29 chapters
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29 chapters
PREFACE.
PREFACE.
The educated and inquiring public of the present day addresses to the experts who have specialized in every imaginable subject the question that was asked in olden times of Euclid by King Ptolemy Philadelphus, Protector of Letters. Recoiling in dismay from the difficulties presented by the study of mathematics and annoyed at his slow progress, he inquired of the celebrated geometer if there was not some royal road, could he not learn geometry more easily than by studying the Elements. The learne
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CHAPTER I. EARLY THEORIES.
CHAPTER I. EARLY THEORIES.
Animism—Vitalism—The Physico-Chemical Theory—Their Survival and Transformations. The fundamental theories of science are but the expression of its most general results. What, then, is the most general result of the development of physiology or biology—that is to say, of that department of science which has life as its object? What glimpse do we get of the fruit of all our efforts? The answer is evidently the response to that essential question—What is Life? There are beings which we call living
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CHAPTER II. ANIMISM.
CHAPTER II. ANIMISM.
The Common Characteristic of Animism and Vitalism: the Human Statue—Primitive Animism—Stahl’s Animism—First Objection with Reference to the Relation between Soul and Body—Second Objection: the Unconscious Character of Vital Operations—Twofold Modality of the Soul—Continuity of the Soul and Life. Children are taught that there are three kingdoms in Nature—the mineral kingdom and the two living kingdoms, animal and vegetable. This is the whole of the sensible world. Then above all that is placed t
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CHAPTER III. VITALISM.
CHAPTER III. VITALISM.
Its Extreme Forms—Early Vitalism, and Modern Neo-vitalism—Advantage of distinguishing between Soul and Life—§ 1. The Vitalism of Barthez —Its Extension—The Seat of the Vital Principle—The Vital Knot—The Vital Tripod—Decentralisation of the Vital Principle—§ 2. The Doctrine of Vital Properties —Galen, Van Helmont, Xavier Bichat, and Cuvier—Vital and Physical Properties antagonistic—§ 3. Scientific Neo-vitalism —Heidenhain—§ 4. Philosophical Neo-vitalism —Reinke. Extreme Forms: Early Vitalism and
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CHAPTER IV. THE MONISTIC THEORY.
CHAPTER IV. THE MONISTIC THEORY.
Physico-chemical Theory of Life.—Iatro-mechanism.—Descartes, Borelli.—Iatro-chemistry.—Sylvius le Boë.—The Physico-chemical Theory of Life.—Matter and Energy.—Heterogeneity is merely the result of the arrangement or combination of homogeneous bodies.—Reservation relative to the world of thought.—The Kinetic Theory. The unicist or monistic doctrine gives us a third way of conceiving the functional activity of the living being, by levelling and blending its three forms of activity—spiritual, vital
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CHAPTER V. THE EMANCIPATION OF SCIENTIFIC RESEARCH FROM THE YOKE OF PHILOSOPHICAL THEORIES.
CHAPTER V. THE EMANCIPATION OF SCIENTIFIC RESEARCH FROM THE YOKE OF PHILOSOPHICAL THEORIES.
The excessive use of Hypothetical Agents in Physiological Explanations—§ 1. Vital Phenomena in Fully-constituted Organisms —Provisory Exclusion of the Morphogenic idea—The Realm of the Morphogenic Idea as the Sanctuary of Vital Force—§ 2. The Physiological Domain properly so called —Harmony and Connection of Phenomena—Directive Forces—Claude Bernard’s Work—Exclusion of Vital Force, of Final Cause, of the “Caprice” of Living Nature—Determinism—The Comparative Method—Generality of Vital Phenomena—
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CHAPTER I. ENERGY IN GENERAL.
CHAPTER I. ENERGY IN GENERAL.
Origin of the Idea of Energy.—The Phenomena of Nature bring into play only two Elements, Matter and Energy.—§ 1. Matter.—§ 2. Energy.—§ 3. Mechanical Energy.—§ 4. Thermal Energy.—§ 5. Chemical Energy.—§ 6. The Transformations of Energy.—§ 7. The Principles of Energetics.—The Principle of the Conservation of Energy.—§ 8. Carnot’s Principle.—The Degradation of Energy. Origin of the Idea of Energy. —A new term, namely energy , has been for some years introduced into natural science, and has ever si
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CHAPTER II. ENERGY IN BIOLOGY.
CHAPTER II. ENERGY IN BIOLOGY.
§ 1. Energy in Living Beings.—§ 2. The First Law of Biological Energetics:—All Vital Phenomena are Energetic Transformations.—§ 3. Second Law:—The Origin of Vital Energy is in Chemical Energy. Functional Activity and Destruction.—§ 4. Third Law:—The Final Form of Energetic Transformation in the Animal is Thermal Energy. Heat is an Excretum. The theory of energy was thought of and utilized in physiology before it was introduced into physics, in which it has exercised such an extraordinary influen
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CHAPTER III. ALIMENTARY ENERGETICS.
CHAPTER III. ALIMENTARY ENERGETICS.
Various Problems of Alimentation. § 1. Food the source of Energy and Matter. The two forms of Energy afforded by Food—Vital Energy, Thermal Energy. Food the source of Heat. The rôle of Heat.—§ 2. Measure of the output of Energy —by the Calometric Method—by the Chemical Method.—§ 3. The regular type of Food, Biothermogenic, and the irregular type, Thermogenic.—§ 4. Food considered as the source of Heat. The Law of Surfaces. The limits of Isodynamics.—§ 5. Plastic rôle of Food. Preponderance of Ni
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CHAPTER I. THE DOCTRINE OF VITAL UNITY.
CHAPTER I. THE DOCTRINE OF VITAL UNITY.
Phenomena common to all living beings—Theory of vital duality—Unity in the formation of immediate principles—Unity in the digestive acts—The common vital fund. When we ask the various philosophical schools what life is, some show us a chemical retort, and others show us a soul. Whether vitalists or of the mechanical school, these are the adversaries who since philosophy began have vainly contested the possession of the secret of life. We need not concern ourselves with this eternal quarrel. We n
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CHAPTER II. MORPHOLOGICAL UNITY OF LIVING BEINGS.
CHAPTER II. MORPHOLOGICAL UNITY OF LIVING BEINGS.
§ 1. The cellular theory. First period: division of the organism—§ 2. Second period: division of the cell—Cytoplasm—The nucleus—§ 3. Physical constitution of living matter—The micellar theory—§ 4. Individuality of complex beings—The law of the constitution of organisms. The first characteristic of the living beings is organization . By that we mean that they have a structure; that they are complex bodies formed of smaller aliquot parts and grouped according to a certain disposition. The most sim
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CHAPTER III. THE CHEMICAL UNITY OF LIVING BEINGS.
CHAPTER III. THE CHEMICAL UNITY OF LIVING BEINGS.
The varieties and essential unity of the protoplasm—Its affinity for oxygen—The chemical composition of protoplasm—Its characteristic substances.—§ 1. The different categories of albuminoid substances—Nucleo-proteids—Albumins and histones—Nucleins.—§ 2. Constitution of nucleins.—§ 3. Constitution of histones and albumins—Schultzenberger’s analysis of albumin—Kossol’s analysis—The hexonic nucleus. The chemical unity of living beings corresponds to their morphological unity. The Varieties and Esse
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CHAPTER IV. THE TWOFOLD CONDITIONING OF VITAL PHENOMENA. IRRITABILITY.
CHAPTER IV. THE TWOFOLD CONDITIONING OF VITAL PHENOMENA. IRRITABILITY.
Appearance of internal activity of the living being—Vital phenomena regarded as a reaction of the ambient world.—§ 1. Extrinsic conditions—The optimum law.—§ 2. Intrinsic conditions—The structure of organs and apparatus—How experiment attacks the phenomena of life. Generalization of the law of inertia—Irritability. Instability. Mutability. The Appearance of Internal Activity of the Living Being. —One of the most remarkable characteristics of the living being is its instability. It is in a state
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CHAPTER V. THE SPECIFIC FORM. ITS ACQUISITION. ITS REPARATION.
CHAPTER V. THE SPECIFIC FORM. ITS ACQUISITION. ITS REPARATION.
§ 1. Specific form not special to living beings—Connected with the whole of the material conditions of the body and the medium—Is it a property of chemical substance?—§ 2. Acquisition and re-establishment of the specific form—Normal regeneration—Accidental regeneration in the protozoa and the plastids—In the metazoa. The Specific Form is not Peculiar to Living Beings. —The position of a specific form —the acquisition of this typical form progressively realized—the re-establishment when some acci
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CHAPTER VI. NUTRITION.
CHAPTER VI. NUTRITION.
FUNCTIONAL ASSIMILATION. FUNCTIONAL DESTRUCTION. ORGANIC DESTRUCTION. ASSIMILATING SYNTHESIS. The extreme importance of nutrition—§ 1. Effect of vital activity—Destruction or growth—Distinction between the living substance and the reserve-stuff mingled with it—Organic destruction—Destruction of reserve-stuff—Destruction of living matter—Growth of living matter—§ 2. The two categories of vital phenomena—Foundations of the idea of functional destruction—The two kinds of phenomena of vitality—Criti
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CHAPTER I. UNIVERSAL LIFE. OPINIONS OF PHILOSOPHERS AND POETS.
CHAPTER I. UNIVERSAL LIFE. OPINIONS OF PHILOSOPHERS AND POETS.
§ 1. Primitive beliefs; the ideas of poets.—§ 2. Opinions of philosophers—Transition from brute to living bodies—The principle of continuity: continuity by transition: continuity by summation—Ideas of philosophers as to sensibility and consciousness in brute bodies—The general principle of homogeneity—The principle of continuity as a consequence of the principle of homogeneity. The teaching of science as to the analogies between brute bodies and living bodies accords with the conceptions of the
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CHAPTER II. ORIGIN OF BRUTE MATTER IN LIVING MATTER.
CHAPTER II. ORIGIN OF BRUTE MATTER IN LIVING MATTER.
Spontaneous generation: an episode in the history of the globe—Verification of the identity between brute and living matter—Slow identification—Rapid identification—Contrary opinion—Hypothesis of cosmozoa; cosmic panspermia—Hypothesis of pyrozoa. There should be two ways of testing the doctrine of the essential identity of brute and living matter—one slow and more laborious, the other more rapid and decisive. Identification of the Two Matters, Brute and Living. —The laborious method, which we wi
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CHAPTER III. ORGANIZATION AND CHEMICAL COMPOSITION OF LIVING AND BRUTE MATTER.
CHAPTER III. ORGANIZATION AND CHEMICAL COMPOSITION OF LIVING AND BRUTE MATTER.
Laws of the organization and of the chemical composition of living beings—Relative value of these laws; vital phenomena in crushed protoplasm—Vital phenomena in brute bodies. Enumeration of the Principal Characters of Living Beings. —The programme which we have just sketched compels us to look in the brute being for the properties of living beings. What, then, are, in fact, the characteristics of an authentic, complete, living being? What are its fundamental properties? We have enumerated them a
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CHAPTER IV. EVOLUTION AND MUTABILITY OF LIVING MATTER AND BRUTE MATTER.
CHAPTER IV. EVOLUTION AND MUTABILITY OF LIVING MATTER AND BRUTE MATTER.
Supposed immobility of brute bodies—Mobility and mutability of the sidereal world.—§ 1. The movement of particles and molecules in brute bodies—The internal movements of brute bodies—Kinetic conception of molecular motion—Reality of the motion of particles—Comparison of the activity of particles with vital activity.—§ 2. Brownian movement—Its existence—Its character—Its independence of the nature of the bodies and of the nature of the environment—Its indefinite duration—Its independence of exter
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CHAPTER V. Specific Form. Living Bodies and Crystals.
CHAPTER V. Specific Form. Living Bodies and Crystals.
§ 1. Specific form and chemical constitution—The wide distribution of crystalline forms—Organization of crystals—Law of relation between specific form and chemical constitution—Value of form as a characteristic of brute and living beings—Parentage, living beings and mineral parentage—Iso-morphism and the faculty of cross-breeding—Other analogies. § 2. Acquisition and re-establishment of the specific form—Mutilation and regeneration of crystals—Mechanism of reparation. § 1. Specific Form and Chem
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CHAPTER VI. NUTRITION IN THE LIVING BEING AND IN THE CRYSTAL.
CHAPTER VI. NUTRITION IN THE LIVING BEING AND IN THE CRYSTAL.
Assimilation and growth in the crystal.—Methods of growth in the crystal and in the living being; intussusception; apposition.—Secondary and unimportant character of the process of intussusception. I have already stated (Chap. VI. p. 209) that nutrition may be considered as the most characteristic and essential property of living beings. Such beings are in a state of continual exchange with the surrounding medium. They assimilate and dissimilate. By assimilation the substance of their being incr
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CHAPTER VII. GENERATION IN BRUTE BODIES AND LIVING BODIES. SPONTANEOUS GENERATION.
CHAPTER VII. GENERATION IN BRUTE BODIES AND LIVING BODIES. SPONTANEOUS GENERATION.
Protoplasm a substance which continues—Case of the crystal—Characteristics of generation in the living being—Property of growth—Supposed to be confined to the living being—Fertilization of micro-organisms—Fertilization of crystals—Sterilization of crystalline and living media—Spontaneous generation of crystals—Metastable and labile zones—Glycerine crystals—Possible extinction of a crystalline species—Conclusion. We have not yet exhausted the analogies between a crystal and the living being. The
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CHAPTER I. VARIOUS WAYS OF REGARDING DEATH.
CHAPTER I. VARIOUS WAYS OF REGARDING DEATH.
Different meanings of the word death—Physiological distinction between elementary and general death—Non-scientific opinions—The ordinary point of view—Medical point of view.—The signs of death are prognostic signs. Different Meanings of the Word Death. —An English philosopher has asserted that the word we translate by “cause” has no less than sixty-four different meanings in Plato and forty-eight in Aristotle. The word “death” has not so many meanings in modern languages, but still it has many.
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CHAPTER II. THE PROCESS OF DEATH.
CHAPTER II. THE PROCESS OF DEATH.
Constitution of organisms.—Partial lives.—Collective life.—The rôle of apparatus.—Death by lesion of the major apparatus.—The vital tripod.—Solidarity of the anatomical elements.—Humoral solidarity.—Nervous solidarity.—Independence and subordination of the anatomical elements. Partial Lives. Collective Life. —With the exception of the physiologist, no one, neither he who is ignorant nor he who is intellectual, nor even the doctor, troubles his head about the life or the death of the element, alt
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CHAPTER III. PHYSICAL AND CHEMICAL CHARACTERS OF CELLULAR DEATH. NECROBIOSIS. GROWING OLD.
CHAPTER III. PHYSICAL AND CHEMICAL CHARACTERS OF CELLULAR DEATH. NECROBIOSIS. GROWING OLD.
Characteristic of elementary life—Changes produced by death in the composition and the death of the cell—Schlemm; Loew; Bokorny; Pflüger; A. Gautier; Duclaux—The processive character of death—Accidental death—Necrobiosis—Atrophy—Degeneration—So-called natural death—Senescence—Metchnikoff’s theory of senescence—Objections. Elementary death is nothing but the suppression in the anatomical elements of all the phenomena of vitality. Characteristics of Elementary Life. —The characteristic features of
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CHAPTER IV. THE APPARENT PERENNITY OF COMPLEX INDIVIDUALS.
CHAPTER IV. THE APPARENT PERENNITY OF COMPLEX INDIVIDUALS.
Millenary trees—Plants with a definite rhizome—Vegetables reproduced by cuttings—Animal colonies—Destruction due to extrinsic causes—Difficulty of interpretation. Popular opinion teaches us that living beings have only a transient existence, and as a poet has said: “Life is but a flash between two dark nights.” But, on the other hand, simple observation shows us, or appears to show us, beings whose duration of existence is far longer, and practically illimitable. Millenary Trees. —We know of tre
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CHAPTER V. THE IMMORTALITY OF THE PROTOZOA.
CHAPTER V. THE IMMORTALITY OF THE PROTOZOA.
Impossibility of life without evolution—Law of increase and division—Immortality of the protozoa—Death, a phenomenon of adaptation which has appeared in the course of the ages—The infusoria—The death of the infusoria—Two kinds of reproduction—The caryogamic rejuvenescence of Maupas—Calkins on rejuvenescence—Causes of senescence—Impossibility of life without evolution. We take into account, a priori , the conditions that must be fulfilled by the monocellular being in order to escape the inevitabi
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CHAPTER VI. LETHALITY OF THE METAZOA AND OF DIFFERENTIATED CELLS.
CHAPTER VI. LETHALITY OF THE METAZOA AND OF DIFFERENTIATED CELLS.
Evolution and death of metazoa.—Possible rejuvenescence of the differentiated cells by the conditions of the medium.—Conditions of the medium for immortal cells.—The immortal elements of metazoa.—The element in accidental and remediable death.—Somatic cells and sexual cells. Evolution and Death of Metazoa. —We have seen that the infusoria are no longer animals in which material exchanges take place with sufficient perfection, and in which cellular division, the consequence of growth, is produced
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CHAPTER VII. MAN. THE INSTINCT OF LIFE AND THE INSTINCT OF DEATH.
CHAPTER VII. MAN. THE INSTINCT OF LIFE AND THE INSTINCT OF DEATH.
The miseries of humanity: 1. Disease; 2. Old age.—Old age considered as a chronic disease.—Its occasional cause.—3. The disharmonies of human nature; 4. The instinct of life and the instinct of death. Man’s unhappy plight is the constant theme of philosophies and religions. Without referring to its moral basis, it has a physical basis due to four causes—the physical imperfection or disharmony of nature, disease, old age, and death—or rather of three, for what we call old age is perhaps a simple
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