ANIMAL MECHANISM

A TREATISE ON TERRESTRIAL
AND AERIAL LOCOMOTION.

BY

E. J. MAREY,

PROFESSOR AT THE COLLEGE OF FRANCE, AND MEMBER OF THE
ACADEMY OF MEDICINE.

WITH

ONE HUNDRED AND SEVENTEEN ILLUSTRATIONS, DRAWN AND ENGRAVED
UNDER THE DIRECTION OF THE AUTHOR.

SECOND EDITION.

BIB

OTHECT

HENRY S. KING & Co.

65, CORNHILL, AND 12, PATERNOSTER ROW, LONDON.

[The Rights of Translation and Reproduction

are

Reserved.]

TABLE OF CONTENTS.

INTRODUCTION

BOOK THE FIRST.

FORCES AND ORGANS.

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1

CHAPTER I.

OF FORCES IN THE INORGANIC KINGDOM AND AMONG

ORGANISED BEINGS.

Matter reveals itself by its properties-When matter acts, we con-

clude that forces exist - Multiplicity of the forces formerly

admitted; tendency to their reduction to one force in the inor-

ganic kingdom-Indestructibility of force; its transformations

-Vital forces, their multiplicity according to the ancient

physiologists-Several vital forces are reduced to physical

forces-Of laws in physics and in physiology-General theory

of physical forces

CHAPTER II.

TRANSFORMATION OF PHYSICAL FORCES.

To prove the indestructibility of forces, we must know how to

measure them-Units of heat and of mechanical work-Ther-

mo-dynamics-Measure of forces in living beings-Successive

phases of the transformation of bodies; successive development

of force under this influence-Thermo-dynamics applied to

living beings

CHAPTER III.

ON ANIMAL HEAT.

Origin of animal heat-Lavoisier's theory-The perfecting of this

theory-Estimates of the forces contained in aliment, and in

the secreted products-Difficulty of these estimates-The force

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13

yielded by alimentary substances is transformed partly into heat

and partly into work-Seat of combustion in the organism-

Heating of the glands and muscles during their functions —Seat

of calorification-Intervention of the causes of cooling-Animal

temperature-Automatic regulator of animal temperature .

CHAPTER IV.

ANIMAL MOTION.

Motion is the most apparent characteristic of life; it acts on

solids, liquids, and gases-Distinction between the motions of

organic and animal life-We shall treat of animal motion only

-Structure of the muscles-Undulating appearance of the still

living fibre-Muscular wave-Shock and myography-Multi-

plicity of acts of contraction-Intensity of contraction in its

relations to the frequency of muscular shocks-Characteristics

of fibre at different points of the body

CHAPTER V.

CONTRACTION AND WORK OF THE MUSCLES.

The function of the nerve-Speed of the nervous agent-Measures

of time in physiology-Tetanus and muscular contraction-

Theory of contraction-Action of the muscles.

CHAPTER VI.

OF ELECTRICITY IN ANIMALS.

Electricity is produced in almost all organised tissues-Electric cur-

rents of the muscles and the nerves-Discharge of electric

fishes; old theories; demonstration of the electric nature of

this phenomenon-Analogies between the discharge of electrical

apparatus and the shock of a muscle-Electric tetanus-Rapidity

of the nervous agent in the electrical nerves of the torpedo;

duration of its discharge

CHAPTER VII.

ANIMAL MECHANISM.

Of the forms under which mechanical work presents itself—Every

machine must be constructed with a view to the kind of work

which it has to perform-Correspondence of the form of muscle

with the work which it accomplishes-Theory of Borelli—

Specific force of muscles-Of machines; they only change the

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form of work, but do not increase its quality- Necessity of

alternate movements in living motive powers-Dynamical energy

of animated motors.

CHAPTER VIII.

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59

HARMONY BETWEEN THE ORGAN AND THE FUNCTION.-

DEVELOPMENT HYPOTHESIS.

Each muscle of the body presents, in its form, a perfect harmony

with the nature of the acts which it has to perform-A similar

muscle, in different species of animals, presents differences of

form, if the function which it has to fulfil in these different

species is not the same-Variety of pectoral muscles in birds,

according to their manner of flight- Variety of muscles of the

thigh in mammals, according to their mode of locomotion-

Was this harmony pre-established ?- Development hypothesis-

Lamarck and Darwin.

CHAPTER IX.

VARIABILITY OF THE SKELETON.

Reasons which have caused the skeleton to be considered the least

variable part of the organism-Proofs of the yielding nature of

the skeleton during life, under the influence of the slightest pres-

sure, when long continued-Origin of the depressions and pro-

jections which are observed in the skeleton-Origin of the

articular surfaces-Function rules the organ-Variability of the

muscular system

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85

BOOK THE SECOND.

FUNCTIONS: TERRESTRIAL LOCOMOTION.

CHAPTER I.

OF LOCOMOTION IN GENERAL.

Conditions common to all kinds of locomotion-Borelli's comparison

--Hypothesis of the reaction of the ground-Classification of the

modes of locomotion, according to the nature of the point of

resistance, in terrestrial, aquatic, and aerial locomotion-Of the