oxide, and thus reduce
an oxide of copper, for instance, to a sub-oxide (Trommer's
test for sugar). According to Gorup-Besanez, even ozone

12

138 OXIDATION IN NERVE TISSUE.

will not oxidise the organic acids except in the presence of
a free alkali or alkaline salts ( Vierordt).

Oxidation in Nerve Tissue.

Nerve-force was thought, at least, to be generated more
directly by oxidation of nerve-substance, as the quantity of
alkaline phosphates in the urine, the product of oxidation
of the phosphorised fats of nervous tissue, stands in close
correspondence to the amount of brain-work. "We may
rightly liken the brain," said Carpenter, "to a galvanic battery,
and the blood to its exciting liquid. When the circuit is
closed, a rapid oxygenation of the nerve-substance, as of
the zinc of the battery, takes place ; and a corresponding
equivalent of nerve-force (which seems closely related to,
but is not identical with, electricity) is generated." Lut
the fact alone of the enormous supply of blood to the brain ;
one-fifth of the whole amount ; though the brain weighs
only one-fortieth of the entire weigh t.of the body ; would in-
dicate that nerve-force, as well as muscular, is almost entirely
derived from oxidation of material furnished by the food.

Paul Bert has been able to prove that the loss of con-
sciousness and motion, which occurs immediately when
the blood-current to the brain is interrupted, is due to the
lack of oxygen rather than of any other nutrient matter.
In cases of partial asphyxia, induced by abstraction or
rarefaction of oxygen (as in mountain ascents) the faintness
and exhaustion are immediately and completely relieved by
the inspiration of oxygen gas or of air which is highly
charged with it. The transformations of force that occur
in the body, that is, the manifestations of life, are, thus, pre-
eminently, processes of oxidation.

The,. Quantity of Oxygen in the Body.
In recognizing this fact we would be led to believe that
the quantity of this gas, and its most frequent product,

QUANTITY OF OXYGEN IN TIIE BODY. 139

carbonic acid, in the blood and tissues would always be
very great. We observe, however, the very reverse to be
true. There can, at no one time, be collected from the
blood more than four grammes of oxygen or carbonic acid,
and adding to this the quantity present in the tissues
(a quantity which can not yet be definitely ascertained,
but which is known to be very small), the whole amount
of these gases is still comparatively little. But this small
amount present at any one time is no true criterion
of the sum-total absorbed in the course of time. For this
small quantity is being so continuously received (and
consumed) as to amount in the course of a year to several
hundred pounds. In fact, more oxygen is ingested than
food (aside from drink). The absolute indispensability of
oxygen gas from moment to moment, is proven by the
serious changes that at once ensue in the body when its
quantity is diminished in the air. Other nutrient matter
may be absent from the body for hours or for days, with-
out discomfort, but the absence of oxygen for a few seconds
or minutes produces serious suffering. It is the long subjec-
tion of individuals with inherited vulnerable constitutions
to an atmosphere whose oxygen has been reduced (as in
factories, badly ventilated houses, etc.) that forms the
principal factor in developing phthisis, pre-eminently a dis-
ease of modern civilisation. And fresh air in abundance is
the only specific in its cure. Fortunately, oxygen
exists in nature in sufficient abundance, for all the wants
of protoplasm. It forms eight-ninths of the wTater of the
globe, nearly one-half of the solid crust of the earth, and one-
fifth of its air.

Oxygen is, in short, an essential constituent of living
protoplasm, which develops only at the bottom of an ocean
of it, thousands of cubic miles in extent. The atmospheric
ocean, which is as much a part of the earth as its water or

140 THE GENESIS OF PROTOPLASM.

its salts, is an inexhaustible, a perpetually-filling reservoir
of oxygen gas.

We have now to consider the mode of origin or birth of
protoplasm, and its mode of dissolution or death.

The Genesis of Protoplasm.

When the microscope first began to disclose its revela-
tions concerning the construction of living things, it was
hoped that we were at last in possession of the means
that would lift the veil of mystery concealing the genesis
of life. If was believed that it would be only necessary
to perfect the instrument for the highest magnification to
enable us to see the first aggregation of atoms to constitute
life. It is needless to say that such extravagant concep-
tions soon proved to be delusive. With the microscope on
the one hand, and chemical analysis on the other, the physi-
cal basis of life was soon resolved into its histological and
chemical elements ; but no peculiar principle of life was
ever thus discovered. It seemed, indeed, a j ustification of
the exclamation of Schiller : —

"Und noch Niemand hat erkundet
Wie die grosse Mutter schafft
Unergriindlich ist das wirken
Unerforschlich ist die Kraft."

(As yet no one has discovered
Nature's secret to produce;
Still impenetrable her method
Yet inscrutable her force).

The microscopists soon found themselves, said Leydig, in
the predicament of individuals who had long studied from
afar the appearance of a meadow or a forest. They thought
that a nearer approach would inform them about the
germination, the growth and the coloration of the plants.
Many new observations they did make, it is true, but the

THE GEXESIS OF PROTOPLASM. 141

puzzling riddles remained the same. They stood before the
same questions, with the difference only that they could
now study the changes in each individual plant, which they
could observe before upon the whole green surface.

The physiologist thus, aided with the microscope and
the test-tube, took only a closer view of the individual
elements aggregated in the construction of living things.

In the impossibility, then, of recognising in the construc-
tion of animate bodies any elements or principles different
from the inanimate, the question at last arose: Is there
really any such difference? Thus the question stands at
the present time, the burden of proof resting upon those
who still maintain the existence of such a difference.

The question of spontaneous generation (autogeny) is now
being examined and discussed with even more interest and
with more probability of final solution than ever before
in the history of science. The doctrine of evolution ; which
may now be regarded as an accepted fact, and which must
soon become incorporated into the curriculum of our com-
mon schools; followed to its utmost limits, compels the
ultimate admission of the spontaneous genesis of living
matter. But an inference, however legitimate or rational,
does not constitute a fact in natural or any other branch of
science. If the question could be settled by the mere ex-
pression of opinion, I should say, with becoming diffidence,
that for my own part, I side completely with Prof. Owen,
the highest living authority in comparative anatomy, and
until very lately, with Quatrefages, the most dangerous
opponent to the theory of evolution, when he declares him-
self the champion of spontaneous generation and maintains,
as in the last pages of the third volume of his Anatomy of
the Vertebrates, that the formation of living beings out of
inanimate matter by the conversion of physical and chemi-
cal into vital modes of force is a matter of daily and hourly

142 OMNE VIVUM EX OVO.

occurrence. But you will accept as conclusive no opinions.
1 leave you, what you will doubtless exercise anyhow, the
widest latitude of belief, until proof positive shall have
been advanced. But I warn you that there is here, as every
where in science, no room for fancy, feeling, or prejudice.
Cold as ice, clear as crystal, science is a synonim of truth.
We cannot mould the truth to our wants and fancies.
There is. nothing left but to adapt ourselves to truth, what-
ever wTreck of prejudice its revelations may imply. Above
all things, truth.

Whatever may have been the genesis of protoplasm
under the very different conditions of the primeval world,
or whatever it may be now under conditions somewhat
similar, at the bottom of the sea, for instance, are questions
still unsettled. So far as we have positive knowledge, and
it is of facts alone that we have any right to speak, every
cell arises from a pre-existent cell.

Omne Vlvum ex Ovo

and omnis cellula e cellulis are other well-known axioms, ex-
pressive of the exclusive derivation of new protoplasm from
older protoplasm before it. Science at present recognises
no other birth of protoplasm save that derived from parent-
age. The microscope, in discovering the eggs of plants and
animals in concealed places, has put to flight many wild
ideas concerning the spontaneous generation of animal and
Vegetable life. And when these ova or germs have been
so minute (in the case of bacteria, etc.) as to have evaded
the highest powers of the microscope, a beam of electric
light (Tyndall) has disclosed to the naked eye myriads of
combustible (organic) particles, the cultivation of which in
breeding experiments (Dallinger & Drysdale) has resulted
in visible forms.

REPRODUCTION AND NUTRITION. 143

Reproduction and Nutrition.

In our day we regard the reproduction of protoplasm
entirely as a phenomenon of nutrition. It is part of the
chemical nature of protoplasm that an isolated mass of it,
increased by assimilation to a certain size, has the dispo-
sition to divide, the divisions again dividing, and so on,
in the formation of new masses, isolated as before. Be-
production is division and separation in growth beyond
the natural limit of size. Nutrition and reproduction are,
as we have seen, the fundamental characteristics of pro-
toplasm, and they stand in the most intimate relation
toward each other. One continues the individual, the
other continues the species. Nutrition consists of a con-
stant change of matter in the body of the individual ; re-
production of a constant change of individuals. Nutri-
tion, in its essence, is only a reproduction of atoms of
matter in the body of the individual, which atoms, when
increased beyond the natural limits of size, separate to
reproduce new individuals. Hence it becomes a physi-
ological law that a more rapid nutrition implies a more
rapid reproduction. The better fed domesticated animals
breed faster than their ancestral wild forms. More human
beings are born in times of plenty than in times of famine.
Of course, if the nutritive matter be consumed in the pro-
duction of other forces, as in the growth of the body,
muscular or mental work, the power of reproduction is
limited. During youth and adolescence the force of re-
production is absent entirely, or is very limited. Animals
made to perform mechanical (muscular) work have less
progeny (stallions, etc., are kept idle in the stalls); and human
beings of high mental activity are comparatively infecund.
Nothing so completely detracts from muscular and mental
force as venereal excess.

144 THE BIRTH OE THE CELL.

Modes of Cell Genesis.

>

With this knowledge of the physics of reproduction,
we are not surprised to learn that its material manifesta-
tions are simply divisions of the parent cell. This division
may concern the protoplasm first, so that a more or
less central constriction, vertical or horizontal, deepens
to a furrow, and finally completely separates the main
mass and its nucleus (when it exists) into two, each of
which then commences its independent existence. In
more complex structures the division of the generative
cell (ovum) proceeds, each division subdividing, until
finally the original cell presents the appearance of a mul-
berry. This process of segmentation, as it is called, pro-
vides separate atoms in each part of the subdivided cell
for the construction of separate organs and tissues. The
wall of the original "mother" cell may remain intact
while this "endogenous" production of new cells is tak-
ing place within it, and may even take part in the construc-
tion of the new product, or it may burst, as it were, and
permit the new "daughter" cells to escape and provide
for themselves. The ovum or primordial cell is a typical
example of the first method of procedure, cartilage cells
of the second. In the cartilage cell, as in the white blood
corpuscles of mammals, birds and amphibious animals,
and in the red blood corpuscles of the embryos of mam-
mals and birds, the division first affects the nucleus,
which splits in two, each half aggregating about itself, by
molecular motion, a quantity of protoplasm until the en-
tire mass is thus divided. Such corpuscles are sometimes
encountered with 1-2-4 nuclei, each of which attracts suffi-
cient protoplasm to subsequently form a separate cell.
So-called "giant cells," which play such an important role
in rapidly proliferating structures (cancer, tuberculosis,

THE DEATH OF CELLS. 145

etc.), are produced by a rapid multiplication of nuclei
■without corresponding division of the surrounding proto-
plasm.

Or, finally, the division of the cell (protoplasm) may be
more lateral than uniform, protrusions shooting out from
the mass of protoplasm to finally separate from the parent
cell. This method of division by budding, as it is called,
is mostly characteristic of the vegetable cell, but occurs
also in animal cells (polyps, tape-worms, etc.), and, as a
rule, in the regeneration of all cells after partial destruc-
tion of tissue. The yeast plants (torulae) which rapidly
develop in myriads in solutions of sugar, and are the imme-
diate cause of all fermentation, are convenient objects for
the study of reproduction by gemmation.

The Death of Cells.

The cell (protoplasm) having thus been born, it serves
its special purpose in the animal economy, and dies. The
final dissolution and disappearance of the individual cell
may occur in several ways. In the first place, it may
simply lose its fluid contents, dry up and desquamate, that
is, be mechanically rubbed away. Such a mode of death
characterises cells exposed to the open air, as the epithel-
ium cells of the skin. Or, cells may perish from excess of
fluid, be washed away and lost. This mode of death oc-
curs in superficial mucus cells. The "rice-water" appear-
ance of cholera discharges is due to the presence of mul-
titudes of intestinal mucus cells, washed off by excessive
drainage into the intestinal tube. Cells again may be killed
by such rapid increase (proliferation) in number as to effect
mutual compression and expression of their fluidity, as in
the caseous degenerations of scrofula and phthisis.

But most cells die by liquefaction of their contents ;
conversion of their protoplasm into fat, or mucus, or water.

13

146 CLASSIFICATIONS OF THE TISSUES.

These substances are then absorbed from the shriveled
cell wall, which, in turn, finally disappears. Lastly, the
protoplasm of the cell may be substituted by the salts of
lime, and, undergoing this calcareous degeneration, cease
to functionate as cells. The vast majority of cells die a
natural death by fatty or calcareous degeneration.

Recapitulation.

The body of an animal or plant consists, as we have
seen, of a single cell, or of an aggregation of such cells.
The single-celled bodies are said to be simple, the many-
celled, compound bodies. These structures are, however,
in essence the same : the simple bodies being simply sep-
arated further from each other. One such body (cell)
depends for its existence (sustenance) upon other bodies.
In the compound body, the single cells are also in a sense
individual, yet they are all mutually dependent. A com-
pound body is like a colony of ants or a hive of bees ;
completely isolated individuals perish. The cells in a
compound body are connected together by fluid, or more
or less solid, intercellular substance. The intercellular
substance is the product of cells. A compound body is
made up of cells and intercellular substance.

Classifications of the Tissues.

Like cells, differentiated from the rest, and grouped to-
gether for a special purpose, constitute the organs or
tissues of a compound body. The body thus comes to be
made up of organs and tissues, each having a special and
particular purpose to subserve for the benefit of other
organs and tissues as well as of itself. The body is, hence,
constructed upon a plan of a division of labor; just as
society is composed of farmers, tradesmen, thinkers, etc.

ANATOMICAL AND CHEMICAL CLASSIFICATION. 147

Anatomical Classification.

If we regard the tissues of the body simply from an
anatomical stand-point, we recognize: —

1. Tissues composed of simple cells, with fluid inter-
cellular substance, as the blood, the lymph and chyle.

2. Tissues composed of simple cells, with a small
amount of solid intercellular substance, as the epithelium,
nail, etc.

3. Tissues composed of simple or transformed cells
cohering (in some cases), situated sometimes in homo-
geneous, sometimes in fibrous, and, as a rule, more or less
solid intermediate substance, as cartilage, colloid tissue,
adipose tissue, fibrous and elastic tissue, dentine and bone
(connective tissue group).

4. Tissues composed of transformed, and, as a rule,
non-cohering cells, with scanty, homogeneous and more
or less solid, intermediate substance, as enamel, lens and
muscle.

5. Tissues so mixed as to admit of no grouping under
any of the above heads; as nerve tissue, gland tissue,
vessels and hairs.

This is the histological classification of Frey.

Chemical Classification.

If we regard the body from a purely chemical stand-
point, we shall have to recognize its separation into the
three great classes of proximate principles: —

1. The inorganic principles ; definite in their chemical
composition, crystallizable, derived exclusively from with-
out (forming to great extent the crust of the earth), sub-
serving their special purpose in the body and then being
voided from it, having undergone little or no change; as
water, common salt, phosphate of lime, etc.

118 PHYSIOLOGICAL CLASSIFICATION.

2. The non-nitrogenized or hydro-carbonaceous prin-
ciples ; which, as their name implies, contain no nitrogen,
but are made up of carbon in large quantity, and of hydro-
gen and oxygen ; principles which do not belong to the
crust of the earth, but are formed exclusively in the
bodies of animals and plants, where they undergo such
changes as to be entirely broken up and consumed as such ;
as starch, the sugars and the fats.

3. The nitrogenized, albumenoid or protein bodies; in-
definite in their chemical composition, containing nitro-
gen and mineral matters in addition to the carbon, hydro-
gen and oxygen, varying in consistency according to the
consistence of the organ in which they are found, hygro-
scopic (that is, having the power to absorb water and be
restored to their original consistence after desiccation),
coagulable, spontaneously or artificially, and undergoing
fermentation and putrefaction, by serving as food to
microscopic animals and plants, which split up their chemi-
cal combinations into new compounds (alcohol, carbonic
acid gas, Water and other products of decomposition),
principles also formed exclusively in the vegetable or ani-
mal cell and undergoing entire change in the body.
Examples of this class of proximate principles, which
includes also the coloring matters and certain crystallized
products of excretion, are albumen, fibrin, casein, myosin,
pepsin, lecithin, hcemoglobulin, urea, etc.

This is the chemical classification of Eobin and Verdeil.

Physiological Classification.

If, however, we regard the construction of the body
from a purely physiological stand-point, we shall have to
separate the tissues into classes according to pre-eminence
in especial properties, with all the rest of which each one
is endowed in subordinate degree, as : —

PHYSIOLOGICAL CLASSIFICATION. 149

1. The tissues eminently mechanical ; bone (including
teeth ), outside layers of epithelium (including hair and nai Is).

2. The tissues eminently contractile; the muscles.

3. The tissues eminently irritable ; the nerves (and nerve-
centers).

4. The tissues eminently secretory (including excretory) ;
the digestive, genito-urinary, pulmonary, etc., epithelium.

5. The tissues eminently metabolic (elaborative or trans-
formative) ; the gland cells.

6. The tissues eminently reproductive ; the ovary and
the testis.

This is essentially the classification of Michael Foster.

A study of these three methods of classification gives
a clear survey of the construction and action of the
various tissues in the body, whether simple or complex.
These properties and actions in the simplest forms of
protoplasm, like the amoeba, are very few and very limited.
Under favoring conditions and in many millions of years,
aggregated masses of protoplasm build up the most
complicated structures. At various periods in the history
of our earth.

"In days of yore, no matter where or when
Before the low creation swarmed with men."

different animals have successively held the dominant
place. At the present time the highest and most complicated
structure is the body of man. But the principles of con-
struction, the general properties of composition, remain
everywhere the same. What is true of the monad, is true
of man. The binary compounds of inorganic matter,
carbonic acid gas (COO), and water (HHO), are raised in
organic matter to ternary compounds, starch, etc. (CHO), and
upon the question whether this rearrangement of elements
happens naturally, i. e., chemically, or supernatural ly, rests
the most momentous problem of our day.

150 BONE AND ITS PROPERTIES.

LECTURE VIII.

BONE AND ITS PROPERTIES.

CONTENTS.

Anatomical Dignity of Bone — Relation of Bone to Nerve Tissue—
The Skeleton— The General Properties of Bones — The Histology of
Bone— The Haversian Canals — The Lamella? — The Bone Corpuscles
and Lacuna? — The Canaliculi — The Chemistry of Bone — Difficulties
Attending the Study of Osteology — Bones as Fuel — Gelatine as an
Aliment — The Resistance and Resilience of Bone — Constancy of
Chemical Composition — Rachitis andOstco-Malacia — The Phosphate
of Lime — The Preservation of Bone — Bone a Connective Tissue —
The Formation of Bone — The Periosteum — The Centre of Ossification
— Tho Determination of Age — The Femoral Epiphyseal Centre — The
Excavation of Bone — Air in Bone — The Marrow — Studies in Living
Bone — Eonc as a Symbol of the Body.

The Anatomical Dignity of Bone.

Bone has a structural dignity which is attained, with one
exception, by no other hard or solid formation in the
economy of nature. The existence of true bone in the
body of an animal brings it to rank at once among
the class of vertebrates. Wherever is bone, is a spinal
column. The hard parts of all invertebrate animals are
made of horn and shell, never of true bone. Even the
teeth, which alone among other solid structures enjoy the
same exceptional place, from the stand-point of compara-
tive anatomy, could not be present at all, were it not for the
fact that their roots are incrusted with a layer of bone, the
cement, whose periosteum fusing with that of the alveolae
of the bones of the jaws, secures their fixation in the body.

Relation of Bone to Nerve Tissue.

For the bone in the spinal column of the vertebrata
stands in the most intimate . relation to the great chain

* c

Fig. 21. — The structure of bone, a, b, the
Haversian canals, c, d, the Haversian lamellae.
e, e, periosteal lamellae. f,g, the bone cells and
canaliculi. (p. 153-156)

-h

Fig. 22. — The structure of
striped muscle, a (left fig-
ure), sarcolemma. b, end of
ruptured fibre, a (right fig-
ure), transverse striae. £, h-
brilla. (p. 178-179)

Fig. 23. — Involuntary
(smooth) muscle fibre, a,
nucleus, (p. 182)

Fig. 24. — Termination of motor nerve in
voluntary muscle. The muscle fibres exhibit
the striae and sarcolemmar nuclei; the nerve,
its constituent parts and the terminal plates.
(P- 231)

Fig. 25. — Schematic representation of re-
flex action. 1, sensitive (epithelial) sur-
face. 2, motor (muscular) structure. A,
afferent (sensitive) nerve; B, nerve cell; -
C, efferent (motor) nerve, (p. 237) L

Fig. 26. — Schematic representation of
volitional action. 1, sensitive surface. 2, motor structure. A, afferent nerve;
C. efferent nerve; B, nerve cell (for simple reriex action). Z>, afferent nerve; F
efferent nerve; £., nerve cell (for volitional action), (p. 238)

The Structure of Bone and Muscle, and the Modus Operandi of Reflex Action.

THE SKELETON. 151

of nervous matter, the spinal cord, which it encloses and
protects. Each vertebra corresponds to, and is developed
in connection with, one of the primitive ganglia of the
nervous system. Above it and below it emerge the spinal
nerves. So that a vertebra has been defined to be "a bone
or axial segment of the skeleton included between two
pairs of nerves." The subsequent growth of the column,
however, faster than the cord, disturbs this topical
relation so that the cord which at the third month
of intra-uterine life reaches as low as the end of the
sacrum, if not to the coccyx, stops short in the adult at the
second lumbar vertebra. The spinal nerves then come to
pass down from the cord and out through the interverte-
bral foramina with such a degree of obliquity, increasing
from the first to the last pair, that it would seem as though
the cord had been drawn upwards, bodily, within the spinal
canal.

The Skeleton.

The bones of various shape and size, jointed together
in various ways, constitute the skeleton or scaffolding, whose
disposition determines the size, shape, posture, in short,
the configuration and habitus of the animal: — Ossa autem
corpori humani for mam, rectitudinem et firmitatem conciliant
(Galen).

The word skeleton is often said to be derived from
ax&hu, to dry up, in the sense in which this term was used
by Herodotus who speaks of the sole aridum et exsiccat-
um cadaver, which the Egyptians exhibited at their festivities,
with the greeting, edite et bibite, post-mortem tales eritis!
Skeleton is more probably derived from gx^oq, thigh
bone, which, as the largest bone in the body, had its name
used as a designation for the whole structure (Hyrtl).

In the Crustacea, molluscs and in insects, the skeleton^

152 GENERAL PROPERTIES OF BOXES.

of shell or horn, is on the exterior of the body. The first
example of internal skeleton is met in the cephalopodous
molluscs in which certain cartilaginous plates are inclosed
in the body of the animal protecting certain parts of the
nervous system.

General Properties of Bones.

The elongated, tubular, bones of the extremities serve as
levers for the muscles, to the action of which, by their
restriction, of movement, they lend precision and effect.
Hence the bones are often mentioned as the passive organs
of locomotion. Spread out in surfaces, more or less flat, or
stretched out in rods, more or less flexible, they form cavities,
the skull ; or basins, the pelvis ; or cages, the thorax, for
the protection and support of the softer organs. Broken up,
as it were, into smaller fragments, with irregular surfaces
and spongier structure, often with intercalated cartilaginous
pads, they act as bumpers or cushions to break the force of
shocks, as at the wrist and ankle and in the spinal column.
Contracted in their shafts, or alternately convex and
concave in their course, as in the long bones and vertebral
column, they give space for the origin and lodgment of
muscles, and support to the heavier organs, and expanded
at their ends, they widen the surface of articulation, afford
room for the insertion of ligaments and tendons, and furnish
fulcra for the action of the muscles, by distancing the
point of insertion from the centre of motion. Increased in
weight and size near the trunk, they give momentum and
range to the movements of the body, and abbreviated in all
their dimensions at their distal extremities, they lend celerity
and accuracy to its various actions. They are thickened
into massive bars and plates as in the pubes and ilium,
thinned down to papyraceous sheets, or rolled up in delicate
scrolls as in the nasal fossa?, projected in vast promontories

THE HAVERSIAN CANALS. 1q3

in the various tuberosities, or reduced to insignificant frag-
ments as in the bones of the ear, all for purposes familiar
to every student of anatomy.

The Histology of Bone.

The microscopic appearance of bone is characteristic.
For bone belongs, histologically, to the group of the con-
nective tissues and hence consists, primarily, of a network
of stellate ramifying cells (bone cells, bone corpuscles, cor-
puscles of Purkinje, etc.). In the subsequent process of
ossification these cells desiccate and leave spaces, lacuna?,
filled with serum or air (carbonic acid gas). The hardness
of bone is due to the deposit of various mineral salts, prin-
cipally of lime, in the intercellular spaces. Any doubt as to
the nature of a substance is at once resolved under the
microscope, so far as bone is concerned, at a single glance.

The distinguishing characteristics of bone are four, viz.,
First,

The Haversian Canals.

These canals are the conduit tubes for the bloodvessels,
the main trunks of which penetrate the surface of the
bones at the so-called nutritious foramina. Reaching the
interior of the bone, the canals ramify throughout
its substance, varying in size from -^ So0- °f an incn
(0.112S-0.0149 mm.) in diameter, so completely sup-
plying all parts of it, that no osseous tissue is removed
from its nutrient blood at a greater distance than
the yi^j of an inch. The abundance of the blood supply to
bone imparts to it a pinkish hue, though the fundamental
color of bloodless bone is a pale gray, except in some fishes
where it is green. Bone, like all other vascular structures,
is liable to inflammations, and wounded bone bleeds. In
cross sections of bone, the bloodvessel canals, called also the

154 THE LAMEL.L2E.

Haversian canals, to perpetuate, the name of their dis-
coverer, Clopton Havers (1691), appear as rounded or ovoid
openings of various size, in long sections as split canals.

Where the bone tissue is so thin that it may be directly
nourished by the vessels in the two enclosing layers of
periosteum, as in the laminae papyraceae of the ethmoid bone
and in the translucent regions of the palate and lachrymal
bones, and in the leaves of spongy tissue every where,
Haversian canals are not developed. In the flat bones of
the cranium, etc., and in the sternum, the Haversian canals
radiate in stellate form from definite points (from the tuber
frontale, parietale, etc.).

Second,

The Lamella?.

Bone tissue is deposited in layers, 6-15 in number, each
about -^oVo of an inch (0.0065 mm.) in diameter, about the
bloodvessels, the oldest layers being, like geological strata, the
deepest, that is, nearest to the vessels. Or, the layers are
formed from the under surface of the periosteum and thus
encircle the entire bone. As the bone continues to grow, the
relation of these layers to each other, of course, undergoes
change. That is, they appear to abut against each other
like the upheaved volcanic strata of the earth against the
horizontal aqueous strata. The Haversian lamellae lie con-
centrically about the bloodvessel canals, and as these
canals in the long bones run, for the most part, parallel
with the long axis of the bone, the Haversian lamellae form
series of columns about each other throughout the length of
the bone, connected with each other, braced, as it were, by
the lateral columns about the lateral anastomosing canals.

A singular system of lamellae first described by Sharpey
(1856), as perforating bone fibres, pass from the under sur-
face of the periosteum downwards through the circular

THE BONE CORPUSCLE^. 155

periosteal layers "like nails through the leaves of a book,
pinning them together." They arc found in human bone as
well as in that of other mammals, but more frequently in
amphibia and fishes. They are the residue of the connec-
tive tissue substance, the original matrix of bone, and hence
are not found among the Haversian canals.

Third,

The Bone Corjjuscles,

corpuscles of Purkinje (1834), or rather the lacunae, the
spaces left after disappearance of the corpuscles.

These lacunae, ovoid, and with their radiating canaliculi,
stellate in shape, are seen profusely scattered about in the
microscopic field (Harting counted 910 in a square milli-
meter of bone), lying between or in the various
lamellae. They measure from tiVo^soo of an inch
in their long diameter by about ^J^y of an inch in width.
(0.0181—0.0514X0.0068 mm.). The lacunae (?mko^ lake),
as already intimated, are the open spaces filled with serum,
in dried bone with air, representing the sites of the original
bone (connective tissue) cells. In the process of ossifica-
tion, mineral matter comes to be deposited about the bone
cells, which finally disappear, leaving the lacunae as moulds
indicating their former site and size. The original bone
corpuscles (protoplasm) or cells, with their elongated
nuclei, may only be obtained from fresh (growing) bone
whose mineral matter has been dissolved out by hydro-
chloric acid.

Fourth,

The Canaliculi.

These are the minute wavy canals which make communi-
cation between different lacunae, between lacunae and Haver-
sian canals, and between lacunae and the general medullary
cavity (the marrow). They merit the diminution appended
to their name, as they measure but from so£>-<roo of ari incn

156 THE COMPOSITION OF BONE.

in length and ^ of an inch (0.0514X0.0008 mm.) in width.
Whether the contractile bone protoplasm protrudes filiform
processes into these tubes, or whether they permit to
circulate in their interior, nutritive juices to ultra-vascular
parts, are questions still unsettled. That they may serve as
communicating tubes is proven by the appearance of mer-
cury in numberless points upon the surface of bone after
its insertion into the medullary cavity. Gerlach succeeded
in injecting bone with various coloring and hardening sub-
stances in the same way.

These are the four distinguishing characteristics of bone.
Any tissue which does not exhibit them under the micro-
scope, however analogous in all its properties, as the ivory
or the dentine of the teeth, is said not to rise to the anatom-
ical dignity of true bone.

The Chemistry of Bone.

Bone has been repeatedly analysed by the most expert
chemists, and though the results obtained have differed in
unimportant details, on account of the difficulty of freeing
its tissue from substances (fat, blood, etc.), with which it is
intimately commingled, the general conclusions remain
about the same. Thus bone is found to be composed of
two-thirds mineral and one-third animal matter, a3 the
following table, deduced by Lehman from the befat umxl v&es,
exhibits :

Composition of Bone.

Phosphate of Calcium, r 57

Carbonate of Calcium, -8

Fluoride of Calcium, «• 1

Phosphate of Magnesium, 1

Mineral matter, -.---. G7
Animal matter, 33

ioa

THE STUDY OF OSTEOLOGY. 157

The mineral may be readily separated from the animal
matter by maceration of the bone in dilute hydrochloric
acid. ' The size and shape of the bone remains perfectly
preserved by the animal matter left, which, however, is so
soft and pliable that long, slender, bones, like the clavicle
or fibula, may be tied in knots, or flat bones, like the scapula,
crumpled in the hand.

The animal matter may be likewise destroyed while the
mineral matter remains. When a bone is subjected to
sufficient heat in an oven to drive off (decompose) animal
matter, the bone first turns black from the carbon deposited
on its surface. The carbon is subsequently volatilised
(oxidised), however, escaping as carbonic acid gas, leaving
only the white bone ash. Though the size and shape of the
bone are still preserved in every particular, the cohesion of
its particles is nearly destroyed, the whole structure crumb-
ling away on the slightest touch. The bones in the ancient
catacombs are thus wholly, or in part, reduced by the
gnawing tooth of time.

Difficulties Attending the Study of Osteology.

If bones be exposed to the air and sun during this pro-
cess of reduction, they gradually dry up and bleach to the
color and consistence of their mineral constituents. It was
only from such specimens, rejected by the Tiber, or found
upon the battle-fields of slaughtered Germans, that the
ancient Romans could prosecute their studies in osteology.
What bones escaped cremation with them had to be
religiously consigned to putrefaction in the earth. Galen
was compelled to travel from Pergamos to Alexandria to see
a perfect skeleton. It is highly probable that he never
opened a human body, as his descriptions of organs are
only those of the ape and dog. "The age in which he lived,
says the historian, offered, yearly, thousands of human lives

158 GELATINE AS AX ALIMENT.

to the caprice of the Roman people, and their cruel Emperor
even cast them as prey to the wild beasts of the Coliseum,
but would not grant one single dead body to the study of
science" (Hyrtl).

Bones as Fuel.

So long as the animal matter of bone remains, however,
it is, of course, combustible, and is even used as fuel in
places where ordinary fuel is scarce. Thus in the Falkland
islands, where trees are few, the inhabitants roast the flesh
of cattle upon fires made from the bones mixed with turf,
and Darwin, in his Voyage Round the World, relates that
the Guachos in South America, where there was very little
brushwood for fuel, soon made, to his great surprise, a fire
nearly as hot as coals, from the skeleton of a bullock lately
killed, whose flesh had been picked away by the carrion
hawks. They told him that in winter they often killed an .
animal, cleaned the flesh from the bones with their knives and
then with these same bones roasted the meat for their suppers.

Gelatine as an Aliment.

When bone is boiled with water, its animal matter is con-
verted into gelatine, proof that bone cartilage is not common
cartilage, which, when boiled, yields chondrin, a very
different substance. Though the gastric juice will attack
and dissolve gelatine, it has very little, if any, nutritive
properties, and should never, in any of its forms (jellies,
isinglass, Iceland moss), be relied upon as an article of diet.
It has the semblance only, not the substance, of food. The
gelatine and the marrow having been extracted from in-
gested bone, the mineral matter escapes with the feces.
Such hard, white, feculent, matter from the dog was admin-
istered as a remedy to epileptics in old times, under the

RESISTANCE AND RESILIENCE OF BONE. 159

classical name of "Album Grecum." It is a subject for con-
gratulation that the therapy of this disease has been somc-
what improved since then.

The Resistance and Resilience of Bone,

The proportions in which the animal and earthy matter
are united in bone endow it with its peculiar combination
of properties, resistance and resilience. Bone has twice the
resisting force of solid oak and nearly three times as much
as ash or elm. The elasticity or resilience of bone, aided by
the cartilaginous structures to which it is attached, enables
it to greatly economise muscular force. For example, the
return of the thorax after inspiration, that is, the whole force
of tranquil expiration is effected by the elasticity of the ribs
and cartilage, and the deflected spinal column resumes its
original position in the same way with the ease and grace of
motion observed in a bent spring when the force has been
relieved. Bone resilience is readily demonstrated on the
skeleton by the force required to hold the fibula against
the tibia. When the clavicle, detached and held at a right
angle to a hard surface, is struck upon the end with a ham-
mer, it will rebound to a distance of two feet or more. The
equal and much greater concussion, often received upon
various parts of the body, is dissipated and lost, on account
of the elasticity of bone, before reaching the delicate organs
enclosed. The relative resistance and resilience of bone is
exhibited in the experiment of Bloan, who found that a
square inch of it (cross section) only broke under a load of
368-743 hundred- weight, while a square inch of copper rod
gave way under 340 and of Swedish wrought-iron under 648.

Constancy of Chemical Composition.

So admirably are the organic and inorganic matters
blended in bone to secure the properties and subserve the
purposes required, that any variation in their proportions

160 CONSTANCY OF CHEMICAL COMPOSITION.

in the different bones of the same animal, or at different
periods of life, or even among different animals, is exceed-
ingly small. There is a little more earthy matter in the
long bones of the extremities than in those of the trunk,
and a little more in the larger bones of the extremities than
in the smaller, but the increase is very slight and is in no
way proportioned to the density or hardness of bone, which
is determined solely by the compactness of its tissue. Thus
the flexible, semi-transparent, easily divided, bones of the
fish contain as large a proportion of earthy matter as the
ivory-like leg bones of the deer or sheep. Bibra found the
proportions of animal and earthy matter, contrary to the
statements usually made, very nearly the same in the bones
of the foetus of seven months, in those of a man of thirty
and in those of a woman of seventy-eight, and Dr. Stark
concludes from his numerous analyses "that the amount of
earthy matter in healthy bones is nearly uniform over the
whole animal kingdom; and that neither the solidity or
sponginess, the rigidity or flexibility, the opacity or trans-
parency of bone depends on an increased or diminished
amount of the earthy matters in its composition." It is
this constancy of composition which justifies the belief
that the union of the animal and earthy matters is not
mechanical, but chemical.

The differences in the bones at different periods of life,
usually ascribed to variations in the amount of earthy
matter, depend entirely upon variations in the amount of
bohe substance, not at all upon variations in its physical
construction. A foetal bone is just as dense and as hard to
cut with a knife as an adult bone ; it is more flexible
simply because there is less of it. It is the difference be-
tween a little stick and a big stick of the same wood. The
child's bones are lighter in correspondence with its nimble
and incessant movements, the bones of the adult are

RACHITIS AND OSTEOMALACIA. 1G1

heavier and stronger in correspondence with the force of
his muscles, and the old man's bones are lighter again in
correspondence with his slower and more cautious move-
ments. But the difference is entirely due to the deposition
and absorption of bone matter in correspondence with the
general nutritive force. A fracture of a child's bone
unites more rapidly and of an old man's bone more slowly,
not because of more animal matter in the child and less in
the old man, but because of the high activity of nutrition
in youth and its gradual failure in advancing age. The
difference in the strength of bone thus induced in the physi-
ological decay of age may be made manifest by direct ex-
periment. Thus a prism from a cross section of the fibula
in an adult aged 30 breaks under a weight of 33 lbs. (15.03
kilogrammes), while the same sized prism from the same
bone in an old man aged 74 breaks under a weight of 9} lbs.
(4.33 kilogrammes).

Rachitis and Osteo-Malacia.

There are, however, certain diseased conditions which
very greatly disturb the proportions of animal and earthy
matter in bone, and thus lead to most disastrous deformities.
In rachitis (rickets) and osteo-malacia, for instance, both
the phosphate and carbonate of lime are often reduced to
less than a quarter of their usual quantities. In rachitis, the
mineral salts are withheld from the bone in the blood. In
osteo-malacia, these salts were originally deposited but have
been subsequently absorbed. Great care has to be exercised
with rachitic children, as the bone yields to every pressure.
Disfigurations of the head ensue from too long decubitus in
one position, and deformities of the pelvis, such as in after-
life may greatly embarrass the accoucheur, result from too
long support of the child in one posture upon the arm of
the nurse. Fortunately, this disease, which is an expres-

14

162 THE PHOSPHATE OF LIME.

sion of innutrition, is very rare in our land of plenty. In
his nutritive experiments upon birds, Chossat found in
withholding the salts of lime from their food, that not only
were the mineral constituents of bone diminished, but also
the animal. All the ingredients were uniformly lessened,
and in progressive inanition the per cent, constitution
of bone undergoes no change.

The Phosphate of Lime.

The phosphate of lime comes to be selected in preference
to the carbonate in the manufacture of bone, because it
forms a more tenacious compound with organic matter.
The carbonate is far more abundant than the phosphate of
lime and is principally used in the construction of shell.
Shell is very fragile and brittle, as compared with bone,
but shell is not subjected to the same demands for strength.
Where force is to be exerted or resisted, as in the vertebrate
animals, the presence of animal matter becomes a necessity
and with the animal matter, the phosphate of lime. In the
hardest of all animal structures, the enamel of the teeth,
organs which lie between a hammer and an anvil, as it were,
the phosphate of lime is present in the proportion of over
80 per cent. This salt must be furnished, therefore, in
quantity by the food. Accordingly, it is found in great
abundance in the nutritious vegetables, as in the various
cereal grains, for which it furnishes, in turn, the most valu-
able manure. The drinking water, too, however pure or
soft, always contains a notable quantity of the salts of lime.
Thus Boussingault observed that a milk cow ingests as
much as an ounce (fifty grammes) of mineral water per day
from the drinking water alone. "By causing one hundred
head of cattle to drink of certain potable waters, this same
observer found that he could recover yearly from their
manure, seven to eight hundred kilogrammes (1540-1760 lbs.)

THE PRESERVATION OF BONE. 163

of mineral salts "eminently useful to vegetation," among
them phosphorus, sulphur, chlorine, silex and the alkalies.
It is a point of extreme physiological interest, the fact that
of all the albumenoids used as food, casein, the chief con-
stituent of the milk, is most remarkable for the large
quantity of phosphate of lime which it is capable of holding
bound up with it, and the tenacity with which it retains it.
The rapid growth of the bones during infancy receives, thus,
satisfactory explanation.

Preservation of Bone.

The intimate union of the animal with the earthy matter
preserves bone from decomposition in remarkable degree.
Thus Bichat found that clavicles which had been exposed
for ten years to the action of the wind and rain in the
cemetery of Clamant, still presented, under the action of an
acid, an abundant cartilaginous basis. Orfila relates that
the bones of King Dagobert, exhumed from St. Denis after
1200 years, were still preserved. This distinguished chemist
actually obtained as much as 27 per cent, of gelatine from
bones known to have been 600 years old. Liman states that
he is in possession of an ulna which was dug up in Pompeii
in 1844, in the presence of Casper, from ashes in which it
had lain for nearly 1800 years, in such perfect preservation
that it may still be used for purposes of anatomical demon-
stration. Davy found in a frontal bone exhumed from
Pompeii 35} per cent, organic and 64} per cent, mineral
matter, and Haller claims to have obtained gelatine from the
bones of a mummy 2000 years old. But what are these
insignificant periods of time to the geological eras which
have elapsed while bone has been still preserved ? Fossil
bones, long antedating the existence of man upon earth,
are often found to exhibit the same true proportions of

164 BONE, A CONNECTIVE TISSUE.

animal and mineral matter. Thus Davy found in the tooth
of a mammoth 30.5 parts animal to 69.5 mineral matter.

Bone, a Connective Tissue.

Notwithstanding its great importance, bone does not
belong to the primary or original tissues of the body.
Many of the remaining tissues are far advanced in develop-
ment before bone puts in any appearance at all. Bone
belongs to the group of connective, or, as Kolliker has
better put it, the "sustentacular" tissues, but a subsequent
transformation or elaboration of this tissue is required to de-
velop bone. As any connective tissue may ossify, bone some-
times appears in strange and unwonted places. The skin, the
fibrous membranes (dura mater), the tendons, the sclerotic
coat of the eye, are naturally partly bony or contain bone
in some of the lower animals and bone not unfrequently
presents in these structures in man. Thus my colleague
Dr. W. W. Seely exhibited to the Cincinnati Academy of
Medicine an eye-ball which he had removed, containing a
capsule of bone covering the entire inner surface of the
choroid coat of the eye and referred to a case on record in
which there was a complete globe of bone covering the choroid
and extending across behind the lens. Most melancholy
are the cases of so-called myositis ossificans progressiva, in
which the inter-muscular connective tissue is converted into
true bone, locking up the action of the muscles as fatally as
in the fabled metamorphoses of Ovid. Cases of this terrible
disease has been put upon record by Rogers, Henry, Skinner
and Nikoladoni and our demonstrator of anatomy,
Dr. Iiansohoff, gives in detail in a recent number of The
Lancet and Clinic an account of a case which fell under his
personal observation, where "the process of placing
the patient on his feet involuntarily suggested that
of placing a statue upon its pedestal." Most of the

TILE FORMATION OF BONE. 105

cases of so-called ossifications of soft parts, however
(as in the larynx, the heart, etc.), turn out to be simple
calcifications (infiltrations with mineral salts), a very inferior
process to the development of true bone.

The Formation of Bone.

For the most part, bone is formed from cartilage. It is
more true to say that bone is formed in cartilage, for the car-
tilage that is to result in bone must entirely disappear
before bone tissue can develop. The inter-cellular spaces
in cartilage dissolve away, leaving medullary canals, and
the cartilage cells become enclosed in lime salts (calcined)
as the first step in the process of ossification. Then the
calcified cartilage itself undergoes liquefaction and young
formative cells (probably lymphoid cells of the blood),
emigrated from advancing bloodvessels, penetrate the
cartilage cavities to become, some of them at least, genera-
tors of the osseous tissue. These "osteoblasts," as they are
now called ; later, they are the stellate bone cells ; secrete
from their interior a thin layer of homogeneous, opalescent
matter, which is subsequently infiltrated with the salts of
lime, to constitute the first layer (lamella) of true bone
tissue. A repetition of this process produces the successive
layers or strata of bone about the bloodvessels, now known
as the Haversian canals.

The vessels in the membrane enveloping bone, the peri-
osteum, which is at first highly vascular, likewise furnish
osteoblasts for the development of successive layers of bone
about its circumference.

There is, however, some exception to the rule that bone
is moulded first in cartilage. For the flat cranial bones,
the upper and lower jaw, the nasal, lachrymal and palate
bones, the vomer, zygoma and finally the inner leaf of the
wings of the sphenoid and the cornua sphenoidalia, in short,

166 THE TEllIOSTEUM.

many of the bones of the face and all the bones of the head
(except the base of the occipital bone, which is often described
as a separate bone belonging to the spinal column), develop
from membrane, that is, from the periosteum or pericranium
in the site of the future bone. In all cases, however, the
process is essentially the same.

So active is the power of the periosteum in the production
of bone that the endeavor is always made by the surgeon to
save it as much as possible in exsectionsof dead bone tissue-
Great masses of bone, the entire clavicle for instance, may
be reproduced, if the under (generating) layer of periosteum
be left uninjured. Indeed, Oilier has found that pieces of
periosteum transplanted from one part to another or from
one animal to another will beget bone even in places where
it must be regarded as a foreign body.

The Periosteum.

The bones, thus, do not lie naked in the body. They are
all clothed with a dense fibrous membrane, the periosteum,
which, in the first place produces the bone tissue, or repro-
duces it after injury, from its under surface, and then,
thickening as the bone develops, isolates and protects it
from circumjacent tissues. The periosteum thus acts as a
barrier against the invasion of disease. The shin bone, for
instance, is long protected against damage from the so
frequent and so extensive ulcers of the leg. In cases where
the periosteum is scant or insufficient to cover the entire
surface, superficial inflammations easily dip down to
involve the underlying bone. That the slightest wounds or
contusions of the ends of the ringers may extend to the
insufficiently covered bone beneath is proven by the frequent
occurrence of those painful affections known as whitlows or,
with us, as felons. Hence the advantage of free and early
incision in their treatment to permit escape of the products

THE DETERMINATION OF AGE. 167

of inflammation. Lastly, the periosteum is a surface sheet
of fibrous tissue wrapped, as it were, about the bone to give
firm origin and fixed insertion to muscles, ligaments and
tendons.

The Centre of Ossification.

The point at which the osteoblasts begin to form and
from which the bone-making process irradiates to the whole
structure is known as the "centre of ossification." But the
period of time at which this centre appears does not at all
correspond to the deposition of the primordial cartilage
in the site of the future bone. Thus the cartilage of the
vertebra, the so-called notochord or chorda dorsalis, appears
in the earliest days or weeks of development, while the first
points of ossification show themselves about the beginning
of the second month almost simultaneously in the clavicle
and lower jaw.

The Determination of Age.

As the exact period of time in which ossification com-
mences in the various bones, and the rate at which it ad-
vances, have been definitely ascertained, it may be readily
understood that we possess in such data the means for accurate
estimate of the age of the bones or of the body. Beale has
discovered that immersion of the body of the foetus, or the
new born child, in alcohol and soda (8 to 10 drops of solution
of caustic soda to the ounce of alcohol) renders the soft parts
so translucent or transparent, without affecting the earthy
matter, that the stage of ossification in the different bones
becomes at once visible to the eye.

Or the age may be determined by the size or length of the
bones. Giinz has carefully prepared for this purpose a table
of the dimensions of the various bones at birth.

168 THE FEMORAL EPIPHYSEAL CENTRE.

The Femoral Epiphyseal Centre.

But the readiest method of deciding the question of
maturity at birth, a question of great importance from a
forensic point of view, was first established by Beclard, and
subsequently elaborated by Ollivier, Hartmann and Mild-
ner. These investigators found that the most reliable sign
of an advanced process of ossification was the presence of a
"centre" in the lower end (epiphysis) of the femur. This
centre develops in the second half of the last month of preg-
nancy, before the existence, thus, of any epiphyseal centre
in any other long bone of the body. Section of the epiphy-
seal cartilage of this bone discloses to the unaided eye, in
the centre of the milk-white, cartilaginous, mass, a more or
less circular, bright, blood-red, disk, whose density easily
distinguishes it as bone in the softer tissue about it. The
comparative imperishability of bone makes this sign all the
more valuable, as it may always be discovered though de-
composition of the remaining structures shall have been far
advanced. In such cases it loses its bright red color, be-
coming of a dirty yellow hue, but it still stands prominently
forth and differentiates itself from the surrounding decom-
posing, reddish, matter by its color and its hardness. Once
seen, it will be always* recognised again. In very small
bones, it must be hunted out with a lens, but in bones of
average size, it is plainly visible to the eye. Li man states,
as the result of G20 observations, that the presence of this
nucleus of bone, with a diameter of over nine millimetres
(4 lines), is the most unmistakable proof that the child was
born mature. A less diameter (3 lines) would, of course,
not disprove maturity at birth, as the bones in some indi-
viduals are unusually small. Cases are narrated by Liman
and Ollivier where decomposed and mummified parts
only were found, and yet maturity at birth was thus
established.

THE EXCAVATION OF BONE. 169

The Excavation cf Lone.

As bone grows upon its exterior it is absorbed from the
interior of its mass. This process of interior absorption oc-
curs in all bones alike, regardless of their size, or shape or
use. Thus the bones, in all cases solid at first, become
hollowed out inside. In the long bones, a great cavity (the
medullary cavity) results, in the flat and irregular bones, a
multitude of small communicating chambers. This spongy
or cancellated tissue left by the absorption of the bone has,
of course, the same texture and composition as the still
compact external layer. But its physical properties differ.
That is, it is lighter and softer, and hence is better fitted to
resist and disperse force. Yet the whole bone loses, in this
loss of substance, little or none of its strength. For the
long bones are thus converted into tubular structures, and
every one, familiar with mechanics, is aware of the greater
strength of the same amount of substance arranged in
tubular over that in solid form. The flat bones, as in the
cranium, become, thus, three tables, of which the outer and
inner are compact, and the central, the diploe (from 61a, -kIeu
to fill through, not from 6i~7,oog double), is spongy tissue.
The excavation of bone tissue in this way, the stuffing of it,
as it were, with resilient tissue, aided, of course, by the
general arched form of the bone, so disseminates, lateralises
and absorbs shocks, in the case of the cranium, for instance,
that the brain is seldom injured by a force insufficient to
crack the skull. The irregular collection of seven or eight
obliquely moulded, soft, bones at the wrist and ankle, bound
so firmly together by ligaments as to practically be one
bone, and yet movable enough to permit wide range of
motion, is an admirable example of the advantage of can-
cellated structure in dissipating shocks as received upon the
hands and feet. The jaw bones, at their free edges, would
be chipped away under the chopping and grinding action of

15

170 AIR IN BONE.

the teeth, were it not for the cushion of spongy tissue (the
alveolae) in which the teeth are embedded.

But this interior absorption of bone does not occur in a
hap-hazard way. If a long bone, for instance, be split in
two, lengthwise, it will be seen that the spongy tissue is
arranged in a definite manner, that is, that the individual
layers of bone, thus resulting, run in definite directions.
Such directions are most markedly manifest about the
heads and extremities of the long bones. The interior
plates here form pillars, arches, buttresses, braces, so con-
structed as to most effectually receive and transmit weight
from the articular surfaces to the compact tissue of the
shaft. This architecture of bone, as it is called, has re-
ceived able exposition at the hands of a number of observers,
Wolfmann, Meyer, and others, in terms of highest admira-
tion. Indeed, the internal architecture of bone was at^one
time triumphantly singled out as an evidence of design in
creation. It is hardly necessary now to state that natural
selection achieves, in the courses of ages, the highest order
of design.

Air in Bone.

The excavation of the interior of bone secures to bones
their lightness. Hence it meets its highest expression in
birds, where the number of bones into which air is admitted
is directly proportionate to the powers of flight. When the
trachea is tied in some birds, respiration may be sustained
for a time through an aperture made in the arm (wing)
bone. Thus, in the swift, air finds its way into most of the
bones ; whereas in the ostrich and its allies, the shafts of the
long bones are partly occupied by spongy tissue, and in the
apteryx, none of the bones receive any air at all (Humphrey).
In fishes, supported as they are, by water, all the bones are
solid, as they are during the aqueous (intra-uterine) stage

THE MARROW. 171

of life in man. The facial bones in all mammals (including
man) are mere shells filled with air for the sake of lightness.
The suppression of these bones in man to give range and
prominence to the higher organs of sense, and their com-
parative lightness are distinguishing characteristics of the
human skull and skeleton to secure the vultus ad sidera.

The Marrow.

The next lightest medium to air is oil. Hence we find
the bones of most land animals filled with liquid fat. The
long bones of the adult contain a marrow of which 96 parts are
oil. Large reservoirs are thus inserted in the body, of this
highly nutritious substance, upon which draft is made in in-
sufficient alimentation or inanition from any cause. The
quantity of oil present in the bones is thus indicative of the
health and vigor of the body ; hence the force of the com-
ment of Job upon a man in the prime of his strength, "his
bones are moistened with marrow." Timon of Athens
says "consumptions sow in hollow bones of man," and Lucio
(Measure for Measure) remarks upon the effects of chronic
syphilis in the accusation "thy bones are hollow ; impiety
has made a feast of thee." It has occasionally happened, as
an anomaly of development, that this process of internal
absorption of bone has not taken place. The bone then re-
mains solid (compact) throughout. The celebrated anato-
mist of Holland, Frid. Ruysch, is said to have possessed a
fork whose handle had been turned from a solid human
bone.

Studies in Living Bone.

In our studies of bone, dead and dried, as in anatomical
specimens, we are apt to forget that bone in the body lives.
Bone is as much alive as brain or blood. It absorbs,
breathes, secretes and reproduces itself like every other

172 STUDIES IX LIVING BONE.

living tissue. It has been shown by Oilier that so long as
bone tissue retains its vitality, it may be removed from one
animal to another, or be transplanted to A'arious parts of the
same animal, and not only continue to live, but also increase
in bulk.

The absorptive power of bone is elegantly exhibited by
feeding animals with coloring matter having an affinity
for the phosphate of lime. It was long ago accidentally
discovered by Belchier that madder fed to pigs imparts its
color to the bones. If the animal be very young, the whole
skeleton may be thus colored in a single day. In older
animals, the coloration is more slow and less perfect, only
the growing parts of the bone, as at the ends and surface,
assuming color. Periodically administered and withheld, it
produces alternate layers of red and white. Belchier first
used this agent as a means of studying the growth of bone,
and Tomes prepared beautifully colored specimens in this
way. That long bones grow in length only at the ends,
after ossification of the shaft, was conclusively proven by
the experiments of Hales and Hunter, who inserted into the
shafts metallic substances, certain distances apart, and
found, after an interval of time, that the distance between
them remained the same, while the extremities of the bones
wTere much further apart. And that bone grows upon its
surface and is hollowed out in its interior, was as conclu-
sively proven by du Hamcl, who put a silver ring on one of
the long bones of a pigeon, and found it later in the
medullary cavity, which had the same diameter as the ring.

Use and disuse exercise the same influence upon bone as
upon other living tissues. Bones increase both in thickness
and length when called upon to support heavier weights.
Different occupations vary the size of the bones iu all direc-
tions. These variations are exemplified in the osseous
changes manifesting themselves upon the domestication of

STUDIES IN LIVING BONE. 173

wild animals. The leg bones, under conditions of security
and plenty, greatly increase in size, while the wing bones
diminish. The legs of sailors employed in the late war were
longer by 0.217 of an inch than those of the soldiers;
though the sailors were, on an average, shorter men ; while
their arms were shorter by 1.09 of an inch, and therefore
out of proportion shorter, in relation to their lesser height.
Bengger attributes the thin legs and thick arms of the
Payaguas Indians, to successive generations having passed
their whole lives in canoes with their lower extremities
motionless. Darwin, in his Descent of Man, from which
work these examples are cited, gives abundant evidence ex-
hibiting the changes occurring in different bones under
different conditions. Thus in long-eared rabbits, even so
trifling a cause as the lopping forward of one ear, drags for-
ward on that side almost every bone of the skull ; so that
the bones on the opposite side no longer strictly correspond.
The life of bone is strikingly shown in the absorptive
changes which ensue upon long continued pressure. The
flat heads of Indians, short feet of Chinese, and bent ribs of
more civilized races, are all proofs of the yielding of bone
under distorting pressure. Not very long ago, a case was
reported in Vienna, where a young girl died of inflamma-
tion of the brain caused by the long continued and gradually
tightening pressure of an elastic cord used to confine a net
for the hair. The cord had absolutely cut through the
cranium to the brain.

Quite recently, M. Oilier has shown that it is possible, by
irritating the ends of bones, or the periosteum upon their
surface, to greatly alter their size and shape. We may thus
secure, he claims, a harmony of development between two
parallel bones, on the one hand, by increasing the activity
of development of the bone in arrears, on the other, by re-
tarding or checking the development of the bone in excess.

174 BONE AS A SYMBOL OF THE BODY.

Nothing, however, has so much elevated the physiological
dignity of bone as the recent revelations of Neumann and
Bizzozero, to the effect that a vast number of the blood
corpuscles, the most essential element of this most essential
fluid, are developed in the marrow of bone. These observers
have discovered in the marrow all the transition forms
between the white lymph corpuscles and the red blood cor-
puscles, so that bone comes to rank with the liver and the
spleen as one of the cradles in the rearing of the blood.

Bone is often used as a symbol of the whole body.
"Flesh of flesh and bone of bone" is the phrase used to ex-
press the intimacy of the conjugal union. "Was not from a
rib in the same symbolic sense developed the whole female
body ? Schiller says jestingly : — •

"Behandelt die Frauen mit Nachsiclit!
Aus krumraer Rippe war sic erschaffen,
Gott konnte sie nicht ganz grade machen,
Willst du sie biegen, sie bricht."

(Handle a woman with care!
She was made from a crooked rib,
God could not make her perfectly straight,
If you bend her, she will break.)

But it was reserved for M. Frederic de Rougemont,
a distinguished theologian, to solemnly announce a
satisfactory reason why "God in his infinite wisdom
selected the rib in preference to any other bone of Adam's
body." He says: "Pie took no piece of the head — woman
would then have had too much intelligence ; He took no
piece of the legs — woman would then have been too much
on the move ; He took a piece near the heart, that woman
should be all love !" Gretchen sings in her utter desolation :

? Wcr fuhlet

Wie wtihlet

Dcr Schmerz mir im Gebein.

(Who fcc!s, how rages, the pain in my bones.)

MUSCLE AND ITS PROPERTIES. 175

Agamemnon (Troilus and Cressida) is addressed :—

"Thou great commander, nerve and bone of Greece."

and when Achilles, later in the same play, wished to express in
the death of Hector, the total overthrow of Troy, he exclaims :

"Now Troy sink down,
Here lies thy heart, thy sinew and thy bone."

LECTURE IX.

MUSCLE AND ITS PROPERTIES.

CONTENTS.

Etymology of Muscle — Muscular Motion — Striped and Smooth Muscle
— The Color of Muscle — The Anatomy of Voluntary Muscle — The
Sarcolemma — The Muscle Fibre — Muscle Protoplasm — General Prop-
erties of Muscles — Names of Muscles — Form and Shape of Muscles —
Smooth Muscle— Disposition of Smooth Muscle — The Chemistry of
Muscle — The Reaction of Muscle — Specific Properties of Muscle —
The Elasticity of Muscle — The Tonicity of Voluntary Muscle —
Tonicity, a Reflex Phenomenon — Tonicity of Involuntary Muscle —
The Sensibility of Muscle — Sensibility and Sensation — The Sensation
of Fatigue — The Exercise of the Muscular Sense.

Etymology of Muscle.

The muscles are the active organs of motion. The word
bone (Saxon, ban ; Swedish, ben ; Danish, been ; German,
bein), means something set or fixed. The word muscle
(Latin, musculus) originates, according to some etymologists,
from [j.vr, a mouse or rat, because the ancients compared the
muscles to flayed rats or mice, but is more probably derived
from (iveiv, to move, motion being the most striking and dis-
tinguishing property of this tissue. Brawn, an old English
synomim. of muscle, expressed the fact that the bulk and

170 MUSCULAR MOTION.

strength of the body was expressed or made manifest in its
flesh or muscle.

Muscular Motion.

Though the mere existence of motion can not, as once
taught, be accepted as a point of differentiation between
animals and plants, because it is a protoplasmic endowment
common to both, nevertheless a high degree of it and a
ready exhibition of it does distinguish animals high in the
scale of development. All visible motion is produced solely
by the action of muscles. The complicated movements of
the higher forms of animal life require a great number of
muscles, properly disposed and adjusted in their arrange-
ment, quickly responsive in their action, and nicely poised,
coordinated, and antagonised, in their effect. In man there
are, subject to the control of his will, over one thousand
muscles, whose mass constitutes half the bulk or volume of
the body.

Besides these so-called voluntary muscles, this tissue in
the form of fibres or layers enters into the composition of
nearly all the organs of the body connected with the vege-
tative life. The digestive, respiratory, circulatory, genito-
urinary, etc., systems are in part constructed of muscular
tissue whose insensible action is involuntary, that is, beyond
the control of the will.

Striped and Smooth Muscle.

The voluntary are readily distinguished from the in-
voluntary muscles under the microscope by the fact that
the voluntary muscle fibres are striped while the involuntary
are smooth. Yet there are some exceptions to this rule.
The muscle-substance of the heart, for instance, is striped,
though its action is entirely beyond the control of the will,
as Is also that of the pharynx, of the rectum and urethra.

THE COLOR OF MUSCLE. 177

Wherever promptitude of response and power of contrac-
tion is needed the muscular tissue is always striped, whether
voluntary or not.

In man and the higher vertebrates these two varieties of
muscular tissue are distinctly separated, but in the lower
vertebrates, and still more markedly in invertebrates, transi-
tion forms occur. In the echinodermata (star-fish, sea-
urchins, etc.), all the fibres are smooth, as also, in the rule, in
the molluscs. In the helminths the muscular fibres are
almost always smooth, the only instance of striped muscle
existing, strange to say, not in the apparatus of locomotion,
but in the uterus of the echinorhynbhus nodulosus (Leydig).
It should be stated also in this connection that some fibres
which were formerly regarded as smooth are now known to
be striped. Thus Margo discovered that the closing muscle
of the bivalves, hitherto described as unstriped, under high
magnification and fine definition, distinctly exhibits very
fine stride or stripes. And that the marked degree of differ-
ence formerly attached to the histological division of muscu-
lar tissue no longer holds good is evidenced by the fact,
reported by Vierordt, that the same organ in different ani-
mals has sometimes striped and sometimes smooth fibres to
accomplish the same purpose. In the body of man, the
heart, whose action is involuntary, is composed of striped
muscle, while the accommodation of vision for objects at
different distances, a voluntary act, is effected by the un-
striped, involuntary, choroid muscle.

The Color of Muscle.

The deep red color of striped muscle, is partly due to
the blood which circulates throughout its substance, in a
rectangular network of capillaries, whose distribution is
among the finest in the body. The cruel custom prevailed
among butchers, formerly more extensively than now, of

178 THE SARCOLEMMA.

subjecting young animals, calves, etc., to frequent bleedings
before final slaughter in order to render the flesh more
tender. The butchers were said to "bleed the animal
white" as the muscle thus became much paler in hue, but
no abstraction of blood will make muscle absolutely color-
less. Even though a muscle be washed free of blood
outside of the body, or water be injected into its vessels
until it escapes colorless, the muscle substance will still
preserve a distinct amber hue, which may be regarded as the
intrinsic color of muscle protoplasm. Kolliker observes
that the color of muscle is duetto the presence of a coloring
matter analogous to, but independent of that of the blood,
and Fremy has given to this peculiar yellow coloring
matter, in the case of the salmon and other fish, the name,
salmonic acid. Kiihne and Eanvier washed out red muscles
with "artificial serum" (a half percent, solution of common
salt) and established the fact that the color of muscle is not
due to the presence of blood, but to haemoglobin.

The Anatomy of Voluntary Muscle.

Striated muscles, of the size and shape adapted for the
special purpose, consist of bundles, fasciculi, aggregated in
mass, and enveloped in firm but elastic sheets of connective
tissue, which also sends in partitions to surround the smaller
bundles within. These smaller bundles, with intervening
bloodvessels, connective tissue, and fat masses, are distinctly
visible on cross section of a muscular mass. In longitu-
dinal separation of the bundles, we finally arrive at the
ultimate muscular fibre, with its investing sheet of connec-
tive and elastic tissue, the sarcolemma.

The Sarcolemma

forms both the dura and pia mater of the muscular fibre
in that by its density it contains the diffluent muscle

THE MUSCLE FIBRE. 179

protoplasm arid restrains it from undue dissemination, by
its surface it gives space for the rich network of vessels
to convey the blood needed in such abundance for muscle
work ; then by its elasticity it greatly economises muscular
force. The transparent, homogeneous, closely adherent,
sarcolemma or primitive sheath is readily exhibited by
forcibly breaking the fibre in two, continuity being still
maintained by the firm, though delicate sheath. On long
maceration in water the sarcolemma is raised in blisters
(blebs) upon the surface of the fibre.

The Muscle Fibre.

The muscle fibre itself is one of the most complex struc-
tures in the animal economy. By long maceration in water
or alcohol, or more especially in solutions of the bichromate
of potash, it splits up into 3-500 finer fibrilla3 running
parallel with each other throughout the length of the fibre.
By maceration in very dilute hydrochloric acid or in gastric
juice it separates into transverse disks with complete ob-
literation of the longitudinal markings of the fibrillse. It is
a question still unsettled as to which of all these structures,
the fiber, the fibrilla or the disk is the ultimate anatomical
element. If the muscle tissue be separated in both direc-
tions, transversely and longitudinally, it is divided into
minute rectangular prisms or caskets, and in sections of
frozen muscle the outlines of these prisms are made apparent
with their intervening cementing substance. Bruecke has
quite recently discovered that the sarcous elements them-
selves are not elementary and simply solid bodies, but
groups of smaller doubly refractile bodies which he calls
"disdiaclasts" after the phrase employed by Bartholin, the
discoverer of double refraction in calc spar. Immersion in
wTater obliterates all traces of the sarcous elements and dissi-
pates the appearance of striatiou in the muscular fibre.

180 THE GENERAL PROPERTIES OF MUSCLE.

In the present unsettled state of opinions upon the sub-
ject, we shall continue to regard the muscular fibre, with its
enveloping, nucleated, sarcolemma, receiving the last distri-
bution of the vessels and nerves, as the ultimate, anatomical,
element of striped muscular tissue. The fibre is the cell
and the sarcolemma is its wall. Krause has repeatedly-
teased out muscle fibre under various reagents and found it
never more than 4 ctm. (1.6 inch) in length.

Muscle Protoplasm.

The proper protoplasm of muscle, in its living state, is
soft, even semi-fluid. For some time after removal from the
body the fresh surface of a mass of muscle in the butcher's
stalls trembles or palpitates under a current of air. The
difiluence of muscle is seen to advantage in the wave-like
flow of its protoplasm towards the negative pole on the
application of electricity. So long as it is not excited, it
follows gravity in all directions. Kuhne has seen a filaria
swimming about among, and winding in between, individual
sarcous elements without injuring or displacing them, the
muscle protoplasm closing in behind it, without leaving any
line or trace of its track.

The muscle fibres collected into primary bundles, fasciculi,
and these again into larger, secondary and tertiary bundles
finally constitute, en masse, as we have seen, the individual
muscle.

General Properties of Muscle.

The muscles vary greatly in their shape, in their bulk
and in their weight. The vastus externus and the glutei
arc masses of muscular substance weighing pounds; the
small muscles of the middle ear weigh but a few grains.
There is full as great variety in their shape. Muscles are
long at the extremities, broad and flat in the trunk, short

THE NAMES OF MUSCLES. 181

and thick about the head and neck. The more fixed point
of origin is called the head or origin of the muscle, the more
movable point of insertion, the tail or insertion, the ex-
panded intervening portion is the body, the venter or the
belly.

Names of Muscles.

Hence are the names gastrocnemius, digastricus, biceps,
triceps, etc., bellied, double bellied, two and three headed
muscles, etc.

Muscles are also named according to their uses, as
diaphragm, buccinator, extensors, flexors, adductors, ab-
ductors, levators, depressors, tensors, dilators, etc. ; or, ac-
cording to their positions, as interspinals, interossei, sub-
clavius, popliteus, temporalis, occipito-frontalis, etc. ; or,
according to their shape, as trapezius, splenitis, lumbricales,
scalenus, deltoid, gracilis, etc. ; according to their dimen-
sions, as pectoralis major and minor, gluteus maximus,
medius and minimus; according to their composition, as
semi-membranosus, semi-tendinosus, complexus, etc. ; ac-
cording to their attachments, as sterno-cleido-mastoideus,
genio-hyo-glossus, etc.. The gemelli form a pair of twins,
the sartorius crosses the legs for the sartorial (tailor's)
posture, and the risorius produces a smile. "He who re-
jects with scorn," said Mr. Darwin, "the belief that the
shape of his own canines and their occasional great develop-
ment in other men, are due to our early progenitors having
been provided with these formidable weapons will probably
reveal by sneering the line of his descent. For, though he
no longer intends, nor has the power, to use these teeth as
weapons, he will unconsciously retract his 'snarling muscles,'
so named by Sir Chas. Bell, so as to expose them ready for
action, like a.dog prepared to fight."

182 THE FORM AND SHAPE OF MUSCLES.

Form and Shape of Muscles.

Muscles are said to be simple, when all the fibres are sim-
ilar in direction in a single body, as in the sartorius ; they
are compound, with one body and several heads or tails, as the
flexors of the fingers and toes ; radiated, when spread out like a
fan or a wheel, as the temporal and the diaphragm ; pennated,
when arranged like the feathers upon a quill, as in the
pal maris longus ; hollow, as in the heart, the uterus and the
bladder (Dunglison).

Most curiously arranged, finally, are those double bellied
muscles, which are caught at the middle by an attachment,
sometimes as by a pulley, and thrown off to exercise their
force in a different line from that assumed at their origin,
as the digastricus, and the superior oblique muscles of the
eyes.

These are mostly anatomical points, it is true, but are
mentioned here for the sake of exhibiting the individuality
of muscles.

Smooth Muscle.

The construction and disposition of the smooth involun-
tary muscle fibre is much more simple. It presents itself
in the form of elongated, spindle-shaped cells, whose ends
appear drawn out to lines of extreme tenuity, and
whose central nucleus, rendered more apparent under
the action of a strong acid, is a long cylindrical rod
with blunt or rounded ends. Sometimes the cell is
so much reduced apparently, by elongation, as to re-
semble the threads of filiform connective tissue. This i3
the case in the intestine, ureters and bladder. On the
other hand, in the trunk of the aorta, the smooth muscle
cell is so short, thick, and irregular, as to be with difficulty
distinguished from epithelial cells. It is only by following
out the vessel into its branches, where the cells begin to

THE DISPOSITION OF SMOOTH MUSCLE. 183

elongate, and observing the transition forms, that the dis-
tinction can be made. These shorter, thicker, cells would
seem to be a persistence of the embryonic stage, for at the
period of original development all the involuntary muscle
cells present this appearance. I may state here, parentheti-
cally, that, according to Lockhardt Clarke, muscular fibre
can be first distinguished in man, about the fourth or fifth
week of utero-gestation.

Disposition of Smooth Muscle.

Smooth cells, arranged side by side, dovetailing, at their
ends, with other cells, form the layers, thin and single, or
thick and multiple, by superimposition, which constitute an
essential feature in the walls of the various vessels, tubes,
bladders, etc., connected with the vegetative apparatus of
the body. Thus, they form the chief coat of the middle
sized arteries, two extensive layers (the submucous and sub-
peritoneal) of the intestine, an important constituent in
the walls of the bronchial tubes, extending down to and be-
tween the pulmonary alveolae, the middle coat of the gall
and urinary bladders, renal pelvis, ureters, and urethra.
They occur in the skin, in the form of small rods or
bundles (arrectores pili) attached to the hair bulbs, and con-
nected with the oil and sweat glands, or in the form of a
more continuous layer, as in the tunica dartos of the scrotum.
In the male organs of generation, smooth fibre is met with
in the ducts in, and leading out from the testicle, in the
large so-called glands (Cowpers and the prostate) at the root
of the penis, and forms an important ingredient in the con-
struction of the penis itself. In the female organs of gener-
ation, it is found in the ovaries, the round and broad liga-
ments, forms a coat in the walls of the Fallopian tubes, and
constitutes the bulk of the uterus, which is the largest mass
of it in the body. Thin layers and fine bundles of smooth

184 THE CHEMISTRY OF MUSCLE.

muscular fibre are also found in the mucous membranes (as
in the digestive tract), in the interior of solid organs (as in
the calyces of the kidney and in the spleen). Finally, of
this tissue are formed the involuntary muscles of the eye,
the contractors and dilators of the pupil, and the (ciliary)
muscle of accommodation. In short, all visible contractility,
independent of the striped fibres, is' due to the presence in
the organ or structure of this smooth, white and involuntary
muscular tissue.

The Chemistry of Muscle.
However much the two kinds of muscular tissue may
differ in appearance or in action, their chemical composition
h precisely the same. Three-fourths of the substance of
muscle is water. Of the remaining fourth, one-half is the
coagulable albumenoid principle peculiar to muscle, known
as myosin. Myosin may be separated from living muscle
by freezing it, mincing it, and rubbing it up in a mortar
with four times its weight of snow, containing one per cent,
of common salt (Kiihne). The resulting mixture, the
muscle plasma, as it is called, soon gelatinises to a firm
mass, which afterwards separates into a clot and surround-
ing fluid. The clot is myosin ; the fluid, muscle serum.
As the products of metamorphosis, there are found in
muscle numerous extractive matters, as creatine, xanthin,
hypoxanthin, sarcosin, inosite, and traces of uric acid,
though "urea is conspicuous by its absence." Nearly 80
per cent, of the ash of muscle is composed of the salts of
potash and phosphorus.

The Reaction of Muscle.

The reaction of fresh muscle, at rest, is neutral or faintly
alkaline, but during and after contraction it is acid. The
peculiar form of lactic acid found in muscle is directly gen-
erated by the oxidation of the carbo-hydrates of the blood,

THE SPECIFIC PROPERTIES OF MUSCLE. 185

and when small in quantity, as during rest of the muscle,
is neutralised by the alkalinity of the blood ; but when its
quantity is much increased, as during the rapid oxidation
attending contraction, it cannot be sufficiently neutralized
at once, and accumulates to render the muscle acid for a
time. So the free access of oxygen soon renders acid a
freshly dissected muscle, separated from the body. The
accumulation of acid in the muscle marks the stage of
weariness or fatigue. Ranke found that a frog's muscle
which had become powerless from fatigue was speedily re-
stored to activity after the injection (from the heart) of
very weak solutions of carbonate of soda, which carried off
the acid by presenting it a base. Fresh and active muscle
is speedily rendered powerless by the injection into its
vessels of even highly diluted lactic acid.

Specific Properties of Muscle.

The muscular is said to be one of the master tissues of the
body, and whether we regard the nature or the mere num-
ber of the properties wrth which it is endowed, there
appears to be justification for assigning it to this dominant
place. For muscle has the passive property of elasticity ;
that kind of constant, effortless, insensible, contraction known
as tonicity; a peculiar sensibility ; and, higher than all these,
a characteristic contractility, which makes itself manifest in,
and is, in part, the immediate cause of nearly all the phe-
nomena of animal life. In addition to all these properties,
muscle generates heat and electricity, and in its action pro-
duces sound, which is, however, an effect rather than property.

The Elasticity of Muscle.
Elasticity is a property possessed by muscular tissue in
high degree. The semi-fluid muscle protoplasm, is itself
somewhat elastic or resilient, and the sarcolemma, the in-
vesting sheet of connective tissue, is highly elastic. It is

16

186 THE ELASTICITY OF MUSCLE.

the extensibility and elasticity of muscles at rest which per-
mit the bones to be moved in different directions by antago-
nistic muscles, and it is to the property of elasticity alone,
or in great part, that is due the restoration of, so to speak,
displaced members to their former place. The purely
passive property of elasticity thus greatly economises active
muscular force. It is always ready, requires no innerva-
tion, and manifests its action at once. It permits the walls
of hollow organs, like the stomach, the bladder, and the
uterus, to be more or less distended, reacting all the time
upon their contents, to assist the active property of muscle
in securing their extrusion. The auricles of the heart, for
instance, are passively distended or dilated with the ease of
a soap bubble, by the influx of blood, and are emptied
almost entirely without the intervention of active muscular
force. The degree of elasticity is different, of course, in
different muscles, being dependent upon the size of the
muscle and the quantity of accessory structure (connective
and elastic tissue) it may contain. But the elasticity of
muscle far surpasses that of most other elastic bodies. A
bundle of silk threads or of metal wires will not suffer the
same extension without rupture. Muscle resembles more
closely a bundle of threads of caoutchouc or India rubber.
The specific elasticity of a substance is determined by the
weight or force required to extend it within the limits of
perfect restoration. If Ave compare, thus, different substances
with muscle, it is found that the weight required to extend
the one-thousandth of its length, a rod or thread of one
square millimeter diameter would be as follows :

Grammes. Grains.
Steel, - - - 17278000 (1151866)
Copper, - - - 10519000 (701266)

Pine wood, - - 1113000 (74200)

Frog's Muscle, - - 273 (18)

THE TON/CITY OF MUSCLE. 187

These figures represent the co-efficient of elasticity of the
different substances.

Of course, there are limits to the elasticity of muscle.
Thus Marey found that the detached gastrocnemius muscle
of the frog could be extended with a weight of 300 grains
to the degree of the one-fiftieth of an inch with perfect re-
covery after removal of the weight, while a weight of 750
grains completely disabled its elasticity. Moreover, rapidly
repeated subjection to experimentation diminishes and
finally exhausts the elasticity of muscle, inducing the re-
laxed and flabby state, characteristic of fatigue.

Tonicity of Muscle.

Tonicity has been described as insensible contraction of
muscle, inherent in the muscle protoplasm itself, and inde-
pendent of the nervous system. It was said to manifest
itself in the retraction of muscle cut across (gaping of
wounds), and in the distortion of the paralysed side of the
face in facial hemiplegia from traction by the sound side.
But recent experiments have clearly demonstrated that
both these phenomena are due to elasticity. The muscles
are always somewhat stretched beyond their normal length,
so that retraction of divided surfaces is a natural result of
section. Both time and force are thus economised by this
elongation and elasticity of muscular fibre. Muscles
stretched by the contraction of opposing muscles fairly
spring back to their former position without effort or loss of
time. When a muscle is separated from its attachments it
shrinks upon itself, and the muscular tubes (fibres) are seen,
under the microscope, not to lie in straight, but in wavy or
zig-zag lines. It is the advantage taken by the persisting
elasticity upon the sound side, of the impaired elasticity on
the affected side, that produces the distortion of the face in
facial palsy.

188 TONICITY, A REFLEX PHENOMENON.

Nevertheless, there is an insensible and involuntary con-
traction (tonicity) of all the muscles, both voluntary and
involuntary, which manifests itself in the muscles of the
skeleton as well as in the smooth fibre, where it secures a
certain tonicity of the vessel walls, of the sphincters, etc.

Tonicity, a Reflex Phenomenon.

But this tonicity is by no means an independent property
in the muscular tissue. It is derived entirely from the
nervous system, and is a purely reflex phenomenon. Up to
even a short time ago, this influence of the nervous system
upon the muscles, was regarded as an automatic, an original
or spontaneous action, developed in the spinal cord. It is
now known, however, that this action is excited by outside
(peripheral) influences, and is conducted through sensitive
nerves (from the skin, etc.) to the cord, whence it is trans-
ferred through motor nerves to the muscles. For it has
been shown by Brondgeest that section of the sciatic plexus
of nerves on one side in the frog, after division of the spinal
cord below the medulla oblongata, destroys the tonicity of
the muscles upon the operated side, while it is left intact
upon the sound side. When a frog thus operated upon is
suspended, all the joints upon the operated side hang loose
and flabby, while those on the sound side still retain their
natural degree of flexion. Liegeois cut the sciatic nerve in
the frog upon one side only, and then divided the gastroc-
nemius muscle upon both sides, when it was observed that
the retraction (gaping) was much less marked upon the
ope rated side.

That this influence from the nervous system is entirely
reflex is proven by the fact that section of the posterior (sen-
sitive) roots of the nerves has the same effect as section of the
entire nerves. Moreover, after section of the posterior
nerve roots, a stronger irritant must be applied to the

THE TONICITY OF INVOLUNTARY MUSCLE. 189

anterior roots to produce the same convulsive movement
in the muscles, proof that additional artificial, is required to
substitute the lacking natural, stimulus.

Tonicity of Involuntary Muscle.

A continuous, though feeble, discharge of nerve force is
also received by the involuntary muscles securing to them
a constant tonicity. After section of the nerves distributed
to their walls, the vessels dilate, and that this influence also
comes from the cord is proven by the observation that
spinal hemiplegias are attended with paralysis of the arteries
only upon one side. Here again, however, we have to deal
with reflex and not automatic processes, for Goltz has dem-
onstrated that vessel tonicity may be affected (increased)
by irritation of distant sensitive nerves or surfaces, as from
the intestines, or paralysed by their destruction. So
strychnia will continue to cause contraction of arteries
below the line of section oil the spinal cord.

The sphincters are held in a state of continuous contrac-
tion in the same way. Giannuzi and Nawrocki found that
more force had to be used to overcome sphincteric contrac-
tion (by the injection of water) when the nerves were intact
than after their division. Heidenham and Colberg had
already demonstrated this fact with regard to the bladder
They introduced water of the temperature of the body into
the interior of the bladder of a rabbit, and observed, by
means of a manometer, that it required a pressure of 27
centimetres to overcome the tonicity of the sphincter and
permit escape of the water. They now killed the animal to
annul all innervation, and found that the water escaped at
a pressure of 5 centimetres. In the dog a higher pressure
was required in both cases, but the result was the same.
It is probable that the remote exciting agencies producing
the tonicity of the sphincters, the bladder, the dilator

190 THE SENSIBILITY OF MUSCLE.

pupillae, etc., are the nutritive changes in constant opera-
tion about the peripheral distribution of the nerves, as well
as in the nerve centres themselves.

The tonus of muscle, therefore, is no proof of the spon-
taneous generation or automatism of force. Closer investi-
gation always dissipates such conceptions and it is probable
that this term will in a few years be entirely discarded from
physiology, will be shelved away along with other "vital
forces," with the autochthonous (spontaneous) or idiopathic
genesis of disease, and other mysteries of medicine.

The Sensibility of Muscle.

Sensibility is that peculiar property which enables us to
estimate the amount of effort necessary to execute different
movements, to overcome resistance or to appreciate different
weights. It is some times described fes a sixth special sense,
oftener as a general sense, and occasionally as a kind of
transition sense between the two. Those who deny its
independent existence regard it as a peculiar modification
of the sense of touch. In fact three theories have been
propounded to account for the muscular sense: 1, that
there are no special sensitive nerve fibres distributed to
muscles. We are cognisant only in a general way of the
amount of nerve force sent to a muscle though its motor
nerves. We recognise the intention of muscular movement
but not its execution (Wundt) : 2, We are informed of the
contraction of muscle only by the sensations produced in
the skin or mucous membrane covering them, that is, through
the tactile sense (Auber) ; 3, Centripetal (sensitive) nerve
fibres pass from the muscles to the nerve centres (Arnold,
Brown-Sequard, etc.).

Sensibility and Sensation of Touch.

That the muscular, is entirely independent of the tactile,
sense, was demonstrated some time ago by Claude Bernard

SENSIBILITY AND SENSATION OF TOUCH. 191

who found that removal of the skin (decortication) did not at
all affect the sensibility of the subjacent muscles. Complete
insensitiveness of the skin was also produced by division of
all the cutaneous nerves, but the muscular sense still remained
intact, as the animal thus operated upon continued to be
able to walk, etc. If, however, the posterior (sensitive) nerve
roots were cut, the muscular sense was very greatly impaired
or entirely destroyed. Moreover, the muscular sense is
much finer than the tactile sense; it will appreciate lighter
shades of difference. The feelings of weariness or fatigue
which supervene after violent or long continued exercise,
the positive pain experienced in the cramp of tetanus, the
spasm of convulsion, or even the exaggerated physiological
action of the uterus (labor), or heart (palpitation), are patho-
logical and physiological proofsof a muscular sense dependent
upon the existence of sensitive nerves. In truth, C. Sachs
found, after division of all the anterior (motor) nerve roots,
some undegenerated nerve fibres in the sartorius muscle of
the frog which could, of course, belong only to the posterior
(sensitive) roots. Terminations of sensitive nerve fibres,
corpuscles of Pacini, had long before been discovered in
quantity in the perimysium, and about the joints, at the
points of insertion of the tendons, whose function in all
probability is to receive and transmit the muscular sense.
Lastly, the tactile sense may be entirely paralysed, while
the muscular sense remains intact, or vice versa. Thus
in locomotor ataxia, the tactile sense may be little or not at
all affected, while the muscular sense is so much impaired
as to require the aid of visual sense in walking. "We lean
upon our eye-sight in walking," said Mr. Mayo, "as upon
crutches." An individual thus affected falls when he closes
his eyes. Duchenne has put upon record the curious case
of a nurse, who had lost the muscular sense in one of her
arms, and who could only carry a child by constantly watch-

192 THE SENSATION OF FATIGUE.

ing that arm ; as soon as she turned her eyes away from it,
the limb would fall helpless to her side. But in this case
the cutaneous sense was not affected. On the other hand,
there are certain diseases of the spinal cord in which the sense
of touch or pressure in the skin is entirely annulled, while
it persists intact in the subjacent muscles. Thus, the case
is reported by Eigenbrodt of a patient who could distinguish,
by the effort of lifting, the difference between thirty and
thirty-two pounds, but could not feel a five pound weight
resting upon his passive hand.

Of the ordinary sense of touch, muscle possesses little or
none. The pain experienced in amputations, belongs to the
section of the skin, and is scarcely perceived in the division
of the muscle or bone. Muscle may be cut, pinched, burned,
subjected to all kinds of irritation, without exciting much,
if any, pain. It is believed that even the intense pains of
cramps are due simply to the violent traction upon the
points of origin and insertion of the muscle. The involun-
tary muscles are equally devoid of the sense of touch or
pain. Haller could never excite pain in his experiments
upon the heart, and Harvey found that he could manipulate
it freely in a case of its exposure after caries of the sternum
without producing the least sensation. Bichat made the
same observation upon the bladder, and every gynaecologist
is aware of the insensibility of the uterus, whose cervix is
burned, scraped and even split, almost without consciousness
on the part of the patient.

The Sensation of Fatigue*

But the muscles are extremely sensitive to the peculiar
pain of muscular fatigue, which continues to be felt long
after its cause has been relieved. Weber has shown that
the fatigue of muscle is due to chemical change in the
muscle substance, to the consumption of oxygen (Petten-

THE EXERCISE OF THE MUSCULAR SENSE. 193

kofer and Yoit) and to the accumulation of the products of
oxidation (carbonic acid, lactic acid, acid phosphate of lime,
etc. — Hanke). We can thus understand how it was that
Bichat could produce violent pain in muscle by injecting
into the arteries of living animals irritating fluids, like ink,
dilute acids, and wine. The fatigue of muscle must continue
until the blood shall have had time to decompose or con-
duct away the irritating matter. Hence, the efficacy of
hot baths and massage (friction), which by accelerating the
capillary circulation, more quickly dissipates the products
of muscular action (products of combustion).

The rapid accumulation of these products of decomposi-
tion in fever, which is, in essence, a too rapid oxidation,
accounts for the deep seated muscular pains (as in "break
bone fever," lumbago of the exanthemata (small pox), etc.)
attending this condition.

The Exercise of the Muscular Sense.

The muscular sense is thus quite distinct from every
other sense. It acquaints us unconsciously with the position
and relations to each other of the various parts of the body
and informs us of the position and properties of external
bodies. It enables us to appreciate differences beyond the
range of other senses. Thus it is finer than the sense of touch.
It will correctly discriminate between weights which stand
to each other in the relation of thirty-nine and forty,
provided the weights are not too light or too heavy (Weber).
Increase is easier detected than decrease (Panum and Dohrn).
It estimates with the finest nicety the degree of contraction
to be excited in a muscle, or group of muscles, for the
execution of a given purpose, and makes us cognisant of the
exact degree of contraction and relaxation existing during
the execution of the movement. The muscular sense thus
establishes the harmonious and coordinate action of the

17

194 THE EXERCISE OF THE MUSCULAR SENSE.

different muscles in all the voluntary and involuntary
acts of the body, in assuming and maintaining its
different positions, as in standing, walking, balancing,
dancing, riding, swimming, etc. ; in executing the finer
movements of the handicrafts, playing upon musical in-
struments, etc. ; in arranging the features and changing the
expression of the face and members in the infinite variety
of gesticulation ; in the quick movements of the eye, and,
finest and nicest of all, in the delicate modulations of voice
and speech.

So it was no wonder that Sir Chas. Bell, the eloquent
English anatomist, could not restrain himself after observ-
ing the fineness and nicety of the action of the muscular
sense, from expressing his admiration in a fitting tribute of
praise. "When," he exclaims, "a blind man or a man
blindfolded, stands upright, neither leaning upon or touch-
ing aught, by what means does he maintain his erect position ?
The symmetry of his body is not the cause. A statue
of the finest proportion must be soldered to its pedestal, or
the wind will cast it down. How is it, then, that a man
sustains the perpendicular posture or inclines in the due
degree towards the wind that blows upon him? It is
obvious that he has a sense by which he knows the inclina-
tion of his body ; and that he has a ready aptitude to adjust
the parts of it so as to correct any deviation from the per-
pendicular. What sense is this? He touches nothing, sees
nothing; it can only be by the adjustment of the muscles
that the limbs are stiffened, the body firmly balanced and
kept erect. In truth, we stand by so fine an exercise of this
power, and the muscles, from habit, are directed with so
much precision and with an effort so slight, that we do not
know how we stand."

Such is what is meant by the muscular sense. The
Germans, very appropriately call it the " Gemein-gefuhl"

MUSCLE AND ITS PROPERTIES. 195

the general or common feeling of the body. The vigor of
this sense is a criterion of health ; it was the euphora of the
ancients, the easy carriage and light weight of the body.
The muscular sense is the physical conscience. The indi-
vidual who has this conscience or consciousness sound,
enjoys a luxury in mere existence.

LECTURE X.
MUSCLE AND ITS PROPERTIES.

C ONTENTS.

Contractility of Muscle — Effects of Muscular Contraction — Degree of
Contraction — Change of Form — Agents which Induce Contraction —
Direct and Indirect Excitation — Thermal Excitation — Electric Excita-
tion— The History of Galvanism — The Action of Induced Electricity
— The Action of Nerve Force — The Sound of Muscle Contraction —
The Muscular "Wave — Independence of Muscular Force — The Action
of the Sulphocyanide of Potassium and Curare — The Generation of
Heat — The Generation of Electricity — Du Bois-Reymond's Theory
of Muscular Action — Rigor Mortis — Post-Mortem Changes in Muscle
—The Fuel of Muscle — The Oxygen Supply — The Dependence of
-MTTscle upon Blood — The Muscles as Levers — The Absolute Power
of Muscle — The Power of Muscle in General — Differences of the
Sexes — Differences in Different Animals — The Velocity and Delicacy
of Muscular Action.

We have to-day to conclude the study of muscle with the

consideration of its remaining properties, the chief of

which is

Contractility.

"We observe then, first, that the mode of con traction is very
different in the two kinds of muscular tissue. Striated
muscle responds to an irritant almost suddenly, always
forcibly, and as quickly returns to its former state. Smooth
muscle responds slowly, always comparatively feebly, and
as slowly returns to its former state. The slow, undulatory,

196 THE CONTRACTILITY OF MUSCLE.

so-called peristaltic, action of the smooth muscle of the
intestinal walls, manifest upon laying open the abdominal
cavity of an animal, best exhibits the mode of contraction
of smooth muscle fibre. The intestines, at first motionless,
soon exhibit feeble contraction, which gradually increases
to vermicular motion, until the whole canal "writhes like a
mass of earth worms," to gradually become again quies-
cent. The uterus in labor typically exemplifies the action
of involuntary muscle. If the hand be placed upon the
abdomen at the commencement of a pain, the uterus is felt to
"gather up" its fibres, to become gradually indurated, and
then slowly to relax to the condition in the intervals
between pains.' The character of the pain itself, a gradual
increment to an acme, and then a gradual decrement to
more or less complete relief, exhibits the absence of any
sudden force.

But there is a difference in the quickness or sluggishness
of response in different involuntary muscles. Thus the
muscles within the eyeball, i. e., the muscles of the iris
and the tensors of the choroid (muscles of accommodation),
respond very nearly as promptly as voluntary muscles ;
next in order of promptness rank the muscular wTalls 7)Tthe
intestines and ureters, and slowest of all, is that of the
bloodvessels, especially of the arteries, which, however,
compensate for it in some degree by the long persistence of
contraction.

Legros and Onimus concluded from their observations,
that smooth muscle was influenced more by direct excitation
of its substance than by excitation of the nerves, and that
the disuse, which would reduce striped muscle to an inactive
mass of fat, had little or no effect upon the anatomical
or physiological integrity of smooth muscle.

The voluntary muscle fibres reach the bones only by the
intervention of membranes and tendons. Each fibre is

THE EFFECT OF MUSCULAR CONTRACTION. 197

reduced at its end to a point, with flat, facetted, sides, like a
diamond or a sharpened lead-pencil, and is thus embraced by
the connective tissue structure of the tendon. The tendon
is the conductor of force. It plays the part of the line
which connects the horse to the canal-boat.

Effect of Muscular Contraction.

Shortening is only another name for contraction. In
contracting, muscle shortens, and, in the case of long muscles,
approximates the connected bones. Muscles in the form of
tubes (canals, vessels, etc.) diminish, in shortening, the caliber
of the tube or obliterate it altogether. It is the spasmodic
contraction of the cerebral vessels, which induces the pro-
found anaemia of the brain and pallor of the face as the
immediate cause of epilepsy. And it is this exercise of
contractility in lesser degree which regulates the blood
supply to individual organs independently of the action
of the heart. The bloodvessels become, thus, local hearts, at
the portals, and in the substance, of each organ and structure
to increase or diminish the supply of blood according to the
demand. Something of this local increase and decrease is
observable in the face under the action of the emotions.
The face is suffused with blood under the excitement of
modesty or shame and is blanched under anxiety or fear.
Thus, Donne says: —

"The eloquent blood
Spoke in her cheeks, and so distinctly wrought,
You might have almost said her body thought."

And Petrarch descants upon

"Quel vago impallidir."
(That charming pallor.)

A vaulted muscle has its arch reduced by contraction,
brought nearer to a plane surface, and thus, in the case of
the diaphragm, is the vertical capacity of the chest increased

198 THE DEGREE OF CONTRACTION.

and inspiration effected. Ring muscles, like the sphincters
and orbiculars, in contracting, "purse up" their respective
orifices, and hollow muscles obliterate their cavities to
entirely empty themselves of contents.

Degree of Contraction.

But it is only in extreme cases of cramp, as in tetanus, or
in extraordinary effort, that a muscle attains its utmost
degree of contraction. The bones very greatly limit the
contraction of the long muscles. Thus the biceps will
contract, when detached, nearly five-sixths of its length,
but, attached, its shortening is limited to but one to two-
sixths. In tetanus it may reach three-fifths. Strange to
say, it is no matter how much muscles vary in size or bulk,
the per cent, shortening remains about the same. Some
muscles (the glutei) weigh pounds, or measure feet in
length (the sartorii), and others, the muscles of the middle
ear, but a few grains, and measure but a few lines, but the
proportionate shortening remains about the same.

Change of Form.

The loss which a contracted muscle has experienced in
length is in very nearly exact correspondence to its gain in
breadth. We may feel the muscles (biceps) in action swell.
It was formerly believed that muscle absolutely gained in
bulk, but the ingenious experiments of the older physiolo-
gists entirely disproved this belief. Thus Sir Gilbert Blane
inserted a glass tube into the perforated cork of a glass jar
and filled the jar with water up to a certain level in the tube.
He now introduced a living eel into the jar and irritated it
t by means of a stick, also inserted through the cork, to
active contractions. Though the slightest increase in the
bulk of the animal would have been registered in the tube
by an elevation in the column of water, no such change in

AGENTS WHICH INDUCE CONTRACTION. 199

its level could be observed. Barzellotti made the same
experiment with a frog, inducing contractions in the half
of its body, which had been introduced into the jar, by means
of galvanism, with the same result. The truth is, muscle
rather diminishes than increases in bulk during contraction.
Erman was able to make this observation by repeating
the experiment of Blaine and taking the precaution to
graduate the glass tube to great nicety. Valentin appended
a weight to a marmot's muscle, suspended in a jar filled
with dilute albumen, so that- its specific gravity could be
accurately weighed upon delicate scales, and observed that
the muscle in contracting, displaced less water than before.
He thus found that while the specific gravity of the muscle
increased from 1061 to 1062, its loss in volume amounted to
T3To °f ^s whole mass, a diminution so slight as to be
generally unconsidered. Practically, a muscle gains in
thickness what it loses in length. If a lever be laid upon a
muscle placed horizontally, "the thickening of the muscle
will raise up the lever, and cause it to describe on a record-
ing surface a curve exactly like that described by a lever
attached to the end of the muscle" (Foster).

Agents which Induce Contrction.

The agents which may induce contraction in muscle are
very various. Any mechanical force (a blow, a prick), any
chemical irritant (cholic acid), sudden change of tempera-
ture, the various forms of electricity, may evoke fibrillar
twitchings or mass motion. But in the body, muscle
contracts only in obedience to nervous influence. In other
words, muscle tissue is something like the machinery of an
engine. It has the capacity for work, but can not work of
itself ; it must first be stimulated by extraneous forces,
that is, muscle is machinery for the transformation of some
other force into muscular force.

200 DIRECT AND INDIRECT EXCITATION.

Direct and Indirect Excitation.

The outside force may act upon the muscle directly, or
it may act upon the muscle through the intervention of the
nerves. As a rule, the agents which superinduce direct
muscular contraction will also effect it indirectly. Iviihne,
who has made an exhaustive study of this subject, states that
there are some substances which easily cause contraction of
muscles when applied to them, even if greatly diluted;
whereas, to produce the same effect through the nerves, they
require to be concentrated. Among these, are the mineral
acids, especially muriatic and nitric acids ; the basic salts,
as chloride of sodium, chloride of potassium, chloride of
lime ; as well as some organic substances, as acetic acid,
lactic acid and glycerine. A second class of substances
induce contraction equally whether applied to the nerve or
to the muscle. Among these are caustic potash or soda. A
third class of chemical substances act powerfully on the
muscle, but not at all upon the nerve ; such as chromic acid,
sulphate of copper, chloride of iron, basic and neutral acetate
of lead, lime and, above all, ammonia. A fourth class of
substances act exactly in an opposite manner, that is, upon
the nerve, but not on the muscle, or very slightly so ; such
as creosote, alcohol, concentrated glycerine and undiluted
lactic acid. Finally, a fifth class exists, which have no
power of producing contraction when applied to either
muscle or nerve ; such as the fatty oils and turpentine
(Bennet).

Thermal Excitation.

Different muscles also react differently to the same irritant.
This is notably the case in regard to the effects of heat.
A moderate degree of heat, 35° C. (95° F.), increases, while
cold diminishes the contractility of muscle. Everyone is
familiar with the sluggishness of muscular action under

ELECTRIC EXCITATION. 201

extreme cold. But an extreme heat absolutely destroys
muscular power aud destroys muscle by coagulating its
myosin. Though myosin coagulates at a much lower
temperature than any other albumenoid substance, the
degree of temperature at which such molecular change
occurs varies in different species of animals. Thus myosin
coagulates in the frog at a temperature of 34° C. (93° F.),
in mammals at 45° C. (113° F.), and in birds at 48° C. (118.] °
F.). Subjected to a temperature of the freezing point of
water, muscle soon loses its irritability, but not beyond the
power of perfect restoration. But if muscle be kept at a
temperature much below this degree, its irritability is soon
permanently destroyed.

Sudden changes of temperature, short of these extremes,
affect different muscles differently. Weber and Calliburces
long ago noticed the fact, wThich is now the subject of daily
observation in physiological demonstration, that the heart's
action when flagging with exhaustion is very decidedly
stimulated by the application of heat, and Milne Edwards
has remarked upon the increased contractility of most of
the smooth fibres, the dartos, the uterus, and the intestines
under the application of heat. The muscles which are thus
excited to contraction are said to be thermosystaltic, while
the muscles of animal life are athermosystaltic. In the
foetus, which has the circulation of a cold-blooded animal,
all the muscles are thermosystaltic. Hence the efficacy of
the application of heat in cases of still birth.

Electric Excitation.

But of all irritants or stimulants of muscular contractility,
none so nearly resembles the natural stimulus of nerve force
as electricity.

The first recognition of the action upon muscles of the
electric spark was made about the middle of the seventeenth

202 THE HISTORY OF GALVANISM.

century, but it was not until a century later, September 20,
1781, that Galvani, Professor of Anatomy and Physiology
at the University of Bologna, made the brilliant observations
that have immortalised his name in that of the form of elec-
tricity which he employed.

The History of Galvanism.

The history of the discovery of galvanism is worthy of
note, as showing how the simplest observations lead, in a re-
flecting mind, to the most important results. The story
runs that Madame Galvani was preparing some recently de-
capitated frogs for the dining table, when she observed that
the apparently dead animals became convulsed when
brought into the neighborhood of an electrical machine in
action. Prof. Galvani next remarked that the convulsions
only ensued when a spark was emitted from the machine,
and when, also, some metal substance came in contact with
the exposed nerves of the frog. With a view of discover-
ing whether atmospheric electricity would exercise the
same effect, he suspended the frogs from the iron trellis
work surrounding the roof of his house by means of copper
hooks "and saw, when they were blown about by the wind,
that convulsions were caused whenever they came in con-
tact with the iron." Galvani, however, made the mistake
of believing that the electricity thus engendered was in-
herent in the muscle and was the source of all vital action,
an error which led to the famous altercation with Volta, ex-
tending over a series of years, conducted on both sides with
much acumen and too much acrimony, and finally
eventuating (but after Galvani's death), as usual in such
cases, in proof that each was right and each was wrong.
"Galvani was right in maintaining the existence of an
animal electricity, but was wrong in believing it proven by

THE ACTION OF INDUCED ELECTRICITY. 203

the contact of two metals ; Volta was right in maintaining
that galvanism could be produced independently of animal
bodies, but was wrong in denying the existence of animal
electricity. "

The immediate response of living muscle to the action of
electricity renders it a galvanometer of exquisite sensitive-
ness. A frog prepared for experimentation by decortication
and exposure of the lumbar nerves, is known as the rheo-
metric or galvanoscopic frog.

The Action of Induced Electricity.

When an interrupted current of electricity, of whatever
source, static, magnetic, galvanic, is sent through a volun-
tary muscle, contraction of the muscle immediately super-
venes. At least, it is immediate to gross observation. If,
however, the periods of time be measured by mathematical
instruments of great nicety, t>r, if the movement of the
muscle be represented in exaggerated form, as by the attach-
ment to it of a long, delicate, lever (the myograph), which
shall register the tracing of the muscle with great accuracy,
it is seen that a short, but appreciable, interval of time
lapses between the application of the stimulus and the
movement of the lever. This interval is known as the
"pose" of the muscle, and occupies about the -^ of a second.
Now the lever is rather abruptly raised, and if its point be
traversed by a sliding plate, evenly run by clock-work, it
traces an obliquely ascending arc, the elevation of which
corresponds to the force of the contraction. "When the
point of the lever has reached its highest point, in a period
of time occupying about ^ of a second, the contraction has
ceased, whereupon it falls in a descending curved line,
occupying in its trace about -^ of a second, to its original
level. The curve registered in this way is known as the

204 THE ACTION OF NERVE FORCE.

"muscle curve." Thus the muscle, in its entire contraction,
occupies the yV+^o+aV^To °f a second.

A second shock of electricity, of course, repeats these
phenomena in every particular, but if a second shock shall
have been entered before entire relaxation has occurred, the
muscle curve will not fall to its original level before it is
caught again, so to speak, and forced to rise. Now, if re-
peated shocks be entered rapidly, but not too rapidly, the
curve will be held high on the plate, and the rise and fall of
each contraction and relaxation will be very slight. At ten
shocks (vibrations of the fork) per second, the distinct
effects of each still remain visible ; at fifteen, the individual
shocks begin to become fused, and at twenty vibrations to
the second, the muscle is held permanently contracted.
This constitutes what is known as tetanus. We use the
ordinary Faradic battery as a good instrument for "the
exhibition of the spasmodic contractions of individual
shocks, and the small French Voltaic battery to exhibit
the tetanising effects of rapidly succeeding shocks.

The Action of Nerve Force.

The constant current of electricity produces contraction
in the muscle only at the moment of making and breaking
contact. During the steady, constant, flow of the electric
force, the muscle remains perfectly passive and unaffected.
When muscle contracts physiologically, that is, under the
influence of nerve force, it is held contracted, as in tetanus,
until the stimulus from the nerve is voluntarily or invol-
untarily withdrawn. The inference is, hence, plain, that
norve force is sent to muscle, not in a continuous, but in an
interrupted current. And as muscle does not contract
spasmodically under nervous force, this force must be
transmitted to muscle in a series of vibrations, numbering
at least twenty to the second.

THE MUSCULAR WAVE. 205

The Sound of Muscle Contraction.

What lends to this inference additional support, is the fact
that muscle, in contracting, produces sound. Sound implies,
of course, a series of vibrations. A body at perfect rest
emits no sound. Muscle emits a sound which is distinctly
audible. If a stethoscope be placed over a contracting
biceps, a humming sound is distinctly perceived, or if, in
the stillness of the night, the ears be stopped with the
fingers and the jaws firmly closed, the sounds of the power-
ful flexors of the jaw may be clearly perceived. The note
emitted by the sound of contracting muscle is always the
same. It indicates twenty vibrations to the second. This
is the "music of motion," and

"Such are the subtle strings in tension found
Like those of lutes, to just proportion wound
Which of the air's vibration is the force." Blackmore.

The Muscular Wave.

From what has been already said, it is plain that muscle
has no power to contract of itself. In other words, muscle
possesses no automatism. It has the capacity for work, but
exhibits this capacity only under stimulus. This stimulus
is imparted physiologically, as we have seen, only by the
nervous system, and is manifested first, as would have been
assumed, at the points where the nerve reaches the muscle.
As a nerve is about to be distributed to muscle, it subdivides
into a leash or into branches, like a whip-lash with many
tails, and these branches, containing at their termination in
the muscle only the essential conducting element of nerve
force, fuse with an accumulation of sarcolemmar nuclei,
which are collected to form a disc or plate at certain points
on the surface of the muscle fibre. The muscle fibre begins
to swell in thickness at this point, and at other similar

206 INDEPENDENCE OF MUSCULAR FORCE.

points, so as to present the appearance of a beaded rod.
The beads or swellings, under continuing contraction, con-
tinue to increase in size, so that the intervals are absorbed, so
to speak, in contiguous enlargements, until the whole fibre and
the whole muscle is gathered up into a globar or rather a
fusiform mass. By means of ingeniously contrived appar-
atus, Aeby was able to estimate the velocity of the muscular
wave at 40 inches (1 meter) per second, a rate, thus, much
more rapid than ordinary protoplasmic (e. #., ciliary)
motion, but much less rapid than nerve force. Hence
muscular force is not nerve force. Nerve force is the sepa-
rate force which evokes muscular force.

Independence of Muscular Force.

The independence of muscular force is likewise proven by
the fact that muscle removed from all connection with the
nervous system will still respond to other stimulus. Still
living muscle will continue to contract, under stimulus,
when entirely removed from the body, and will continue to
respond to artificial excitation in the body after the nerve
force has been annulled by section of the nerve fibre and
death of its peripheral end. Thus Longet, in 1841, cut the
facial nerve and found that it lost its irritability entirely in
four days. But the muscles supplied by this nerve con-
tinued contractile for more than twelve weeks.

Action of Sulphocyanide of Potassium and Curare.

But the most striking and irrefragable proof of the inde-
pendence of muscular contractility was established by
Claude Bernard in the discovery of the action of an
agent, the sulphocyanide of potassium, which paralysed
muscular irritability without affecting that of the nerve,
and of the action of an agent, woorara, which paralysed
nervous irritability without affecting that of the muscle.

THE ACTION OF CURARE. 207

The solution of sulphocyanide of potassium (KCyS) is
made by simply boiling sulphur with a solution of pure
cyanide of potassium. It is used in commerce as the basis
(with mercury) for the manufacture of the dangerous little
fire cones, known as Pharaoh's serpents. When a small
quantity of the sulphocyanide of potassium is introduced
beneath the skin of the frog, the muscular system becomes
entirely paralysed to every other stimulus than that trans-
mitted through the nerves. Electricity applied directly to
the muscle now produces no effect, but still exerts its power
upon the muscle when applied directly to the nerves dis-
tributed to the muscle.

The real nature and composition of woorara (curare) con-
tinue unknown. It is an extract of one or several vege-
tables, and probably contains also several animal products.
The Indians dip the points of their arrows in it and thus
kill their foes by the slightest wounds. They use it also for
hunting purposes, experience having taught them its per-
fect innocuousness when introduced into the stomach, not-
withstanding its deadly effects upon the blood. The flesh
of animals killed by woorara is eaten with perfect impunity,
while if the poison be extracted from the stomach of an
animal to which it had been administered in its food, and
injected into the blood of another animal, it will promptly
exhibit its toxic effect ; proof that the immunity which the
stomach enjoys, is not due to neutralisation of the poison
by the gastric j uice, but to refusal to absorb it. In this re-
spect it resembles the poison of snakes, on which account its
active principle has been supposed to be the venom of the
crotalus (Fournie).

When a small quantity of curare is introduced beneath
the skin of an animal, it paralyses all the motor nerves,
but has no effect whatever upon the sensitive nerves, or
upon the muscles. Electricity or other excitant may now

208 THE GENERATION OF HEAT.

be applied to the nerves without the least effect upon the
muscle, but the muscle still continues to respond to direct
excitation of its substance. Curare acts by first destroying
the irritability of the end plates of the nerves within
the muscles. Some of the derivatives of strychnia,
ethylstrychnia, methylstrychnia, etc., produce the same effect.
Thus is absolutely determined the question of the inde-
pendence of muscular contractility and its inherence in
muscular tissue itself. But the solution of this question in
no way invalidates the fact that muscle never contracts
spontaneously, but always, and only, in obedience to some
force outside of the muscle substance. It is only within a
very few years that the heart has been proven to be no ex-
ception to this absolute law. Bernstein found that if the
ventricle be compressed transversely in the middle with a
pair of narrow-bladed forceps, the part beyond the line of
compression remains absolutely inactive, though its nutri-
tion is perfectly provided for by the persistence of the
normal movements in the rest of the heart, and Bowditch
concludes from his experiments that "when after transverse
compression of the ventricle, the apex, at first brought to
rest, recommences to beat, this renewal of activity depends
upon the restoration of an imperfectly destroyed connection
between the apex and the motor apparatus at the base of
the heart."

The Generation of Heat.

Muscle, in contracting, develops heat. Every one is
familiar with the fact that the temperature of the body in-
creases during exercise. In the absence of fire, we depend
upon exercise to furnish means of sustaining the body heat
under exposure to cold. But exercise also increases the
activity of the circulation, of respiration, etc., as more
probable sources of the origin of heat. To determine

THE GENERATION OF ELECTRICITY. 209

whether muscle developed heat, and if so, its exact amount,
Becquerel and Brechet made use of an instrument known as
a thermo-multiplicator, so constructed as to cause wide
deviations of a needle under fractions of a degree of tempera-
ture. A needle connected with the apparatus was now
stuck into the biceps muscle of a man. When the biceps
contracted, it registered a deviation corresponding to an
increase of 1° C. Helmholtz experimented with frog's
muscle connected with the body only by its nerve ; removed,
thus, from the circulation ; and observed, by means of a very
sensitive multiplicator, a deviation, during contraction, cor-
responding to an elevation of 0.1° C. In a frog's muscle a
single contraction may develop 0.005° C, which tetanus may
increase to 0.15° C. Beclard, Thyry and Meyerstein,
Heidenhain, and, more recently, Fick, have all, by numerous
experiments, demonstrated the increase of temperature in
the contraction of muscle. Fick observed that when a
muscle was allowed to extend itself with the weight, which
it had just lifted, still attached to it, it gave out more heat
than when it was allowed to extend itself without the
weight, that is, with the weight removed at the maximum
of contraction. For, in the sinking of the weight, while
muscle regains its former length, the mechanical work is
changed into an equivalent quantity of heat. This fact,
Cyon remarks, can only be construed as an irresistible sub-
stantiation of the law of the conservation of force in
muscular work. So, too, it has been observed that if a
muscle be held down during contraction, or during the
effort of contraction, more heat is developed ; the chemical
force in the muscle not being able to expend itself in
mechanical work, appears as heat.

The Generation of Electricity.
Lastly, muscle, in contracting, develops electricity.

18

210 THE GENERATION OF ELECTRICITY.

When this fact was first discovered by Galvani, the most
extravagant conceptions were entertained as to its signifi-
cance. It was believed that animal electricity was the
fons et origo, the supreme source and cause of all vitality.
This idea seems to us now sufficiently absurd, but in view
of our so recent release from the thralldom of a mysterious
"vital force," that refuge of ignorance and phantom of
superstition, infinitely more illusive and delusive than
animal electricity, which has at least demonstrable existence,
we may not cast reflections upon the credulity of the older
physiologists. The electricity evolved from muscle may be
readily demonstrated by applying the exposed nerve of the
frog's leg to the separated muscle of the thigh, so that the
nerve will touch the muscle at two points only, viz., on the
surface of the muscle, and on its cut end. By arranging a
series of separate thighs (frogs), so that one rested into the
other like a set of cups, the outside of one resting in the in-
side of the one below it, Matteucci constructed a so-called
frog battery. By connecting with wires, attached to a
galvanometer, the two end thighs, of a series of ten, an
electric current was obtained, sufficient to deflect the needle
thirty degrees.

Our positive knowledge regarding the electric currents in
muscle and nerve dates from the remarkable experiments of
Du Bois-Reymond, of Berlin. This observer has shown that
t'.ic current of electricity runs, in all cases, from the surface
to the cut end of a muscle, and this is the case whether the
observation be made upon a whole muscle or upon any part
of a muscle. The surface is hence positive, and the cut end
negative. So soon as the muscle is called into action, the
strength of this current is at once diminished, and the
current is hence said to experience a "negative variation."
This diminution of the current during the contraction of
muscle, is a result which would have been premised from our

DU bois-tieymond's theory. 211

knowledge of the law of conservation of force. For the
electricity evolved from muscle has its origin in the
chemical changes constantly at work in the muscle, and if
these chemical changes may expend their force in muscular
work, the electric current must, of necessity, be diminished
in strength.

Du Bois-ReymoncVs Theory of Muscular Action.

In order to explain the peculiar direction assumed by the
electric current in muscle, Du Bois-Reymond has proposed
the theory that muscle fibre is composed of molecules, each
of which has an equatorial belt or zone manifesting positive
electricity, and two polar zones manifesting negative
electricity. The equatorial zones being always on the sur-
face, no matter how much the muscle be divided longitu-
dinally, will always exhibit positive electricity, while the
polar zones, being exposed by transverse section, will
always exhibit negative electricity. Hence the current
must pass from the natural or artificial surface of muscle
towards its transversely cut end. The subject of muscle
electricity is still in its infancy, and while it is possible that
further investigations may yield results of the highest prac-
tical interest, regarding the molecular construction and
essential action of muscle, it may "not be claimed that they
have as yet been obtained. It is stated, indeed, that the
mere shape of the pieces of muscle employed in experi-
ments has great effect upon the direction of the current.
And it is stated by Kiiss that "a muscle may possess its
normal electric current and yet have lost all its other
properties; thus poisons, which kill the muscle, have not
always the same effect upon its electro-motor power ; finally,
similar currents have been observed in living tissue of
various kinds, even in vegetables, as, for instance, in pieces
of the pulp of a potato."

212 RIGOR MORTIS.

Rigor Mortis.

We may take up now the changes which muscle under-
goes at and after death. It is a familiar fact that death of
all the tissues does not take place simultaneously. For a
long time after volitional or reflex control has been lost, by
suspension of volition or reflex action, a muscle will still
continue to respond to artificial stimulus. The muscles of
cold blooded animals remain irritable for 8-10 days after
the death of the animals, and under favorable circumstances,
much longer. Thus my colleague, Dr. Longworth, reported
to our Academy of Medicine, the continuing pulsation of
the heart of a boa constrictor twenty-one days after it had
been sent in dead from the Zoological Garden for purpose
of post-mortem examination, and Redi saw contractility
persist in a tortoise twenty-three days after death. But the
muscles of warm blooded animals lose their irritability in a
few hours, or at most, in a few days. The muscles of birds
cease to respond to irritation sooner than those of mammals.

The precise time at which muscle irritability is lost,
depends then upon the nature of the animal. It depends
also upon surrounding conditions. Thus it is preserved
longest at a temperature of 0° C. ; a lower temperature
freezes muscle and thus speedily destroys its irritability,
and a much higher temperature hastens chemical change
and thus exercises the same effect.

The death of muscle is characterised by a peculiar change
in its substance. It becomes gradually more dense and less
extensible. When this stage has wholly developed, muscle
is said to be in the stage of cadaveric rigidity or rigor
mortis. The immediate cause of these physical changes is
the coagulation of the myosin, or muscle protoplasm.
Myosin clots after death just as fibrin clots in the blood,
and thus change** the consistency of muscle substance. The

RIGOR MORTIS. 213

members of the body must be composed shortly after death
to anticipate these changes by a fixation in the position in
which it is intended they shall remain. For, after rigidity
is developed, the posture of the body, or the position of
members, can be changed only with considerable force.

Rigidity first establishes itself in the muscles of the neck
and jaws, next in those of the trunk and lastly in those of
the upper and lower extremities, and it is in this order or
sequence that it gradually disappears to putrefactive
change. It never occurs immediately after death, and is
never entirely absent, though it may be comparatively
slight in degree. Involuntary muscle experiences the same
change, but at a later period. The very last muscle to sur-
render to rigor mortis is the right auricle of the heart, and
because this fact was first noticed by Haller, this organ was
complimentarily designated the "ultimum moriens Halleri"

Such radical change occurs in muscle substance when
undergoing rigor mortis, that it is only at the commence-
ment of this process that its irritability can be restored by
the transfusion of fresh blood. Preyer was able, however,
by dissolving the coagulated myosin with a solution of
.common salt, and then injecting blood, to restore irritability
to muscle in cadaveric rigidity. This recovery of tone
was, of course, due to the fact that all the myosin does not
coagulate at once ; enough for purposes of demonstration
still remains fluid, and able to act, when relieved from the
clogging action of the coagulum about it.

Post-mortem . rigidity sets in very speedily in muscles
whose tone has been exhausted just before death, as in
hunted animals, or after poisoning with strychnia, tetanus
from septic disease, or other cause. It is stated by Sommer
that it never manifests itself sooner than seven minutes 'cr
later than ten hours. Although army surgeons have con-
tended, from observations of the postures of soldiers killed

214 POST-MORTEM CHANGES IN MUSCLE.

on the field of battle, that rigidity is occasionally immediate,
it is known that some interval of time always intervenes.
But in cases of very sudden death the interval is very short.
As a rule, the more slowly it develops, the longer it lasts.
In cases of death by stroke of lightning or poisoning by
prussic acid, its persistence is so short as to have given rise
to the erroneous belief that it had not occurred at all. We
know of no agent that may temporarily induce it after the
manner of the drug which the friar gave to Juliet, that

"Each part deprived of supple government,
Shall stiff and stark and cold appear like death."

Post-Mortem Changes in Muscle.

Very curious changes sometimes occur in muscle after
death. In the presence of much moisture, bodies are occa-
sionally completely saponified, converted into adipocire, and
are thus indefinitely preserved. Or, muscle, with other soft
parts, may become dried up, mummified, and be thus pre-
served for thousands of years. Both these processes, as well
as that of calcification (lithopaedion), may occur also in the
foetus in utero. But, in the rule, muscle substance under-
goes gradual liquefaction and resolution by ordinary putre-
factive changes. But all the muscles do not suffer dissolu-
tion to the same degree. Thus the walls of the aorta persist
long after the smaller vessels and the voluntary muscles
have disappeared. The tissue or structure which survives,
or rather persists, the longest, is the uterus, and it is to call
your attention to this fact, which is of great value from a
medico-legal point of view, that I make mention of a subject
not strictly physiological. The uterus remains fresh and
firm long after destruction of all other soft parts in the
body. In- the midst of universal decomposition it may still
be removed from the body in its entirety, be opened and ex-
amined, and thus the presence or absence of pregnancy at

THE FUEL OP MUSCLE. 215

or prior to death, established. The uterus of the new-born
child persists in the same way. In his monumental work on
Legal Medicine, Casper details cases of extreme interest in
which the persistence and appearance of the uterus furnished
positive evidence concerning conditions at the time of
death.

The Fuel of Muscle.

The muscle machinery is no more capable of action
without food than a steam engine without fuel, and the
promptitude and power of muscular action depends, as in
the machine, upon two factors: (1), upon the character of
the fuel, and (2), upon the capacity of the muscle to convert
latent into active force. The fuel from which the most
force can be evolved is that which contains the most
combustible material. The most combustible material (that
is least expensive) is carbon. The fuel which contains the
most carbon is coal, hence coal is the best fuel for the
engine. The food which contains the most carbon is fat,
and the various hydrocarbons, hence these aliments form
the best fuel for muscular work. It has always been
maintained up to very recent years that muscle consumed
its own substance in its work, but this view was easily dis-
proven by the observation that the products of muscular
work are not products of muscular consumption. Muscle
protoplasm is largely composed, as we have seen, of myosin,
a pecular albumenoid substance, which occupies a place
between fibrin and globulin. Oxidation of myosin, which
with all the albumenoids is a nitrogenised matter, must
yield nitrogenised products (urea) in the excretions. But
observation has shown that the urea is not increased in the
urine as the result of muscular work. This conclusion has
been reached from many directions, but nowhere so decisively
as from the observations of Fick and Wiscilenus, who as-

216 THE OXYGEN SUPPLY.

cended, fasting, a high mountain in the Bernese Alps,
carefully measuring the urine voided at every stage of
progress, for its quantity of urea. The quantity of urea
was not increased by this severe physical exercise, but
the exhalation of carbonic acid gas from the lungs and
skin was very markedly increased, proof that the material
used as fuel was not the muscle substance itself, but the
hydrocarbons of the blood. Indeed, Mayer has made a
calculation showing that if muscle consumed itself in action
the whole muscular system would be burnt up (oxidised) in
just eighty days.

But though muscle machinery does not use up itself as
fuel any more than any other engine, it does, like every
other engine, undergo the wear and tear of daily use and
thus experience waste in slight degree. That this waste
may be repaired and the physiological integrity of the
muscles preserved, nitrogenous food is also a necessity.

The Arab, says Donders, never lets his horse eat grass
and hay to satiety. Its chief food is barley, and in the
wilderness it gets milk, and if great effort is required, even
camels flesh. A super-abundance of nitrogenous food is
found for animals in corn, which, notwithstanding its excess
of hydro-carbons, contains more albuminates than any
other vegetable food. Oats, too, furnish horses an
abundance of nitrogenous matter, and jockeys have a
saying, on witnessing spirited work in horses, that they
"feel their oats."

The Oxygen Supply.

The food thus furnishes the oxidisable material. Then
muscle must also receive abundant supply of oxygen. We
have already seen, that this supply is brought to muscle
by the blood, which reaches it red and leaves it blue. If the
muscle be at rest, however, the blood is so little deoxygenated

THE MUSCLES AS LEVERS. 217

that its escaping blood preserves its arterial hue. It is said
that oxygen administered roughly, as by the injection of a
highly oxygenated substance, permanganate of potash, for
instance, will restore irritability to a dying muscle, and it
is well known that the transfusion of fresh blood will, by
means of its oxygen, effect this result up to, and even after the
commencement of, cadaveric rigidity.

Dependence of Muscle upon Blood.

The necessity of a continuous supply of material for
consumption (food), and material for consuming (oxygen),
by the blood, is conclusively demonstrated by the observa-
tion of the effects attending ligation of the vessels supplying
muscles. Thus Longet tied the abdominal aorta in five
dogs and found that voluntary motion ceased in about a
quarter of an hour, and response to artificial stimulus in two
and a quarter hours. When the ligature was removed,
irritability to stimulus, and afterwards voluntary motion,
shortly returned. Brown-Sequard made some similar ex-
periments of more striking nature upon the human body.
In the cases of two decapitated criminals, he transfused
fresh blood into the arteries of the hand, thirteen hours and
ten minutes after death, when all muscular irritability had
disappeared, and cadaveric rigidity was quite marked, and
found that it reappeared and could be demonstrated in all
but two of the muscles of the hand. On a subsequent
occasion, he used the defibrinated blood of the dog with the
same effect (Flint).

The Muscles as Levers.

Let us now look at the muscles from a purely mechanical
point of view, viz., as levers. Those of us who are at all
acquainted with the laws of mechanics are aware that there
are three different classes of levers. The first is represented in

19

218 THE ABSOLUTE POWER OF MUSCLE.

using the common crowbar, or in working the pump handle,
or in raising coals with a poker in a grate. The fulcrum
rests between the power and the weight. Though there is
in this form of lever considerable power, there is not much
range of movement. The chief advantage of this lever is
celerity of action. A typical illustration of this form of
lever in the body is the action of the muscles which move
the head upon the spine. The muscles of the neck constitute
the power, the head is the weight, and the spine is the
fulcrum.

In a lever of the second class, the weight is between the
power and the fulcrum, as in the case of trundling the
common Avheelbarrow. Here there is great power, but
little velocity, and less range. The best, and almost the
only, example of this lever in the body, is the action of the
tendon of Achilles in lifting the whole body in walking.
The muscle of the calf form the power, the body is the
weight, and the toes are the fulcra.

In the lever of the third class the power is between the
weight and the fulcrum. It is represented in lifting a ladder
up against, or away from, a wall. There is here but little
advantage for power, there is less velocity, but there is wide
range. The free end of the ladder has enormous sweep.
The lever of the third class is the feeblest of all the levers,
but every thing here is sacrificed to range. This is by far
the most common form of lever in the body, and is typically
represented in the action of the biceps brachialis.

The Absolute Power of Muscle.

The absolute power of muscle is dependent, as would have
been inferred, upon its bulk, as exhibited on cross section,
and is determined by observing the weight which it will
lift. It has been observed that the power of contraction is
at its maximum on the beginning of shortening, and thus

THE POWER OF MUSCLE IN GENERAL. 219

Weber has been able to fix the absolute power of one square
centimetre of frogs muscle (hyoglossus), under the most
favorable circumstances at 0.G02 kilogrammes (24 oz.).
Rosenthal succeeded later in obtaining better results, viz.,
for the same quantity of muscle a little over one kilogramme
(35 oz.). Weber found that muscle exerted its maximum
effect when he loaded the same piece of muscle with only
450 grammes (15 oz.). The muscle then lifted 93 times its
weight 15 millimeters (006 in.) high. In subsequent experi-
mentation on man, Weber found that the absolute power of
human muscle is very much greater. Thus a square centimeter
(0.4 in.) of the gastrocnemius muscle of man has an absolute
power of 700-1087 grm. (24-38oz.). Henke and Kosterhave,
also, obtained better results, observing that a square centi-
meter of muscle from the thigh had a power 5.9 kilogrammes
(215 oz.) and from the arm of 8 kilogrammes (282 oz.),
a difference, as Bruecke observes, which was clearly due to
difference in the muscular power of the individuals under
observation.

The Power of Muscle in General.

The general power or force of muscles may be readily
estimated by means of an instrument first devised by
Regnier, the dynamometer, which consists of a steel spring
whose compression (by the hand or other group of muscles),
moves a needle along a scale graduated to represent equiva-
lents of weight. This instrument of precision is of great
value in clinical medicine in enabling the physician to
accurately guage the effects of treatment of paralysed
muscles and has enabled physiologists to make the observa-
tion that the muscles differ in force in different individuals,
and in different muscles in the same individual at different
times. Thus Koster found that the power from the same
sections, was for the biceps brachialis 17 kilogrammes, for the

220 THE DIFFERENCE IN THE SEXES.

gastrocnemius 10 kilogrammes and for the posterior tibial
only 2 kilogrammes. The difference in different individuals
is generally determined after the method first employed by
Begnier, which consists in lifting a weight- from the ground
between the feet. Quetelet called the force thus employed
the renal force, and remarked that in youth it is very slight;
it increases rapidly up to the age of 17 or 18 and attains its
maximum at 25 years. It now remains stationary for a
time and then declines markedly towards 40 years. It is
always much less in woman than in man. Desaguliers states
that the weakest men in health may lift 125 lbs., and the
strongest of ordinary men, 400 lbs. Topham, a so-called
Sampson, could lift 800 lbs.

Differences in the Sexes.

It is a subject of daily observation that the female of most
animals is capable, though of less powerful, of more sustained
effort. And this observation is supported by anatomical
and physiological differences in the construction and action
of the muscles. The action of muscular fibres has been not
inaptly compared by Milne Edwards to the work of a
number of laborers. The fibres are laborers in long parallel
lines. They do not all pull at once or with the same degree
of exertion. Hence the greater the number of fibres the
greater the number of rested or resting fibres. The muscular
fibres in the female, though individually smaller, are
numerically greater, and hence the capacity for greater sus-
tentation of effort.

Differences in Different Animals.

C. Sachs has shown that the muscle caskets are smaller in
warm than in cold blooded animals, and smaller in cold
blooded animals than in anthropods. In the smaller pieces
the physiological surface of tissue is increased and the

VELOCITY AND DELICACY OF MUSCULAR ACTION. 221

energy of metamorphosis is greater. Hence the mechanical
effects of smaller fibres is heightened, "just as a bundle of
magnets has a greater effect than one massive magnet of the
same weight." The force of the muscle of mammals is
hence greater than that of the frog.

The remarkable duration and sustentation of muscular
effort in birds thus also finds satisfactory explanation. Mon-
tague, a celebrated ormithologist, estimates that hawks fly
at the rate of 150 miles an hour and various birds often
travel 600 to 1000 miles without food in their winter and
summer migrations. But it is in insects, in which the
muscle caskets have been discovered to be minute structures
distinctly suspended in fluid, that the force of contraction
is greatest in proportion to their size. Thus Dunglison
states that the lucanus cervus, or stag-beetle, has been known
to gnaw a hole, of an inch diameter, in the side of an iron
canister in which it had been confined, and the same author
calls attention to the persistence and apparent ease with
which flies will keep up with the fleetest racehorse, sweeping
large circles about him all the time. The stridulations
(scrapings of wing covers) made by crickets and grasshoppers
can be heard a mile, whence it is estimated that if man
could emit sounds whose intensity should be proportionate
to his size, he could make himself heard all around the
earth.

The Velocity and Delicacy of Muscular Action.

We may not take final leave of the properties of
muscle without calling attention to the readiness of its re-
sponse to stimulus, its capacity for swift repetition of con-
traction, and the degree of delicacy and accuracy of its action
under proper cultivation. The ready response of muscle has
been clearly shown by Kronecker and Stirling in their demon-
strations that muscle replies to stimuli, which reach their

222 VELOCITY AND DELICACY OF MUSCULAR ACTION.

maximum in the nerve in less than the ^rroVoo Par* °f a second.
And as to the capacity for swift repetition of contraction,
these same experimenters quote the observations of llanvier,
who remarked that the pale muscle of the rabbit could
indicate 357 single contractions in a second, and of Marey
that the common horse-fly can make voluntarily 330
movements of the wing in a second. The musical tone
emitted by the contraction of muscle gives an accurate
estimate of the rapidity of muscular movement. A certain
tone corresponds, of course, to a certain number of vibrations,
and hence it is calculated that the wings of insects strike the
air even many thousand times every second. The finest
muscular movements in man, are those which change the
position and tension of the vocal cords. Muller has observed
that there are at least 240 different states of tension of the
vocal cords, and as the whole variation is not more than
one-fifth of an inch, the variation required to pass from one
interval to another will not be more than x^Vu" of an inch.

The quick, deft and delicate play of muscles is hardly
anywhere better exhibited in man than in the modulations
of the voice, in the shades of expression of the face, and in
the infinite variety of gesticulation. Thus: —

"With hurried voice and eager look
Fear not, he said, * * *
* * * but there the accents clung
In tremor to his faltering- tongue." Scott.

"The arched and polished forehead," says Sir Charles Bell,
"terminated by the distinct line of the brow, is a table, on
which we may see written in perishable characters, but dis-
tinct while they continue, the prevailing cast of thought."

"You may sometimes trace
A feeling in each footstep, as disclosed
By Sallust in his Cataline who, chased
By all the demons of all passions showed
Their work even by the way in which he trode." Byron.

NERVE AND ITS PROPERTIES. 223

LECTURE XI.

NERVE AND ITS PROPERTIES.

CONTENTS.

The Prime Function of Nervous Tissue— Subordination to Other Tissues
—Independence of Nerve Force— Genesis of Nerve Force— Arrange-
ment of Nerve Tissue— White and Gray Matter— The Cerebro-Spinal
and Sympathetic Systems— The Nerve Cells— The Nerve Fibres—
The Neurilemma— The Axis Cylinder— The Gray Fibres— The Prop-
erties of Nerves — Terminations of Sensitive Nerves— Terminations
of Motor Nerves— Course of Nerve Fibres — Identity of Nerve Fibres
— Indifference of Direction of Nerve Force— The Chemistry of Nerve
Tissue — The Action of Electricity upon Nerve Tissue— The Nature
of Nerve Force— Rate of Conduction of Nerve Force — Nerve Force
and Electricity— Comparative Velocity of Nerve and Other Forms of
Force — The Reception and Perception of Impressions — Ancient Sig-
nificance of Nerves— The Effects of Use, Disuse and Age.

The primary object of the nervous tissue is to link together
different and often widely distant structures. The nervous
system is thus the supreme regulator of the actions of the
body. It secures harmonious and consentaneous, or coordi-
nated, operations. Thus, if muscular activity is to be in-
creased (exercised), the muscle substance must needs
have more fuel in the way of additional supply of blood ;
it must also have more oxygen to effect the consumption of
the fuel and thus the liberation of additional force. Hence
increased muscular activity implies accelerated circulation
and accelerated respiration. It is the function of the nervous
system to secure this consentaneous and correspondent
activity on the part of the heart and lungs as well as on the
part of the muscle. The nervous system has, at the same
time, to regulate the activity of the secretory organs to
provide for the escape of the products of combustion.
Complexity of organisation implies, therefore, a nervous

224 THE XERVOUS, STJBSIDARY TO OTHER TISSUES.

system in high degree of development. An animal takes
rank in the animal scale, according to the degree of develop-
ment of its nervous system, that is, according to the quantity
and quality of its nervous tissue.

The Nervous, Subsidary to Other Tissues.

But so much stress has been laid upon the supremacy of the
nervous system that we are apt to forget that the rest of the
animal was not constructed for the nervous system; the ner-
vous system is constructed rather for the benefit of the animal.
In fact, the nervous system stands towards the rest of the
body, much in the light of telegraphy to the inhabitants of
a country. It signalises wants and supplies, regulates
transmissions, warns of dangers and furnishes intelligence.
"We look back with a feeling of pity and contempt, upon
that state of society which enjoyed no system of telegraphy,
no means of rapid communication, just as we look down
upon animals not endowed with nervous tissue, yet we may
not forget that such states of society, and such kinds of
animals, did and do exist. The nervous system is thus an
addendum to a higher grade of development. We may not,
therefore, look upon the body as a collection of cells attached
to the nervous tissue like the leaves, for example, upon the
trunk and twigs of a tree. On the contrary, it is the nervous
system which is attached to the cells. The nerve fibres
are to be looked upon as offshoots from the cells for the
purpose of association and interaction.

Independence of Nerve Force.

It was once believed, is taught now by some meta-
physicians, that nerve force is born in nerve centres and is
sent through nerve fibres to muscles, for instance, where it
acts as motion. That is, that motion is only a transformed
nerve force. But the physiologist can not accept such a

GENESIS OF NETtVE FORCE. 225

doctrine. The nerve force is not the fuel for the
muscle. The blood, which is the prepared food, is the fuel
that furnishes the muscle with force. The nerve force is
simply the excitant of the muscle. A very small amount
of nerve force suffices to induce a very great amount of
muscular force. Muscle is a machine, as we have seen, like
an engine. It stands ready to act. There is steam in the
boiler, that is, there is blood in its substance. Still the
engine does not move. The nerve force is the hand that
opens the throttle and thus causes the machinery to move.
I might make this point plainer by likening the parts of the
body to different branches of a great army out upon the
field. The nervous system is the system of telegraphy
which directs the movements of the army. But no one
would claim that the movements of the army, were trans-
formations or transubstantiations of the force of electricity
in the battery of the telegraph.

Genesis of Nerve Force.

The nerve force is generated in nerve cells and is conducted
along nerve fibres or tubes. The study of the nervous system
divides itself, thus, physiologically, into the study of the
generators and the conductors. Cells never conduct and
fibres never generate. Of course, in using the term generate,
it is not meant to imply the creation of a new force. Such
a conception is unscientific, that is, false. The nerve cells
generate nerve force in the sense in which the cups of a
galvanic battery generate electricity. The electricity from
galvanism is the result of chemical force which, in turn, is
liberated from force latent in metals,etc, stored up in the past.
So the nerve cells are simply means of transforming latent
force in the blood into nerve force. We return again to the
galvanic battery.

226 THE DIVISIONS OF NERVE TISSUE.

Arrangement of Nerve Tissue.

The nervous system, we find to be arranged like the
telegraph system of a nation or state. There is a great central
battery in the capital, represented in the brain ; there are
smaller batteries in smaller cities, as in the separate collec-
tions of nerve cells (ganglions) in different organs, and where
distances are great, there are reenforcing batteries, as along the
sympathetic and pneumogastric nerves. The connecting
wires are represented by the nerve tubes.

The Color of Nerve Tissue.

The nerve cells, en masse, present a more or less grayish
hue, while the tubes, en masse, present a distinct white color.
Hence the terms gray matter and white matter. The
outside (cortex) of the brain and the inside of the spinal
cord are mainly composed of cells, gray matter, while the
interior mass of the brain and the exterior of the cord, are
composed of nerve fibres, white matter. The great ganglia
at the base of the brain and the smaller ganglia scattered
over the body, everywhere, are composed of both cells and
fibres, and show colors according to the relative arrangement
or predominance of one or other structure.

The Cerebro-Spinal and Sympathetic Systems.

Finally, the mass of nerve substance accumulated in the
cranial cavity (the brain), and in the great tube formed by
the imposition above each other of the arches of the vertebra?
(the spinal cord), together with all the nerves (cranial and
spinal) which issue from their base and sides, constitute the
cerebro-spinal system (voluntary), presiding over animal
life ; and the ganglionic masses, disposed along each side of
the spinal column and extending into the cavity of the
cranium, connected with each other and with the cerebro-

THE NERVE FIBRES. 227

spinal nerves by commissures and supplying motor and
sensitive structures with nerve filaments, constitute the
sympathetic (involuntary) system, presiding over vegetative
life.

The Nerve Cells.

The nerve cells are readily recognised under the microscope
by their irregular, often almost fantastic, shape, their bright
nucleus and nucleolus, the amount of colored protoplasm
(pigment) which they contain, and by the prolongations
which issue from their circumference. The prolongations
are known as poles. We observe, thus, unipolar, bipolar,
multipolar cells. Apolar cells are probably artificial creations
that is, they are results of accidents in the examination.
Else, having no use, they would have to be regarded as
foreign bodies or parasites.

We may mostly recognise among the poles one which
seems to be composed of the essential element only of the
nerve fibre. It is, in fact, the commencing nerve fibre. Some
of these fibres pass out to the periphery as nerves, others
pass to other cells, connecting them, as commissures. The
great transverse bridge of the brain, the corpus callosum, is
made up, for the most part, of these internuncial fibers,
connecting the cerebral hemispheres.

The Nerve Fibres.

Nerves are bundles of nerve fibres. The ultimate nerve
fibre is composed of three parts ; the investing membrane
neurilemma, or tubular sheath ; the medulla or white sub-
stance of Schwann ; and the essential element or axis
cylinder.

The Tubular Sheath,

or neurilemma, is an exceedingly delicate, translucent, but
highly resistant and elastic membrane which envelops the
exterior of the nerve throughout its course. It is absent

228 THE AXIS CYLINDER.

at its inception from the nerve cell, it is absent also in
places where the nerve is already sufficiently protected, in
cavities containing only nerves, as in the substance (white
matter) of the brain, and is absent again where the nerve
passes to its ultimate distribution.

The White Substance of Schwann,

unfortunately named the medulla, as it does not occupy the
centre of the tube, like the medulla of bone, is the gelati-
nous, translucent, substance, which composes the bulk of
the nerve fibre. Shortly after death of the nerve, it coagu-
lates to an opaque, white mass, and gives to the nerve a
quite characteristic, varicose, appearance. The medulla is
also absent in central nerves and at the beginning and end
of nerves.

The Axis Cylinder,

or axial band, is the central, rather flattened band of clear,
glassy, jelly-like matter, which occupies the centre of the
nerve tube. The axis cylinder is the sole essential conduct-
ing element. The nerve issues from the cell as the axis
cylinder only, and the medulla and the tubular sheath are
subsequent additions of structure. At its final distribu-
tion, the tubular sheath and medulla both disappear, and
the axis cylinder alone passes to the substance of the
muscle, gland cell, hair bulb, or other structure, destined to
receive it. Just before its termination, the nerve divides
into a number of branches, each commencing with a con-
striction, and then expanding to the full size of the original
trunk. The axis cylinder throughout exhibits fine longitu-
dinal striae or lines, which are supposed to represent
fibrilla;, like the subdivisions of muscle fibre, and which are
regarded by some histologists (Schultze) as the ultimate
elements of composition. When staining solutions, aniline,

THE PROPERTIES OF NERVES. 229

carmine, etc., are brought into contact with a piece of
living nerve under the microscope, it is the axis cylinder
alone which is colored.

The Gray Fibres.

Besides these so-called medullated fibres, there exists a
different variety of very delicate fibres, whose interior con-
sists of a uniform, grayish matter, and whose rather thick
sheath is provided with distinct nuclei. Such fibres are
found only in the sympathetic system. They are commonly
known, from their discoverer, as the fibres of Remak.

Most nerve fibres of the sympathetic system, however,
are constituted upon the same plan as those of the cerebro-
spinal axis, and the several parts are roughly likened to the
constituents of the sub-marine cables ; the envelop repre-
senting the neurilemma; the rubber or silk insulating
matter, the medulla; and the conducting wire, the axis
cylinder.

The Properties of Nerves.

It is the function of some of the nerves to conduct from
the nerve cells, motion, and of other nerves to conduct to
the cells, sensation. Other nerves passing to and from the
various glands, to regulate secretion, are known as secretory
nerves, and still other nerves passing to the walls of blood-
vessels, to regulate their calibre, are known as vaso-motor
nerves. The secretory and vaso-motor nerves, including
fibres of motion and sensation, are described with the rest as
motory and sensory nerves. Motor and sensitive nerves are
such exclusively at their origin from motor and sensitive
nerve cells, but shortly after emergence from the brain,
spinal cord, or ganglion, the fibres commingle to constitute
what are known as mixed nerves.

230 TERMINATION OF SENSITIVE NERVE FIBRES.

Terminations of Sensitive Nerve Fibres.

The nerve fibres issue, as we have seen, from the nerve
cells, and are to be regarded as prolongations from the
nerve cells to the periphery, where they terminate in special
structures.

The sensitive nerves terminate in a number of peculiar
bodies, corpuscles of Pacini or Vater, corpuscles of Meissner
and Wagner (tactile corpuscles), and corpuscles of Krause.
These bodies consist of rounded or ovoid layers of connec-
tive tissue, in the interior of which, or upon the exterior of
which, the axis cylinder ends. In the case of the large
Pacinian bodies, located in the tendons, and especially
abundant about the mesentery, the axis cylinder enters its
base and divides, in its central cavity, like a fork with
prongs, into two or three branches, which finally terminate
in granular expansions. In the case of the smaller tactile
corpuscles, found in such abundance in the papillae in the
cutis vera, the axis cylinder is wound spirally about the ex-
terior to finally terminate in a point of extreme tenuity.
In the still smaller corpuscles of Krause, found in the
tongue, conjunctiva, glans penis and clitoridis, and in the
nipple, surfaces of extreme sensitiveness, the axis cylinder
penetrates the base and terminates in the interior in a loose
coil.

All these bodies would seem to exist for the purpose, in
the first place, of acting as points oVappui, points of support,
and, secondly, of increasing the area of surface for the
termination of the nerve fibre. They officiate something
like the thickenings of epidermis on the feet, commonly
known as corns. Though the epidermic mass has in itself
no sensation, it transmits pressure from every part of its
surface to the few nerve fibres at its base, and thus is a
conductor of sensation, which often amounts to positive
pain.

TERMINATIONS OF MOTOR NERVE FIBRES. 231

But the greater number of the sensitive nerve fibres pass
to terminate in the hair bulbs. It is a well-known fact that
we experience tactile sensation before absolute contact with
the skin is effected. The touch is felt by the hairs, which so
uniformly cover the whole surface of the body. The hairs,
of course, simply transmit pressure to the nerve endings in
their bulbs. These endings are especially abundant about
the face, and, in the case of some animals, are peculiarly
large and sensitive about the various vibrissae or whiskers.
Thus, a cat will readily wander about a darkened chamber,
guided by the exercise of the fine sense of touch in its
whiskers, which correspond to the antennae of insect life.
It is said that a kitten will thus find its way even though
perfectly blind. But if, in addition to its loss of sight, it is
made to lose its whiskers, it will knock its head against
every obstacle.

Nerve fibres terminate in the glands by effecting with the
secreting cells the most intimate union. Ends of nerve
fibres have been absolutely traced by Pflueger to the
nucleoli of the cells composing the salivary gland and the
pancreas.

Terminations of Motor Nerve Fibres.

In smooth muscle, nerve fibres have been traced by
Frankenhseuser and Arnold into very fine networks, which,
connect together the nucleoli of the muscle fibres.

The final distribution of the nerves in striped muscle is
still, however, a question of doubt. It is conceded by all
observers that the nerve fibre, after penetration of a muscular
mass, splits into a number of branches, that it then loses its
medulla, and that a number of nuclei present themselves
upon the still persisting neurilemma. These nuclei, accumu-
lated in mass as the nerve fibre approaches the muscle
fibre, fuse with accumulated nuclei in the sarcolemma of

232 COURSE OF NERVE FIBRES.

muscle fibre, to constitute a disk or plate upon the surface
of the muscle fibre. So far, there' is general agreement.
The disagreement concerns the ultimate disposition of the
nerve fibre. While Doyere, Krause and Engelmann main-
tain that the muscle plate is the end of the nerve fibre,
Kiihne and Gerlach claim that the axis cylinder afterwards
leaves the muscle plate and passes in to make immediate
connection with the muscle protoplasm. From among the
many opinions expressed by the most competent observers,
we elicit the fact that the difference concerns the question
whether the axis cylinder touches the muscle fibre at one
point only, or whether it absolutely fuses^with it within its
sarcolemma. This latter view is probably most correct ;
but the muscle may not be regarded as the end of, or attach-
ment to, the nerve, as Gerlach has advocated ; the true ex-
pression of the fact is that the nerve is an offshoot or an
addendum to the muscle.

Course of Nerve Fibres.

Except at their final termination, nerve fibres never
divide or anastomose (if we may use such an expression of
tubes whose contents are more or less solid) with each other.
Each fibre pursues a course, as straight as may be, from the
centre to the periphery, or vice versa. To this anatomical
fact is due the precise circumscription or localisation of
sensation or motion. A motor nerve fibre, irritated any-
where in its course, produces spasmodic contraction in the
muscle or part of muscle to which it is distributed, and no-
where else. So irritation of a sensitive nerve, in any part
of its course, causes sensation to be perceived at, or referred
to, the peripheral distribution of the nerve, and nowhere
else. A blow received upon the ulnar nerve at the elbow,
for instance, is felt as a tingling sensation in both sides of
the little finger and the little finger side of the ring finger,

COURSE OF NERVE FIBRES. 233

[surfaces receiving the entire peripheral distribution of this
nerve. So a tumor or foreign body pressing upon the intra-
cranial trunk of the fifth pair of nerves, may be the cause
of the intense pain of tic-douloureux experienced in the face.
Romberg reports a most instructive case illustrative of this
point. It was a case in which the patient had suffered for years
previous to his death from most distressing and frequent
paroxysms of facial neuralgia, the cause of which, as re-
vealed on post-mortem examination, was an aneurismal en-
largement of the carotid artery, which made direct pressure
upon the fifth nerve in the vicinity of the Casserian
ganglion. The aneurism had surmounted the process of
bone on the lateral aspect of the body of the sphenoid,
which process Hilton has signalised and denominated the
"carotid process," having to exercise "the important func-
tion of preventing the artery, during its pulsations, from
pressing on the second division of the fifth — a nerve en-
dowed with such exquisite sensibility, that the slightest
injury or pressure would lead to the production of serious
pain and distress."

So definitely and. distinctly are sensations referred to the
periphery of nerves, that individuals who have suffered
amputation wTill imagine, on experiencing irritation in the
stump, the presence of the foot or hand, and cases are
recorded in which patients have thus injured the parts in
the attempt to step upon an ununited stump of the leg.
This distressing feeling, or imagination of feeling, in absent
fingers or toes is, as a rule, gradually corrected by educa-
tion or habit, but it has persisted in some cases for 15-20
years. It is also because of this distinct localisation of sen-
sation, that individuals who have undergone plastic opera-
tions, as in the transplantation of skin from the forehead
for the creation of a nose, still refer impressions received
upon the nose to the forehead. Of course, this reference

20

234 IDENTITY OF NERVE FIBRES.

only applies to cases in which cutaneous continuity has
been maintained, as in the stem of the graft which is twisted
upon itself, not dissevered, to become the root of the nose.
The facetious comment of Hudibras, therefore, regarding
absolute ablation of skin and transplantation at distant
points, finds no foundation in fact.

Identity of Nerve Fibres.

The nerve fibres are thus so distinctly separated into con-
ductors of motion and sensation as to preserve their charac-
teristics throughout their course. Nevertheless, there is no
anatomical or chemical difference between motor and sensi-
tive nerves. It is- the connection of a nerve fibre, and not
its construction, which determines its use. A nerve con-
nected with a muscle is a motor nerve ; a nerve connected
with a gland is a secretory nerve ; a nerve connected with a
sensitive surface is a sensitive nerve. So the nerves are
compared to battery wires which may conduct force to ring
a bell, show a light, or write a message, according to the con-
struction of the end apparatus. Experiments have been
made to exhibit this indifference of the nerve fibre, so to
speak, by transferring the cut end of a motor fibre to the
cut end of a sensitive fibre, and securing or awaiting union
of the apposed ends. Philipeaux and Vulpian thus
observed after union of the lingual (sensitive) and hypo-
glossal (motor) nerves of the tongue, that irritation of
the lingual produced contraction in the tongue. It is only
fair to state, however, that the results of later experiments
by Vulpian have left this question somewhat in doubt.
For Vulpian observed that contraction of the tongue
supervened upon irritation of the lingual, thus united to the
hypoglossal, only when the chorda tympani fibres in the
lingual remained intact. When the chorda tympani was
divided, the contractions did not supervene. These experi-

THE CHEMISTRY OF NERVE TISSUE. 235

ments, therefore, simply prove that motor nerves will con-
duct for each other.

Indifference of Direction of Nerve Force.

It is, however, a clearly established fact that nerve fibres
will conduct just the same in both directions. That is, if
a nerve fibre be exsected and reversed, so that its peripheral
end is now central, nerve force will travel along it, after
union of the ends, just as before. This fact was very
strikingly demonstrated by Paul Bert, who inserted and
fastened the denuded tip of a rat's tail into an incision over
the centre of its back. After firm union had been secured,
he separated the tail from the rump of the animal by
division of its base. The positions of the free and fastened
ends were now exactly the reverse of the natural condition.
At the end of three months, irritation of the end of the
tail was evidently perceived, and at the end of six months,
sensation was as distinct as before the operation. The sensi-
tive nerve now conducted the impression in a reverse direc-
tion.

The Chemistry of Nerve Tissue.

Four-fifths of nervous tissue is water, and of the remain-
ing fifth, the most essential element part is the peculiar
albumenoid substance, known as lecithine, which is remark-
able for the amount of phosphorus which it contains.
Lecithin is a nitrogenous, organic, phosphorised acid,
a glycerinphosphoricacid, which is made up of radical fatty
acids (stearic, oleic, etc., acids), and a derivative of
ammonia (neurine). Lecithin and cerebrin, an additional
albumenoid body of somewhat similar constitution (but
more easily soluble in alcohol and less easily in ether), give
to nerve tissue its physical characteristics. Both these sub-
stances swell in water, and thus form the drops of medullary

236 ACTION OF ELECTRICITY UPON NERVE TISSUE.

tissue which exude from the nerve on microscopic examina-
tion. Both these substances more nearly resemble casein
(in easy solubility in dilute acids and solutions of soda) than
any other familiar albumenoid body. The predominance of
phosphorus also makes itself manifest in the mineral salts
entering into the composition of nerve tissue. The analyses
of Bibra show that of 100 parts of mineral matter from the
human brain, the phosphates of potassium, sodium, iron,
lime and magnesium form 84.5 parts. This presence of
phosphorus, in such quantities, in all parts of nervous
matter, is the fact of highest interest from a chemical
point of view.

That chemical processes are continually at work in living
nerves is proven by the existence of electric currents in the
nerves. In the absence of any other cause, electricity cannot
exist, or be developed, without chemical action. The fact, too,
that nerve fibres degenerate so soon as they are separated
from their central connections, also proves the presence of
chemical action. We may surmise that the chemical pro-
cesses in nerve fibres consist essei tially in oxidation of the
non-nitrogenous elements of the blood, whose chief product
is carbonic acid gas, but we have as yet no positive and
definite knowledge concerning the fuel of nerve tissue.

The Action of Electricity upon Nerve Tissue.

Nerve fibre differs from muscle in not manifesting the
action of stimulants or irritants in any visible effects.
Nerve fibre does not shrink, contract, or undergo, under irri-
tation, any perceptible change. Nerve fibre exhibits its
susceptibility to irritants only in the effects produced in the
structures innervated; that is, in the contraction of muscle,
secretion of glands, perceptions of impressions of general or
special sense, or manifestations of the intellect. Neverthe-
less, a nerve fibre is affected by the passage along its course

NERVE FORCE. 237

of the electric current. When the constant current of
electricity is brought to bear upon a nerve, the whole nerve
is brought to a condition of electric tension, the so-called
electrotonus, during the existence of which, the sensitive-
ness of the nerve is very curiously changed. For in the
part of the nerve near the positive pole the sensitiveness to
irritation and the rate of conduction are markedly lessened,
while in the part of the nerve near the negative pole the
sensitiveness to irritation and the rate of conduction are as
markedly increased. The condition of the nerve at the
region of diminished sensitiveness is known as anelectrotonus,
while the condition at the region of increased sensitiveness
is known as catelectrotonus. These regions, however, are
not confined to the intrapolar spaces, but extend on either
side beyond the poles throughout the entire course of the
nerve. Between the poles is a point where neither increase
nor decrease may be observed and this point is known as
the neutral point. Finally, the arrest or diminution of the
natural electric current, caused by the passage of the natural
nerve force, constitutes what is known as the negative
variation of the electric current.

Nerve Force.

"We are as ignorant of the ultimate changes in nerve cells,
which attend the conversion of latent force in the blood
into active nerve force, as of the ultimate changes which
take place in any body, when it produces light, heat,
electricity, or any physical force. We are forced to content
ourselves, therefore, with the study of the properties and
actions of nerve or other force. We recognise the fact that
the influence of irritants or impressions are conducted along
afferent nerve fibres to nerve cells, whence they are trans-
mitted through efferent nerves to motor, glandular, etc.,
structures. Such a process constitutes a reflex action.

238 REFLEX AXD VOLITIONAL ACTION.

But the nerve cell has also the property of retaining the in-
fluence of the external impression, and releasing it at a later
period. This later period may be very remote from that of
the original impression. When the action then supervenes,
it is known as a volitional act. Acts of volition therefore
are, in reality, reflex actions, whose constituents are
separated by longer intervals.

We do not, of course, look upon nerve force as a simple
transfer of the external irritant. The nerve force is just as
different from the external force, as muscular force is from
nerve force. And just as a small amount of nerve force
may call into action a large amount of muscular force, so
a small amount of external force may evoke a large amount
of nerve force. The nervous system is, thus, just as much a
machine as is the muscular system, or the gland system.
The nervous system is a machine for the transformation of
outside force into nerve force. We can, therefore, no more
conceive of force being developed spontaneously, or
automatically, in the case of nerves,, than in the case of
muscles. What is true, thus, of the grosser phenomena of
nerve tissue, sensation, motion, secretion, etc., must be true
of the more intricate processes connected with the special
senses, and the faculties of the mind. Impressions are
made upon the nerve cells through the avenues of nerve
fibres of general or special sense. These impressions may
be reflected to act at once through motor nerves, or they
may be stored up to constitute memory. We do not know
what material changes occur in the nerve cells during the
reception, reflection or retention of these impressions, any
more than we know what changes take place in any proto-
plasm when it absorbs, assimilates, or excretes matter, or any
more than we know what changes take place in an iron bar
when it becomes magnetic. We appeal in our ignorance to
molecular changes, but we do not accept them as positive

KEFLEX AND VOLITIONAL ACTION. 239

facts until their character and degree shall have been
definitely demonstrated.

What shall we say then of the higher actions of the nerve
cells (cerebrum), which have come to be differentiated
from the rest and set apart for purely intellectual pur-
pose?

We observe, in the first place, that the development of
these cells is a gradual process. The cerebrum is an
addition to forms of life highest in the animal scale. Its
cells are intimately linked with the cells of all other
ganglionic masses lower in physiological dignity. We should
therefore naturally infer that the same laws which apply to
the nerve fibres and cells composing the spinal cord and
sympathetic system would also apply to the nerve fibres and
cells of the cerebrum. We observe, then, in the second place,
that no intellectual phenomena of any kind are born with
an individual of even the very highest form of life in the
animal scale. All the movements and actions of the body
are as distinctly reflex in the new born child as in the foetus
in utero. The cry, the seizure of the breast, the direction
of the eyes towards a light, are all purely and simply reflex
actions. The intellectual manifestations are in every case
slowly, and we might almost say painfully, acquired. The
capacity or aptitude for acquisition exists, it is true, because
the character of the apparatus is rigidly determined by
inheritance, but the acquisition itself is entirely a matter
of education. A human being kept away from light, would
not be able to see ; kept from sound, it could not hear or
speak ; kept from the reception of ideas, it could not think.
We find ourselves forced to the conclusion that the purely
intellectual processes, as they are called, the memory, the
reason, the will, result entirely from the impression of
outside influences. Inheritance determines the aptitude
or plasticity of the brain cells to impressions, and the

240 THE RATE OF CONDUCTION.

character of the impressions determines the character of
the mind. In other words : —

•'L'instruction fait tout ; et les mains de nos peres
Grave en nos faible cceurs ces premieres characteres"
Que l'example et le temps nous viennent retracer
Et que peut-etre en nous Dieu seul peut effacer." Voltaire.

(Instruction does all ; our father's hands
Engrave in our hearts indelible bands,
Which time and example only retrace
And which God [death] alone may ever efface.)

Hate of Conduction.

Although we are ignorant of the ultimate essence of nerve
force we are by no means entirely unacquainted with its
properties and effects. We have in the first place some
quite definite information as to the velocity or rapidity
with which it travels. When this question first excited
the attention of physiologists, it was considered a subject
beyond the possibilities of human comprehension. Haller
thought that it would be impossible to measure the rate of
conduction of nerve force because there was not sufficient
distance for estimate as in the case of light. But as Goethe
has said "one must continue to believe the inconceivable to
be conceivable, else there will be no discovery." Continued
investigation has at last been rewarded with positive results
so that we possess now tolerably accurate data regarding
the velocity of nerve force. By attaching two levers to two
different parts of a muscle and causing the muscle to
contract by stimulating successively two different parts of
the trunk of the nerve terminating in the muscle, Marey
wras able to determine that the response of the muscle was
quicker to the irritation nearer the muscle. The interval
which lapsed between response to stimulus at different
points along the nerve corresponds to the rate of conduction
between the points. The distance between these points

NERVE FORCE AND ELECTRICITY. 241

being known, it is easy to estimate the rate of conduction
along the entire nerve. In like manner, by noting the
interval of time which lapses between perception of an
irritation at a distant point, as at the foot, and at a near
point, as on the face, the rate of conduction along sensitive
nerves was approximately established. Though this rate
of conduction differs in different animals, being more rapid
in warm blooded animals; differs in the same animal at
different degrees of temperature, being increased by heat
and diminished by cold ; differs also in the same nerve at
different parts of it course, being increasing in motor nerves
as the nerve approaches the periphery, and in sensitive
nerve as it approaches the centre ; differs, lastly, according
to the degree of freshness or fatigue, being much slower in
fatigue ; the general velocity of conduction is estimated at
about 100 feet per second. Auerbach and v. Kries have
shown that the perception of the difference between two
different impressions upon the sense of touch requires, as a
rule, 0.021-0.036 of a second ; of hearing 0.019-0.053 second,
according to the quality of the tone ; but the localisation of
a noise required 0.032-0.077 second. The perception of the
difference of two objects addressed to the sense of sight
required 0.011-0.017 second. The recognition of the differ-
ence between two different colors (blue and red) required
0.012-0.034 second. In appeals to the sense of touch and
taste in the tongue, Yintschgau and Honigsmied found that
touch was always experienced first. The perception of taste
required for salt 0.05, for sugar 0.20, for quinine 0.49
second.

Nerve Force Analogous to, but not Identical with, Electricity.

Though electricity more closely than any other force re-
sembles nerve force, their rates of travel alone afford positive
evidence that nerve force is not electricity. For electricity

21

242 RECEPTION AND PERCEPTION OF IMPRESSIONS.

travels at the rate of many thousand miles a second. While
it is true that electricity is developed in nerves during rest
of the nerve, as the result of the chemical operations in
continuous operation, this electricity is at once arrested so
soon as the chemical force may expend itself as nerve force.
That is, the most delicate galvanometer fails to register in
nerves the faintest electrical current during the transmission
of nerve force. This fact is, of course, simply another
illustration of the operation of the law of the conservation
of force.

Comparative Velocity of Nerve and other Forms of Force.

Nerve force, thus, travels at about the rate of an express
train. It is much more rapid than muscle force, but is
infinitely more slow than light or electricity. We may form
some more definite idea of the velocity of nerve force by a
comparison with that of some more familiar forces. Le Bon
presents us for this purpose the following table in which the
figures represent so many metres (a metre is about 40 inches)
per second : —

Muscular Contraction - 1

Race Horse ----- 26

Locomotive - - 27

Nerve Force 30

Eagle's Flight 35

Sound in Air ----- 332

Cannon Ball 550

Earth's Revolution about the Sun - 30,800

Light 300,000,000

Electricity - - - - 464,000,000

The Reception and Perception of Impressions.

We fail to appreciate the interval of time between the
reception and perception of an impression simply because of

RECEPTION AND PERCEPTION OF IMPRESSIONS. 243

the short distance to be traversed between the brain and
the ends of the most distant nerves. In very large animals,
that is, in animals with very long nerves, as in the whale, a
harpoon, thrust into the body near the tail, is not felt for an
entire second, and as an additional second must elapse before
responding motor force can be sent down from the brain,
the movement of the animal could not occur in less than
two seconds. So, in the case of a tall man, a mosquito
operating upon the foot, would have the one-sixth of a second
to make its escape, ample time, as we have seen, for the
quick movements of insect life. Mr. Flower has expressed
the opinion that the large animals of the tertiary epoch were
all slow of motion and stupid, in comparison with modern
species, and this sluggishness and dulness finds explanation
in the mere size of the animals and corresponding length
of the nerves. So the proverbial obtuseness and imper-
turbability of giants stands in marked contrast to the acute-
ness and activity of small people. Ponies and terriers are
much more active and vivacious than horses and mastiffs.

But we are not to forget that the character of the receiv-
ing and generating centres is also an important factor in
this consideration. Thus children "lose the benefit of their
small stature from want of command and correlation of
their faculties," that is, from want of development of the
nerve cells. Cold blooded feel much less acutely than
warm blooded animals. In Chamber's Journal is the story
of a shark caught with a line, the hook of which tore open
the abdominal cavity, cut out the liver, and left the intes-
tines hanging from the body. The sailors, in abhorrence,
threw it into the sea, but it continued near the boat and
shortly afterwards pursued and attempted to devour a
mackerel. In one of the older numbers of The Clinic is a
well authenticated statement to the same effect. A fish
was caught in the eye by a hook, and the eye ball was torn

244 THE ANCIENT SIGNIFICANCE OF NEHVES.

from the socket. The eye ball was then left upon the hook
as a bait, and in a little while it secured the rest of the
animal in the usual way.
It is therefore not true that

"The poor beetle that we tread upon
In corporal sufferance finds a pang as great
As when a giant dies."

though the pain experienced by the albatross, shot by the
ancient mariner, may have been as keen as that felt by
a human being. The sportsman, who so cruelly wounds
birds and runs down mammals, inflicts far more torture
than the physiologist with his experiments upon frogs, and
has less justification for his work.

Ancient Significance of Nerves.

Nerves were not known as such by the older anatomists
and physiologists. Hippocrates always confounded nerves
and tendons. Hence the derivation of the word nerve
(vr.vpov, cord). We speak yet of a strong nervous man, with
reference to the original meaning of the term, and a weak
nervous woman, with reference to its modern significance.
Although the true nature of nerves was known to Erasis-
tratus and Galen, we do not find any general recognition of
it until almost within our own times. All the allusions of
Shakespere concerning nerves, evidently refer to the sinews
or tendons. Thus Macbeth cries out to the ghost: —

"Take any shape but that, and my firm nerves
Shall never tremble."

And Hamlet says, alluding to bloodvessels as cords: —

"As hardy as the Nemean lion's nerve."

The French translate the "sinews of war" literally, "ks nerfs
de la guerre"

THE EFFECTS OF USE AND DISUSE. 245

The Effects of Use and Disuse.

The literary allusions to the nervous system, therefore,
still have reference to the mind and the mental faculties,
chiefly from a metaphysical point of view, as sufficient
time has scarcely yet elapsed for general appreciation of
the physicial significance of nervous tissue. But there is
one point connected with this tissue which has not, in its
effects, at least, escaped general recognition. And that is,
that the tone of the nervous tissue is only maintained and
sustained by its exercise. If a nerve of whatever character
be cut, and union of the divided ends be prevented, atrophy
of the nerve inevitably ensues. The essential element of
the nerve undergoes a granulo-fatty degeneration and at
last entirely loses its capacity to conduct force. This atrophy
then not only affects the nerve, but also the end apparatus
of the nerve. The structure innervated dies with the nerve.
Nor is the field of destruction limited to the nerve and its
distribution ; the nerve centres also suffer atrophy and
finally cease to functionate at all. The same effect follows
disuse of the centre, even though anatomical integrity of
structure be preserved. The brain develops by use and
atrophies by disuse. No sight is more melancholy than
that gradual contraction of ideas, that irritability to trival
cause, which inevitably supervenes in an active and liberal
mind when its faculties cease to be exercised. Middle aged
men who retire from active pursuits to secure the otium cum
dignitate, secure the dignity perhaps, but generally lose the
ease. Some allowance must, of course, be made for the
defective nutrition of advancing age, but aside from this
factor, or superadded to it, is the more marked desolation
effected by atrophy from disuse. There are forms of animal
life which in the earlier phases of existence are endowed
with motion (cilia) and various organs of special sense. No

246 THE EFFECTS OF USE AND DISUSE.

sooner, however, do they become fixed in a convenient place
than they lose their microscopic oars, lose, one after another,
their special senses,- become thus reduced to shapeless, inert,
masses of protoplasm, and thus vegetate simply for the rest
of their existence. Such reduction and waste occurs as the
result of disuse throughout the animal scale.

Wo realise thus the force of Schiller's observation to
Korner; ilDie Hauptsache ist der Fleisz; clenn dleser giebt
iiicht nur die Mlttel des Lebens, sondern er giebt ihm auch
seinen alleinigen Werth." (The chief thing is industry ; it
not only furnishes the means of living, but also gives to
life its sole worth).

The atrophic changes in the nervous tissue incident
to age, make themselves manifest in the action of the nerve
centres as well as in the loss of conductivity in the nerve
fibres. The intellectual and moral faculties suffer the same
alterations as the special senses. The organs of communica-
tion with the external world being blunted in their nice
perceptions, the old man has only his memories whence to
derive his intellectual food. As he cannot comprehend the
world about him in its new order, he looks upon all that is
new with distrust, if not absolute aversion. But this,
blunting of the sympathies enables age to regard events and
occurrences dispassionately, and hence peculiar wisdom is
ascribed to this period of life by all peoples and in all lands,
"If we consider this epoch," remarks Carl Vogt, one of the
most profound philosophers of his day, "in its retrocessions
of the feelings, in its insensibility to external impressions,
in its lack of the loftier inspirations, in its insipidity of
intellectual productions, we may well cease to begrudge it,
the wisdom usually ascribed to it."

At last, ensues the last stage of atrophy, and : —

"From Marlborough's eyes the tears of dotage flow
And Swift expires a driveler and a show."

THE BLOOD AND ITS PROPERTIES. 247

LECTURE XII.
THE BLOOD AND ITS PKOPERTIES.

CONTENTS.

The Value of the Blood— The Transfusion of Blood— The Constitu-
tion of the Blood — The Color of the Blood — Reaction of the Blood
—The Odor of the Blood— The Taste of the Blood— The Temperature
of the Blood— The Weight of the Blood— The Quantity of the Blood
— The Morphology of the Blood — The Red Blood Corpuscles — Size
of the Red Corpuscles — Number of the Red Corpuscles — Elasticity
of the Red Corpuscle — Constitution of the Red Corpuscles — Use of
the Red Corpuscles — The Colorless Blood Corpuscles— The Blood
Plasma— The Coagulation of the Blood— The Blood as the Substitute
of the Body.

The Value of the Blood.

The blood is for the most part, the prepared, digested,
fluidified, food. Bub the blood is made up also of the
waste products of the body. The blood thus officiates as
the fresh food (solid, liquid, and gaseous) supply and at the
same time, as the sewage escape. No where in art may we
observe a nutrient supply conveyed along the same conduits
or tubes with waste matter without suffering contamination.
"The blood circulating through the body may be regarded
as a river flowing by numerous canals through a populous
city, which not only supplies the wants of the inhabitants,
but conveys from them, all the impurities which through
various channels find their way into its stream" (Bennet).

The mass of the blood is the digested food. To secure
the elaboration of the coarse elements of the food into the
finished elements of the blood, is the work of a digestive
apparatus, which is extensive and complicated according to
the nature of the food. For food is of no use to the body

248 THE TRANSFUSION OF BLOOD.

until it is converted into blood. It is the blood which is
consumed in the processes of life ; thus directly or indirectly,
all animals are carnivorous.

The blood of plants is the sap which is made up of the
fluidified salts of the earth. The material which acts as
blood for the lowest forms of animal life is the sea or the
water in which they live.

Blood (Saxon, blod), in some form or other, is thus the
most important juice in the body, and its value was recog-
nised long before its nature and character were established.
We observe something of the popular recognition of its
significance in the aversion, or feeling of horror, which
the mere sight of it occasions. The shedding of blood
is associated with the loss of life. So blood is the fluid,
so to speak, with which tragic artists paint. Helena, when
she finds Lysander asleep (Midsummer Nights Dream), can
not believe him hurt, because as she says : —

"I see no blood, no wound!"

And the watchman in the grave yard scene (Romeo and
Juliet) appreciates the injury to life with the exclamation
and injunction: —

"The ground is bloody; search about the church yard:
Go, some of you, whoe'er you find, attach."

The Transfusion of Blood.

Perhaps no single experiment so convincingly exhibits
the fact that "the blood is the life" as the practice of inject-
ing fresh healthy blood into the veins of an animal dying
from its loss. Almost simultaneously with the reception
of the blood, the respiration becomes more profound, the
pulse becomes again perceptible, consciousness returns
with motion and sensation, in short, the animal is restored
to life.

TIIE TRANSFUSION" OF BLOOD. 249

The operation of transfusion of blood was first practised
on man by a French physician, Denis, June 15, 1667,
with defibrinated blood from a calf, though numerous
experiments had been previously made upon lower animals.
The first recorded inti%ition of the operation is found in
Ovid's Metamorphoses, book vii, fable ii, in the order of
Medea to the daughters of Pelos : "unsheath your swords,
and exhaust the ancient gore, that I may replenish his
empty veins with youthful blood." But this statement is
usually construed by commentators to have only meta-
phorical meaning, and to have reference to the vivifying effect
of a potent decoction which Medea had previously used on
animals and men. However this may be, it is known that
the modern operation of transfusion was largely discussed
by the metaphysicians of the middle ages, that period
so replete^ with curious and fantastic projects, and was even
practised to some extent upon lower animals. As a sample
of the fabulous expectations entertained of transfusion, at
this time, I may mention that it was generally believed
that the long sought secret of rejuvenation had been at last
discovered. Very soon after the first practice of the opera-
tion upon man, marvelous results began to be reported.
Cases of insanity were cured, lost special senses were restored,
and aged and decrepit constitutions rehabilitated with the
vigor of youth. Time, the experimentum cruets of all dis-
coveries, soon dissipated all these conceits, and the number
of accidents and fatal results which attended the operation
at last brought it into disrepute, when legal injunction caused
the practice of it to be suspended and forgotten. In this
oblivion it laid, then, until the beginning of our own century,
when it was revived by a distinguished obstetrician of
Dublin, Blundell (1818), with such improvements in method
and restriction in practice, as to give it permanent place
among the most valuable acquisitions to modern therapy.

230 THE TRANSFUSION OF BLOOD.

Iii our day, transfusion is limited to cases of hemorrhage,
where it is peculiarly adapted to meet the indications, and
to cases of poisoning by toxic agents (sewer gases, for
instance) for which we have no antidote. A temporary
renewal or protraction of life m^- also be effected with
it in cases of phthisis, and sometimes permanent relief
afforded in cases of inanition from any cause, when the
ordinary avenues of food are temporarily blocked, or may
not be addressed, as in cases of gastric ulcer. It is highly
probable, however, that other nutrient fluids, an artificial
serum, or milk, will gradually substitute blood in the
majority of cases.

Though the transfusion of a few ounces of blood usually
suffice, according to the observations of J. Worm Muller,
rabbits and dogs may receive as much as eighty per cent,
additional blood without permanent injury. Inexplicable
laws regulate the kind of blood which an animal may receive.
The transfusion of the blood of birds into the veins of mam-
mals produces convulsions and death, as does also the trans-
fusion of some mammals blood into the veins of other mam-
mals. Dogs blood may be injected into the veins of rabbits
with perfect impunity, while sheeps blood rapidly proves
fatal (Mittler).

Most remarkable results have been obtained by the injec-
tion of blood into the veins of animals recently dead. Brown-
Scquard has performed a great many experiments of this
kind, and his accounts of effects secured would seem incredi-
ble, were they not in full accord with our knowledge of the
part the blood plays in the animal economy. On one
occasion, he decapitated a dog, taking care to make the
section below the point where the vertebral arteries pene-
trate their osseous canals. "Ten minutes after cessation of
the respiratory movements of the nafes, lips and lower jaw,
I inserted into the three arteries of the head canuke con-

THE CONSTITUTION OF TIIE BLOOD. 251

nectcd by caoutchouc tubes to a copper cylinder contain-
ing oxygenated blood. The blood was now injected by
means of a syringe. In two or three minutes, the eyes
began to move, as also the muscles of the face, and these
movements seemed directed by the will. I prolonged this
experiment a quarter of an hour, and during all this time,
these movements, apparently voluntary, continued to take
place. When I ceased the injections, the movements ceased
and were soon replaced by convulsive movements of the
eyes, face, respiratory movements of the nose, lips and jaws,
and finally by the tremors of the death agony. The
pupils now dilated and became fixed as in ordinary death."
On a subsequent occasion, the same experimenter injected
into the veins of a dog, just dead from peritonitis, some
fresh blood from a living dog, and the dead dog so far re-
vived, as to stand upon his feet, wag his tail, make various
voluntary movements, and survive for twelve and a half
hours, when he again laid down, and died the second time.
No physiologist has, as yet, had the temerity to practice
this operation upon the brain, or the whole body, of a human
being, not even for juridical purposes, where it might seem
justifiable, but there can, of course, be no doubt as to its
result. Prof. Vulpian remarks upon this subject : — "If a
savant should attempt this experiment upon the head of an
individual who had been decapitated, he would assist in the
production of a grand and terrible spectacle ; he would
re-awaken in the head all its cerebral functions ; he wTould
restore, in the eyes and facial muscles, the movements, which
in man are evoked by the emotions, and the thoughts, of
which the brain is the seat."

Constitution of the Blood.

The blood consists of a fluid, the so-called plasma (Schultze),
and of formed elements suspended in the fluid, the so-called

252 THE COLOE OF THE BLOOD.

blood corpuscles (Miiller). The only exception to this con-
stitution of blood is offered by certain worms, the nemertinea,
in whose blood no corpuscles have as yet been dis-
covered.

The Color of the Blood,

The blood of all vertebrate animals, with the single ex-
ception of the lowest of all, the lancelet, is red. The blood
of invertebrate animals is either colorless, or is of other color
than red, as blue, yellow, green, brown, etc. When the
blood of invertebrate animals is colored, it is the plasma
which contain the coloring matter, whereas, in vertebrate
animals, the corpuscles contain the coloring matter, and the
plasma is colorless, except in cephalopods, where the cor-
puscles have a violet hue, and the terebella, whose corpuscles
are yellowish-red (Gscheidlen).

But the red blood of vertebrate animals varies in its tint.
Like all other colored fluids (sea-water, for instance), the
blood is darker when present in quantity. A thin layer of
blood or a single corpuscle presents a faint amber hue,
which may be regarded as the intrinsic color of blood. The
freshly oxygenated blood as it leaves the lungs- and heart to
circulate throughout the body in the arteries is a bright
scarlet red. The deoxygenated and carbonised blood as it
collects in the veins to be returned to the heart and lungs is
purple or blue. The intrinsic color of blood is due to the
presence in the corpuscles, as one of the ingredients of con-
struction, of haemoglobin, which, as its name implies, con-
tains iron. The degree in which the iron is oxydiscd de-
termines the tint of the blood. Thus the coloring matter of
the blood is iron, a fact which gave to Mr. Ruskin the oppor-
tunity for a bit of sentiment in the comment that it seems
strange that iron, one of the sternest and hardest substances

THE ODOR OF THE BLOOD. 253

in nature, should be selected to give expression in the face
to the most delicate emotions of the heart.

"Behold how like a maid she blushes here:
Conies not that blood, as modest evidence
To witness simple virtue?"

Reaction of the Blood.

The blood of all animals is alkaline. We have already
seen how this alkalinity of the blood favors oxidation pro-
cesses, and the importance of this reaction becomes evident
with the statement that so soon as the alkalinity of the blood
of an animal is neutralised, by the injection of an acid into the
vessels, the animal inevitably dies. But it is only fresh and
living blood that exhibits alkalescense. Dissolved, dried
blood is mostly acid and the alkalescence of fresh blood con-
tinues to diminish after withdrawal from the body. Thus
40 cubic centimetres of phosphoric acid are required to
neutralise 100 cubic centimetres of blood freshly drawn,
while 31 centimetres suffice to neutralise blood which has
been drawn five minutes. It is by reason of the alkalinity
of the blood which is chiefly effected in man by the phos-
phate of soda entering into its composition, that the fluidity
of the blood is preserved. Blood withdrawn from the body
is kept fluid by the addition of alkalies, as of ammonia or
the sulphate of soda.

The Odor of the Blood.

The blood has a peculiar odor, which is different in differ-
ent animals. Thus oxen blood smells of musk, and the
blood of many insects (caterpillars) has an exceedingly dis-
agreeable odor. In fact, it is the blood which largely gives
the characteristic odor to the animal. The odor of the
blood is due to the existence in it of certain volatile fatty
acids, in alkaline combinations, whose quantity and exact

254 THE TEMPERATURE OF THE BLOOD.

nature is as yet undetermined. Concentrated sulphuric
acid liberates the characteristic odor of the blood in much
greater intensity, or develops it when not present in sufficient
degree to be perceptible (Barruel), and valuable juridical
evidence has been furnished in this way in doubtful cases.
This halitus sanguinis of the older physiologists is somewhat
more marked in male animals. To obtain or develop the
odor of the blood in any intensity, it should be received
from a vein in a glass vessel and concentrated sulphuric
acid should be added to it, in the proportion of one-third to
one half the quantity of blood. The odor of cattle, sheep,
dogs or fishes may be distinctly recognised in this way.

The odor of fresh human blood is not very distinct at best.
It was a psychical conception and not a physical impression
which Lady Macbeth perceived with such intensity, when
in her somnambulism she muttered : —

"Here's the smell of the blood still: all
the perfumes in Arabia will not sweeten
this little hand."

The Taste of the Blood,

though not so distinctly characteristic of its source, is
nevertheless peculiar. The taste of the salty, sweet, and
extractive elements so mask each other as to render the
gustative impression of the blood sui generis.

The Temperature of the Blood.

The blood is kept in the body at a temperature of about 100°
F. (38°C.) But much variation in temperature is encountered
in different vessels. The blood of the surface capillaries,
being cooled by exposure, may fall, even a degree or
two, according to the external temperature, while in the
interior of the body, it may be elevated six or seven degrees.
As all chemical action develops heat, we might naturally

THE WEIGHT OF THE BLOOD. 255

infer, what direct observation positively confirms, that the
blood is warmest in places where chemical processes are
most active. So the very hottest blood in the body is found
in the hepatic veins, vessels which receive the blood after
the intensely active chemical processes of the liver. The
temperature of the blood here mounts up to 107° F. (41.6° C),
a degree which if maintained for a length of time upon the
surface of the body would indicate inevitably fatal oxidation.
But the general heat of the blood and of the body is almost
exclusively sustained by the oxidation processes effected
by muscular tissue. Donyza's servant then gives his mis-
tress proper counsel in the advice : —

"Pray you walk softly, do not heat your blood."

The Weight of the Blood.

The specific gravity of the blood varies between 1054
and 1060. To obtain it, the blood must of course be
thoroughly defibrinated. This is accomplished by flagella-
tion of the blood with a wisp of straw, or by stirring it
with a spatula or glass rod. The specific gravity of the
plasma is 1028, and of the corpuscles 1088. The corpuscles
being thus much the heavier, sink in the plasma whenever
the blood comes to rest. The red corpuscles being heavier
than the white sink faster, and leave the white to form the
"buffy coat" on the surface of the clot. The buffy coat is
thus no sign of inflammation (crusta inflammatoria) as
formerly believed. It simply indicates in its depth the
sluggishness of coagulation. It is always seen in the blood
of the horse withdrawn from the body of the animal. The
specific gravity of the blood is markedly decreased by
hemorrhage and increased by transfusion.

The Quantity of Blood.

It would seem to be an easy matter to arrive at the whole
quantity of blood in the body of an animal by simply open-

250 THE QUANTITY OF BLOOD.

ing large vessels and collecting it as it flows. But the blood
will not all flow out from the body. When syncope super-
venes, the blood ceases to flow in quantity from paralysis of the
vaso-motor nerves, and no posture can be secured which will
permit gravity to effect the discharge of blood from all the
vessels.

A more effective method is to collect all the blood that
will flow spontaneously, and then wash out the rest by
injection with a known quantity of water, which could be
subtracted from the whole amount. The objection to this
method lies in the fact that a forcible injection would carry
out other fluids, lymph, chyle, muscular fluids, synovial
serum, etc., which would pass into the bloodvessels by
diffusion and thus invalidate conclusions.

Some idea of the difficulties encountered in computing
the whole amount of blood may .be gathered from the
different estimates obtained by different experimenters.
Thus Harvey, Lister, and Moulins compute that the human
body contains about 8 lbs. of blood, Miiller and Burdach
20 lbs., Haller 28-30 lbs., Hamberger 80 lbs., and Keill
100 lbs., differences which sufficiently exhibit the defective-
ness of the methods employed. From among the many
improved methods of more modern investigators, I may
mention that of Lehmann and Weber which consisted in
collecting all the blood which would flow spontaneously
from the divided vessels of decapitated animals, washing
out the vessels until the water injected escaped colorless, and
then evaporating the fluid to a solid residue which repre-
sented, of course, a certain amount of blood. In this way
these observers estimated that the proportion of blood to
the body was about that of one to eight ; that is, the body
of a man of average weight, 145 lbs., contains about 18 lbs.
of blood, a quantity too great because of admixture with
other fluids.

TIIE QUANTITY OF BLOOD. 257

Vierordt made a computation by multiplying the quantity
of blood expelled from the heart at each ventricular con-
traction by the number of beats required to effect the entire
round of the circulation. If the ventricle pump out G.3 oz.
(an amount evidently too great), and 27.7 contractions are
necessary to effect the round of the circulation, as he
maintains, the proportion of blood to the body would be
fa- fa about 11-12 lbs. Welcker first employed the color
test, which consists in mincing the body of the animal after
all its blood has escaped, and been washed out. The mince
meat was then infused and the color of the infusion compared
with that of previously prepared color tests containing
a known quantity of blood. Welcker concluded that the
body of a man (143 lbs.) contains about 11 lbs. of blood.
Preyer's spectroscopic test (estimation of the amount of
haemoglobin) yields about the same result, as does also the
entirely different method of Brozeit, which consisted in the
recovery of the haematin from the washed out blood, so that
this proportion, the fa may be assumed to represent the
amount of blood in the body. The proportion of blood to
the rest of the body in different animals is about as follows :
guinea pig, tW*, rabbit fa-^Ut doS tVtV, cat fa birds

tVtV > f ™SS TTio. fisnes TV-A-
lt must not be forgotten, of course, that the quantity of

blood varies very greatly at different times of the day, with

reference especially to the hours of taking food. Bernard

illustrated this fact by drawing ten and a half ounces of

blood from a rabbit, after eating, without serious result to

the life of the animal, whereas the withdrawal of five ounces

proved fatal to the animal fasting. According to Colard de

Martigny, the quantity of blood in a rabbit, in a healthy

well-fed state, is about 30 grammes, which is reduced by

three days fasting to 20 grammes, and by ten days fasting to

only 7 grammes. This great variation with reference to

258 THE MORPHOLOGY OF THE BLOOD.

meals may account, as Carpenter suggests, for the wide dis-
crepancies observable in different estimates of the whole
quantity of blood. Then the average quantity is widely
departed from in cases of plethora and anaemia. Thus
Wrisberg states that a plethoric woman, who died of metro-
rhagia, lost 26 lbs. of blood, and reports the fact that as
much as 24 lbs. was collected from the vessels of a woman
who had suffered death by decapitation.

The Morphology of the Blood.

The blood as it flows from a divided vessel is apparently
a perfectly homogeneous fluid. But on examination under
the microscope it is seen to contain, in myriad numbers,
certain formed elements, the corpuscles. The corpuscles
seem to occupy about half the space in the microscopic
field. It was not given to Harvey, the discoverer of the
circulation of the blood, to ever see the blood corpuscles or
the capillaries in which their course and conduct in life are
distinctly visible. The blood corpuscles were first recognised
by Malpighi (1661), as peculiar and hitherto unrecognised
particles, floating in the current of the blood. Malpighi,
however, did not appreciate their significance ; he regarded
them as particles of fat. It was only then after the lapse
of twelve years, that Leeuwenhoek was able to describe the
true nature of the red corpuscles, as morphotic elements,
always present in the blood. And it was not until a hundred
years later still, that the second variety of bodies, the white
corpuscles, were pointed out by a distinguished English
observer, Wm. Hewson. The recognition of the morphotic
elements of the blood, was then only finally complete with
the discovery by Schultze (1865) of certain, minute, irregular,
colorless, granules, distinguished by their varying quantity
and their great refrangibility.' As we have as yet no
knowledge of these bodies, other than that of their existence,

THE 11ED BLOOD CORPUSCLES. 259

we may pass to the consideration of the elements with
whose nature and use we are most familiar.

The Bed Blood Coiyuscles.

There is a description of the red blood corpuscle that is
so concise and complete as to have been adopted in most
works on physiology. The blood corpuscles are described
viz., as "flattened, biconcave, circular disks." So, then, we
may say, roughly, that red blood corpuscles look like
biconcave lenses, or like crackers (butter crackers), without
their central elevation. The camel and the lama are the
only mammals whose corpuscles depart from this shape, in
that in these animals, the red corpuscles, like those of fishes,
amphibious animals, reptiles, and birds are elliptical. The
exceptional shape of the corpuscles in the camel species is
very remarkable, in that the small family of the camelidse
is thus distinguished alone among all mammals. Milne
Edwards sought for elliptical corpuscles in more than 200
species selected from all the natural subdivisions of this
group, but could not find them "even among the marsupials
and monotremata, which seem, in certain respects, to establish
a transition between ordinary mammals and oviparous
vertebrates." The elliptical shape of the blcod corpuscles
of the camel tribe, like the existence in the small intestine,
of the same tribe, of valvulse conniventes, which were once
believed to be characteristic of man, is, when properly
interpreted, additional evidence of the mutability of species.

In the study of the structure and properties of red blood
corpuscles, the precaution must always be taken to add to
the specimen of blood some diluent. Else, the corpuscles
speedily shrink from evaporation of their fluid contents,
become crenated upon their edges, and finally shrivel away.
But the character of the diluent must be selected with
caution. The addition of simple water dissipates the cor'

260 SIZE OF THE BLOOD CORPUSCLES.

puscles from the field in a very few minutes. The water
is very quickly absorbed, the coloring matter is separated, the
corpuscles swell to colorless spheres, burst, or are entirely
dissolved from vision. The best fluid in which to preserve
corpuscles is the natural serum of the blood, and the serum
should be taken from the same animal or from the same
species of animal. For, according to Landois, the blood
corpuscles of the rabbit, for instance, are transformed,
on the addition of the serum from dogs blood, to spheres
or balls, and the coloring matter is dissolved out. In the
absence of serum, a six per cent, solution of common salt
exercises the least injurious effect upon the size, shape, and
structure of the corpuscles. Blood corpuscles (of any ani-
mal) are best preserved by holding a thin layer of blood
over an aqueous solution of perosmic acid, in such a way
that its vapor may pass to the blood. The blood corpuscles
are hardened in this way, without change of form or color.
They maintain also their central depression and become so
consistent that they may be kept unaltered for a very long
time in water or in glycerine. It is the central depression
which gives to red corpuscles their peculiar optical appear-
ance. Either the centre is dark and the circumference light,
or vice versa, according as one or other is in focus.

Size of the Blood Corpuscles.

By means of a micrometer it is not difficult to measure
the exact size of the blood corpuscles of an animal, a point
of great medico-legal interest. Yet there is by no means
that unaminity of statement upon this subject that might
naturally be expected. Thus Kulliker, the highest German
authority says, as regards human corpuscles, that 95 out of
every 100 corpuscles measure ^p of an inch (0.0071 mm.)
in diameter ; Robin, tjie highest French authority states the
exact diameter to be ^Vr °* an *ncu (0.0073 mm.) ; while

SIZE OF THE BLOOD CORPUSCLES. 261

Gulliver, who examined the corpusclesof all the animals in the
London Zoological Garden, and hence had great experience
in measurements, puts the diameter of human corpuscles at
■52W °f an inch, a fraction which is undoubtedly too high.

That there is no relation whatever, between the size of
an animal and the size of its blood corpuscles is evidenced
by reference to Gulliver's table, showing the size of the
corpuscles in 176 mammals. The ox, for example, a
very large animal, has a blood corpuscle whose diameter is
exceedingly small, T^Vr °f an inch, much smaller, thus, than
that of the corpuscles of man ; while the cat, a small animal,
has a corpuscle -^W °f an inch diameter, very nearly as
large as that of the ox, and the mouse, which is much
smaller than the cat, has a much larger corpuscle, viz.,
^ttt °f an inch diameter, much larger, thus, than that of
the ox.

Milne Edwards has endeavored to show that there is an
inverse relation between the size of the corpuscle and the
muscular activity of the animal, that is, the more active
animals have the smallest corpuscles. There is much
foundation for this observation, which may, indeed, be
considered a rule, but it is a rule, not without exceptions.
Thus the dog, a very active animal, has a corpuscle which
is generally regarded as having exactly the dimensions of
the human corpuscle, viz., -g-Jjjrr of an inch, while the ox, a
very sluggish animal, has a mnch smaller corpuscle, ^^^ of
an inch. As the size and shape of blood corpuscles are
among the chief factors in the identification of blood, and its
source, it is important to have definite and accurate data
concerning every point. The differentiation of human blood
from that of fishes, reptiles and birds, never offers the least
difficulty, because of the elliptical shape of their corpuscles.
They are not only ellipses, whose long diameter is about
twice as great as the broad diameter^ but they are also

262 SIZE OF THE BLOOD CORPUSCLES.

distinctly embossed (biconvex). But the differentiation of
human blood from that of lower mammals is effected with
great difficulty and in some cases can not be effected at all.

The most recent and reliable measurements of blood cor-
puscles have been furnished by Welcker, who estimated
the size of his own blood corpuscles from 130 observations
as follows : —

Greatest transverse diameter - 0,00774 mm.
thickness - - - - 0.00190 "

These measurements were made by introducing into the
eye-piece of a microscope, a micrometer, whose lines stood,
under a magnification of 620 diameters, 0.001723 mm. apart,
and the tenths of a division could be estimated with accu-
racy. The blood corpuscles were suspended in serum, and
evaporation, as well as agitation, was prevented by fastening
down the edges of the cover glass with Canada balsam
(Gscheidlen).

Welcker also made measurements in the case of other ani-
mals as follows : —

Animals. No. of Observations. Average Diameter.

Elephant 20 0.0094 mm.

Dog - 10 - 0.0073 "

Eabbit - - - 20 - - 0.0069 "

Cat - - 20 - 0.0065 "

Sheep 20 0.0050 "

Goat 20 - 0.0041 "

Deer - 5 0.0025 "

And of animals having elliptical corpuscles as follows: —

Animals. No. Obs. Long- Diameter. Short Diameter.

Lama 20 0.0080 0.0040 mm.

Pigeon 20 0.0147 0.0065 "

Frog 50 0.0223 0.0157 "

Triton 20 0.0293 0.0195 "

ELASTICITY OP THE HED CORPUSCLE. 263

The Number of Red Corpuscles,

The number of blood corpuscles in a given quantity of blood
may be ascertained by directly counting them in a known
quantity under the microscope, and multiplying this known
quantity, a fractional part of a drop, by the whole quantity
under consideration. A better method, however, is to
dilute a known quantity of blood with a known quantity of
serum or salt solution, and then count and compute as before.
From these methods it is estimated that a cubic centimetre
of human blood contains 4,231,500 (Stoltzing), 4,620,000
(Welcker), 5,174,000 (Vierordt), corpuscles. In ansemia,
leucocythsemia, etc., this number may be reduced by millions,
to be again restored by chalybeate, or other suitable treat-
ment. The whole number of corpuscles in the blood of a man
of average weight is roughly estimated at about twenty-five
billions.

Elasticity of the Red Corpuscle.

The red blood corpuscles are highly elastic bodies. When
studied under the microscope it is observed that pressure of
the cover upon the object glass flattens them, but they
speedily recover their original shape and size when the pres-
sure is relieved. Observed in the capillary vessels (web of
frog's foot, tail of lizard, mesentery of mouse, or lung of
frog) they are seen to become elongated almost to a thread,
and thus succeed in traversing capillaries whose diameter is
much less than their own, to resume their original size and
shape on escape into wider tubes. So they are sometimes
caught at an angle, formed by the division of one capillary
into two, and to be swung first partly into one tube, then
partly into another, changing their shape (passively) con-
tinually, until, finally, sufficient vis a tergo from the proper
direction sweeps them entirely into one or other tube. The

264 THE CONSTITUTION OF THE CORPUSCLES.

elasticity of the corpuscle is also manifest in the constant
change of shape they are made to undergo under permeation
and surrender of various gases. Carbonic acid gas distends
the corpuscle, and oxygen leaves them more flat, a factor
which partially effects the difference of color between arterial
and venous blood. The red corpuscles, therefore, are rather
semi-fluid than semi-solid. They are to be regarded as
thoroughly homogenous bodies, like particles of jelly and
are in no sense cells, in the ordinary acceptation of the term,
with walls, contents and nuclei.

Constitution of the Corpuscles.

The red blood corpuscles are composed of a gelatinous basis;
the stroma, and the iron containing, albumenoid, coloring
matter ; the haemoglobin. The haemoglobin is easily soluble
in water or serum but is so intimately blended with the
stroma, as to require artificial intervention to effect its
separation. If blood be repeatedly frozen and thawed, or if
successive strokes of electricity be transmitted through its
mass, the haemoglobin is separated, and is held in solution
by the plasma, so that the blood loses its opacity (which
is due to the different angles at which the corpuscles and the
plasma refract light) and becomes quite translucent like
colored varnish. Dilution with water, the addition of bile
salts, agitation with ether, chloroform, alcohol or bisulphide
of carbon effect the same result (Fick). So also septic
and miasmatic germs, in disorganising the corpuscles, liber-
ate the coloring matter, so that the skin, mucous membranes,
in fact, all the tissues, become stained with it. This con-
stitutes the hematogenous icterus of yellow, malarial, typhus,
etc., fevers. The haemoglobin when thus separated assumes
special rhombic forms which may be differentiated from
the forms assumed by the haemoglobin of lower animals.
One of the most reliable of all the tests for blood is the

THE USE OF THE RED BLOOD CORPUSCLE. 265

spectroscopic test afforded by the lines formed in the spectrum
by hemoglobin, when oxidised (oxyhemoglobin), as in
arterial blood, or when reduced, as in venous blood. Reduced
hemoglobin distinguishes itself by an absorption band
in the yellow part of the spectrum. If new this solution
of reduced hemoglobin be agitated with oxygen, the absorp-
tion band falls into two, one of which approaches the line
D, the other the line E of the solar spectrum, and the space
formerly occupied by the- absorption band of the reduced
hemoglobin is now clear. Hemoglobin on standing for any
length of time separates into an albumenoid substance and
the iron coloring matter hematin. The addition of acids
effects the same division. Hematin, dissolved in ether or in
alkalies, or reduced, gives also special bands in the spectrum.
The stroma of the corpuscles is a very complicated com-
bination of an albumenoid substance (protagon or lecithin)
with salts of potash and phosphorus and with fats and
cholesterine. It is markedly hygroscopic, swells by imbibi-
tion with water, and thus restores the size and shape of
blood corpuscles after the dessication of years. Blood
stains, shaved up from floors or scraped from knives, have
been recognised as such, by this restoration of the size and
shape of dried corpuscles, after the lapse of several years.

Use of the Red Blood Corpuscles.

The red blood corpuscles are the oxygen carriers to the
tissues. They arrive at the lungs partly emptied of oxygen,
receive an additional quantity as the result of inspiration,
and are swept off into the general circulation by the action
of the heart. In the capillaries, the oxygen, a great part of
it, at least, is surrendered to the tissues, and carbonic acid
gas is received in its place. The blood corpuscles have the
property of absorbing ten to thirteen times as much oxygen
as water. The blood plasma will absorb two or three times

23

266 THE COLORLESS BLOOD CORPUSCLES.

as much oxygen as water, and this constituent officiates in
its conduction, though to much less degree than in the con-
duction of carbonic acid gas.

The red corpuscles being thus so distinctly the oxygen
carriers, any marked diminution in their amount should
produce symptoms of asphyxia. And, in fact, it is observed
that animals dying of hemorrhage experience first vertigo
and syncope, from lack of oxygen for nervous supply,
become finally convulsed, and die panting for air. So Paul
Bert has shown that the resistance to asphyxia manifested
by diving animals, so long inexplicable, is due to the simple
fact that these animals have more blood, and consequently
more blood corpuscles. Thus a chicken can be drowned or
strangled in two minutes, while a duck of the same weight
will survive seven or eight minutes. The duck has, how-
ever, one-third or one-half more blood than the chicken,
and each additional corpuscle is, of course, an additional
reservoir of oxygen gas.

The Colorless Blood Corpuscles.

Colorless corpuscles exist in the blood of both vertebrate
and invertebrate animals. The first noticeable fact con-
cerning the white corpuscles in the blood of man is their
comparative paucity. They exist in the proportion of one
to three to four hundred of the red corpuscles, but their
absolute and relative number varies greatly according to the
period of observation. That is, they are very markedly in-
creased after meals. Thus Hirt found them present before
breakfast, at the period of greatest fasting, in the proportion
of 1:1800, after breakfast 1:700, before dinner 1:1500, after
dinner 1:400, etc.

The white blood corpuscle diners from the red in other
respects than color. In the first place it is larger than the
red. Though Schultze describes three different sizes of

THE COLORLESS BLOOD CORPUSCLES. 267

white corpuscles, that which exists in greatest number and
which is mostly studied, measures vr-1^ of an inch (0.0101 mm.)
in diameter. Secondly, the white blood corpuscle is not a
disk. It is spherical in shape. It differs additionally in
being abundantly granulated, and in containing a distinct
nucleus.

Bodies which have always been regarded as similar, and
which are now known to be identical in every respect to
white corpuscles, are found also in the lymph and chyle, in
colostrum, semen and in the vitreous humor of the eyeball.
Such bodies constitute the morphotic elements of pus, where
they are known as pus cells.

But what especially distinguishes white blood corpuscles
(leucocytes), is their property of motion. They move like
the amoebae, which we have already studied, and hence are
often known as the amoeboid cells. Circulating in the ves-
sels, they keep close to the wall of the vessel, while the red
corpuscles form an axial mass in quicker motion.

This amoeboid motion of the white corpuscles may be very
easily brought under observation. A watch glass is filled
with frogs blood, which is allowed to coagulate. The coagu-
lum is then separated with a needle from the edge of the
glass, and when a little serum has exuded, a drop of it is let
fall upon a .cover glass, which is then placed upon an object
glass, so arranged that it can be kept warm. The edge of
the object glass should be covered with oil, to prevent
evaporation. The object glass is now to be gently heated.
So soon as the temperature rises to 36° C. (96° F.) the well
known processes of motion ensue. The movements of the
white corpuscles of human blood, and their response to
various stimulants, may be studied in the same way. The
white blood corpuscles represent the incunabular stages of
the red corpuscles, as transition forms have been discovered
in abundance in the lymph glands, in the spleen, thymus

268

THE BLOOD PLASMA.

and thyroid glands, supra-renal capsules, marrow of bones,
etc., structures, all of them, found only in vertebrate ani-
mals, in which alone red corpuscles are found.

The Blood Plasma.

The plasma contains all the remaining ingredients of
the blood except the corpuscles. To obtain a satisfactory
analysis of the plasma it is necessary to examine the blood
before coagulation and after the sinking of the corpuscles.
As the corpuscles sink very rapidly in the blood of the
horse, leaving a supernatural clear plasma, the most reliable
results have been obtained from this animal. The following
table exhibits the composition of the blood of the horse :

1000
Parts
Blood
Cont'n

r Water

184.30
' Haemoglobin 122.75

' Corpuscles 324.2 '

Solids

Albumen 17.80

[ 141.9

Lecithin 0.84

Cholesterin 0.51

' Water

579.4
" Fibrin 6.4

^ Plasma 673.8

Albumen 43.1

Solids

Fat 0.8

b 58.4

Extracts 2.5

Soluble Salts 4.1
Insoluble Salts 1.1

No fluid in the body has been subjected to so many and such
careful and skilful analyses as the blood, but the conclusions
reached by different observers have shown very marked
differences. When we recall, however, what changes the
blood must undergo, not only daily, and hourly, but in every
second of time, in yielding up constituents for continu-
ous supply, and in receiving as continuously the products
of combustion and waste, we cease to wonder at any quanti-
tative or qualitative discrepancies in the results of chemical
analyses.

"Xor are, although the river keep the name
Yesterday's waters and to-day's the same."

THE COAGULATION OF THE BLOOD. 269

The blood in its entirety contains, thus, proximate princi-
ples of the three different classes ; of the inorganic class in
its water, iron and salts, of the non-nitrogenous class in its
fat, extractives and part of the lecithin, and of the nitro-
genised class in its albumen, globulin and fibrin. Hence it
is that the blood is the pabulum of all the tissues. It
contains the materials out of which the protoplasm of all
the tissues may evolve work, that is fuel, and it contains
materials from which the tissues may repair their own
waste. But all these matters do not really exist in the
blood as such, and hence are not, strictly speaking, proximate
principles. This is notably the case with regard to fibrin.
Fibrin does not exist in the blood as such, and only presents
itself as an ingredient when physiological conditions are in
some way disturbed. Fibrin is a product of two substances,
the so-called fibrin generators, paraglobulin and fibrin-
ogen (A. Schmidt). Both these substances exist as such
in the blood, and may be recovered from it by suitable
manipulation. Nor is the albumen in the blood the same
as ordinary albumen (white of egg). It differs from it in
many chemical reactions, and more especially in its osmotic
properties. If ordinary albumen be injected into the blood,
it is not absorbed, but is rejected by the kidneys, while
blood albumen is retained and absorbed.

The Coagulation of the Blood.

Within five minutes after blood is withdrawn from the
body it begins to clot. A gelatinous pellicle first forms
upon its surface and afterwards extends down the sides of
the vessel containing the blood. When the vessel is now
agitated, the mass of blood does not spill out ; it quivers
like a mass of jelly. Gradually now the process of coagula-
tion invades the whole mass of the blood until, finally, the
entire quantity has become "set." The time occupied in

270 THE COAGULATION OF THE BLOOD.

this solidification of the whole mass is, according to Nasse,
from seven to sixteen minutes. The clot next begins to
contract, and pellucid drops of fluid exude from its surface.
The further process of coagulation consists in the continua-
tion of contraction of the coagulum and expression of
fluid until, in from 10-12 hours, the whole mass of the blood
has become separated into "a clot" and surrounding "serum."
The clot is composed of the fibrin, entangling the corpuscles,
and the serum contains the water, the albumen and the
salts.

The coagulation of the blood depends upon the fact
that the fibrin generators, when placed under abnormal con-
ditions, pass from the fluid to the solid state, that is, that
the fibrin generators unite to generate fibrin. If a drop of
blood be observed under the microscope, this gradual
development of fibrin manifests itself in the formation of
threads or fibrillar, which extend across the microscopic field,
entangling the corpuscles, Avhich have now become packed up
against each other, in rows or rouleaux, like coins upon a
banker's table. The corpuscles escape entanglement if time
be allowed for their subsidence. Thus when the blood
coagulates slowly, naturally, or artificially (as by the addition
of alkalies), the corpuscles gravitate to the bottom of the
vessel. The position of the body at death, after subsequent
change, has sometimes been determined by the location of
the corpuscles in the clot, as in the longitudinal sinus. We
have as yet no satisfactory explanation of the cause of the
coagulation of the blood. None the less, however, are we
able to appreciate its utility. Were it not for this forma-
tion of fibrin under certain conditions, to officiate as a plug
for divided vessels, the slightest solution of continuity in
the walls of a bloodvessel would be attended with fatal
hemorrhage. In fact there are cases characterised by a
deficiency in its formation, the so-called cases of hemorrhagic

THE COAGULATION OF THE BLOOD. 271

diathesis in which the extraction of a tooth, the scratch of
a pin, the slightest lesions, permit the most disastrous
hemorrhage. In these, cases, pressure or ligation of vessels,
if of sufficient size, affords only temporary relief. When
the pressure is relieved, or the ligature comes away, the hem-
orrhage, of course, recurs. Ordinarily, however, the coagu-
lating blood blocks the orifice in the wounded vessel, and thus
checks further loss. The great vessels in the walls of the uterus,
after the extensive lacerations of parturition, are stuffed by
clots of blood and, further escape is thus, as a rule, prevented.
Thus, also, successive layers of fibrin are sometimes deposited
in the walls of a vessel, weakened and distended by disease
(aneurism), so that the weakest places become the strongest
by this adventitious padding. Unfortunately, fibrin some-
times exercises a more malign influence, in being swept off
in the torrent of the circulation, from surfaces upon which
it has become deposited, to distant places, to block up most
important vessels. Masses of fibrin (emboli) are thus
occasionally detached from valves of the heart, upon which
they have come to be deposited, in consequence of the
roughening induced by endocardial inflammations, and
carried to plug the great vessels feeding the brain, and thus
cause the most serious lesions, and often death.

Here, then, we must conclude our brief survey of the
properties of the blood. And whether we look upon it in
the light of its mere complexity of construction, of the grave
symptoms induced by even its partial loss, of its speedy
reproduction after hemorrhage, of its maintenance of itself
under the constant consumption which it must suffer, we
can not fail to appreciate its importance. Magendie says
that a celebrated physiologist became so convinced of the
value of the blood as to define life as "the contact of arterial
blood with the organs of the body, especially with the
brain." If he had said, the consumption of the blood by

272 THE BLOOD AS THE SOURCE OF LIFE.

the organs, and liberation of its latent force, he would
have told all the truth. The older physiologists were
fond of locating life as a peculiar principle or essence
in the blood. It lodged in the pure or arterial blood.
It was the promulgation of this delusion, that the soul
dwelt in the arterial blood, that cost Servetus his life.
Such temerity as the attempt to localise the soul awakened
the ire of the theologians, and at the instigation and by the
order of John Calvin, Servetus was publicly burned at the
stake in Geneva, and nearly every copy of his works was
thrown into the flames.

The older clinicians waged bitter war among themselves
concerning the part the blood played in disease. The
"humoral" pathologists maintained that the blood was the
seat of all disease. Much of the popular conceit of our own
times regarding "impurities" of the blood is derived from
the doctrines of humoral pathology. The impurities, which
we are called upon to treat, are, for the most part, impurities
of the skin, animal and vegetable parasites, with which the
blood has nothing to do, except to nourish their host. The
real impurities of the blood are the acute infectious dis-
eases, the germs of which breed in the blood, with character-
istic fecundity, feed upon it, disorganise and corrupt it, so
that : —

"The life of all his blood is touched corruptibly."

The blood, as the source of life, has always been recognised
as the maternal substitute of the body from which it is
derived. The contract for the sale of the soul had always
to be signed in blood. So Mephistopheles insists that Faust
shall sign his compact with him with a pen dipped in his
blood, because as he says of this subtle fluid — a saying to
which we are now prepared to agree: — "Blub ist ein ganz
besonderer Saft" (Blood is a very peculiar juice).

INDEX.

PAGE.

Absorption and assimilation 132

Adaptation, force of. 90

Age, determination of 1C7, 1G8

" effect of upon nerve tissue 245

" of the earth 59

Air in bone 170

Albumen and its products 130

" of the blood.., 2G9

Alcohol, action of. 12

Alkalinity as favoring- oxidation 137

Amoeba, the 114

Amoeboid motion of white blood corpuscles 207

Aneurism, Hunter's treatment of. 4

Animal bodies as machines 43

Animals, fertility of 94

Appendix vermiformis as rudiment 80

Artificial selection 90

" " effects of. 92

" construction of organic bodies 41

Assimilation, the property of 52, 132

Atavism 87,89

Atmosphere, maintenance of composition of 43

Aubrey John, remarks concerning Harvey 3

Autogeny 141

Axis cylinder, the 228

Bathybius, the 113

Bee, generation of 127

Birds, action of muscles in 221

*' classifications of. 92

Blood albumen 269

M and its properties 247

** as source of life 272

" as substitute of the body 272

" coagulation of. 2G9

« color of 252

*« constitution of 251, 268

274 INDEX.

Blood corpuscles colored 265

" " colorless 2G6

** " affected by coagulation 270

" " red 250

" " " constitution of .., 2G4

" " " elasticity of. 203

" " " number of. 203

" " " size of. 2C0

" " " use of. 2G5

" dependence of muscle on 217

" fibrin of. 269

" " use of 270

" morphology of. 258

" odor of. 253

" of man and animals 71

" oxidation processes in 136

" . plasma 2G8

" proximate principles of. 2G9

" quantity of. 255

" reaction of. 253

'* spectroscopy of 265

" taste of. 254

** temperature of. 254

" transfusion of 248

" value of 247, 272

" weight of 255

" vessels, contractility of. 197

Bone, absorption by 172

" air in 170

" and its properties 150

" as a connective tissue 164

" as fuel 158

** as symbol of the body 174

" canaliculi 155

" centres of ossification in 1G7

" chemistry of. 15G, 159

" corpuscles 155

" constancy of composition of 159

14 distortion effected by weight 173

•* effects of use and disuse on 172

" excavation of 109

" formation in anomalous places 164

*' " of 105

M general properties of. 152

index. 275

Bone, harmony of development of. 173

" Haversian canals of. 153

" histology of. 153

44 lamellae of 154

44 marrow of. 171

44 studies in living 171

44 preservation of. 103

" phosphate of lime in 1C2

44 relation to nerve tissue 150

44 resistance and resilience of 150

44 rudiments 78

Brain of man and animals 70, 71

Brambles, classification of 92

Branchial clefts 75

Cadaveric rigidity 212

Canaliculi of bone 155

Cancellated structure of bone 109

Carbon compounds in plants 40

Carbonic acid gas, decomposition of in plants 39

Carotid process, the 233

Cataclysms of Cuvier 58

Caterpillar, colors of 98

Cats and red clover 101

Caul, the 10

Cell, chemistry of. 131

44 contents or protoplasm 113

44 derivation and import of the term 110

44 discovery and history of the 108

44 metabolism of 133

44 mode of birth of. 144

44 44 44 death of. 145

44 nucleus and nucleolus „ 112

44 pigment in chameleon 118

44 shape and size of. 109

44 wall ..: HI

Centre of ossification KJ7

Cerebro-spinal and sympathetic systems 220

Cerebrum, action of cells of 239

Chameleon, color changes in 117

Chamisso on alternation of generation 87

Channel of Mt. Pilatus 37

Chemistry of blood 2G4, 208

44 44 bone 15G, 159

" 44 the cell 131

276 index.

Chemistry of muscle 184

" " nerve tissue 2)15

" " protoplasm ; 123, 1.11

Child, resemblance of to parent 80, 00

Chorda dorsalis, discovery of cell structure of 110

" " ossification in 1G7

Cilia and ciliary motion 110

Ciliary motion, conditions affecting- : 121

Circulation, discovery of..... 2

" value of knowledge of 4

" work on.... 2

Classification of tissues 146

" ". " anatomical 147

" " " chemical 147

" " " physiological 148

" " animals and plants, difficulty of. 01

Clocks, the force which runs 27

Clover, red and cats 101

Coagulation of the blood » 200

Coal, magazines of 40

Coccyx as rudimentary organ 78

" muscles of 70

Color changes in chameleon 117

" of blood 252

" " flowers, use of 101

" " muscle 177

" " nerve tissue 226

Colors, protective 07

'* warning 07

Combustion, excretions as products of 41

" gases of 41

Comparative anatomy, evidence furnished by 01, 65

" embryology 73

Conservation of force 2')

Contraction process as cause of heat of the sun 36

Conservatoire des Arts et des Metiers 29

Contractility of muscle (see muscle)

Convertibility of the forces 26, 29

Corpuscles, blood (see blood).
" bone (see bone).

" of Pacini 230

" of Krause 230

" tactile 230

Cranium, bones of. C8

INDEX. 277

Curare, action on muscle 207

Curve, the muscle 203

Cuvier, cataclysms of 58

" on comparative anatomy C5

** " footprints G2

Darwin Charles Robert, discoveries of 91

" Erasmus 70

" on imperfection of geological record G3

" views on rudiments 83

Death of cells 145

Decay, action of upon matter 25

Denudation of earth, rate of. 58

Diemerbroeck's treatment of small-pox 7

Digestive system, rudiments in 79

Digitalis, action of 12

Disease, ontological conception of 5

Diseases transmitted by inheritance 85

Drinking water, lime salts in 162

Du Bois-Reymond1s theory of muscular action 210, 211

Duck, resistance of to asphyxia 2G6

Dynamometer, the 219

Ear, comparative anatomy of. G5

" external as rudiment ; 81

" lopped in rabbits effect on bones 173

" rudimentary muscles of xm 79

" the point of as rudiment ; 81

Earth, age of 59

" effect of arrest of rotation of 35

" past history of 55

Egg (see ovum).

Egg, oxidation processes in 135

Elasticity of muscle „ 185

Electricity, action of on muscle 201 203 201

" action of upon nerve tissue... 23G

u and nerve force 241

" generation in muscle 209

44 light from 31

" motion from : 31

Electrotonus of nerve fibre 237

Elements, ultimate composing organic matter 129

Emboli 271

Embryology comparative 73

Endogenous development of cells 144

278 INDEX.

Epiphyseal centre in femur 108

Equivalence of the forces 28

Ergot, physiological action of. 14

Evolution, the theory of. 50

Excretions as products of combustion 41

Exercise, influence of on nerve tissue 245

Existence, the struggle for ." 94, 96

Existing causes, operation of 59

Experience, the fallacy of 4

Eye, rudimentary structure in 81

** comparative anatomy of. 65

Facial bones, air in 171

" neuralgia nerves affected in 12

Fatigue, effect on muscle 1S5

" sensation of. 191, 102

Femur, epiphyseal centre in 108

Fertility of plants and animals 94

Fcetus of man and animals 74, 75

Fibrin, blood 209,270

Filum terminale as rudiment 80

Fire, action of upon matter 24

Fishes, air in bones of. 170

Flowers, use of smell and colors of. 101

Food and fuel, relative cost of. 44

" as source of force 39

11 force value of 4.1

" in relation to work 44

Foot of man and animals 76

Foot prints as evidence 62

Force, conservation of 2i>

" machinery a means of changing 27

« muscular 218, 219

M nerve, the 237

" no matter without 25

" perpetuity of 38

M physiological 39

Forces, convertibility of the 26

M equivalence of 28

Fossils, explanations of 56

Fuel, bones as l,r'8

" and food relative cost of 44

Galvani and galvanism 202

Gases of combustion 41

Gelatine as an aliment *58

INDEX. 279

Generation, alternation of. 87

*' spontaneous 141

Genesis of protoplasm 140

GcofFroy St. Ililaire on rudiments <c2

Geological record, imperfection of 63

Germinal vesicle, molecules in 89

Gesticulation, action of muscle in 222

Gladstone's response 16

Goethe, views on development of life G9

" Wilhelm, work of OS

Gravitation, conversion of into heat 37

Haeckel Ernst, work of. 74

Hair bulbs, terminations nerve fibres in 231

Hairs as rudiments 80

Haller Albert, sketch of life of 19

" works of, opinions concerning 21

Hand and its homologies 72

Haversian canals 153

Harvey William, discovery of the circulation 2

. " " life of 17

Heat caused by gravitation 37

" effect on muscle 200

" generation of, in muscle 208

" mechanical equivalent of. 29

" motion converted into 30

" of sun from contraction 36

" solar, origin of 25

Hemaglobin 264

Hematin 264

Heredity (see inheritability).

Histology, history of 105

Homoeopathy and the school of Naples 15.

Homochronous transmissions 87

Horses, phenomena of reversion in 88

Human beings, fecundity of 95

Humboldt's estimate of forms of life 64

Humerus, supra-condyloid process of. 78

Hunger as cause of preservation of race 103

Hunter John, treatment of aneurism 4

Inheritability, examples of 85

" explanation of 89

" homochronous 87

*4 in lower animals 86

280 IXDEX.

Inheritability, influence on the mind 239

'* laws of. 84

Infusoria, fecundity of 95

Insects, action of muscles in 221

winged and wingless ..7. 96

Intermaxillary process 09

Janssens Zacharias and the microscope 107

Jellies, nutritive principles in 15S

Kant, nebular hypothesis of 34

King's evil, royal touch as cure of 9

Kolliker on the cell.. 112

Lamarck Jean, works of 6G, 90

Lamellae of bone 154

Lanugo as rudimentary structure 81

Laplace, nebular hypothesis of 34

Laryngismus stridulus a reflex affection 12

Lecithin and cerebrin 235

Leeuwenhoek, discoveries of. 107

Leg of man and animals 76

Levers, muscles as 217 "

Life, definitions of 48

" period of development of 54

Light from electricity 31

Lime phosphate in bone 102

Links missing, cause of 62

Liquor sanguinis 26S

Locomotive, derivation of force of 28

Machinery, a means of changing force 27

Machines, animal bodies as 43

Madder, absorption of by bone 172

Malpighi, discoveries of 107

Man, ancient 61

" position of in animal scale 72

Marrow of bone , 171

Matter indestructibility of 24, 38

no, without force 25

Maturitv at birth, determination of 168

Mechanisms and organisms 51

Meckel, ganglion of. 12

Metabolism of the cell 133

Meteors, fall of upon the earth 30

Metrorrhagia, ancient treatment of. 13

Microscope, history of 1Q7

INDEX. 281

Mid-jaw bone 69

Miraculous and non-miraculous theories of life 54

Molecular movements 123

Molecules, size and number of in ovum 89

Moliore's satires upon medicine 8

Monkeys, sense of taste in 71

Motion as essence of reproduction 12G

" ciliary 119

" conversion of into heat 30

" from electricity, examples of 31

" molecular 123

*' muscular 176

" of white blood corpuscles 2G7

" property of in protoplasm HG

Mueller Johannes and the chorda dorsalis 110

Muscle, absolute power of. 218

" action of curare on 207

" " " nerve force on 203,225

" '* " sulphocyanide of potash on 206

" « persistence of after death 212

*' and nerve plate . 232

" and its properties 175, 195

" as levers 217

" chemistry of 184

" color of 177

" connection with tendons 197

" contractility 195

*« " agents which induce 199

** " change of form in 198

" " degree of 198

" " direct and indirect excitation of 200

" ' « effect of 197

« " independence of. 20G, 208

« «« electric excitation of 201,203,204

" " thermal excitation of 200

" " rate of conduction of 20G

« « sound of. 205

*' curve 203

" dependence of upon blood 217

" difference in different animals 220

" disks 179

*' elasticity of. 1S5

" etymology of 175

«4 fibre and fibrilla 179

24

282 INDEX.

Muscle, force and nerve force 238

" form and shape of 182

" fuel of. 23

" general power of 219

" " properties of. 180

*' generation of electricity in 209

" " " heat in 208

" in birds action of. . 221

" in insects " ** 221

" involuntary 182

" " contractility of 196

u " disposition of ,...„■ 183

u motion effected by 176

" names of 181

'* oxidation of 216

" " processes in 135

" oxygen supply to 216

" post-mortem changes in ., 214

" products of action of a 215

" protoplasm 180

" reaction of. 184

" rigor mortis of 212

" rudiments , 79

" sarcolemma of. 178

" sense, exercise of , 193

" " and sense of touch 190

" sensibility of 190

" sexual differences in ..„ 220

" specific properties of. 185

" striped and smooth 176

" termination of nerve fibres in 231

" tonicity of 187, 188, 189

" transfusion of blood nto 47

M velocity and delicacy of action of 221

" voluntary, anatomy of. 178

" wave, the 205

Muscular force, source of in food 39

Naples, school of and homoeopathy 15

Napoleon, advice to Antonamarchi 8

Natural selection 90

" " complications in 100

" " illustrations of. 96

Nebular hypothesis 34

Nerve, ancient significance of. 244

INDEX. 283

Nerve and its properties 223

as tendon 244

cells 227

" and fibres 225

fibres 227

" axis cylinder of 228

" course of 232

" gray .229

" identity of. 234

" indifference of direction of nerve force in 235

" medulla of. 228

" motor, terminations of. 231

" sensitive " " 230

" sheath of . 227

force, action of in cold blooded animals 243

" " " upon muscle 204,225

44 and electricity 241

44 genesis of. 225

" independence of. 224

" nature of. 237

" rate of conduction of 240, 242

tissue action of electricity upon 236

44 arrangement of. 22G

44 chemical processes in 236

44 chemistry of 235

44 color of. '.'. 226

44 divisions of. 226

44 effects of age on 246

44 44 44 use and disuse „. 245

44 oxidation in 138

44 prime function of. 223

44 reception and perception of impressions by ". 242

44 relation of bone to 150

44 subordination of. 224

Nerves, properties of. „ 229

Nictitating membrane of the human eye 81

Nucleus and nucleolus of the cell 112

44 44 44 44 44 44 chemistry of 132

Number of species 94

Nutrition and reproduction 143

44 the circle of. 42

Occupation, effect of on bones 173

Ophthalmology, progress of 13

Opinions of medicine by noted men „ 7

284 raDEx.

Organic and inorganic matter, difference between 51

" bodies, artificially compounded 41

" matter, chemistry of 128

Organisms and mechanisms 51

Ossification, the centre of. 1G7

Osteology, difficulties attending the study of. 157

Osteo-malacia and rachitis 161

Ova, number of in human being 96

Ovum as typical cell 109

" molecular changes in 124

" multiplication of cells of 89

" oxidation processes in 134

M size and number of molecules in 89

Oxidation, processes of 133

Oxygen, absorption of in blood 265

" consumption of in the body 42

" quantity of in the body 138

" supply to muscle 216

Ozone in blood corpuscles 137

Palaeontology, the science of 56

Palm tree, fructification of 100

Paracelsus Theophrastus 5

Paraguay, absence of wild cattle in : 100

Parent, resemblance of child to 89, 90

Parthenogenesis 126

Periosteum, the , 166

Perpetuity of matter and force 38

Phosphate of lime in bone 162

Phosphorus in nerve tissue .- 236

Phthisis, treatment by venesection 6

Physician, requisitions of ancient 16

" the modern 15

Physics of reproduction 88

Physiological force 39, 46

Physiologists, characteristics of. 21

Physiology, contributions of to practice 11

" definitions and synonims of 47, 50

M influence of on practice 1

'* study of as a refuge 22

Pigeon breeders, experiments of 93

Pigeons, varieties of under artificial selection 93

Pigs, fecundity of. 102

Pigment cells in chameleon 118

Pilatus Mt., channel of 37

INDEX. 2S5

Planetary system, commencement of 34

Plants, carbon compounds in 40

" fertility of 94

Plasma, the blood 268

Plica semilunaris 81

Point of the ear as rudiment 81

Pregnancy, post-mortem recognition of previous 25

Prescriptions ancient, specimens of 5

Preservation of individual and race 102

Primrose Dr. Jacob 1

Protective colors 97

Protoplasm and its properties 105, 113, 115, 128

" chemistry of. 131

'* examples of. 115

" genesis of 140

" muscle, fluidity of 180

Proximate principles 129

" " in the blood 269

Pus corpuscles 267

Rabbits, displacement of bones of. 173

" varieties of under artificial selection 94

Rachitis and osteo-malacia 161

Rattle snake, rattle of 99

Reflex action 237

" affections 13

Renal force, the 220

Reproduction and nutrition 143

" instinct of in preservation of race 103

" process of as distinction of organic matter 52

'• the physics of 88, 124

Resemblance between man and animals 70

" of child to parent, reason of 89, 90

Resiliency of bone 159

Resistance of bone 159

Reversion, phenomena of 87, 89

Rib, manufacture of female from 174

Rigor mortis 212

Royal touch, the 9

Rudimentary organs 77

" " bone 78

" " digestive system 79

" u explanations of 82, 83

" " from eye and ear 81

" " hair as 81

286 ixdex.

Rudimentary organs, muscle t 79

" " spinal cord 80

Salpae, alternation of generation in 87

Sarcolemma of muscle 178

Schwann Carl Theodor and the cell 108

" white substance of ....228

Science versus practice -m 3

Sea-buoys, alternation of generation in 88

Segmentation process of in ovum 125

Selection, artificial 00

" " effects of. 92

" natural GO

" " complications in 100

" " illustrations of. 96

" " sexual 98

Semilunar fold in the eye as rudiment 81

Sensibility of muscle 190

" " " and sense of touch , 190

Sense muscular, exercise of. 193

Sensitive nerves, terminations in' muscle 191

Sexes, difference of muscle in 220

Sexual selection 98

Sharpey's bone lamellae 154

Sheath of nerve tubes 227

Ships and force of the wind ; 28

Signatures, doctrine of in the treatment of small-pox 6

Skeleton, the 151

Smell of flowers, use of 101

Small-pox, doctrine of signatures in 6

Sound of muscle contraction 205

Solar origin of heat 25

Species, mutabdity of. 92

Spectroscopy of the blood 265

Spermatozoids as cdiated cells 122

" action of towards ovum 125

" discovery of 107

Spinal cord, termination of as rudiment 80

" u relation of bone to 150

Spontaneous generation 141

Starch, formation of 26

Steam engine, the force of 28

Stephenson George, conception of heat 25

Sterne, description of receipt by 5

" opinion of medicine by 8

INDEX. 287

Struggle for existence 94, 90

Succession, order of vertebrate , 66

Sugar, formation of 26

Sun as the source of force 25, 32

" dimensions of 32

*' heat of caused by processes of contraction 36

" origin of forces of 33

Sympathetic and cerebro-spinal systems 226

Tad-poles, cells of chorda dorsalis of. , 110, 111

Temperature of the blood 254

Tendons and nerves 244

" connection With muscle fibre 197

Theories of life .....* 54, 55

Tic doloureux 12

Tissues, classification of the , 146

Tonicity of involuntary muscle 189

" " muscle 187

" " " a reilex phenomena 188

Tooth, wisdom as rudiment 79

Touch, sense and sensibility of muscle 190

" the royal : 9

Transfusion of blood 248

" " " into muscles 217

Uterus, resistance to putrefactive change 214

Universe, infinitude of. 38

Valves of veins, Harvey's study of 18

Velocity of muscular contraction 221

Vermiform appendix as rudiment 80

Vertebrata, structures peculiar to 268

Vertebrate animals, bone tissue in 150

Vesicle germinal, molecules in 89

Volitional action 238

Virchow's opinion of ophthalmology 13

Virgin generation 126

Vital force, the 210

Vocal cords, muscular movements of. 222

Vulpian on brain of man and animals 70

Wall, the cell Ill

Warning colors 97

Water drinking, lime salts in 162

" -wheels, the force of 27

Wave, the muscle 205

Whale, perception of impressions in 243

288 index.

Wind, fertilisation by „ 102

Windmills, the force of '. 27

Wisdom tooth as rudiment 79

Woorara, action on muscle 206

Work, relation of food to , 44

THE PMI jBfffflU OF MM IS- PROTOPLASM,

A BOOK FOR STUDENTS BEGINNING

THE

STUDY OF MEDICINE.

Preliminary Course Lectures

ON

Physiology.

BY

JAMES T. WHITTAKER, M.A., M.D.,

PROFESSOR OF PHYSIOLOGY AND CLINICAL MEDICINE IN THE MEDICAL

COLLEGE OF OHIO; LECTURER ON CLINICAL MEDICINE AT THE

GOOD SAMARITAN HOSPITAL; MEMBER OF THE CINCINNATI

ACADEMY OF MEDICINE, AND OF THE CINCINNATI

SOCIETY OF NATURAL HISTORY:

FOR SALE BY

Chancy R. Murry, Publisher, 103 West Sixth St.,

Cincinnati. Price $1.75.
Jggg^Mailed to any address on receipt of price; money
may be sent by P. o. Order or Registered Letter.

COMMENTS OF THE MEDICAL PRESS.

"This little work was published at the request of many of the author's
students, and we do not wonder at the request. As one would infer
from the subject, the author does not pretend to give an exhaustive ac-
count of the extensive field of physiology, but he does what is equally
essential: he inspires his readers with the enthusiasm with which he
himself is inspired. He takes up the prominently interesting parts of
physiology as a man passionately fond of and well" acquainted with chil-
dren, will take them up and talk to them and about them. The book
will be of great interest to the student, and a pleasant recreation to the
active practitioner. "—Chicago Medical Journal and Examiner.

"The abstract reasoning is entirely after Draper and Darwin, and the
advanced views of the great evolutionist are given in a most concise and
comprehensible form. As for the purely physiological portion of this
little book, it bears all the signs of having been compiled by a first-rate
teacher and a good master in English composition, excepting in a few
involved transatlantic idioms. The method by which the author teaches
the composition and nature of the blood contrasts very favorably with
the manner in which the same subject is treated in many of the physio-
logical text-books read in British schools of medicine. " — The British
Medical Journal.

"We have really not met with as readable a work for a longtime. The
style of the author is ven' plain and lucid, and facts and descriptions are
presented in such a natural and interesting manner that the reader, before
he is aware, has become interested, and is deeply absorbed in the perusal
of the work. Even with one who is quite conversant with physiology,
and, therefore, meets with nothing that he is not already familiar with
there is an attractiveness in the lectures which begets "an interest and
leads him to become engrossed in reading. * * We advise our readers,
if they wish something readable, something they can give their whole
attention to without any effort, something that will instruct at the same
time it affords relaxation, like J. S. C. Abbott's histories, to purchase this
little work on physiology by Dr. Whittaker." — Cincinnati Medical News.

"Our author makes no claim to originality or to full exposition of the
principles of Physiology, but he has given a readable little volume,
written in novel style, well arranged and filled with much that will be
new and curious to the first course student, for whom the work is mainlv
designed. * * The publishers deserve credit for the admira-

ble appearance of the work." — Philadelphia Medical Bulletin.

[»]

"It is, moreover, one of the best, if not the best, books we know of to

filace in the hands of the young' man just taking up the study of medicine,
t will, we are confident, interest him in the study of physiology, and
qualify him for more thorough reading." — Michigan Medical News.

"We heartily commend this work to all lovers of the charming study
of physiology.'1 — Denial News'.

"This book of nearly three hundred pages is well bound, printed and
illustrated, and is besides, well written. The style is easy and flowing;
in a word, it is very interesting, and we can commend the book to lovers
of Physiology." — St. Louis Medical Brief.

"This volume of nearly three hundred pages is made up, as its title
implies, of the lectures which its author has delivered preliminary to his
courses upon Physiology in the Ohio Medical College. * * These_
matters are treated in a very scholarly and graphic manner. Indeed
Prof. Whittaker is one of the most accomplished of American medical
writers, and seldom fails to invest his themes with great interest. There
is much in his present work to instruct and to be enjoyed." — Louisville
Medical News.

"Dr. Whittaker has given the profession a little volume, which he
designs for first course students. The reading is delightful, the text and
paper excellent, and the whole subject fully up to t lie times. While it
may be specially intended for students, no practitioner can read it with-
out being benefited. There is a great deal of matter entirely new to us,
and the doctor, it seems, is not only a good physiologist, but a chaste
scholar, as is evinced by his thorough acquaintance with classical medi-
cal literature, and the pleasant style of his writing. No student of
medicine should be without this sine qua non in physiology." — Southern
(Richmond) Clime.

"The work is one which, while it will be most thoroughly enjoyed by
those who heard the gii'ted author originally, will be fully appreciated by
students everywhere, and by practitioners as well. We have read the
work carefully, and, though there are a few minor points for criticism,
the book is thoroughly enjoyable from beginning to end." — Ohio Medical
Recorder.

"We hail this little book with^leasure; it is, as the author states in his
preface, and as the title shows, a course of preliminary lectures, such as
are intended for the student before entering the study of physiology
proper and the remaining purely medical subjects. It is time that pre-
liminary work of this sort should be done by the student, and the only
excuse that could be given, heretofore, was, that we possessed no text
books from which this knowledge could be obtained. * *

This little book is so written that it fills one of these vacuoles. In
taking up the subjects as 1 as been done, the author has furnished a work
not only useful to the medical man but also instructive to the layman. * *

"From this brief outline can be seen what is aimed at by the author.
We can not claim anything original for the little work, except for the
manner in which the material has been handled and brought together.
For this we can say that it has been done in a masterly way. Prof.
Whittaker has capital ideas ret,-:'. rding the getting up of a book; thus we
see an outline of the book published under the title of contents, this out-
line carried out throughout the whole book, the captions serving, as it
were, for paragraphs, bringing the matter treated of directly and posi-
tively to the attention of the reader, and, in addition aiding him in keep-
ing up a logical connection of thought. The book is illustrated by three
pages of very good engravings, the typographical work has been well
done, and the modest, tasteful appearance of the work will do no little to
recommend it. Let us have more of this kind of work, and the American
student will soon be able to cope with his foreign brethren in regard to
preliminary knowledge." — Cincinnati Lancet and Clinic.

"Professor Whittaker is well known as a thinker and a writer, and he
gives us here a very interesting and useful book, so well spiced with the
assumed facts and doubtful conclusions of the extreme physiological
school of the day, as to impart to it the air of a pleasant romance. One
of the heads we notice is: 'The Fallacy of Experience.' The doctrine of
evolution and the eternhy of matter arc taught as settled questions. We
doubt the propriety of traveling beyond the strict limits of physiology in
a medical school, to inculcate sentiments which may be hostile to the
religious opinions of the youtii who are committed to the charge of the
professors. — Pacific Medical and Surgical Journal.

\

[3]

"The lectures are interspersed with anecdotes, apt quotations from all
sources, scientific and literary; a little biography, notably of Harvey and
Haller, the founders of modern physiology; and historical sketches of
some of the fundamental principles of natural science. * *

'-While only the outlines of the several subjects are given, the book is
most interesting and instructive, not only to hrst-course students, but to
many whose 'first course' was taken years ago. It presents in concise and
agreeable form the general principles of physiology and the doctrines of
evolution and development, and of conservation and correlation of
force. * *

"The work displays extensive reading and the possession of a wonder-
ful memory on the part of the brilliant lecturer. It is not surprising that
the class urgently requested putting the lectures into book form." —
Toledo Medical and Surgical journal.

"It occupies a position that has heretofore been vacant, at least so far
as any single work is concerned. It is a work valuable to every specialist
as well as to the general practitioner.' ' — The Dental Register.

"Any student who may have the fortune to have as good a foundation
in physiology as Dr. Whittaker's book can give him, may feel sure that
he i.i in the right way to a comprehensive grasp of the complete subject.
Students are very prone to neglect the history upon which our modern
science of physiology is built, and in doing this they neglect the most
charming chapter in the development of human learning." — North
Carolina Medical Journal.

"Wo regret very much that our space will not allow us to say what we
would like to say in favor of this work.

"Its style is classic. It is up to the times. It is scientific in its method.
It is comprehensive and instructive, especially to those wishing to become
familiar with Darwinism. We wish we could reprint the lecture on 'The
Influence of Physiology upon the Practice of Medicine,' for we believe
it would be especially useful to the young men of the profession." — The
Herald of Health.

"This is a series of preliminary lectures upon the subject of physiology,
the object of which is to inculcate the lessons of the ground work of that
great subject in the minds of students and to familiarize him with great
truths in small compass, which can only be obtained otherwise after
laborious search through the extensive literature upon the subject. It is
well written and does the distinguished author credit." — Nashville
Journal of Medicine and Surgery.

"Dr. Whittaker has presented his students with a most readable volume,
one that many old students, i. e., practitioners, might read with great
advantage. The theory of evolution is taught with much clearness and
force, and even those who disbelieve the doctrines of Darwin and Huxley
will find it very interesting and instructive. We do not know of a better
presentation of the subjects treated of in concise form than this handy
volume. We heartily commend the book to our younger readers." — St.
Louis Clinical Record.

"All well wishers of doctors and their clients owe Dr. Whittaker
thanks for the elevated ideas of physiology and its mission inculcated in
these lectures; for although he presents them as only the introduction to
the great science, still we can feel assured that when an architect
fashions and finishes a portal in beauty and appropriateness, the temple
to which it leads has been conceived and constructed in harmonious aad
symmetrical grandeur." — American Practitioner.

"These are very admirable lectures, and deserve to become popular.
The author has covered ground which is of vital importance in physio-
logical teaching, but which few lecturers have time to go over. We refer
especially to the subjects of conservation of force, evolution, and the
properties of protoplasm. The author's treatment of these questions is
clear and thorough, and though somewhat elementary, probably few will
find it too much so. Evolution is taught as an accepted fact. To this
there can be no objection as long as the evolutionist does not claim to
know and teach all the forces and laws which govern development, and
does not, further, claim that the process is one of gradual and uniform
progression. That the present orderly universe has been slowly evolved
from a low and simple to a higher and complex form, cannot be doubted.
* * It is but just to say that in this book there is no dogmatism any-
where, but disputed questions are stated fairly and left to the judgment
of his readers." — N. T. Medical Record.

L4J

"We could hope that every doctor in the land, anct every intelligent
person, would read these pages, because we are perfectly satisfied "that
the change of thought thus induced would redound to the advancement
of general medicine." — The Detroit Lancet.

"It is written in a very interesting and attractive style.'1 — Canada
Lancet.

"This little book is very different from what we ordinarily expect to
find in an elementary treatise. Instead of being a hasty and incomplete
summary of the more salient points of physiology, a style of work which
is only suitable for those who desire the most superficial information,
Dr. Whittaker's lectures are only elementary in that they treat of the
'foundation facts and principles on which the stately edifice of physiology
is built,' while they are in all respects in accord with the latest researches.
They therefore serve as an excellent introduction to more extended study,
and are admirably suited to the wants of a first course medical student.
The book contains twelve lectures on the influence of physiology on
practice, on the conservation of force, on the origin of life, and the evolu-
tion of its forms, and on protoplasm, bone, muscle, nerve, and blood; the
chapters on bone, muscle, and nerve being particularly good. The paper,
binding, and type are excellent." — American Journal of the Medical
Sciences.

"A small book in octavo form, two hundred and eighty-two pages,
containing lectures 'on the foundation facts and principles upon which
physiology is built.' The students of the Medical College of Ohio can be
content if all their teachers give proof of the same deep and manifold
study as these lectures, delivered during the preliminary course, are
evidence of. Hypocrisy and superstition would soon disappear, and the
medical profession in our great country would be in eveuy respect the
advance-guard of civilization, if it were possible to promulgate the study
of physiology and to omit nothing it teaches. 'The exhibition of life is
no more due to an innate principle, a separate essence, a quid intus, than
is the registrv of time in a clock,' are words that give us an idea on what
scientific basis the author wishes the modern physician to stand. 'It is
no answer whatever to say that life is creation. Such an assertion may
satisfy the wants of the' emotions, but it will in no way appease the
demands of the intellect trained, by cultivation in physical science, to
entirely ignore unnatural explanations for natural events.' We know a
lecturer on physiology in a large medical school who would tremble to
utter such words, less yet put them in print. The author's description of
the influence of physiology on practice and practitioners; his almost
poetical rendering ot the conservation and correlation of force; the origin
and evolution of life and its forms, wherein he follows Darwin; and his
masterly lectures on protoplasm and its properties, and on bone, muscle,
nerves, and blood, form together a series of instructions which may not
be only of value to the student of medicine, to give him a deeper inside
view of the workshop of nature, but which should be read by every indi-
vidual claiming classical modern education. There can be no doubt that,
if the author somewhat differently arranged his book, to make it accessi-
ble to a larger circle of intelligent laymen, this volume, as well as its
author, would soon be as favorably known, wherever the English tongue
is spoken, as, for instance, the Works of Bock, Buchner, anciMolcschott
are in Germany. We have never before seen, in the English language,
a book on a subject connected with physiology, where so much is con-
densed into such a small space, and where with a scholarly English, the
rare facultas docendi is so effectively made use of. 'Du sublime au
ridicule il n'y a qu'un pas' is so frequently lost sight of in these condensed
works on momentous questions, that they only should be written by a
master-mind who thoroughly controls his subject.

"The author cites, with "the same facility, Jansen, Kant, Koerner,
Moliere, Shakspeare, and Schiller, with which he quotes Haller, Harvey,
Haeckel, Kolliker, Tyndal, Schwann, Virchow, Carl Yogt, and Goethe,
the latter in his double capacity as poet and naturalist. That he mentions,
besides these names, many Others well known in the history of biology,
Hie reader can imagine from the nature of the subject. The work is
made more interesting yet, by the author giving, of each different subject
he speaks of, a history of its evolution ; i. e., he follows up the gradual
development of each theory from its beginning to its present condition.
The latest achievements of comparative embryology are noted and made
more apparent by well-executed drawings. We heartily recommend our
readers to add this small but valuable book to their library, and are only
sorry that want of spaee forbids us to give a larger abstract from it." —
Philadelphia Medical Times.