NormalizeHEADmain

126 files changed, 17 insertions, 22828 deletions

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..d7b82bc
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,4 @@
+*.txt text eol=lf
+*.htm text eol=lf
+*.html text eol=lf
+*.md text eol=lf
diff --git a/LICENSE.txt b/LICENSE.txt
new file mode 100644
index 0000000..6312041
--- /dev/null
+++ b/LICENSE.txt
@@ -0,0 +1,11 @@
+This eBook, including all associated images, markup, improvements,
+metadata, and any other content or labor, has been confirmed to be
+in the PUBLIC DOMAIN IN THE UNITED STATES.
+
+Procedures for determining public domain status are described in
+the "Copyright How-To" at https://www.gutenberg.org.
+
+No investigation has been made concerning possible copyrights in
+jurisdictions other than the United States. Anyone seeking to utilize
+this eBook outside of the United States should confirm copyright
+status under the laws that apply to them.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..8ac65a3
--- /dev/null
+++ b/README.md
@@ -0,0 +1,2 @@
+Project Gutenberg (https://www.gutenberg.org) public repository for
+eBook #60773 (https://www.gutenberg.org/ebooks/60773)
diff --git a/old/60773-0.txt b/old/60773-0.txt
deleted file mode 100644
index 3230e29..0000000
--- a/old/60773-0.txt
+++ /dev/null
@@ -1,8879 +0,0 @@
-The Project Gutenberg EBook of The Philosophy of Health; Volume 1 (of 2), by 
-Thomas Southwood-Smith
-
-This eBook is for the use of anyone anywhere in the United States and most
-other parts of the world at no cost and with almost no restrictions
-whatsoever.  You may copy it, give it away or re-use it under the terms of
-the Project Gutenberg License included with this eBook or online at
-www.gutenberg.org.  If you are not located in the United States, you'll have
-to check the laws of the country where you are located before using this ebook.
-
-Title: The Philosophy of Health; Volume 1 (of 2)
-       or, an exposition of the physical and mental constitution of man
-
-Author: Thomas Southwood-Smith
-
-Release Date: November 23, 2019 [EBook #60773]
-
-Language: English
-
-Character set encoding: UTF-8
-
-*** START OF THIS PROJECT GUTENBERG EBOOK PHILOSOPHY OF HEALTH, VOLUME 1 ***
-
-
-
-
-Produced by Chris Curnow, Brian Wilsden and the Online
-Distributed Proofreading Team at http://www.pgdp.net (This
-file was produced from images generously made available
-by The Internet Archive)
-
-
-
-
-
-TRANSCRIBER'S NOTE: Italic text is denoted by _underscores_ and bold
-text by =equal signs=.
-
-
-
-
-  THE
-
-  PHILOSOPHY OF HEALTH;
-
-  OR,
-
-  AN EXPOSITION
-
-  OF THE
-
-  PHYSICAL AND MENTAL CONSTITUTION
-  OF MAN,
-
-  WITH A VIEW TO THE PROMOTION OF
-
-  HUMAN LONGEVITY AND HAPPINESS.
-
-  BY
-
-  SOUTHWOOD SMITH, M.D.,
-
-  _Physician to the London Fever Hospital, to the Eastern Dispensary,
-  and to the Jews' Hospital._
-
-  IN TWO VOLUMES. VOL. I.
-
-  _THIRD EDITION._
-
-  LONDON:
-  C. COX, 12, KING WILLIAM STREET, STRAND.
-
-  1847.
-
-
-
-
-London: Printed by W. CLOWES and SONS, Stamford Street.
-
-
-
-
-CONTENTS OF VOL. I.
-
-
-    INTRODUCTION                                                Page 1
-
-
-    CHAPTER I.
-
-    Characters by which living beings are distinguished
-    from inorganic bodies—Characters by which
-    animals are distinguished from plants—Actions
-    common to plants and animals—Actions peculiar
-    to animals—Actions included in the ORGANIC
-    circle—Actions included in the ANIMAL
-    circle—Organs and functions defined—Action of
-    physical agents on organized structures—Processes
-    of supply, and processes of waste—Reasons why the
-    structure of the animal is more complex than that
-    of the plant                                                    13
-
-
-    CHAPTER II.
-
-    Two distinct lives combined in the
-    animal—Characters of the apparatus of the organic
-    life—Characters of the apparatus of the animal
-    life—Characteristic differences in the action of
-    each—Progress of life—Progress of death                       51
-
-
-    CHAPTER III.
-
-    Ultimate object of organization and life—Sources
-    of pleasure—Special provision by which the
-    organic organs influence consciousness and afford
-    pleasure—Point at which the organic organs cease
-    to affect consciousness and why—The animal
-    appetites: the senses: the intellectual faculties:
-    the selfish and sympathetic affections: the moral
-    faculty—Pleasure the direct, the ordinary,
-    and the gratuitous result of the action of the
-    organs—Pleasure conducive to the development
-    of the organs, and to the continuance of their
-    action—Progress of human knowledge—Progress of
-    human happiness                                                 73
-
-
-    CHAPTER IV.
-
-    Relation between the physical condition
-    and happiness, and between happiness and
-    longevity—Longevity a good, and why—Epochs of
-    life—The age of maturity the only one that admits
-    of extension—Proof of this from physiology—Proof
-    from statistics—Explanation of terms—Life a
-    fluctuating quantity—Amount of it possessed in
-    ancient Rome: in modern Europe: at present in
-    England among the mass of the people and among the
-    higher classes                                                 106
-
-
-    CHAPTER V.
-
-    Ultimate elements of which the body is composed—
-    Proximate principles—Fluids and solids—Primary tissues—
-    Combinations—Results—Organs, systems, apparatus—
-    Form of the body—Division into head, trunk, and
-    extremities—Structure and function of each—Regions—
-    Seats of the more important internal organs                   148
-
-
-    CHAPTER VI.
-
-    Of the blood—Physical characters of the blood:
-    colour, fluidity, specific gravity, temperature;
-    quantity—Process of coagulation—Constituents of
-    the blood; proportions —Constituents of the body
-    contained in the blood—Vital properties of the
-    blood—Practical applications                                  334
-
-
-    CHAPTER VII.
-
-    Of the circulation—Vessels connected with the
-    heart; chambers of the heart—Position of the
-    heart—Pulmonic circle; systemic circle—Structure
-    of the heart, artery, and vein—Consequences
-    of the discovery of the circulation to the
-    discoverer—Action of the heart; sounds occasioned
-    by its different movements—Contraction;
-    dilatation—Disposition and action of the
-    valves—Powers that move the blood—Force of
-    the heart—Action of the arterial tubes; the
-    pulse; action of the capillaries; action of the
-    veins—Self-moving power of the blood—Vital
-    endowment of the capillaries; functions—Practical
-    applications                                                   357
-
-
-    FOOTNOTES.                                                     408
-
-
-
-
-INTRODUCTION.
-
-
-The object of the present work is to give a brief and plain account
-of the structure and functions of the body, chiefly with reference
-to health and disease. This is intended to be introductory to an
-account of the constitution of the mind, chiefly with reference to
-the development and direction of its powers. There is a natural
-connexion between these subjects, and an advantage in studying them
-in their natural order. Structure must be known before function can
-be understood: hence the science of physiology is based on that of
-anatomy. The mind is dependent on the body: hence an acquaintance with
-the physiology of the body should precede the study of the physiology
-of the mind. The constitution of the mind must be understood before its
-powers and affections can be properly developed and directed: hence a
-knowledge of the physiology of the mind is essential to a sound view of
-education and morals.
-
-In the execution of the first part of this work, that which relates
-to the organization of the body, a formidable difficulty presents
-itself at the outset. The explanation of structure is easy when the
-part described can be seen. The teacher of anatomy finds no difficulty
-in communicating to the student a clear and exact knowledge of the
-structure of an organ; because, by the aid of dissection, he resolves
-the various complex substances, of which it is built up, into their
-constituent parts, and demonstrates the relation of these elementary
-parts to each other. But the case is different with him who attempts
-to convey a knowledge of the structure of an organ merely by the
-description of it. The best conceived and executed drawing is a
-most inadequate substitute for the object itself. It is impossible
-wholly to remove this difficulty: what can be done, by the aid of
-plates, to lessen it, is here attempted. A time may come when the
-objects themselves will be more generally accessible: meanwhile, the
-description now given of the chief organs of the body may facilitate
-the study of their structure to those who have an opportunity of
-examining the organs themselves, and will, it is hoped, enable every
-reader at once to understand much of their action.
-
-Physical science has become the subject of popular attention, and
-men of the highest endowments, who have devoted their lives to the
-cultivation of this department of knowledge, conceive that they can
-make no better use of the treasures they have accumulated, than that of
-diffusing them. Of this part of the great field of knowledge, to make
-"the rough places plain, and the crooked places straight," is deemed a
-labour second in importance only to that of extending the boundaries of
-the field itself. But no attempt has hitherto been made to exhibit a
-clear and comprehensive view of the phenomena of life; the organization
-upon which those phenomena depend; the physical agents essential
-to their production, and the laws, as far as they have yet been
-discovered, according to which those agents act. The consequence is,
-that people in general, not excepting the educated class, are wholly
-ignorant of the structure and action of the organs of their own bodies,
-the circumstances which are conducive to their own health, the agents
-which ordinarily produce disease, and the means by which the operation
-of such agents may be avoided or counteracted; and they can hardly be
-said to possess more information relative to the connexion between the
-organization of the body and the qualities of the mind, the physical
-condition and the mental state; the laws which regulate the production,
-combination, and succession of the trains of pleasurable and painful
-thought, and the rules deducible from those laws, having for their
-object such a determination of voluntary human conduct, as may secure
-the pleasurable and avoid the painful.
-
-Yet nothing would seem a fitter study for man than the nature of man in
-this sense of the term. A knowledge of the structure and functions of
-the body is admitted to be indispensable to whoever undertakes, as the
-business of his profession, to protect those organs from injury, and to
-restore their action to a sound state when it has become disordered;
-but surely some knowledge of this kind may be useful to those who
-have no intention to practise physic, or to perform operations in
-surgery; may be useful to every human being, to enable him to take a
-rational care of his health, to make him observant of his own altered
-sensations, as indications of approaching sickness; to give him the
-power of communicating intelligibly with his medical adviser respecting
-the seat and the succession of those signs of disordered function, and
-to dispose and qualify him to co-operate with his physician in the use
-of the means employed to avert impending danger, or to remove actual
-disease.
-
-But if to every human being occasions must continually occur, when
-knowledge of this kind would be useful, the possession of it seems
-peculiarly necessary to those who have the exclusive care of infancy,
-almost the entire care of childhood, a great part of the care of
-the sick, and whose ignorance, not the less mischievous because its
-activity is induced by affection, constantly endangers, and often
-defeats, the best concerted measures of the physician.
-
-The bodily organization and the mental powers of the child depend
-mainly on the management of the infant; and the intellectual and
-moral aptitudes and qualities of the man have their origin in the
-predominant states of sensation, at a period far earlier in the history
-of the human being than is commonly imagined. The period of infancy is
-divided by physiologists into two epochs; the first, commencing from
-birth, extends to the seventh month: the second, commencing from the
-seventh month, extends to the end of the second year, at which time
-the period of infancy ceases, and that of childhood begins. The first
-epoch of infancy is remarkable for the rapidity of the development
-of the organs of the body: the processes of growth are in extreme
-activity; the formative predominates over the sentient life, the chief
-object of the action of the former being to prepare the apparatus
-of the latter. The second epoch of infancy is remarkable for the
-development of the perceptive powers. The physical organization of
-the brain, which still advances with rapidity, is now capable of a
-greater energy, and a wider range of function. Sensation becomes more
-exact and varied; the intellectual faculties are in almost constant
-operation; speech commences, the sign, and, to a certain extent, the
-cause of the growing strength of the mental powers; the capacity of
-voluntary locomotion is acquired, while passion, emotion, affection,
-come into play with such constancy and energy, as to exert over the
-whole economy of the now irritable and plastic creature a prodigious
-influence for good or evil. If it be, indeed, possible to make correct
-moral perception, feeling, and conduct, a part of human nature, as much
-a part of it as any sensation or propensity—if this be possible for
-every individual of the human race, without exception, to an extent
-which would render _all_ more eminently and consistently virtuous than
-_any_ are at present (and of the possibility of this, the conviction
-is the strongest in the acutest minds which have studied this subject
-the most profoundly), preparation for the accomplishment of this object
-must be commenced at this epoch. But if preparation for this object
-be really commenced, it implies, on the part of those who engage in
-the undertaking, some degree of knowledge; knowledge of the physical
-and mental constitution of the individual to be influenced; knowledge
-of the mode, in which circumstances must be so modified in adaptation
-to the nature of the individual being, as to produce upon it, with
-uniformity and certainty, a given result. The theory of human society,
-according to its present institutions, supposes that this knowledge is
-possessed by the mother; and it supposes, further, that this adaptation
-will actually take place in the domestic circle through her agency.
-Hence the presumed advantage of having the eye of the mother always
-upon the child; hence the apprehension of evil so general, I had almost
-said instinctive, whenever it is proposed to take the infant, for the
-purpose of systematic physical and mental discipline, from beyond the
-sphere of maternal influence. But society, which thus presumes that
-the mother will possess the power and the disposition to do this, what
-expedients has it devised to endow her with the former, and to secure
-the formation of the latter? I appeal to every woman whose eye may
-rest on these pages. I ask of you, what has ever been done for you to
-enable you to understand the physical and mental constitution of that
-human nature, the care of which is imposed upon you? In what part of
-the course of your education was instruction of this kind introduced?
-Over how large a portion of your education did it extend? Who were
-your teachers? What have you profited by their lessons? What progress
-have you made in the acquisition of the requisite information? Were
-you at this moment to undertake the guidance of a new-born infant to
-health, knowledge, goodness, and happiness, how would you set about
-the task? How would you regulate the influence of external agents upon
-its delicate, tender, and highly-irritable organs, in such a manner
-as to obtain from them healthful stimulation, and avoid destructive
-excitement? What natural and moral objects would you select as the best
-adapted to exercise and develope its opening faculties? What feelings
-would you check, and what cherish? How would you excite aims; how would
-you apply motives? How would you avail yourself of pleasure as a final
-end, or as the means to some further end? And how would you deal with
-the no less formidable instrument of pain? What is your own physical,
-intellectual, and moral state, as specially fitting you for this
-office? What is the measure of your own self-control, without a large
-portion of which no human being ever yet exerted over the infant mind
-any considerable influence for good? There is no philosopher, however
-profound his knowledge, no instructor, however varied and extended his
-experience, who would not enter upon this task with an apprehension
-proportioned to his knowledge and experience; but knowledge which men
-acquire only after years of study, habits which are generated in men
-only as the result of long-continued discipline, are expected to come
-to you spontaneously, to be born with you, to require on your part no
-culture, and to need no sustaining influence.
-
-But, indeed, it is a most inadequate expression of the fact, to say
-that the communication of the knowledge, and the formation of the
-habits which are necessary to the due performance of the duties of
-women, constitute no essential part of their education: the direct
-tendency of a great part of their education is to produce and foster
-opinions, feelings, and tastes, which positively disqualify them for
-the performance of their duties. All would be well if the marriage
-ceremony, which transforms the girl into the wife, conferred upon the
-wife the qualities which should be possessed by the mother. But it is
-rare to find a person capable of the least difficult part of education,
-namely, that of communicating instruction, even after diligent study,
-with a direct view to teaching; yet an ordinary girl, brought up in
-the ordinary mode, in the ordinary domestic circle, is intrusted with
-the direction and control of the first impressions that are made upon
-the human being, and the momentous, physical, intellectual, and moral
-results that arise out of those impressions!
-
-I am sensible of the total inadequacy of any remedy for this
-evil, short of a modification of our domestic institutions. Mere
-information, however complete the communication of it, can do little
-beyond affording a clearer conception of the end in view, and of
-the means fitted to secure it. Even this little, however, would be
-something gained; and the hope of contributing, in some degree, to
-the furtherance of this object, has supplied one of the main motives
-for undertaking the present work. Meantime, women are the earliest
-teachers; they must be nurses; they can be neither, without the risk
-of doing incalculable mischief, unless they have some understanding
-of the subjects about to be treated of. On these grounds I rest their
-_obligation_ to study them; and I look upon that notion of delicacy,
-which would exclude them from knowledge calculated, in an extraordinary
-degree, to open, exalt, and purify their minds, and to fit them for the
-performance of their duties, as alike degrading to those to whom it
-affects to show respect, and debasing to the mind that entertains it.
-
-Though each part of this work will be made as complete in itself as
-the author is capable of rendering it, and to that extent independent
-of any other part, yet there will be found to be a strict connexion
-between the several portions of the whole; and greatly as the topics
-included in the latter differ from those which form the earlier
-subjects, the advantage of having studied the former before the latter
-are entered on, will be felt precisely as the word _study_ can be
-justly applied to the operation of the mind on such matters.
-
-In the expository portion of the work I have not been anxious to
-abstain from the employment of technical terms, when a decidedly useful
-purpose was to be obtained by the introduction of them; but I have been
-very careful to use no such term without assigning the exact meaning
-of it. A technical term unexplained is a dark spot on the field of
-knowledge; explained, it is a clear and steady light.
-
-In order really to understand the states of health and disease,
-an acquaintance with the nature of organization, and of the vital
-processes of which it is the seat and the instrument, is indispensable:
-it is for this reason that the exposition of structure and function,
-attempted in this first part of the work, is somewhat full; but there
-cannot be a question that, if it accomplish its object, it will not
-only enable the account of health and disease in the subsequent part of
-it to be much more brief, but that it will, at the same time, render
-that account more intelligible, exact, and practical.
-
-  S. S.
-
-
-
-
-THE
-
-PHILOSOPHY OF HEALTH.
-
-
-
-
-CHAPTER I.
-
-  Characters by which living beings are distinguished
-  from inorganic bodies—Characters by which animals are
-  distinguished from plants—Actions common to plants and
-  animals—Actions peculiar to animals—Actions included in the
-  organic circle—Actions included in the animal circle—Organs
-  and functions defined—Action of physical agents on
-  organized structures—Processes of supply, and processes
-  of waste—Reasons why the structure of the animal is more
-  complex than that of the plant.
-
-
-The distinction between a living being and an inorganic body,
-between a plant and a stone, is, that the plant carries on a number
-of processes which are not performed by the stone. The plant absorbs
-food, converts its food into its own proper substance, arranges this
-substance into bark, wood, vessels, leaves, and other organized
-structures; grows, arrives at maturity, and decays; generates and
-maintains a certain degree of heat; derives from a parent the primary
-structure and the first impulse upon which these varied actions depend;
-gives origin to a new being similar to itself, and, after a certain
-time, terminates its existence in death.
-
-No such phenomena are exhibited by the stone; it neither absorbs
-food, nor arranges the matter of which it is composed into organized
-structure; nor grows, nor decays, nor generates heat, nor derives its
-existence from a parent, nor gives origin to a new being, nor dies.
-Nothing analogous to the processes by which these results are produced,
-is observable in any body that is destitute of life; all of them are
-carried on by every living creature. These processes are, therefore,
-denominated vital, and, being peculiar to the state of life, they
-afford characters by which the living being is distinguished from the
-inorganic body.
-
-In like manner the distinction between an animal and a plant is, that
-the animal possesses properties of which the plant is destitute. It is
-endowed with two new and superior powers, to which there is nothing
-analogous in the plant; namely, the power of sensation, and the power
-of voluntary motion; the capacity of feeling, and the capacity of
-moving from place to place as its feeling prompts. The animal, like
-the plant, receives food, transforms its food into its own proper
-substance, builds this substance up into structure, generates, and
-maintains a certain temperature, derives its existence from a parent,
-produces an offspring like itself, and terminates its existence in
-death. Up to this point the vital phenomena exhibited by both orders of
-living creatures are alike: but at this point the vital processes of
-the plant terminate, while those of the animal are extended and exalted
-by the exercise of the distinct and superior endowments of sensation
-and voluntary motion. To feel, and to move spontaneously, in accordance
-with that feeling, are properties possessed by the animal, but not by
-the plant; and therefore these properties afford characters by which
-the animal is distinguished from the plant.
-
-The two great classes of living beings perform, then, two distinct
-sets of actions: the first set is common to all living creatures; the
-second is peculiar to one class: the first set is indispensable to
-life; the second is necessary only to one kind of life, namely, the
-animal. The actions included in the first set, being common to all
-living or organized creatures, are called ORGANIC; the actions included
-in the second class, belonging only to one part of living or organized
-creatures, namely, animals, are called ANIMAL. The ORGANIC actions
-consist of the processes by which the existence of the living being is
-maintained, and the perpetuation of its species secured: the ANIMAL
-actions consist of the processes by which the living being is rendered
-percipient, and capable of spontaneous motion. The ORGANIC processes
-comprehend those of nutrition, respiration, circulation, secretion,
-excretion, and reproduction; the first five relate to the maintenance
-of the life of the individual being; the last to the perpetuation of
-its species. The ANIMAL processes comprehend those of sensation and
-of voluntary motion, often denominated processes of relation, because
-they put the individual being in communication with the external
-world. There is no vital action performed by any living creature
-which may not be included in one or other of these processes, or in
-some modification of some one of them. There is no action performed
-by any inorganic body which possesses even a remote analogy to either
-of these vital processes. The line of demarcation between the organic
-and the inorganic world is, therefore, clear and broad; and the line
-of demarcation between the two great divisions of the organic world,
-between the inanimate and the animate, that is, between plants and
-animals, is no less decided: for, of the two sets of actions which have
-been enumerated, the one, as has just been stated, is common to the
-whole class of living beings, while the second set is peculiar to one
-division of that class. The plant performs only the organic actions:
-all the vital phenomena it exhibits are included in this single circle;
-it is, therefore, said to possess only organic life: but the animal
-performs both organic and animal actions, and is therefore said to
-possess both organic and animal life.
-
-Both the organic and the animal actions are accomplished by means
-of certain instruments, that is, organized bodies which possess a
-definite structure, and which are moulded into a peculiar form. Such
-an instrument is called an organ, and the action of an organ is called
-its function. The leaf of the plant is an organ, and the conversion
-of sap by the leaf into the proper juice of the plant, by the process
-called respiration, is the function of this organ. The liver of the
-animal is an organ; and the conversion of the blood that circulates
-through it into bile, by the process of secretion, is its function. The
-brain is an organ; the sentient nerve in communication with it is also
-an organ. The extremity of the sentient nerve receives an impression
-from an external object, and conveys it to the brain, where it becomes
-a sensation. The transmission of the impression is the function of
-the nerve; the conversion of the impression into a sensation is the
-function of the brain.
-
-The living body consists of a congeries of these instruments or
-organs: the constituent matter of these organs is always partly in a
-fluid and partly in a solid state. Of the fluids and solids which thus
-invariably enter in combination into the composition of the organs, the
-fluids may be regarded as the primary and essential elements, for they
-are the source and the support of the solids. There is no solid which
-is not formed out of a fluid; no solid which does not always contain,
-as a constituent part of it, some fluid, and none which is capable of
-maintaining its integrity without a continual supply of fluids.
-
-Whatever be the intimate composition of the fluids out of which the
-solids are formed, the investigation of which is more difficult than
-that of the solids and the nature of which is therefore less clearly
-ascertained, it is certain that all the matter which enters into
-the composition of the solid is disposed in a definite order. It is
-this disposition of the constituent matter of the living solid in a
-definite order that constitutes the arrangement so characteristic of
-all living substance. Definite arrangements are combined in definite
-modes, and the result is what is termed organization. From varied
-arrangements result different kinds of organized substances, each
-endowed with different properties, and exhibiting peculiar characters.
-By the recombination of these several kinds of organized substances,
-in different proportions and different modes, are formed the special
-instruments, or organs, of which we have just spoken; while it is the
-combining, or the building up of these different organized substances
-into organs, that constitutes structure.
-
-In the living body, not only is each distinct organ alive, but, with
-exceptions so slight that they need not be noticed here, every solid
-which enters into the composition of the organ is endowed with vital
-properties. This is probably the case with the primary substances or
-tissues which compose the several organs of the plant; but that the
-animal solids are alive is indubitable; nay, the evidence is complete,
-that many even of the animal fluids possess vitality. The blood in the
-animal is as truly alive as the brain, and the bone as the flesh. The
-organized body, considered as a whole, is the seat of life; but life
-also resides in almost every component part of it.
-
-Yet the matter out of which these living substances is formed is not
-alive. By processes of which we know nothing, or, at least, of which
-we see only the first steps,—matter, wholly destitute of life, is
-converted into living substance. The inorganic matter, which is the
-subject of this wonderful transformation, is resolvable into a very
-few elementary substances. In the plant, these substances consist of
-three only, namely, oxygen, hydrogen, and carbon. The first two are
-aëriform or gaseous bodies; the last is a solid substance, and it is of
-this that the plant is chiefly composed: hence the basis of the plant
-is a solid. The elementary bodies, into which all animal substance is
-resolvable, are four, namely, azote, oxygen, hydrogen, and carbon.
-Into every animal fluid and solid this new substance azote enters so
-largely, that it may be considered as the fundamental and distinctive
-element of the animal organization: hence the basis of the animal is
-an aëriform or gaseous fluid. The animal is composed of air, the plant
-of solid matter; and this difference in their elementary nature gives
-origin to several distinctive characters between the plant and the
-animal, in addition to those which have been already stated.
-
-Thus the characters of the plant are solidity, hardness, fixedness, and
-durability; while the animal is comparatively fluid, soft, volatile,
-and perishable; and the reason is now manifest. The basis of the animal
-being an aëriform fluid, its consistence is softer than that of the
-plant, the basis of which is a firm solid; and, at the same time, the
-component elements of the animal being more numerous than those of the
-plant, and the fluidity of these elements, and of the compounds they
-form, greatly favouring their action and reaction on each other and on
-external agents, the animal body is more volatile and perishable during
-life, and more readily decomposed after death.
-
-It has been stated, that the object of every structure or organ
-of the living body, is the performance of some special action or
-function,—the ultimate object of the fluids being the production of
-the solids; the ultimate object of the solids being the formation of
-organs; the ultimate object of organs being the performance of actions
-or functions; while it is in the performance of actions or functions
-that life consists. Functions carried on by organs; organs in action;
-special organs performing definite actions, this it is that constitutes
-the state of life. Every particle of matter which enters into the
-composition of the living body has thus its own place, forming, or
-destined to form, a constituent part of some organ; every organ has
-its own action; all the organs of the body form the body; and all
-the actions of all the organs constitute the aggregate of the vital
-phenomena.
-
-Every organ is excited to action, or its function is called into
-operation by means of some external body. The external bodies capable
-of exciting and maintaining the functions of living organs, consist
-of a definite class. Because these bodies belong to that department
-of science which is called physical, they are termed physical agents.
-They are air, water, heat, cold, electricity, and light. Without the
-living organ, the physical agent can excite no vital action: without
-the physical agent, the living organ can carry on no vital process.
-The plant cannot perform the vital process of respiration without the
-leaf, nor, with the leaf, without air. The physical agent acts upon the
-living organ; the living organ reacts upon the physical agent, and the
-action between both is definite. In the lung of the animal a certain
-principle of the air unites, in definite proportions, with a certain
-principle of the blood; the oxygen of the air combines with the carbon
-of the blood; the air is changed by the abstraction of its oxygen;
-the blood is changed by the abstraction of its carbon. Atmospheric
-air goes to the lung, but atmospheric air does not return from the
-lung; it is converted into a new substance by the action of the organ:
-it is changed into carbonic acid by the union of a given quantity of
-oxygen, which it transmits to the organ, with a given quantity of
-carbon which the organ conveys to it. Venous blood goes to the lung,
-but venous blood does not return from the lung; it is converted, by
-the instrumentality of the organ, into a new substance, into arterial
-blood, by giving to the air carbon, and by receiving from the air
-oxygen. In this manner the change in the physical agent is definite and
-uniform; and the change in the living substance is equally definite and
-uniform.
-
-It is this determinate interchange of action between the living organ
-and the physical agent that constitutes what is termed a vital process.
-All vital processes are carried on by living organs; the materials
-employed in all vital processes are physical agents; the processes
-themselves are vital functions. All the changes produced by all the
-organs of the plant upon physical agents, and all the changes produced
-by all physical agents upon the organs of the plant, constitute all
-the vital processes of the plant—comprehend the whole sum of its
-vital phenomena. The root, the trunk, the woody substance, the bark,
-the ascending vessels bearing sap, the descending vessels bearing
-secreted fluids, the leaves, the flowers, these are the living organs
-of the plant. Air, water, heat, cold, electricity, light, these are the
-physical agents which produce in these organs definite changes, and
-which are themselves changed by them in definite modes; and the whole
-of these changes, taken together, comprehend the circle of actions, or
-the range of functions performed by this living being.
-
-In the state of life, during the interchange of action which thus
-incessantly goes on between physical agents and vital organs, the
-laws to which inorganic matter is subject are resisted, controlled,
-and modified. Physical and chemical attractions are brought under the
-influence of a new and superior agency, with the laws of which we are
-imperfectly acquainted, but the operation of which we see, and which we
-call the agency of life. Air, water, heat, electricity, are physical
-agents, which subvert the most intimate combinations of inorganic
-bodies, resolving them into their simple elements, and recombining
-these elements in various modes, and thus forming new bodies, endowed
-with totally different properties; but the physical and chemical
-agencies by which these changes are wrought in the inorganic, are
-resisted, controlled, and modified by the living body: resisted, for
-these physical agents do not decompose the living body; controlled
-and modified, for the living body converts these very agents into the
-material for sustaining its own existence Of all the phenomena included
-in that circle of actions which we designate by the general term life,
-this power of resisting the effects universally produced by physical
-agents on inorganic matter, and of bringing these very agents under
-subjection to a new order of laws, is one of the most essential and
-distinctive.
-
-All vital processes are processes of supply, or processes of waste. By
-every vital action performed by the organized body, some portion of its
-constituent matter is expended. Numerous vital actions are constantly
-carried on for the sole purpose of compensating this expenditure. Every
-moment old particles are carried out of the system; every moment new
-particles are introduced into it. The matter of which the organized,
-and more especially the animal, body is composed, is thus in a state
-of perpetual flux; and in a certain space of time it is completely
-changed, so that of all the matter that constitutes the animal body at
-a given point of time, not a single particle remains at another point
-of time at a given distance.
-
-All the wants of the economy of the plant are satisfied by a due
-supply of air, water, heat, cold, electricity, and light. Some of
-these physical agents constitute the crude aliment of the plant;
-others produce in this aliment a series of changes, by which it is
-converted from crude aliment into proper nutriment, while others act
-as stimulants, by which movements are excited, the ultimate object of
-which is the distribution of the nutriment to the various parts of the
-economy of the plant.
-
-The same physical agents are indispensable to the support of the animal
-body; but the animal cannot be sustained by these physical agents
-alone; for the maintenance of animal life, in some shape or other,
-vegetable or animal matter, or both in a certain state of combination,
-must be superadded: hence another distinction between the plant and the
-animal,—the necessity, on the part of the animal, of an elaborated
-aliment to maintain its existence. By the vital processes of its
-economy, the plant converts inorganic into organic matter; by the vital
-processes of its economy, the animal converts matter, already rendered
-organic, into its own proper substance. The plant is thus purveyor to
-the animal: but it is more than purveyor to it; for while it provides,
-it also prepares its food; it saves the animal one process, that of
-the transmutation of inorganic into organic matter. The ultimate end,
-or the final cause of the vital processes performed by the first class
-of living beings, is thus the elaboration of aliment for the second:
-the inferior life is spent in ministering, and the great object of its
-being is to minister to the existence of the superior.
-
-At the point at which organization commences structure is so simple
-that there is no manifest distinction of organs. Several functions are
-performed apparently by one single organized substance. The lowest
-plants and the lowest animals are equally without any separate organs,
-as far as it is in our power to distinguish them, for carrying on the
-vital actions they perform. An organized tissue, apparently of an
-homogeneous nature, containing fluid matter, is all that can be made
-out by which the most simply-constructed plant carries on its single
-set, and by which the most simply-constructed animal carries on its
-double set, of actions. But this simplicity of structure exists only
-at the very commencement of the organized world. Every advancement in
-the scale of organization is indicated by the construction of organs
-manifestly separate for the performance of individual functions;
-and, invariably, the higher the being, the more complete is this
-separation of function from function, and, consequently, the greater
-the multiplication of organs, and the more elaborate and complex the
-structure;—and hence another distinction between the plant and the
-animal. The simplicity of the structure of the plant is in striking
-contrast to the complexity of the structure of the animal; and this
-difference is not arbitrary; it is a matter of absolute necessity, and
-the reason of this necessity it will be instructive to contemplate.
-
-The plant, as has been shown, performs only one set of functions, the
-organic; while the animal performs two sets of functions, the organic
-and the animal. The animal, then, performs more functions than the
-plant, and functions of a higher order; it carries on its functions
-with a greater degree of energy; its functions have a more extended
-range, and all its functions bear a certain relation to each other,
-maintaining an harmonious action. The number, the superiority, the
-relation, the range, and the energy of the functions performed by
-the animal are, then, so many conditions, which render it absolutely
-indispensable that it should possess a greater complexity of structure
-than the plant.
-
-1. To build up structure is to create, to arrange, and to connect
-organs. Organs are the instruments by which functions are performed,
-and without the instrument there can be no action. With as many
-more organs than the plant possesses the animal must, therefore, be
-provided, as are necessary to carry on the additional functions it
-performs. Organs, for its organic functions, it must have as well as
-the plant; but to these must be superadded organs of another class, for
-which the plant has no need, namely, organs for its animal functions.
-Two sets of organs must, therefore, be provided for the animal, while
-the plant requires but one.
-
-2. Some functions performed by the animal are of a higher order than
-any performed by the plant, and the superior function requires a higher
-organization. The construction of an organ is complex as its action is
-elevated; the instrument is elaborately prepared in proportion to the
-nobleness of its office.
-
-[Illustration: Fig. I.]
-
-[Illustration: Fig. II.]
-
-[Illustration: Fig. III.]
-
-[Illustration: Fig. IV.]
-
-3. But this is not all; for the addition of a superior function
-requires not only the addition of an organ having a corresponding
-superiority of structure, but it requires, further, that a certain
-elevation of structure should be communicated to all the organs of
-all the inferior functions, on account of the relation which it is
-necessary to establish between function and function. Unless the organ
-of an inferior function be constructed with a perfection corresponding
-to that of the organ of a superior function, the inferior will be
-incapable of working in harmony with the superior. Take, for example,
-the inferior function of nutrition: nutrition is an organic function
-equally necessary to the plant and to the animal, and requiring in
-both organs for performing it; but this function cannot be performed
-in the animal by organs as simple as suffice for the plant. Nutrition,
-in the plant, is carried on in the following mode:—The root of the
-plant is divided, like the trunk, into numerous branches (fig. I. 1).
-These branches divide and subdivide into smaller and smaller branches,
-until at last they reach an extreme degree of minuteness (fig. I. 2 2).
-The smallest of these divisions, called, from their hair-like tenuity,
-_capillary_ (fig. I. 2 2), are provided with a peculiar structure,
-which is endowed with a specific function. In most plants this peculiar
-structure is found at the terminal point of the rootlet (fig. I. 2 2);
-but in some plants the capillary branches of the rootlets are provided
-with distinct bodies (fig. II. 1 2), scarcely to be discerned when
-the root has been removed some time from the soil, and has become dry
-(fig. II. 2 2); but which, in a few minutes after the root has been
-plunged in water, provided the plant be still alive, become turgid with
-fluid, and, consequently, distinctly visible (fig. II. 1 1 1). These
-bodies, when they exist, or the terminal point of the rootlet when
-these bodies are absent, are termed _spongeolæ_, or spongeoles; and the
-structure and function of the organ, in both cases, are conceived to
-be precisely the same. In both the organ consists of a minute cellular
-structure. Fig. III. 1, shows this structure as it appears when the
-object is magnified. The office of this organ is to absorb the aliment
-of the plant from the soil; and so great is its absorbing power, that,
-as is proved by direct experiment, it absorbs the colouring molecules
-of liquids, though these molecules will not enter the ordinary pores,
-which are of much greater magnitude. With the spongeoles are connected
-vessels which pass through the substance of the stem or trunk to the
-leaf. Fig. III. 2, shows these tubes springing from the cellular
-structure of the spongeole, and passing up to the stem or trunk. Fig.
-IV. 2, exhibits a magnified view of the appearance of the mouths of
-these tubes on making an horizontal section of the spongeole. Fig. V.
-1 1 1, exhibits a view of these tubes passing to the leaf. Figs. VI.
-and VII. 1 1 1 1, show these vessels spread out upon, and ramifying
-through, the leaf. The crude aliment, borne by these tubes to the leaf,
-is there converted into proper nutriment; and from the leaf, when
-duly elaborated, this proper nutriment is carried out by ducts to the
-various organs of the plant, in order to supply them with the aliment
-they need.
-
-[Illustration: Fig. V.]
-
-Now, for carrying on the process of nutrition in this mode, there
-must be organs to absorb the crude aliment, organs to convey the crude
-aliment to the laboratory, the leaf, in which it is converted into
-proper nutriment; and, finally, organs for carrying out this proper
-nutriment to the system. Complication of structure, to this extent, is
-indispensable; and, accordingly, with spongeolæ, with sap-vessels, with
-leaves, with distributive ducts, the plant is provided. Without all the
-parts of this apparatus it could not carry on its function: any further
-complication would be useless.
-
-[Illustration: Fig. VI.]
-
-But, suppose a new and superior function to be added to the plant;
-suppose it to be endowed with the power of locomotion, what would be
-the consequence of communicating to it this higher power? That its
-former state of simplicity would no longer suffice for the inferior
-function. Why? because the exercise of the superior would interrupt
-the action of the inferior function. Nutrition by imbibition, and
-the exercise of locomotion, cannot go on simultaneously in the same
-being. The plant is fixed in the soil by its roots; and from this, its
-state of immobility, results this most important consequence, that its
-spongeolæ are always in contact with its food.
-
-[Illustration: Fig. VII.]
-
-[Illustration: Fig. VIII.]
-
-But we may imagine a plant not fixed to the soil; a plant so
-constituted as to be capable of moving from place to place; such a
-plant would not be always in contact with its food, and therefore, as
-it exercised its faculty of locomotion, it could not but interrupt
-or suspend its function of nutrition. In a being capable of carrying
-on these two functions simultaneously, the entire apparatus of the
-function of nutrition must then be modified. Instead of having
-spongeolæ fixed immovably in the earth, and spread out in a soil
-adapted to transmit to these organs nutrient matter in a state fitted
-for absorption, it must be provided with a reservoir for containing
-its food, in order that it may carry its aliment about with it in
-all its changes of place. And such is the modification uniformly
-found in all animals: an internal reservoir for containing its food
-is provided, perhaps, for every animal without exception. Even the
-simplest and minutest creatures with which the microscope has made
-us acquainted, the lowest tribes of the Infusoria (fig. VIII.), the
-sentient, self-moving cellules, placed at the very bottom of the
-animal scale, possess this modification of structure. For a long
-time it was conceived that these minute and simple creatures were
-without distinction of parts, that they had no separate organs for the
-reception and digestion of their food; that they absorbed their aliment
-through the porous tissue of which their body is composed; that thus,
-instead of having a separate stomach, their entire body is a stomach,
-and instead of having even as much as a separate organ for absorption,
-like the more perfect plant, the whole body might be considered as a
-single spongeole.
-
-But, by a simple and beautiful experiment, a German physiologist
-has shown the incorrectness of this opinion, and has established the
-fact, that the distinction between the plant and the animal, here
-contended for, is found even at the very lowest point of the animal
-scale. Like other physiologists, conceiving that the difficulty of
-discovering the structure of the lower tribes of the animalculi
-might be owing to the transparency or the tissues of which they are
-composed, it struck Ehrenberg, that if he could feed them with coloured
-substances, he might obtain some insight into their organization.
-In his first endeavours to accomplish this object he failed, for he
-employed the pigments in ordinary use; but either the animals would not
-touch aliment thus adulterated, or those that did so were instantly
-killed. It then occurred to him, that these colours are adulterated
-with lead and other substances, in all probability noxious to the
-little subjects of his experiment. "What I require," said he, "is some
-vegetable or animal colouring matter perfectly pure." He then tried
-perfectly pure indigo and perfectly pure carmine. His success was
-now complete: in a minute or two, after mixing with their food pure
-vegetable colouring matter, he observed in the interior of the body of
-these creatures minute spots of a definite figure, and of the colour
-of the pigment employed (fig. VIII. 1 1 1 1). The form and magnitude
-of these spots were different in different tribes, but the same in the
-same individual, and even in the same species (fig. IX. 1 1, fig. X.
-1 1). No other parts of the body were tinged with the colour, though
-the animals remained in the coloured fluid for days together. This was
-decisive. This physiologist had now obtained an instrument capable of
-revealing to him the interior organization of a class of beings, the
-structure of which had heretofore been wholly unknown. On applying
-it to the MONAS TERMO (fig. VIII.), the animated point, or cellule,
-which stands at the bottom of the animal scale, he discovered, in the
-posterior portion of its body, several coloured spots which constitute
-its stomachs (fig. VIII. 1 1 1 1). The different situations and
-different forms of the stomach in different tribes of these creatures,
-are represented by the coloured portions (fig. VIII. 1, fig. IX. 1,
-fig. X. 1), in which the currents of fluid flowing to their mouths
-are seen (fig. IX. 2, fig. X. 2). These experiments go far towards
-establishing the fact, that every animal, even the very lowest, has an
-external mouth and an internal stomach, and that it takes its food by
-an act of volition.
-
-[Illustration: Fig. IX.]
-
-[Illustration: Fig. X.]
-
-But if the proof of this must be admitted to be still imperfect
-with regard to the lowest tribes of animals, it is certain that, as
-we ascend in the scale of organization, the nutritive apparatus is
-uniformly arranged in this mode. Every animal of every class large
-enough to be distinctly visible, and the structure of which is not
-rendered inappreciable by the transparency of its solids and fluids, is
-manifestly provided with a distinct internal reservoir for containing
-its food. On the internal surface of this reservoir open the mouths of
-vessels, minute in size but countless in number, which absorb the food
-from the stomach.
-
-Fig. XI. shows these vessels opening on the inner surface of the
-stomach, the white points representing their mouths, turgid with the
-food they have absorbed. Fig. XII. exhibits magnified views of the same
-vessels, the points representing their open mouths, and the lines the
-vessels themselves in continuation with their mouths. Fig. XIII. shows
-the appearance of the inner surface of the intestine soon after the
-animal has taken food; the smaller white lines (1 1 1 1) representing
-the absorbent vessels full of digested food, and the larger lines (2 2
-2 2) the trunks of the absorbent vessels formed by the union of many of
-the smaller.
-
-[Illustration: Fig. XI.]
-
-[Illustration: Fig. XII.]
-
-From this account, it is clear that the absorbing vessels of the
-stomach perform an office precisely analogous to that of the spongeoles
-of the root. What the soil is to the plant, the stomach is to the
-animal. The absorbing vessels diffused through the stomach, as long
-as the stomach contains food, are in exactly the same condition as
-the spongeoles of the root spread out in the soil; and the absorbing
-vessels of the stomach are as much and as constantly in contact with
-the aliment, which it is their office to take into the system, as the
-spongeoles of the root. Such, then, is the expedient adopted to render
-the function of nutrition compatible with the function of locomotion.
-A reservoir of food is placed in the interior of the animal, provided
-with absorbent vessels which are always in contact with the aliment. In
-this mode, contact with aliment is not disturbed by continual change of
-place; the organic process is not interrupted by the exercise of the
-animal function.
-
-[Illustration: Fig. XIII.]
-
-But the more elaborate organization which it is necessary to impart
-to the apparatus of the inferior function, in consequence of the
-communication of a superior faculty, is not completed simply by the
-addition of this new organ, the stomach. Other complications are
-indispensable; for if food be contained in an isolated organ, placed in
-the interior of the body, means must be provided for conveying the food
-into this organ; hence the necessity of an apparatus for deglutition.
-Moreover, the food having been conveyed to the stomach, and having
-undergone there the requisite changes, means must next be provided for
-conveying it from the stomach to the other parts of the body; hence
-the necessity of an apparatus for the circulation. But food, however
-elaborately prepared by the stomach, is incapable of nourishing the
-body, until it has been submitted to the action of atmospheric air;
-hence the necessity of an additional apparatus, either for conveying
-food to the air, or for transmitting air to the food, or for bringing
-both the food and the air into contact in the same organ. And, when
-structure after structure has been built up, in order to carry on this
-extended series of processes, the number of provisions required is
-not even yet complete; for of the most nutritious fond the whole mass
-is not nutritive; and even the whole of that portion of it which is
-actually applied to the purpose of nutrition, becomes, after a time,
-worn out, and must be removed from the system; hence the necessity of a
-further apparatus for excretion.
-
-That nutrition and locomotion may go on together, it is clear, then,
-that there must be provided a distinct apparatus for containing
-food, a distinct apparatus for deglutition, a distinct apparatus for
-circulation, a distinct apparatus for respiration, a distinct apparatus
-for excretion, and so on; and that, in this manner, the communication
-of a single function of a superior order renders a modification not
-merely of one but of many inferior functions absolutely indispensable,
-in order to adjust the one to the other, and to enable them to act in
-harmony.
-
-But the necessary complication of structure does not stop even here;
-for the communication of one function of a superior order imposes
-the necessity of communicating still another. Locomotion cannot be
-exercised without perception; sensation is indispensable to volition,
-and volition, of course, to voluntary motion. A being endowed with
-the power of moving from place to place, without possessing the power
-of perceiving external objects, must be speedily destroyed. The
-communication of sensation to a creature fixed immovably to a single
-spot, conscious of the approach of bodies, but incapable of avoiding
-their contact, would be not only useless but pernicious, since it
-would be to make a costly provision for the production of pain, and
-nothing else; but the communication of locomotion without sensation
-would be as unwisely defective, as the former would be perniciously
-expensive; since it would be to endow a being with a faculty, the
-exercise of which would be fatal to it for the want of a second faculty
-to guide the first. Nor could the possession of locomotion, without the
-further possession of sensation, be otherwise than fatal, for another
-reason. Consciousness is not necessary to nutrition as performed by
-the plant, but it is indispensable to nutrition as performed by the
-animal: for if the food of the animal be not always on the same spot
-with itself; if it be under the necessity of searching for it, and of
-conveying it, when found, into the interior of its body, it must, of
-course, possess the power of perceiving it when within its reach, and
-of apprehending and appropriating it by an act of volition, of none of
-which actions is it capable without the possession of sensation. Again,
-then, we see that, in order to secure harmonious action, function must
-be put in relation with function. In order to prevent jarring and
-mutually-destructive action, function must be superadded to function,
-and throughout the animal creation the complication of structure, which
-is necessary for the accomplishment of these ends, is given without
-parsimony, but without profusion: nothing is given which is not needed,
-nothing is withheld which is required.
-
-4. As we ascend in the scale of organization, numerous functions being
-carried on, and numerous organs constructed for performing them, it
-is obvious that the range of each function must be proportionally
-extended; the range necessarily increasing with the multiplication
-of organ and function: and this is another cause of the unavoidable
-complication of structure. Slight consideration will suffice to show
-the necessary connexion between an extended range of action and
-complication of structure. Take, as an example, the organic function
-of respiration: respiration is the function by which air is brought
-into contact with food; it is the completion of digestion. The sole
-end of all the apparatus that belongs to this function is to bring the
-air and the food into a certain degree of proximity. Now, when all the
-substances that enter into the composition of the body of an animal are
-slight, delicate, and permeable to air (as in fig. XIV.), and when the
-body is always surrounded by air, air must at all times be in contact
-with the particular organ that contains the food, no less than with
-the general system to which the food is distributed. In this case, to
-construct a separate apparatus for containing air would be useless,
-because wherever food is, there air must be, since it constantly
-permeates every part of the body.
-
-[Illustration: Fig. XIV.]
-
-When, on the other hand, the tissues are so firm and dense as to be
-impermeable; when they are folded into bulky and complex organs, and
-when these organs are placed in situations to which the external air
-cannot reach, the construction of a separate apparatus for respiration
-is indispensable. The respiratory apparatus consists either of organs
-for carrying air to the food, or of organs for carrying food to the
-air. The one or the other is adopted, according to the nature of the
-body. If the size of the animal be small; if the tissues which form
-the solid portion of its body be delicate in texture; if, at the same
-time, the wants of its economy require that its food should be highly
-aërated (for there is the closest connexion between energy of function
-and perfect aëration of the food), an apparatus of sufficient magnitude
-to aërate the food in a high degree would occupy the entire bulk of the
-body. In such a case, it is easier to carry air to the food than food
-to the air; it is better to make the entire body a respiratory organ,
-than to construct a respiratory organ disproportioned to the magnitude
-of the body. Air-tubes diffused through every part of the body, and
-opening on its external surface, would obviously afford to every point
-of the system an easy access of air. By an expedient of this kind the
-system might be highly aërated, while the respiratory apparatus would
-occupy but a comparatively small space; the function might be performed
-on an extended scale, while there would be no necessity for encumbering
-a minute body with a bulky organ. And this is the mode in which
-respiration is carried on in large tribes of creatures, whose body
-is small in size and delicate in texture, and the functions of whose
-economy are performed with energy (fig. XV.).
-
-[Illustration: Fig. XV.
-
-  The Achilles Butterfly of South America (_Papilio Achilles_),
-  showing the tracheæ on the upper and under side of the wings.]
-
-But this contrivance will not do when the animal is of large
-magnitude; when its body is divided into numerous compartments; when
-these compartments extend far beneath the external surface; when
-important organs are placed in deeply-seated cavities; and when
-the substances that compose the organs are dense, hard, thick, and
-convoluted. To construct air-tubes of the requisite diameter and
-length, always open, always in a condition to permit the ingress and
-egress of an adequate current of air to and from the remotest nook and
-corner of a body such as this, would be difficult, if not impossible.
-At all events, it is easier, in such a case, to carry the food to the
-air, than the air to the food. But, for the accomplishment of this
-purpose, what is necessary? An organ for containing food; an organ
-for containing air; vessels to carry food to and from the receptacle
-of the aliment; vessels to carry air to and from the receptacle of
-the air; expedients to expose a stream of food to a current of air;
-and, finally, tubes to carry out to the system the product of this
-complicated operation. Accordingly, a reservoir of food and a reservoir
-of air; an apparatus by which both are conveyed to their respective
-receptacles; and an apparatus by which both are brought into contact
-sufficiently close to admit of their mutual action, are all combined
-in the lung of the animal, and in the mechanism by which its movements
-are effected. The object is accomplished, but the apparatus by which it
-is effected is as complex in structure as it is efficient in action;
-the result simple; the means by which the result is secured, highly
-complicated.
-
-And if this be true of an inferior or organic function, it is still
-more strikingly true of a superior or animal function. The relation is
-still stricter between the complexity of the apparatus of sensation and
-the range of feeling, than between the complexity of the apparatus of
-respiration and the range of the respiratory process. The greater the
-number of the senses, the greater the number of the organs of sense;
-the more accurate and varied the impressions conveyed by each, the more
-complex the structure of the instrument by which they are communicated;
-the more extended the range of the intellectual operations, the larger
-the bulk of the brain, the greater the number of its distinct parts,
-and the more exquisite their organization. From the point of the animal
-scale, at which the brain first becomes distinctly visible, up to man,
-the basis of the organ is the same; but, as the range of its function
-extends, part after part is superadded, and the structure of each part
-becomes progressively more and more complex. The evidence of this,
-afforded by comparative anatomy, is irresistible, and the interest
-connected with the study of it can scarcely be exceeded.
-
-5. In the last place, structure is complex in proportion to the
-energy of function. The greater the power with which voluntary motion
-is capable of being exerted, the higher the organization of the
-apparatus by which it is performed; the more compact and dense the
-shell, the cartilage, the bone, the firmer the fibre of the muscle,
-and, in general, the greater its comparative bulk. The wing of the
-eagle is as much more developed than the wing of the wren, as its
-flight is higher, and its speed swifter. The muscles which give to the
-tiger the rapidity and strength of its spring possess a more intense
-organization than those which slowly move on the tardigrade sloth. The
-structure of the brain of man is more exquisite than that of the fish,
-as his perceptions are more acute, and capable of greater combination,
-comprehension, and continuity.
-
-Thus we see that the organization of the animal is more complex than
-that of the plant, not from an arbitrary disposition, but from absolute
-necessity. The few and simple functions performed by the plant require
-only the few and simple organs with which it is provided: the numerous
-and complicated functions performed by the animal require its numerous
-and complicated organs: the plant, simple as it is in structure, is
-destitute of no organ required by the nature of its economy; the
-animal, complex as it is in structure, is in possession of no organ
-which it could dispense with: from the one, nothing is withheld which
-is needed; to the other, nothing is given which is superfluous: in the
-one, there is economy without niggardliness; in the other, munificence
-without waste.
-
-
-
-
-CHAPTER II.
-
-  Two distinct lives combined in the animal—Characters of the
-  apparatus of the organic life—Characters of the apparatus of
-  the animal life—Characteristic differences in the action of
-  each—Progress of life—Progress of death.
-
-
-Of the two sets of functions carried on by living beings, it has been
-shown, that the plant performs only one, while the animal exercises
-both. The two lives thus in continual play in the animal differ from
-each other as much as the process of vegetation differs from that of
-thought, yet they are united so closely, and act so harmoniously,
-that their existence as distinct states is not only not apparent to
-ordinary observation, but the very discovery of the fact is of recent
-date, and forms one among the splendid triumphs of modern physiology.
-Their action is perfect, yet their separate identity is so distinctly
-preserved, that each has its own apparatus and its own action, which
-are not only not the same, but, in many interesting circumstances, are
-in striking contrast to each other.
-
-1. In general the organs that belong to the apparatus of the organic
-life are single, and not symmetrical; the organs that belong to the
-apparatus of the animal life are either double, or symmetrical, or
-both. As will be shown hereafter, the heart, the lungs, the stomach,
-the intestines, the liver, the pancreas, the spleen, the instruments
-by which the most important functions of the organic life are carried
-on, are single organs. (Chap. 5.) The figure of each is more or less
-irregular, so that if a line were carried through their centre, it
-would not divide them into two equal and precisely corresponding
-portions. On the contrary, the organs of the animal life are
-symmetrical. The brain and the spinal cord are divisible into two
-perfectly equal parts. (Chap. 5.) The nerves which go off from these
-organs for the most part go off in pairs equal in size and similar
-in distribution. (Ibid.) The trunk, so important an instrument of
-voluntary motion, when well formed, is divisible into two perfectly
-corresponding portions. (Ibid.) The muscular apparatus of one half
-of the body is the exact counterpart of that of the other; while the
-arms, the hands, and the lower extremities are not only double, but the
-organization of the one is precisely similar to that of its fellow.
-
-2. In general, the apparatus of the organic life is placed in the
-interior of the body, while that of the animal life is placed on the
-external surface. The organic organs are the instruments by which
-life is maintained. There is no action of any one of them that can
-be suspended even for a short space of time without the inevitable
-extinction of life. But the animal organs are not so much instruments
-of life as means by which a certain relation is established between the
-living being and external objects. And this difference in their office
-is the reason of the difference in their position. Existence depending
-on the action of the organic organs, they are placed in the interior of
-the body; they are fixed firmly in their situation in order that they
-may not be disturbed by the movements of locomotion; they are enveloped
-in membranes, covered by muscles, placed under the shelter of bones,
-and every possible care is taken to secure them from accident and to
-shield them from violence. Existence not being immediately dependent
-on the action of the organs of the animal life, they do not need to
-be protected from the contact of external objects with extraordinary
-care, but it is necessary to the performance of their functions that
-they should be placed at the exterior of the body. And there they are
-placed, and so placed as to afford an effectual defence to the organic
-organs. Thus the groundwork of the animal is made the bulwark of the
-organic life. The muscles, the immediate agents by which voluntary
-motion is effected, and the bones, the fixed points and the levers by
-which that motion acquires the nicest precision and the most prodigious
-rapidity and power, are so disposed that, while the latter accomplish,
-in the most perfect manner, their primary and essential office in
-relation to the muscles, they serve a secondary but scarcely less
-important office in relation to the internal viscera. As we advance
-in our subject, we shall see that a beautiful illustration of this is
-afforded in the structure and action of the trunk; that the trunk is
-moveable; that it is composed of powerful muscles, and of firm and
-compact bones; and that while its movements are effected by the action
-of the muscles which are attached to the bones, these bones enclose
-a cavity, in which are placed the lungs, the heart, the great trunks
-of the venous system, the great trunks of the arterial system, and
-the main trunk of the thoracic duct, the vessel by which the digested
-aliment is carried into the blood. (Chap. 5.) Thus, by these strong and
-firm bones, together with the thick and powerful muscles that rest upon
-them, is formed a secure shelter for a main portion of the apparatus
-of the organic functions of respiration, circulation, and digestion.
-The bones and muscles of the thorax, themselves performing an important
-part in the function of respiration, afford to the lungs the chief
-organ of this function, composed of tender and delicate tissues, easily
-injured, and the slightest injury perilling life, a free and secure
-place to act in. The fragile part of the apparatus is defended by the
-osseous portion of it, the play of the latter being equally essential
-to the function as that of the former. In like manner the tender and
-delicate substance of the brain and spinal cord, the central seat of
-the animal life, with which all the senses are in intimate communion,
-is protected by bones and muscles which perform important voluntary
-movements while the organs of sense which put us in connexion with the
-external world, which render us susceptible of pleasure, and which
-give us notice of the approach of objects capable of exciting pain,
-are placed where external bodies may be brought most conveniently
-and completely into contact with them; and where alone they can be
-efficient as the sentinels of the system. For this reason, with the
-exception of the sense of touch, which, though placed especially at the
-extremities of the fingers, is also diffused over the whole external
-surface of the frame, all the senses have their several seats in the
-head, the most elevated part of the body, of an ovoid figure, capable
-of moving independently of the rest of the fabric, and which, being
-supported on a pivot, is enabled to describe at least two-thirds of a
-circle.
-
-Such is the difference in the structure and position of the apparatus
-of the two lives, but the difference in their action is still more
-striking.
-
-1. The action of the apparatus of the organic life when sound is
-without consciousness; the object of the action of the apparatus of
-the animal life is the production of consciousness. The final cause
-of the action of the apparatus of the organic life is the maintenance
-of existence; the final cause of the action of the apparatus of the
-animal life is the production of conscious existence. What purpose
-would be answered by connecting consciousness with the action of
-the organic organs? Were we sensible of the organic processes; did
-we know when the heart beats, and the lung plays, and the stomach
-digests, and the excretory organ excretes, the consciousness could
-not promote, but might disturb the due and orderly course of these
-processes. Moreover they would so occupy and engross our minds that
-we should have little inclination or time to attend to other objects.
-Beneficently therefore are they placed equally beyond our observation
-and control. Nevertheless, when our consciousness of these processes
-may be of service; when they are going wrong; when their too feeble or
-too intense action is in danger of destroying existence, the animal
-life is made sensible of what is passing in the organic, in order that
-the former may take beneficial cognizance of the latter, may do what
-experience may have taught to be conducive to the restoration of the
-diseased organ to a sound state, or avoid doing what may conduce to the
-increase or maintenance of its morbid condition.
-
-But while the action of the organic organs is thus kept alike from our
-view and feeling, the sole object of the action of the animal organs is
-to produce and maintain a state of varied and extended consciousness.
-We do not know when the heart dilates to receive the vital current,
-nor when it contracts to propel it with renewed impetus through the
-system; nor when the blood rushes to the lung to give out its useless
-and noxious particles; nor when the air rushes to the blood to take
-up those particles, to replace them by others, and thus to purify and
-renovate the vital fluid. Many processes of this kind are continually
-going on within us during every moment of our existence, but we are
-no more conscious of them than we are of the motion of the fluids in
-the blade of grass on which we tread. On the contrary when an external
-object produces, in a sentient nerve, that change of state which we
-denote by the words "an impression;" when the sentient nerve transmits
-this impression to the brain; when the brain is thereby brought into
-the state of perception, the animal life is in active operation, and
-percipient or conscious existence takes place. Consciousness does not
-belong to the organic, it _is_ the animal life.
-
-2. The functions of the organic life are performed with uninterrupted
-continuity; to those of the animal life rest is indispensable. The
-action of the heart is unceasing; it takes not and needs not rest.
-On it goes, for the space of eighty or ninety years, at the rate of
-a hundred thousand strokes every twenty-four hours, having at every
-stroke a great resistance to overcome, yet it continues this action for
-this length of time without intermission. Alike incessant is the action
-of the lung, which is always receiving and always emitting air; and the
-action of the skin, which is always transpiring and always absorbing;
-and the action of the alimentary canal, which is always compensating
-the loss which the system is always sustaining.
-
-But of this continuity of action the organs and functions of the
-animal life are incapable. No voluntary muscle can maintain its action
-beyond a given time; no effort of the will can keep it in a state of
-uninterrupted contraction; relaxation must alternate with contraction;
-and even this alternate action cannot go on long without rest. No organ
-of sense can continue to receive impression after impression without
-fatigue. By protracted exertion the ear loses its sensibility to sound,
-the eye to light, the tongue to savour, and the touch to the qualities
-of bodies about which it is conversant. The brain cannot carry on
-its intellectual operations with vigour beyond a certain period; the
-trains of ideas with which it works become, after a time, indistinct
-and confused; nor is it capable of reacting with energy until it
-has remained in a state of rest proportioned to the duration of its
-preceding activity.
-
-And this rest is sleep. Sleep is the repose of the senses, the rest of
-the muscles, their support and sustenance. What food is to the organic,
-sleep is to the animal life. Nutrition can no more go on without
-aliment, than sensation, thought, and motion without sleep.
-
-But it is the animal life only that sleeps: death would be the
-consequence of the momentary slumber of the organic. If, when the brain
-betook itself to repose, the engine that moves the blood ceased to
-supply it with its vital fluid, never again would it awake. The animal
-life is active only during a portion of its existence; the activity of
-the organic life is never for a moment suspended; and in order to endow
-its organs with the power of continuing this uninterrupted action,
-they are rendered incapable of fatigue: fatigue, on the contrary, is
-inseparable from the action of the organs of the animal life; fatigue
-imposes the necessity of rest, rest is sleep, and sleep is renovation.
-
-3. Between all the functions of the organic life there is a close
-relation and dependence. Without the circulation there can be no
-secretion; without secretion, no digestion; without digestion, no
-nutrition; without nutrition, no new supply of circulating matter,
-and so through the entire circle. But the functions of the animal
-life are not thus dependent on each other. One of the circle may be
-disordered without much disturbance of the rest; and one may cease
-altogether, while another continues in vigorous action. Sensation may
-be lost, while motion continues; and the muscle may contract though it
-cannot feel. One organ of sense may sleep while the rest are awake.
-One intellectual faculty may be in operation while others slumber. The
-muscle of volition may act, while there is no consciousness of will.
-Even the organs of the voice and of progression may perform their
-office while the sensorium is deeply locked in sleep.
-
-4. The two lives are born at different periods, and the one is in
-active operation before the other is even in existence. The first
-action observable in the embryo is a minute pulsating point. It is the
-young heart propelling its infant stream. Before brain, or nerve, or
-muscle can be distinguished, the heart is in existence and in action;
-that is, the apparatus of the organic function of the circulation is
-built up and is in operation before there is any trace of an animal
-organ. Arteries and veins circulate blood, capillary vessels receive
-the vital fluid, and out of it form brain and muscle, the organs of the
-animal, no less than the various substances that compose the organs of
-the organic life. The organic is not only anterior to the animal life,
-but it is by the action of the organic that existence is given to the
-animal life. The organic life is born at the first moment of existence;
-the animal life not until a period comparatively distant; the epoch
-emphatically called the period of birth, namely, the period when
-the new being is detached from its mother; when it first comes into
-contact with external objects; when it carries on all the functions
-of its economy by its own organs, and consequently enjoys independent
-existence.
-
-5. The functions of the organic life are perfect at once. The heart
-contracts as well, the arteries secrete as well, the respiratory
-organs work as well the first moment they begin to act as at any
-subsequent period. They require no teaching from experience, and they
-profit nothing from its lessons. On the contrary, the operations
-of the brain, and the actions of the voluntary muscles, feeble and
-uncertain at first, acquire strength by slow degrees, and attain
-their ultimate perfection only at the adult age. How indistinct
-and confused the first sensations of the infant! Before it acquire
-accuracy, precision, and truth, how immense the labour spent upon
-perception! Sensations are succeeded by ideas; sensations and ideas
-coalesce with sensations and ideas; combinations thus formed suggest
-other combinations previously formed, and these a third, and the third
-a fourth, and so is constituted a continuous train of thought. But
-the infantile associations between sensation and sensation, between
-idea and idea, and between sensations and ideas, are, to a certain
-extent, incorrect, and to a still greater extent inadequate; and the
-misconception necessarily resulting from this early imperfection in the
-intellectual operations is capable of correction only by subsequent and
-more extended impressions. During its making hours, a large portion of
-the time of the infant is spent in receiving impressions which come
-to it every instant from all directions, and which it stores up in
-its little treasury; but a large portion is also consumed in the far
-more serious and difficult business of discrimination and correction.
-Could any man, after having attained the age of manhood, reverse the
-order of the course through which he has passed; could he, with the
-power of observation, together with the experience that belong to
-manhood, retrace with perfect exactness every step of his sentient
-existence, from the age of forty to the moment that the air first came
-into contact with his body at the moment of his leaving his maternal
-dwelling, among the truths he would learn, the most interesting, if
-not the most surprising, would be those which relate to the manner in
-which he dealt with his earliest impressions; with the mode in which
-he combined them, recalled them, laid them by for future use; made his
-first general deduction; observed what subsequent experience taught to
-be conformable, and what not conformable, to this general inference;
-his emotions on detecting his first errors, and his contrasted feelings
-on discovering those comprehensive truths, the certainty of which
-became confirmed by every subsequent impression. Thus to live backwards
-would be, in fact, to go through the analysis of the intellectual
-combinations, and, consequently, to obtain a perfect insight into the
-constitution of the mind; and among the curious results which would
-then become manifest, perhaps few would appear more surprising than the
-true action of the senses. The eye, when first impressed by light, does
-not perceive the objects that reflect it; the ear, when first impressed
-by sound, does not distinguish the sonorous body. When the operation
-for cataract has been successfully performed in a person born blind,
-the eye immediately becomes sensible to light, but the impression of
-light does not immediately give information relative to the properties
-of bodies. It is gradually, not instantaneously; it is even by slow
-degrees that luminous objects are discerned with distinctness and
-accuracy. To see, to hear, to smell, to taste, to touch, are processes
-which appear to be performed instantaneously, and which actually are
-performed with astonishing rapidity in a person who observes them
-in himself; but they were not always performed thus rapidly: they
-are processes acquired, businesses learnt; processes and businesses
-acquired and learnt, not without the cost of many efforts and much
-labour. But the senses afford merely the materials for the intellectual
-operations of memory, combination, comparison, discrimination,
-induction, operations the progress of which is so slow, that they
-acquire precision, energy, and comprehensiveness only after the culture
-of years.
-
-And the same is true of the muscles of volition. How many efforts are
-made before the power of distinct articulation is acquired! how many
-before the infant can stand! how many before the child can walk! The
-organic life is born perfect; the animal life becomes perfect only by
-servitude, and the aptitude which service gives.
-
-6. The organic life may exist after the animal life has perished. The
-animal life is extinguished when sensation is abolished, and voluntary
-motion can be performed no more. But disease may abolish sensation and
-destroy the power of voluntary motion, while circulation, respiration,
-secretion, excretion, in a word, the entire circle of the organic
-functions continues to be performed. In a single instant apoplexy may
-reduce to drivelling fatuity the most exalted intellect, and render
-powerless and motionless muscles of gigantic strength; while the action
-of the heart and the involuntary contractions of the muscles may not
-only not be weakened, but may act with preternatural energy. In a
-single instant, apoplexy may even completely extinguish the animal
-life, and yet the organic may go on for hours, days, and even weeks;
-while catalepsy, perhaps the most singular disease to which the human
-frame is subject, may wholly abolish sensation and volition, while
-it may impart to the voluntary muscles the power of contracting with
-such unnatural energy and continuity, that the head, the trunk, the
-limbs may become immoveably fixed in whatever attitude they happen
-to be at the moment the paroxysm comes on. In this extraordinary
-condition of the nervous system, however long the paroxysm last, and
-however complete the abolition of consciousness, the heart continues
-to beat, and the pulse to throb, and the lungs to respire, and all the
-organic organs to perform their ordinary functions. Dr. Jebb gives the
-following description of the condition of a young lady who was the
-subject of this curious malady.
-
-"My patient was seized with an attack just as I was announced. At that
-moment she was employed in netting; she was in the act of passing
-the needle through the mesh; in that position she became immoveably
-rigid, exhibiting, in a pleasing form, a figure of death-like sleep,
-beyond the power of art to imitate, or the imagination to conceive.
-Her forehead was serene, her features perfectly composed. The paleness
-of her colour, and her breathing, which at a distance was scarcely
-perceptible, operated in rendering the similitude to marble more exact
-and striking. The position of her fingers, hands, and arms was altered
-with difficulty, but preserved every form of flexure they acquired:
-nor were the muscles of the neck exempted from this law, her head
-maintaining every situation in which the hand could place it, as firmly
-as her limbs."
-
-In this condition of the system the senses were in a state of profound
-sleep; the voluntary muscles, on the contrary, were in a state of
-violent action; but this action not being excited by volition, nor
-under its control, the patient remained as motionless as she was
-insensible. The brain was in a state of temporary death; the muscle
-in a state of intense life. And the converse may happen: the muscle
-may die, while the brain lives; contractility may be destroyed, while
-sensibility is perfect; the power of motion may be lost, while that of
-sensation may remain unaffected. A case is on record, which affords
-an illustration of this condition of the system. A woman had been for
-some time confined to her bed, labouring under severe indisposition.
-On a sudden she was deprived of the power of moving a single muscle of
-the body; she attempted to speak, but she had no power to articulate;
-she endeavoured to stretch out her hand, but her muscles refused to
-obey the commands of her will, yet her consciousness was perfect, and
-she retained the complete possession of her intellectual faculties.
-She perceived that her attendants thought her dead, and was conscious
-of the performance upon her own person of the services usually paid to
-the dead; she was laid out, her toes were bound together, her chin was
-tied up; she heard the arrangements for her funeral discussed, and yet
-she was unable to make the slightest sign that she was still in the
-possession of sense, feeling, and life.
-
-In one form of disease, then, the animal life, both the sensitive and
-the motive portions of it, may perish; and in another form of disease,
-either the one or the other part of it may be suspended, while the
-organic life continues in full operation: it follows that the two
-lives, blended as they are, are distinct, since the one is capable of
-perishing without immediately and inevitably involving the destruction
-of the other.
-
-7. And, finally, as the organic life is the first born, so it is the
-last to die; while the animal life, as it is the latest born, and
-the last to attain its full development, so it is the earliest to
-decline and the first to perish. In the process of natural death, the
-extinction of the animal is always anterior to that of the organic
-life. Real death is a later, and sometimes a much later event than
-apparent death. An animal appears to be dead when, together with the
-abolition of sensation and the loss of voluntary motion, respiration,
-circulation, and the rest of the organic functions can no longer be
-distinguished; but these functions go on some time after they have
-ceased to afford external indications of their action. In man, and the
-warmblooded animals in general, suspension or submersion extinguishes
-the animal life, at the latest, within the space of four minutes from
-the time that the atmospheric air is completely excluded from the
-lung; but did the organic functions also cease at the same period, it
-would be impossible to restore an animal to life after apparent death
-from drowning and the like. But however complete and protracted the
-abolition of the animal functions, re-animation is always possible as
-long as the organic organs are capable of being restored to their usual
-vigour. The cessation of the animal life is but the first stage of
-death, from which recovery is possible; death is complete only when the
-organic together with the animal functions have wholly ceased, and are
-incapable of being re-established.
-
-In man, the process of death is seldom altogether natural. It is
-generally rendered premature by the operation of circumstances which
-destroy life otherwise than by that progressive and slow decay which is
-the inevitable result of the action of organized structure. Death, when
-natural, is the last event of an extended series, of which the first
-that is appreciable is a change in the animal life and in the noblest
-portion of that life. The higher faculties fail in the reverse order of
-their development; the retrogression is the inverse of the progression,
-and the noblest creature, in returning to the state of non-existence,
-retraces step by step each successive stage by which it reached the
-summit of life.
-
-In the advancing series, the animal is superadded to the organic
-life; sensation, the lowest faculty of the animal life, precedes
-ratiocination, the highest. The senses called into play at the moment
-of birth soon acquire the utmost perfection of which they are capable;
-but the intellectual faculties, later developed, are still later
-perfected, and the highest the latest.
-
-In the descending series, the animal life fails before the organic, and
-its nobler powers decay sooner and more rapidly than the subordinate.
-First of all, the impressions which the organs of sense convey to
-the brain become less numerous and distinct, and consequently the
-material on which the mind operates is less abundant and perfect; but
-at the same time, the power of working vigorously with the material it
-possesses more than proportionally diminishes. Memory fails; analogous
-phenomena are less readily and less completely recalled by the presence
-of those which should suggest the entire train; the connecting links
-are dimly seen or wholly lost; the train itself is less vivid and less
-coherent; train succeeds train with preternatural slowness, and the
-consequence of these growing imperfections is that, at last, induction
-becomes unsound just as it was in early youth; and for the same
-reason, namely, because there is not in the mental view an adequate
-range of individual phenomena; the only difference being that the
-range comprehended in the view of the old man is too narrow, because
-that which he had learnt he has forgotten; while in the youth it is
-too narrow, because that which it is necessary to learn has not been
-acquired.
-
-And with the diminution of intellectual power the senses continue
-progressively to fail: the eye grows more dim, the ear more dull, the
-sense of smell less delicate, the sense of touch less acute, while
-the sense of taste immediately subservient to the organic function of
-nutrition is the last to diminish in intensity and correctness, and
-wholly fails but with the extinction of the life it serves.
-
-But the senses are not the only servants of the brain; the voluntary
-muscles are so equally; but these ministers to the master-power, no
-longer kept in active service, the former no longer employed to convey
-new, varied, and vivid impressions, the latter no longer employed
-to execute the commands of new, varied, and intense desires, become
-successively feebler, slower, and more uncertain in their action.
-The hand trembles, the step totters, and every movement is tardy and
-unsteady. And thus, by the loss of one intellectual faculty after
-another, by the obliteration of sense after sense, by the progressive
-failure of the power of voluntary motion; in a word, by the declining
-energy and the ultimate extinction of the animal life, man, from the
-state of maturity, passes a second time through the stage of childhood
-back to that of infancy; lapses even into the condition of the embryo:
-what the fœtus was, the man of extreme old age is: when he began to
-exist, he possessed only organic life; and before he is ripe for the
-tomb, he returns to the condition of the plant.
-
-And even this merely organic existence cannot be long maintained. Slow
-may be the waste of the organic organs; but they do waste, and that
-waste is not repaired, and consequently their functions languish, and
-no amount of stimulus is capable of invigorating their failing action.
-The arteries are rigid and cannot nourish; the veins are relaxed and
-cannot carry on the mass of blood that oppresses them; the lungs,
-partly choked up by the deposition of adventitious matter, and partly
-incapable of expanding and collapsing by reason of the feeble action
-of the respiratory apparatus, imperfectly aërate the small quantity
-of blood that flows through them; the heart, deprived of its wonted
-nutriment and stimulus, is unable to contract with the energy requisite
-to propel the vital current; the various organs, no longer supplied
-with the quantity and quality of material necessary for carrying on
-their respective processes, cease to act; the machinery stops, and this
-is death.
-
-And now the processes of life at an end, the body falls within the
-dominion of the powers which preside universally over matter; the tie
-that linked all its parts together, holding them in union and keeping
-them in action, in direct opposition to those powers dissolved, it
-feels and obeys the new attractions to which it has become subject;
-particle after particle that stood in beautiful order fall from their
-place; the wonderful structures they composed melt away; the very
-substances of which those structures were built up are resolved into
-their primitive elements; these elements, set at liberty, enter into
-new combinations, and become constituent parts of new beings; those new
-beings in their turn perish; from their death springs life, and so the
-changes go on in an everlasting circle.
-
-As far as relates to the organized structures in which life has its
-seat, and to the operations of life dependent on those structures,
-such is its history; a history not merely curious, but abounding with
-practical suggestions of the last importance. The usefulness of a
-familiar acquaintance with the phenomena which have now been elucidated
-will be apparent at every step as we proceed.
-
-
-
-
-CHAPTER III.
-
-  Ultimate object of organization and life—Sources of
-  pleasure—Special provision by which the organic organs
-  influence consciousness and afford pleasure—Point at which
-  the organic organs cease to affect consciousness, and
-  why—The animal appetites: the senses: the intellectual
-  faculties: the selfish and sympathetic affections: the
-  moral faculty—Pleasure the direct, the ordinary, and the
-  gratuitous result of the action of the organs—Pleasure
-  conducive to the development of the organs, and to
-  the continuance of their action—Progress of human
-  knowledge—Progress of human happiness.
-
-
-The object of structure is the production of function. Of the two
-functions combined in the living animal, one is wholly subservient
-to the other. To build up the apparatus of the animal life, and to
-maintain it in a condition fit for performing its functions, is the
-sole object of the existence of the organic life. What then is the
-object of the animal life? That object, whatever it be, must be the
-ultimate end of organization, and of all the actions of which it is the
-seat and the instrument.
-
-Two functions, sensation and voluntary motion, are combined in the
-animal life. Of these two functions, the latter is subservient to the
-former: voluntary motion is the servant of sensation, and exists only
-to obey its commands.
-
-Is sensation, then, the ultimate object of organization? Simple
-sensation cannot be an ultimate object, because it is invariably
-attended with an ultimate result; for sensation is either pleasurable
-or painful. Every sensation terminates in a pleasure or a pain.
-Pleasure or pain, the last event in the series, must then be the final
-end.
-
-Is the production of pain the ultimate object of organization? That
-cannot be, for the production of pain is the indirect, not the
-direct,—the extraordinary, not the ordinary, result of the actions
-of life. It follows that pleasure must be the ultimate object, for
-there is no other of which it is possible to conceive. The end of
-organic existence is animal existence; the end of animal existence
-is sentient existence; the end of sentient existence is pleasurable
-existence; the end of life therefore is enjoyment. Life commences with
-the organic processes; to the organic are superadded the animal; the
-animal processes terminate in sensation; sensation ends in enjoyment;
-it follows, that enjoyment is the final end. For this every organ is
-constructed; to this every action of every organ is subservient; in
-this every action ultimately terminates.
-
-And without a single exception in the entire range of the sentient
-creation, the higher the organized structure the greater the enjoyment,
-mediately or immediately, to which it is subservient. From its most
-simple to its most complex state, every successive addition to
-structure, by which function is rendered more elevated and perfect,
-proportionally increases the exquisiteness of the pleasure to which the
-function ministers, and in which it terminates.
-
-Pleasure is the result of the action of living organs, whether
-organic or animal; pleasure is the direct, the ordinary, and the
-gratuitous result of the action of both sets of organs; the pleasure
-resulting from the action of the organs is conducive to their complete
-development, and thereby to the increase of their capacity for
-affording enjoyment; the pleasure resulting from the action of the
-organs, and conducive to their development, is equally conducive to the
-perpetuation of their action, and consequently to the maintenance of
-life; it follows not only that enjoyment is the end of life, but that
-it is the means by which life is prolonged. Of the truth of each of
-these propositions, it will be interesting to contemplate the plenitude
-of the proof.
-
-1. In the first place, pleasure is the result of the action of the
-organic organs. It has indeed been shown that the very character by
-which the action of these organs is distinguished is that they are
-unattended with consciousness. Nevertheless, by a special provision,
-consciousness is indirectly connected with the processes of this
-class, limited in extent indeed, and uniformly terminating at a
-certain point; but the extent and the limitation alike conducing to
-the pleasurableness of its nature. And this is an adjustment in the
-constitution of our frame which is well deserving of attention.
-
-Organic processes are dependent on a peculiar influence derived from
-that portion of the nervous system distinguished by the term organic.
-The organic nerves, distributed to the organic organs, take their
-origin and have their chief seat in the cavities that contain the main
-instruments of the organic life, namely, the chest and abdomen (see
-chap. v.). As will be fully shown hereafter, these nerves encompass
-the great trunks of the blood-vessels that convey arterial blood
-to the organic organs. In all its ramifications through an organic
-organ, an arterial vessel is accompanied by its organic nerve; so that
-wherever the capillary arterial branch goes, secreting or nourishing,
-there goes, inseparably united with it, an organic nerve, exciting and
-governing.
-
-Among the peculiarities of this portion of the nervous system, one
-of the most remarkable is, that it is wholly destitute of feeling.
-Sensibility is inseparably associated with the idea commonly formed of
-a nerve. But the nervous system consists of two portions, one presiding
-over sensation and voluntary motion, hence called the sentient and
-the motive portions; the other destitute of sensation, but presiding
-over the organic processes, hence called the organic portion. If the
-communication between the organic organ and the organic nerve be
-interrupted, the function of the organ, whatever it be, is arrested.
-Without its organic nerves, the stomach cannot secrete gastric juice;
-the consequence is, that the aliment is undigested. Without its organic
-nerves, the liver cannot secrete bile, the consequence is, that the
-nutritive part of the aliment is incapable of being separated from its
-excrementitious portion. The organic organ receives from its organic
-nerve an influence, without which it cannot perform its function;
-but the nerve belonging to this class neither feels nor communicates
-feeling, and hence it imparts no consciousness of the operation of any
-process dependent upon it. Yet there is not one of these processes that
-does not exert a most important influence over consciousness. How? By a
-special provision, as curious in its nature as it is important in its
-result.
-
-Branches of sentient nerves are transmitted from the animal to the
-organic system, and from the organic to the animal; and an intimate
-communication is established between the two classes. The inspection
-of fig. XVI. will illustrate the mode in which this communication is
-effected. A B represents a portion of the spinal cord (one of the
-central masses of the sentient system), covered with its membranes. The
-part here represented is a front view of that portion of the spinal
-cord which belongs to the back, and which is technically called the
-dorsal portion.
-
-[Illustration: Fig. XVI.]
-
-1, 2, 3, 4, 5, 6, 7, 8, 9, the second, &c. ribs with the corresponding
-dorsal (sentient) nerves, _a_, _b_, _c_, _d_, _e_, _f_, _g_, _h_, going
-out to supply their respective organs with sensation.
-
-C D E, a portion of the main trunk of the organic (non-sentient) nerve,
-commonly called the Great Sympathetic.
-
-F G H, the membrane of the spinal cord cut open and exposing I K, the
-spinal cord itself, L, the anterior branch of one of the dorsal nerves,
-arising from the anterior surface of the spinal cord by several bundles
-of fibres.
-
-M, the posterior branch of the same nerve, arising in like manner from
-the posterior surface of the spinal cord by several branches of fibres.
-
-The anterior and posterior branches uniting to form one trunk N.
-
-Two branches, P Q, sent off from the spinal (sentient) trunk to unite
-with the organic (non-sentient) trunk.
-
-R S T U V W, other branches of the sentient, connected with the
-branches of the non-sentient nervous trunks in the same mode.
-
-X Y, the main trunk of the sympathetic (non-sentient) nerve cut across
-and turned aside, in order that the parts beneath it (P N) may be more
-distinctly seen.
-
-From this description, it is apparent that each sentient nerve,
-before it goes out to the animal organs, to which it is destined to
-communicate sensation, sends off two branches to the organic or the
-non-sentient. These sentient nerves mix and mingle with the insensible
-nerves; accompany them in their course to the organic organs, and
-ramify with them throughout their substance. It is manifest, then,
-that sentient nerves, that nerves not necessary to the organic
-processes, having, as far as is known, nothing whatever to do with
-those processes, enter as constituent parts into the composition of the
-organic organs. What is the result? That organic organs are rendered
-sentient; that organic processes, in their own nature insensible,
-become capable of affecting consciousness. What follows? What is the
-consciousness excited? Not a consciousness of the organic process.
-Of that we still remain wholly insensible. Not simple sensation. The
-result uniformly produced, as long as the state of the system is that
-of health, is pleasurable consciousness. The heart sends out to the
-organs its vital current. Each organ, abstracting from the stream the
-particles it needs, converts them into the peculiar fluid or solid
-it is its office to form. The stomach, from the arterial streamlets
-circulating through it, secretes gastric juice; the liver, from the
-venous streamlets circulating through it, secretes bile. When these
-digestive organs have duly prepared their respective fluids, they
-employ them in the elaboration of the aliment. We are not conscious
-of this elaboration, though it go on within us every moment; but is
-consciousness not affected by the process? Most materially. Why?
-Because sentient mingle with organic nerves; because the sentient
-nerves are impressed by the actions of the organic organs. And how
-impressed? As long as the actions of the organic organs are sound,
-that is, as long as their processes are duly performed, the impression
-communicated to the sentient nerves is in its nature agreeable; is,
-in fact, THE PLEASURABLE CONSCIOUSNESS WHICH CONSTITUTES THE FEELING
-OF HEALTH. The state of health is nothing but the result of the
-due performance of the organic organs: it follows that the feeling
-of health, the feeling which is ranked by every one among the most
-pleasurable of existence, is the result of the action of organs of
-whose direct operations we are unconscious. But the pleasurable
-consciousness thus indirectly excited is really the consequence of a
-special provision, established for the express purpose of producing
-pleasure. Processes, in their own nature insensible, are rendered
-sentient expressly for this purpose, that, over and above the special
-object they serve, they may afford enjoyment. In this case, the
-production of pleasure is not only altogether gratuitous, not only
-communicated for its own sake, not only rested in as an ultimate
-object, but it is made to commence at the very confines of life; it is
-interwoven with the thread of existence: it is secured in and by the
-actions that build up and that support the very framework, the material
-instrument of our being.
-
-But if the communication of sensibility to processes in their own
-nature incapable of exciting feeling, for the purpose of converting
-them into sources of pleasurable consciousness, indicate an express
-provision for the production of enjoyment, that provision is no less
-exemplified in the point at which this superadded sensibility is made
-to cease.
-
-Some of the consequences of a direct communication of consciousness
-to an organic process have been already adverted to. Had the eye,
-besides transmitting rays of light to the optic nerve, been rendered
-sensible of the successive passage of each ray through its substance,
-the impression excited by luminous bodies, which is indispensable to
-vision, the ultimate object of the instrument, if not wholly lost,
-must necessarily have become obscure, in direct proportion to the
-acuteness of this sensibility. The hand of the musician could scarcely
-have executed its varied and rapid movements upon his instrument, had
-his mind been occupied at one and the same instant with the process
-of muscular contraction in the finger, and the idea of music in the
-brain. Had the communication of such a twofold consciousness been
-possible, in no respect would it have been beneficial, in many it would
-have been highly pernicious; and the least of the evils resulting
-from it would have been, that the inferior would have interrupted the
-superior faculty, and the means deteriorated the end. But in some
-cases the evil would have been of a much more serious nature. Had we
-been rendered sensible of the flow of the vital current through the
-engine that propels it; were the distension of the delicate valves that
-direct the current ever present to our view; by some inward feeling
-were we reminded, minute by minute, of the progress of the aliment
-through the digestive apparatus, and were the mysterious operations
-of the organic nerves palpable to sight, the terror of the maniac,
-who conceived that his body was composed of unannealed glass, would
-be the ordinary feeling of life. Every movement would be a matter of
-anxious deliberation; and the approach of every body to our own would
-fill us with dismay. But adjusted as our consciousness actually is,
-invariably the point at which the organic process begins is that at
-which sensation ends. Had sensation been extended beyond this point, it
-would have been productive of pain: at this point it uniformly stops.
-Nevertheless, by the indirect connexion of sensation with the organic
-processes, a vast amount of pleasure might be created: a special
-apparatus is constructed for the express purpose of establishing the
-communication. There is thus the twofold proof, the positive and the
-negative, the evidence arising as well from what they do, as from
-what they abstain from doing, that the organic processes are, and are
-intended to be, sources of enjoyment.
-
-But the production of pleasure, commencing at this the lowest point
-of conscious existence, increases with the progressive advancement of
-organization and function.
-
-The appetite for food, and the voluntary actions dependent upon it,
-may be considered as the first advancement beyond a process purely
-organic. The function by which new matter is introduced into the
-system and converted into nutriment, is partly an animal and partly an
-organic operation. The animal part of it consists of the sensations of
-hunger and thirst, by which we are taught when the wants of the system
-require a fresh supply of aliment, together with the voluntary actions
-by which the aliment is introduced into the system. The organic part
-of the function consists of the changes which the aliment undergoes
-after its introduction into the system, by which it is converted into
-nutriment. Sensations always of a pleasurable nature arise indirectly
-in the manner already explained, from the due performance of the
-organic part of the function; but pleasure is also directly produced by
-the performance of the animal part of it. Wholesome food is grateful;
-the satisfaction of the appetite for food is pleasurable. Food is
-necessary to the support of life; but it is not indispensable to the
-maintenance of life that food should be agreeable. Appetite there
-must be, that food may be eaten; but the act of eating might have
-been secured without connecting it with pleasure. Pleasure, however,
-is connected with it, first directly, by the gratefulness of food,
-and secondly indirectly, by the due digestion of the food. And the
-annexation of pleasure in this twofold mode to the performance of the
-function of nutrition is another case of the gratuitous bestowment of
-pleasure; another instance in which pleasure is communicated for its
-own sake, and rested in as an ultimate object. Pleasures of this class
-are sometimes called low; they are comparatively low; but they are not
-the less pleasures, because they are exceeded in value by pleasures of
-a nobler nature. Man may regard them with comparative indifference,
-because he is endowed with faculties which afford him gratifications
-superior in kind and larger in amount; but it is no mark of wisdom to
-despise and neglect even these: for they are annexed to the exercise
-of a function which is the first to exalt us above a merely organic
-existence; they are the first pleasures of which, considered merely as
-sentient creatures, we are susceptible; they amount in the aggregate to
-an immense sum; and they mark the depth in our nature in which are laid
-the fountains of enjoyment.
-
-Organs of sense, intellectual faculties, social affections, moral
-powers, are superadded endowments of a successively higher order:
-at the same time, they are the instruments of enjoyment of a nature
-progressively more and more exquisite.
-
-An organ of sense is an instrument composed of a peculiar arrangement
-of organized matter, by which it is adapted to receive from specific
-agents definite impressions. Between the agent that produces and the
-organ that receives the impression, the adaptation is such, that the
-result of their mutual action is, in the first place, the production of
-sensation, and, in the second place, the production of pleasure. The
-pleasure is as much the result as the sensation. This is true of the
-eye in seeing, the ear in hearing, the hand in touching, the organ of
-smell in smelling, and the tongue in tasting. Pleasure is linked with
-the sense; but there might have been the sense without the pleasure.
-A slight difference in the construction of the organ, or in the
-intensity of the agent, would not merely have changed, it would even
-have reversed the result; would have rendered the habitual condition of
-the eye, the ear, the skin, not such as it now is in health, but such
-as it is in the state of inflammation. But the adjustment is such as
-habitually to secure that condition of the system in which every action
-that excites sensation produces pleasure as its ordinary concomitant;
-and the amount of enjoyment which is thus secured to every man, and
-which every man without exception actually experiences in the ordinary
-course of an ordinary life, it would be beyond his power to estimate
-were he always sensible of the boon; but the calculation is altogether
-impossible, when, as is generally the case, he merely enjoys without
-ever thinking of the provisions which enable him to do so.
-
-But if the pleasures that arise from the ordinary operations of sense
-form, in the aggregate, an incalculable sum, how great is the accession
-brought to this stock by the endowments next in order in the ascending
-scale, namely, the intellectual faculties!
-
-There is one effect resulting from the operation of the intellectual
-faculties on the senses that deserves particular attention. The higher
-faculties elevate the subordinate in such a manner as to make them
-altogether new endowments. In illustration of this, it will suffice
-to notice the change wrought, as if in the very nature of sensation,
-the moment it becomes combined with an intellectual operation, as
-exemplified in the difference between the intellectual conception of
-beauty, and the mere perception of sense. The grouping of the hills
-that bound that magnificent valley which I behold at this moment spread
-out before my view; the shadow of the trees at the base of some of
-them, stretching its deep and varied outline up the sides of others;
-the glancing light now brightening a hundred different hues of green
-on the broad meadows, and now dancing on the upland fallows; the
-ever-moving, ever-changing clouds; the scented air; the song of birds;
-the still more touching music which the breeze awakens in the scarcely
-trembling branches of those pine trees,—the elements of which this
-scene is composed, the mere objects of sense, the sun, the sky, the
-air, the hills, the woods, and the sounds poured out from them, impress
-the senses of the animals that graze in the midst of them; but on their
-senses they fall dull and without effect, exciting no perception of
-their loveliness, and giving no taste of the pleasures they are capable
-of affording. Nor even in the human being, whose intellectual faculties
-have been uncultivated, do they awaken either emotions or ideas; the
-clown sees them, hears them, feels them no more than the herds he
-tends: yet in him whose mind has been cultivated and unfolded, how
-numerous and varied the impressions, how manifold the combinations, how
-exquisite the pleasures produced by objects such as these!
-
-And from the more purely intellectual operations, from memory,
-comparison, analysis, combination, classification, induction, how
-still nobler the pleasure! Not to speak of the happiness of him who,
-by his study of natural phenomena, at length arrived at the stupendous
-discovery that the earth and all the stars of the firmament move, and
-that the feather falls to the ground, by the operation of one and the
-same physical law; nor of the happiness of him who sent his kite into
-the cloud, and brought down from its quiet bed the lightning which
-he suspected was slumbering there; nor of the happiness of him who
-concentrated, directed, and controlled that mighty power which has
-enabled the feeble hand of man to accomplish works greater than have
-been feigned of fabled giant; which has annihilated distance; created,
-by economizing time; changed in the short space in which it has been in
-operation the surface of the habitable globe; and is destined to work
-upon it more and greater changes than have been effected by all other
-causes combined; nor of the happiness of him who devoted a longer life
-with equal success to a nobler labour, that of REARING THE FABRIC OF
-FELICITY BY THE HAND OF REASON AND OF LAW. The intellectual pleasures
-of such men as Newton, Franklin, Watt, and Bentham, can be _equalled_
-only by those who possess equal intellectual power, and who put forth
-equal intellectual energy: to be greatly happy as they were, it were
-necessary to be as highly endowed; but to be happy, it is not necessary
-to be so endowed. In the ordinary intellectual operations of ordinary
-men, in their ordinary occupations, there is happiness. Every human
-being whose moments have passed with winged speed, whose day has been
-short, whose year is gone almost as soon as it seemed commenced, has
-derived from the exercise of his intellectual faculties pleasures
-countless in number and inestimable in value.
-
-But the sympathetic pleasures, out of which grow the social, are of
-a still higher order even than the intellectual. The pleasures that
-result from the action of the organic organs, from the exercise of the
-several senses, and from the operation of the intellectual faculties,
-like the sensations in which they arise, belong exclusively to the
-individual being that experiences them, and cannot be communicated
-to another. Similar sensations and pleasures may be felt by beings
-similarly constituted; but the actual sensations and pleasures afforded
-by the exercise of a person's own organs and faculties are no more
-capable of becoming another's than his existence. These, then, are
-strictly the selfish pleasures; and the provision that has been made
-for securing them has been shown.
-
-But there are pleasures of another class, pleasures having no relation
-whatever to a person's own sensation or happiness; pleasures springing
-from the perception of the enjoyment of others. The sight of pleasure
-not its own affects the human heart, provided its state of feeling be
-natural and sound, just as it would be affected were it its own. Not
-more real is the pleasure arising from the gratification of appetite,
-the exercise of sense, and the operation of intellect, than that
-arising from the consciousness that another sentient being is happy.
-Pleasures of this class are called sympathetic, in contradistinction to
-those of the former class, which are termed selfish.
-
-There are then two principles in continual operation in the human
-being, the selfish and the sympathetic. The selfish is productive of
-pleasure of a certain kind; the sympathetic is productive of pleasure
-of another kind. The selfish is primary and essential; the sympathetic,
-arising out of the selfish, is superadded to it. And so precisely
-what the animal life is to the organic, the sympathetic principle is
-to the selfish; and just what the organic life gains by its union
-with the animal, the mental constitution gains by the addition of
-the sympathetic to the selfish affection. The analogy between the
-combination in both cases is in every respect complete. As the organic
-life produces and sustains the animal, so the sympathetic principle
-is produced and sustained by the selfish. As the organic life is
-conservative of the entire organization of the body, so the selfish
-principle is conservative of the entire being. As the animal life is
-superadded to the organic, extending, exalting, and perfecting it,
-so the sympathetic principle is superadded to the selfish, equally
-extending, exalting, and perfecting it. The animal life is nobler than
-the organic, whence the organic is subservient to the animal; but there
-is not only no opposition, hostility, or antagonism between them, but
-the strictest possible connexion, dependence, and subservience. The
-sympathetic principle is nobler than the selfish, whence the selfish is
-subservient to the sympathetic; but there is not only no opposition,
-hostility, or antagonism between them, but the strictest possible
-connexion, dependence, and subservience. Whatever is conducive to the
-perfection of the organic, is equally conducive to the perfection of
-the animal life; and whatever is conducive to the attainment of the
-true end of the selfish is equally conducive to the attainment of the
-true end of the sympathetic principle. The perfection of the animal
-life cannot be promoted at the expense of the organic, nor that of the
-organic at the expense of the animal; neither can the ultimate end of
-the selfish principle be secured by the sacrifice of the sympathetic,
-nor that of the sympathetic by the sacrifice of the selfish. Any
-attempt to exalt the animal life beyond what is compatible with the
-healthy state of the organic, instead of accomplishing that end, only
-produces bodily disease. Any attempt to extend the selfish principle
-beyond what is compatible with the perfection of the sympathetic,
-or the sympathetic beyond what is compatible with the perfection of
-the selfish, instead of accomplishing the end in view, only produces
-mental disease. Opposing and jarring actions, antagonizing and mutually
-destructive powers, are combined in no other work of nature; and it
-would be wonderful indeed were the only instance of it found in man,
-the noblest of her works, and in the mind of man, the noblest part of
-her noblest work.
-
-No one supposes that there is any such inharmonious combination in
-the organization of his physical frame, and the notion that it exists
-in his mental constitution, as it is founded in the grossest ignorance,
-so it is productive of incalculable mischief. In both, indeed, are
-manifest two great powers, each distinct; each having its own peculiar
-operation; and the one being subservient to the other, but both
-conducing alike to one common end. By the addition of the apparatus of
-the animal to that of the organic life, a nobler structure is built
-up than could have been framed by the organic alone: by the addition
-of the sympathetic to the selfish part of the mental constitution, a
-happier being is formed than could have been produced by the selfish
-alone. And as the organic might have existed without the animal life,
-but by the addition of the animal a new and superior being is formed,
-so might the selfish part of the mental constitution, and the pleasures
-that flow from it, have existed alone; but by the addition of the
-sympathetic, a sum is added to enjoyment, of the amount of which some
-conception may be formed by considering what human life would be, with
-every selfish appetite and faculty gratified in the fullest conceivable
-degree, but without any admixture whatever of sympathetic or social
-pleasure. Selfish enjoyment is not common. If any one set himself to
-examine what at first view might seem a purely selfish pleasure, he
-will soon be sensible that, of the elements composing any given state
-of mind to which he would be willing to affix the term pleasurable,
-a vast preponderance consists of sympathetic associations. The more
-accurately he examine, and the farther he carry his analysis, the
-stronger will become his conviction, that a purely selfish enjoyment,
-that is, a truly pleasurable state of mind, in no degree, mediately or
-immediately, connected with the pleasurable state of another mind, is
-exceedingly rare.
-
-But if the constitution of human nature and the structure of human
-society alike render it difficult for the human heart to be affected
-with a pleasure in no degree derived from—absolutely and totally
-unconnected with sympathetic association, of that complex pleasure
-which arises out of social intercourse, partly selfish and partly
-sympathetic, how far sweeter the sympathetic than the selfish
-part; and as the sympathetic preponderates over the selfish, how
-vast the increase of the pleasure! And when matured, exalted into
-affection—affection, that holy emotion which exerts a transforming
-influence over the selfish part of human nature, turning it into the
-sympathetic; affection, which renders the happiness of the beloved
-object inexpressibly dearer to the heart than its own; affection,
-among the benignant feelings of which as there is none sweeter so
-there is none stronger than that of self-devotion, nay, sometimes even
-of self-sacrifice; affection, which is sympathy pure, concentrated,
-intense—Oh how beautiful is the constitution of this part of our
-nature, by which the most transporting pleasures the heart receives are
-the direct reflection of those it gives!
-
-Nor ought it to be overlooked, that, while nearly all the selfish,
-like all the sensual pleasures, cannot be increased beyond a fixed
-limit, cannot be protracted beyond a given time, are short-lived in
-proportion as they are intense, and satiate the appetite they gratify,
-the sympathetic pleasures are capable of indefinite augmentation; are
-absolutely inexhaustible; no limit can be set to their number, and no
-bound to their growth; they excite the appetite they gratify; they
-multiply with and by participation, and the more is taken from the
-fountain from which they flow, the deeper, the broader, and the fuller
-the fountain itself becomes.
-
-But not only is the mental state of affection in all its forms and
-degrees highly pleasurable, but the very consciousness of being the
-object of affection is another pleasure perfectly distinct from that
-arising immediately from the affection itself. It has been said of
-charity, that it is twice blessed, that it blesses alike him that
-gives and him that receives; but love has in it a threefold blessing:
-first, in the mental state itself; secondly, in the like mental state
-which the manifestation of it produces in another; and thirdly, in the
-mental state inseparable from the consciousness of being the object of
-affection. And this reflex happiness, this happiness arising from the
-consciousness of being the object, is even sweeter than any connected
-with being the subject of affection.
-
-In like manner there is pleasure in the performance of beneficent
-actions; in energetic, constant, and therefore ultimately successful
-exertions to advance the great interests of human kind, in art, in
-science, in philosophy, in education, in morals, in legislation,
-in government; whether those exertions are put forth in the study,
-the school, the senate, or any less observed though perhaps not
-less arduous nor less important field of labour. Exertions of this
-kind beget in those for whom, towards those by whom, they are made,
-benignant feelings—respect, veneration, gratitude, love. With
-such feelings the philosopher, the instructor, the legislator, the
-statesman, the philanthropist, knows that he is, or that, sooner or
-later, he will be regarded by his fellow men; and in this consciousness
-there is happiness: but this is another source of happiness perfectly
-distinct from that arising from the performance of beneficent actions;
-it is a new happiness superadded to the former, and, if possible,
-still more exquisite. Thus manifold is the beneficent operation of the
-sympathetic affection: thus admirable is the provision made in the
-constitution of our nature for the excitement and extension of this
-affection, and, through its instrumentality, for the multiplication and
-exaltation of enjoyment!
-
-In affections and actions of the class just referred to, and in the
-pleasures that result from them, there is much of the nature which is
-commonly termed moral. And the power to which the moral affections and
-actions are referred is usually and justly considered as the supreme
-faculty of the mind; for it is the regulator and guide of all the
-others; it is that by which they attain their proper and ultimate
-object. Of whatever pleasure human nature is capable in sensation, in
-idea, in appetite, in passion, in emotion, in affection, in action;
-whatever is productive of real pleasure, in contradistinction to what
-only cheats with the false hope of pleasure; whatever is productive
-of pure pleasure, in contradistinction to what is productive partly
-of pleasure and partly of pain, and consequently productive not of
-pure, but of mixed pleasure; whatever is productive of a great degree
-of pleasure in contradistinction to what is productive of a small
-degree of pleasure; whatever is productive of lasting pleasure, in
-contradistinction to what is productive of temporary pleasure; whatever
-is productive of ultimate pleasure, in contradistinction to what is
-productive of immediate pleasure, but ultimate pain; this greatest and
-most perfect pleasure it is the part of the moral faculty to discover.
-In the degree in which the operation of this faculty is correct and
-complete, it enables the human being to derive from every faculty of
-his nature the greatest, the purest, the most enduring pleasure; that
-is, the maximum of felicity. This is the proper scope and aim of the
-moral faculty; to this its right exercise is uniformly conducive; and
-this, as it is better cultivated and directed, it will accomplish in
-a higher degree, in a continual progression, to which no limit can
-be assigned. But if the operation of this faculty be to render every
-other in the highest degree conducive to happiness, conformity to
-the course of conduct required by it, must of course be that highest
-happiness. Conformity to the course of conduct pointed out by the
-moral faculty as conducive in the highest degree to happiness is moral
-excellence, or, in the definite and exact sense of the word, virtue.
-And in this sense it is that virtue is happiness. It is because it
-discriminates the true sources of happiness, that is, directs every
-other faculty into its proper course, and guides it in that course to
-the attainment of its ultimate object, that the moral faculty is ranked
-as the highest faculty of the mind. Supposing the operation of this
-faculty to be perfect, it is but an identical expression to say, that
-to follow its guidance implicitly is to follow the road that leads to
-the most perfect happiness. But, over and above the happiness thus
-directly and necessarily resulting from yielding uniform and implicit
-obedience to the moral faculty, there is, in the very consciousness of
-such conformity, a new happiness, as pure as it is exalted. Thus, in
-a twofold manner, is the moral the highest faculty of the mind, the
-source of its highest happiness; and thus manifest it is, from every
-view that can be taken of the constitution of human nature, that every
-faculty with which it is endowed, from the highest to the lowest, not
-only affords its own proper and peculiar pleasure, but that each, as
-it successively rises in the scale, is proportionately the source of a
-nobler kind, and a larger amount of enjoyment.
-
-And the pleasure afforded by the various faculties with which the human
-being is endowed is the immediate and direct result of their exercise.
-With the exception of the organic organs, and the reason for the
-exception in regard to them has been assigned, the action of the organs
-is directly pleasurable. From the exercise of the organs of sense, from
-the operation of the intellectual faculties, from appetite, passion,
-and affection, pleasure flows as directly as the object for which the
-instrument is expressly framed.
-
-And pleasure is the ordinary result of the action of the organs; pain
-is sometimes the result, but it is the extraordinary not the ordinary
-result. Whatever may be the degree of pain occasionally produced, or
-however protracted its duration, yet it is never the natural, that
-is, the usual or permanent state, either of a single organ, or of an
-apparatus, or of the system. The usual, the permanent, the natural
-condition of each organ, and of the entire system, is pleasurable.
-Abstracting, therefore, from the aggregate amount of pleasure, the
-aggregate amount of pain, the balance in favour of pleasure is immense.
-This is true of the ordinary experience of ordinary men, even taking
-their physical and mental states such as they are at present; but the
-ordinary physical and mental states, considered as sources of pleasure
-of every human being, might be prodigiously improved; and some attempt
-will be made, in a subsequent part of this work, to show in what manner
-and to what extent.
-
-It has been already stated that there are cases in which pleasure is
-manifestly given for its own sake; in which it is rested in as an
-ultimate object: but the converse is never found: in no case is the
-excitement of pain gratuitous. Among all the examples of secretion,
-there is no instance of a fluid, the object of which is to irritate
-and inflame: among all the actions of the economy, there is none, the
-object of which is the production of pain.
-
-Moreover, all such action of the organs, as is productive of pleasure,
-is conducive to their complete development, and consequently to the
-increase of their capacity for producing pleasure; while all such
-action of the organs as is productive of pain is preventive of their
-complete development, and consequently diminishes their capacity
-for producing pain. The natural tendency of pleasure is to its own
-augmentation and perpetuity. Pain, on the contrary, is self-destructive.
-
-Special provision is made in the economy, for preventing pain
-from passing beyond a certain limit, and from enduring beyond a
-certain time. Pain, when it reaches a certain intensity, deadens the
-sensibility of the sentient nerve; and when it lasts beyond a certain
-time, it excites new actions in the organ affected, by which the organ
-is either restored to a sound state, or so changed in structure that
-its function is wholly abolished. But change of structure and abolition
-of function, if extensive and permanent, are incompatible with the
-continuance of life. If, then, the actions of the economy, excited by
-pain, fail to put an end to suffering by restoring the diseased organ
-to a healthy state, they succeed in putting an end to it by terminating
-life. Pain, therefore, cannot be so severe and lasting as materially to
-preponderate over pleasure, without soon proving destructive to life.
-
-But the very reverse is the case with pleasure. All such action of the
-organs as is productive of pleasure is conducive to the perpetuation
-of life. There is a close connexion between happiness and longevity.
-Enjoyment is not only the end of life, but it is the only condition
-of life which is compatible with a protracted term of existence. The
-happier a human being is, the longer he lives; the more he suffers,
-the sooner he dies; to add to enjoyment, is to lengthen life; to
-inflict pain, is to shorten the duration of existence. As there is a
-point of wretchedness beyond which life is not desirable, so there is
-a point beyond which it is not maintainable. The man who has reached
-an advanced age cannot have been, upon the whole, an unhappy being;
-for the infirmity and suffering which embitter life cut it short.
-Every document by which the rate of mortality among large numbers of
-human beings can be correctly ascertained contains in it irresistible
-evidence of this truth. In every country, the average duration of life,
-whether for the whole people or for particular classes, is invariably
-in the direct ratio of their means of felicity; while, on the other
-hand, the number of years which large portions of the population
-survive beyond the adult age may be taken as a certain test of the
-happiness of the community. How clear must have been the perception of
-this in the mind of the Jewish legislator when he made the promise,
-THAT THY DAYS MAY BE LONG IN THE LAND WHICH THE LORD THY GOD HATH GIVEN
-THEE—the sanction of every religious observance, and the motive to
-every moral duty!
-
-Deeply then are laid the fountains of happiness in the constitution
-of human nature. They spring from the depths of man's physical
-organization; and from the wider range of his mental constitution
-they flow in streams magnificent and glorious. It is conceivable that
-from the first to the last moment of his existence, every human being
-might drink of them to the full extent of his capacity. Why does he
-not? The answer will be found in that to the following question. What
-must happen before this be possible? The attainment of clear and just
-conceptions on subjects, in relation to which the knowledge hitherto
-acquired by the most enlightened men is imperfect. Physical nature,
-every department of it, at least, which is capable of influencing
-human existence and human sensation; human nature, both the physical
-and the mental part of it; institutions so adapted to that nature
-as to be capable of securing to every individual, and to the whole
-community, the maximum of happiness with the minimum of suffering—this
-must be known. But knowledge of this kind is of slow growth. To
-expect the possession of it on the part of any man in such a stage of
-civilization as the present, is to suppose a phenomenon to which there
-is nothing analogous in the history of the human mind. The human mind
-is equally incapable of making a violent discovery in any department of
-knowledge, and of taking a violent bound in any path of improvement.
-What we call discoveries and improvements are clear, decided, but
-for the most part gentle, steps in advancement of the actual and
-immediately-preceding state of knowledge. The human mind unravels the
-great chain of knowledge, link by link; when it is no longer able to
-trace the connecting link, it is at a stand; the discoverer, in common
-with his contemporaries, seeing the last ascertained link, and from
-that led on by analogies which are not perceived by, or which do not
-impress, others, at length descries the next in succession; this brings
-into view new analogies, and so prepares the way for the discernment
-of another link; this again elicits other analogies which lead to the
-detection of other links, and so the chain is lengthened. And no link,
-once made out, is lost.
-
-Chemists tell us that the adjustment of the component elements of
-water is such, that although they readily admit of separation and are
-subservient to their most important uses in the economy of nature
-by this very facility of decomposition, yet that their tendency to
-recombination is equal, so that the quantity of water actually existing
-at this present moment in the globe is just the same as on the first
-day of the creation, neither the operations of nature, nor the purposes
-to which it has been applied by man, having used up, in the sense of
-destroying, a single particle of it. Alike indestructible are the
-separate truths that make up the great mass of human knowledge. In
-their ready divisibility and their manifold applications, some of
-them may sometimes seem to be lost; but if they disappear, it is only
-to enter into new combinations, many of which themselves become new
-truths, and so ultimately extend the boundaries of knowledge. Whatever
-may have been the case in time past, when the loss of an important
-truth, satisfactorily and practically established, may be supposed
-possible, such an event is inconceivable now when the art of printing
-at once multiplies a thousand records of it, and, with astonishing
-rapidity, makes it part and parcel of hundreds of thousands of minds.
-A thought more full of encouragement to those who labour for the
-improvement of their fellow beings there cannot be. No onward step is
-lost; no onward step is final; every such step facilitates and secures
-another. The savage state, that state in which gross selfishness seeks
-its object simply and directly by violence, is past. The semi-savage or
-barbarous state, in which the grossness of the selfishness is somewhat
-abated, and the violence by which it seeks its object in some degree
-mitigated, by the higher faculties and the gentler affections of our
-nature, but in which war still predominates, is also past. To this has
-succeeded the state in which we are at present, the so-called civilized
-state—a state in which the selfish principle still predominates, in
-which the justifiableness of seeking the accomplishment of selfish
-purposes by means of violence, that of war among the rest, is still
-recognized, but in which violence is not the ordinary instrument
-employed by selfishness, its ends being commonly accomplished by the
-more silent, steady, and permanent operation of institutions. This
-state, like the preceding, will pass away. How soon, in what precise
-mode, by what immediate agency, none can tell. But we are already
-in possession of the principle which will destroy the present and
-introduce a better social condition, namely, the principle at the basis
-of the social union, THE MAXIMUM OF THE AGGREGATE OF HAPPINESS; THE
-MAXIMUM OF THE AGGREGATE OF HAPPINESS SOUGHT BY THE PROMOTION OF THE
-MAXIMUM OF INDIVIDUAL HAPPINESS!
-
-
-
-
-CHAPTER IV.
-
-  Relation between the physical condition and happiness, and
-  between happiness and longevity—Longevity a good, and
-  why—Epochs of life—The age of maturity the only one that
-  admits of extension—Proof of this from physiology—Proof
-  from statistics—Explanation of terms—Life a fluctuating
-  quantity—Amount of it possessed in ancient Rome: in modern
-  Europe: at present in England among the mass of the people
-  and among the higher classes.
-
-
-Life depends on the action of the organic organs. The action of the
-organic organs depends on certain physical agents. As each organic
-organ is duly supplied with the physical agent by which it carries on
-its respective process, and as it duly appropriates what it receives,
-the perfection of the physical condition is attained; and, according to
-the perfection or imperfection of the physical condition, supposing no
-accident interrupt its regular course, is the length or the brevity of
-life.
-
-It is conceivable that the physical condition might be brought to a
-high degree of perfection, the mind remaining in a state but little
-fitted for enjoyment; because it is necessary to enjoyment that there
-be a certain development, occupation, and direction of the mental
-powers and affections: and the mental state may be neglected, while
-attention is paid to the physical processes. But the converse is not
-possible. The mental energies cannot be fully called forth while the
-physical condition is neglected. Happiness presupposes a certain degree
-of excellence in the physical condition; and unless the physical
-condition be brought to a high degree of excellence, there can be no
-such development, occupation, and direction of the mental powers and
-affections as is requisite to a high degree of enjoyment.
-
-That state of the system in which the physical condition is sound is
-in itself conducive to enjoyment; while a permanent state of enjoyment
-is in its turn conducive to the soundness of the physical condition.
-It is impossible to maintain the physical processes in a natural and
-vigorous condition if the mind be in a state of suffering. The bills
-of mortality contain no column exhibiting the number of persons who
-perish annually from bodily disease, produced by mental suffering;
-but every one must occasionally have seen appalling examples of the
-fact. Every one must have observed the altered appearance of persons
-who have sustained calamity. A misfortune, that struck to the heart,
-happened to a person a year ago; observe him some time afterwards; he
-is wasted, worn, the miserable shadow of himself; inquire about him at
-the distance of a few months, he is no more.
-
-It is stated by M. Villermé, that the ordinary rate of mortality in
-the prisons of France, taking all together, is one in twenty-three—a
-rate which corresponds to the age of sixty-five in the common course
-of life. But in the vast majority of cases the unfortunate victims
-of the law are no older than from twenty-five to forty-five years of
-age. Taking them at the mean age of thirty-five, it follows that the
-suffering from imprisonment, and from the causes that lead to it, is
-equivalent to thirty years wear and tear of life. But this is not all;
-for it is found that, during imprisonment, the ordinary chances of
-death are exactly quadrupled.
-
-In regard to the whole population of a country, indigence may be
-assumed to be a fair measure of unhappiness, and wealth of happiness.
-If the rate of mortality in the indigent class be compared with that
-of the wealthy, according to M. Villermé, it will be found in some
-cases to be just double. Thus it is affirmed that, in some cases in
-France, taking equal numbers, where there are one hundred deaths in a
-poor arrondissement, there are only fifty in a rich; and that taking
-together the whole of the French population, human life is protracted
-twelve years and a half among the wealthy beyond its duration among
-the poor: consequently, in the one class, a child, newly born, has a
-probability of living forty-two and a half years; in the other only
-thirty years.
-
-In the great life-insurance establishments in England, a vast
-proportion of the persons who insure their lives are persons compelled
-to do so by their creditors; while three-fourths of those who
-voluntarily insure their lives are professional men, living in great
-towns, and experiencing the anxieties and fatigues, the hopes and
-disappointments of professional life. In one of these establishments in
-London, out of 330 deaths that happened in twenty-six years preceding
-the year 1831, it was found that eleven died by suicide, being one
-in thirty, implying the existence of an appalling amount of mental
-suffering. The number of persons belonging to an insurance office who
-perish by suicide is sure to be accurately known, death by suicide
-rendering the policy void. It would be most erroneous to suppose that
-these persons put an end to their existence under the mere influence of
-the mental states of disappointment and despondency. The mind reacted
-upon the body: produced physical disease, probably inflammation of the
-brain, and under the excitement of this physical disease, the acts of
-suicide were committed. More than one case has come to my knowledge
-in which inflammation of the brain having been excited by mental
-suffering, suicide was committed by cutting the throat. During the flow
-of blood, which was gradual, the brain was relieved; the mind became
-perfectly rational; and the patient might have been saved had a surgeon
-been upon the spot, or had the persons about the patient known where
-and how to apply the pressure of the finger to staunch the flow of
-blood, until surgical aid could be procured.
-
-By a certain amount and intensity of misery life may be suddenly
-destroyed; by a smaller amount and intensity, it may be slowly worn out
-and exhausted. The state of the mind affects the physical condition;
-but the continuance of life is wholly dependent on the physical
-condition: it follows that in the degree in which the state of the
-mind is capable of affecting the physical condition, it is capable of
-influencing the duration of life.
-
-Were the physical condition always perfect, and the mental state always
-that of enjoyment, the duration of life would always be extended to
-the utmost limit compatible with that of the organization of the
-body. But as this fortunate concurrence seldom or never happens,
-human life seldom or never numbers the full measure of its days.
-Uniform experience shows, however, that, provided no accident occur to
-interrupt the usual course, in proportion as body and mind approximate
-to this state, life is long; and as they recede from it, it is short.
-Improvement of the physical condition affords a foundation for the
-improvement of the mental state; improvement of the mental state
-improves up to a certain point the physical condition; and in the ratio
-in which this twofold improvement is effected, the duration of life
-increases.
-
-Longevity then is a good, in the first place, because it is a sign
-and a consequence of the possession of a certain amount of enjoyment;
-and in the second place, because this being the case, of course in
-proportion as the term of life is extended, the sum of enjoyment must
-be augmented. And this view of longevity assigns the cause, and shows
-the reasonableness of that desire for long life which is so universal
-and constant as to be commonly considered instinctive. Longevity and
-happiness, if not invariably, are generally, co-incident.
-
-If there may be happiness without longevity, the converse is not
-possible: there cannot be longevity without happiness. Unless the state
-of the body be that of tolerable health, and the state of the mind
-that of tolerable enjoyment, long life is unattainable: these physical
-and mental conditions no longer existing, nor capable of existing, the
-desire of life and the power of retaining it cease together.
-
-An advanced term of life and decrepitude are commonly conceived to
-be synonymous: the extension of life is vulgarly supposed to be the
-protraction of the period of infirmity and suffering, that period which
-is characterized by a progressive diminution of the power of sensation,
-and a consequent and proportionate loss of the power of enjoyment, the
-"sans teeth, sans eyes, sans taste, sans every thing." But this is so
-far from being true, that it is not within the compass of human power
-to protract in any sensible degree the period of old age properly so
-called, that is, the stage of decrepitude. In this stage of existence,
-the physical changes that successively take place clog, day by day, the
-vital machinery, until it can no longer play. In a space of time, fixed
-within narrow limits, the flame of life must then inevitably expire,
-for the processes that feed it fail. But though, when fully come, the
-term of old age cannot be extended, the coming of the term may be
-postponed. To the preceding stage, an indefinite number of years may be
-added. And this is a fact of the deepest interest to human nature.
-
-The division of human life into periods or epochs is not an arbitrary
-distinction, but is founded on constitutional differences in the
-system, dependent on different physiological conditions. The periods
-of infancy, childhood, boyhood, adolescence, manhood, and old age, are
-distinguished from each other by external characters, which are but
-the outward signs of internal states. In physiological condition, the
-infant differs from the child, the child from the boy, the boy from the
-man, and the adult from the old man, as much in physical strength as in
-mental power. There is an appointed order in which these several states
-succeed each other; there is a fixed time at which one passes into
-another. That order cannot be inverted: no considerable anticipation
-or postponement of that fixed time can be effected. In all places and
-under all circumstances, at a given time, though not precisely at the
-same time in all climates and under all modes of life, infancy passes
-into childhood, childhood into boyhood, boyhood into adolescence, and
-adolescence into manhood. In the space of two years from its birth,
-every infant has ceased to be an infant, and has become a child; in the
-space of six years from this period, every male child will have become
-a boy; add eight years to this time, and every boy will have become a
-young man; in eight years more, every young man will have become an
-adult man; and in the subsequent ten years, every adult man will have
-acquired his highest state of physical perfection. But at what period
-will this state of physical perfection decline? What is the maximum
-time during which it can retain its full vigour? Is that maximum fixed?
-Is there a certain number of years in which, by an inevitable law,
-every adult man necessarily becomes an old man? Is precisely the same
-number of years appointed for this transition to every human being?
-Can no care add to that number? Can no imprudence take from it? Does
-the physiological condition or the constitutional age of any two
-individuals ever advance to precisely the same point in precisely the
-same number of years? Physically and mentally, are not some persons
-older at fifty than others are at seventy? And do not instances
-occasionally occur in which an old man, who reaches even his hundredth
-year, retains as great a degree of juvenility as the majority of those
-who attain to eighty?
-
-If this be so, what follows? One of the most interesting consequences
-that can be presented to the human mind. The duration of the periods of
-infancy, childhood, boyhood, and adolescence, is fixed by a determinate
-number of years. Nothing can stay, nothing retard, the succession of
-each. Alike incapable of any material protraction is the period of old
-age. It follows that every year by which the term of human existence is
-extended is really added to the period of mature age; the period when
-the organs of the body have attained their full growth and put forth
-their full strength; when the physical organization has acquired its
-utmost perfection; when the senses, the feelings, the emotions, the
-passions, the affections, are in the highest degree acute, intense,
-and varied; when the intellectual faculties, completely unfolded
-and developed, carry on their operations with the greatest vigour,
-soundness, and continuity; in a word, when the individual is capable of
-receiving and of communicating the largest amount of the highest kind
-of enjoyment.
-
-A consideration more full of encouragement, more animating, there
-cannot be. The extension of human life, in whatever mode and degree it
-may be possible to extend it, is the protraction of that portion of it,
-and only of that portion of it, in which the human being is capable of
-RECEIVING AND OF COMMUNICATING THE LARGEST MEASURE OF THE NOBLEST KIND
-OF ENJOYMENT.
-
-Considerations, purely physiological, establish this indubitably; but
-it is curious that a class of facts, totally different from those of a
-physiological nature, equally prove it; namely, the results obtained
-from the observation of the actual numbers that die at different ages,
-and the knowledge consequently acquired of the progressive decrement
-of life. Mortality is subject to a law, the operation of which is as
-regular as that of gravitation. The labours of my valued friend Mr.
-Finlaison, the actuary of the National Debt, have not only determined
-what that law is in relation to different nations at different periods
-of their history, but this celebrated calculator has also invented a
-striking mode of expressing and representing the fact. He constructed
-a chart on which 100 perpendicular lines, answering to the respective
-ages of human life, are laid down and numbered in succession. These
-are crossed at right angles by 500 horizontal lines; so that, in the
-manner of musical notation, a point may be laid down either on the
-horizontal line, or on the space between any two of them: and thus,
-1000 points may be laid down on each of the perpendicular lines. The
-horizontal lines are in like manner numbered from 1 to 1000, ascending
-from the base. Taking any observation which shows the number of living
-persons that commence, and in like manner the number that die in each
-particular year of human life, the calculator reduced by the rule of
-three every such actual number of living persons for every separate
-year to 10,000: he next showed the corresponding proportion of deaths
-out of such 10,000. These proportions he represented on the chart by
-a point inserted on the horizontal line or space for the number of
-deaths, and on the perpendicular line for the particular age. He then
-connected all the points so laid down, and the result is a curve,
-representing the track of death through an equal number of human beings
-existing at each age of life. As the curve rises on the perpendicular
-line, at any given age, it indicates by so much an increase of the
-mortality at that age; and as the curve falls, the reverse is denoted.
-
-Now, it is a highly interesting fact, that the curves on this chart
-drawn upon it before the physiological phenomena were known to the
-operator, placed there because such he found to be the actual path
-along which death marshals his course, exactly correspond to the epochs
-which physiology teaches to be determinate stages of human existence.
-The infant, the child, the boy, the adolescent, the man, the old man,
-are not exposed to the same danger. The liability of each to death
-is not merely different; it is widely different; the liability of
-each class is uniformly the same, the circumstances influencing life
-remaining the same; and under no known change of circumstances does
-the relative liability of the class vary; under no change does the
-liability of the adolescent become that of the infant, or the liability
-of the adult that of the aged. Take from any statistical document any
-number of persons; observe out of this number the proportion that
-dies at the different stages just enumerated; and the period of human
-life which admits of extension will be strikingly manifest. Take with
-this view the Prussian statistical tables, the general correctness of
-which is admitted. From these tables it appears, and the correctness
-of the result is confirmed by a multitude of other tables, that out
-of a million living male births, there will die in the first year of
-life 180,492 infants, and out of the like number of living female
-births, there will die 154,705 infants. Let us follow up the decrement
-of life through the different epochs of human existence, confining
-our observations to the male sex, in which the development is more
-emphatically marked.
-
-In Mr. Finlaison's report, printed by the House of Commons on the 30th
-of March, 1829, there are six original observations on the mortality of
-as many separate sets of annuitants of the male sex.
-
-From an examination and comparison of these observations, it
-appears—1st. That the rate of mortality falls to a minimum at
-the close of the period of childhood. 2d. That from this point
-the mortality rises until the termination of adolescence or the
-commencement of adult age. 3d. That from the commencement of adult age
-the mortality again declines, and continues to decline to the period of
-perfect maturity. And 4th. That from the period of perfect maturity,
-the mortality rises, and uniformly, without a single exception,
-returns, at the age of forty-eight, to the point at which it stood at
-the termination of adolescence. These results clearly indicate that
-certain fixed periods are marked by nature as epochs of human life;
-and that at the date of the recorded facts which furnish the data
-for these observations, and as far as regards the class of persons
-to which they relate, the age of forty-eight was the exact point at
-which the meridian of life was just passed, and a new epoch began. The
-following table exhibits at one view the exact results of each of the
-observations. For example,
-
-  According to The mortality   From whence  From this  And from this
-      the          is at a       it rises   point it    age it again
-  observation,  minimum at the   until      declines   rises, but is not
-      No.           age of     the age of    to the     equal to the
-                                             age of      mortality in
-                                                       the 2d column
-                                                       until the age of
-
-       15   —     13      —     23    —     34   —     48
-
-       16   —     13      —     23    —     35   —     48
-
-       17   —     14      —     22    —     33   —     48
-
-       18   —     13      —     23    —     33   —     48
-
-       19   —     13      —     24    —     34   —     48
-
-       20   —     13      —     24    —     34   —     48
-
-The observation, No. 15, is founded on the large mass of 9,347 lives
-and 4,870 deaths. From this observation, it appears that, at the age of
-thirteen, the mortality out of a million is 5,742, being 174,750 less
-than in the first year of infancy At the age of twenty-three, it is
-15,074, being 9,332 more than at the close of childhood. At the age of
-thirty-four, the period of complete manhood, it falls to 11,707, being
-3,367 less than at the close of adolescence. At the age of forty-eight,
-the mortality returns to 14,870, all but identically the same as at
-twenty-three, the adult age. From the age of forty-eight, when, as
-has been stated, life just begins to decline from its meridian, the
-mortality advances slowly, but in a steady and regular progression.
-Thus, at the age of fifty-eight it is 29,185, being 14,315 more than
-at the preceding decade, or almost exactly double. At the age of
-sixty-eight, it is 61,741, being 32,556 more than at the preceding
-decade, or more than double. At the age of seventy-eight, it is
-114,255, being 52,514 more than at the preceding decade. At the age of
-eighty-eight, it is 246,803, being 132,548 more than at the preceding
-decade.
-
-During the first year of infancy, as has been shown, the mortality
-out of a million is 180,492. At the extreme age of eighty-four, it
-is 178,130, very nearly the same as in the first year of infancy.
-Greatly as the mortality of all the other epochs of life is affected
-by country, by station, by a multitude of influences arising out of
-these and similar circumstances; yet the concurrent evidence of all
-observation shows that at this and the like advanced ages the mean term
-of existence is nearly the same in all countries, at all periods, and
-among all classes of society. Thus, among the nobility and gentry of
-England, the expectation of life at eighty-four is four years; among
-the poor fishermen of Ostend, it is precisely the same. M. De Parcieux,
-who wrote just ninety years ago, establishes the expectation of life
-at that time in France, at the same age, to have been three and a half
-years; and Halley, who wrote 120 years ago, and whose observations are
-derived from documents which go back to the end of the seventeenth
-century, states the expectation of life at eighty-four to be two years
-and nine months.
-
-From these statements, then, it is obvious, that from the termination
-of infancy at three years of age, a decade of years brings childhood to
-a close, during which the mortality, steadily decreasing, comes to its
-minimum. Another decade terminates the period of adolescence, during
-which the mortality as steadily advances. A third decade changes the
-young adult into a perfect man, and during this period, the golden
-decade of human life, the mortality again diminishes; while, during
-another decade and a half, the mortality slowly rises, and returns
-at the close of the period to the precise point at which it stood at
-adult age. Thus the interval between the period of birth and that of
-adult age includes a term of twenty-three years. The interval between
-the period of adult age and that when life just begins to decline from
-its meridian, includes a term of twenty-four years: consequently, a
-period more than equal to all the other epochs of life from birth
-to adult age is enjoyed, during which mortality makes no advance
-whatever. Now the term of years included in the several epochs that
-intervene between birth and adult age is rigidly fixed. Thus the
-period of infancy includes precisely three years, that of childhood
-ten years, and that of adolescence ten years. Within the space of time
-comprehended in these intervals, physiological changes take place,
-on which depend every thing that is peculiar to the epochs. These
-changes cannot be anticipated, cannot be retarded, except in a very
-slight degree. In all countries, among all classes, they take place in
-the same order and nearly in the same space of time. In like manner,
-in extreme old age, or the age of decrepitude, which may be safely
-assumed to commence at the period when the mortality equals that of the
-first year of infancy, namely, the age of eighty-four, physiological
-changes take place, which, within a given space of time, inevitably
-bring life to a close. That space of time, in all countries, in all
-ranks, in all ages, or rather as far back as any records enable us to
-trace the facts, appears to be the same. As within a given time the
-boy must ripen into manhood, so within a given time the man of extreme
-old age must be the victim of death. Consequently, it is the interval
-between the adult age and the age of decrepitude, and only this, that
-is capable of extension. During the interval between adult age and the
-perfect meridian of life, comprehending at present, as we have seen,
-a period of twenty-four years, the constitution remains stationary,
-mortality making no sensible inroad upon it. But there is no known
-reason why this stationary or mature period of life should, like
-the determinate epochs, be limited to a fixed term of years. On the
-contrary, we do in fact know that it is not fixed; for we know that the
-physiological changes on which age depends are, in some cases, greatly
-anticipated, and in others, proportionately postponed; so that some
-persons are younger at sixty, and even at seventy, than others are at
-fifty; whereas, an analogous anticipation or postponement of the other
-epochs of life is never witnessed. So complete is the proof, that the
-extension of human life can consist in the protraction neither of the
-period of juvenility, nor in that of senility, but only in that of
-maturity.
-
-Were it necessary to adduce further evidence of this most interesting
-fact, it would be found equally in the statistics of disease as
-in those of mortality. Indeed, the evidence derived from both
-these sources must be analogous, because mortality is invariably
-proportionate to the causes of mortality, of which causes, sickness, in
-all its forms, may be taken as the general or collective expression.
-
-We do not possess the same means of illustrating the prevalence
-of disease through all the epochs of life as we do of showing the
-intensity of mortality; yet the report of Mr. Finlaison, already
-referred to, enables us to show its comparative prevalence at several
-of those stages. Thus, from this document, it appears, that among
-the industrious poor of London, members of benefit societies, out
-of a million of males, the proportion constantly sick at the age of
-twenty-three, is 19,410; at the age of twenty-eight, it is 19,670; at
-the age of thirty-three, it is 19,400; at the age of thirty-eight,
-it is 23,870; at the age of forty-three, it is 26,260; at the age of
-forty-eight, it is 26,140; at the age of fifty-three, it is 27,060;
-at the age of fifty-eight, it is 36,980; at the age of sixty-three,
-it is 57,000; at the age of sixty-eight, it is 108,040; at the age of
-seventy-three and upwards, it is 317,230. The prevalence of sickness
-is not an exact and invariable measure of the intensity of mortality;
-but there is a close connexion between them, as is manifest from
-the progressively increasing amount of sickness, as age advances.
-Thus, in the first ten years from the age of twenty-three to that of
-thirty-three, there is no increase of sickness, its prevalence is
-all but identically the same; in the next ten years from the age of
-thirty-three to that of forty-three, the increase of sickness, as
-compared with that of the preceding decade, is 6,860; in the next ten
-years from the age of forty-three to that of fifty-three, the increase
-is only 800; in the next ten years from the age of fifty-three to
-that of sixty-three, the increase is 29,940, while from the age of
-sixty-three to seventy-three, it is 260,230.
-
-Such are the results derived from the experience of disease considered
-in the aggregate, all its varied forms taken together. I am enabled
-further to present an exact and most instructive proof, that one
-particular disease which, in this point of view, may be considered
-as more important than any other, because it is the grand agent of
-death, namely fever, carries on its ravages in a ratio which steadily
-and uniformly increases as the age of its victim advances. Having
-submitted the experience of the London Fever Hospital for the ten
-years preceding January 1834, an observation including nearly 6,000
-patients affected with this malady, to Mr. Finlaison, it was subjected
-by him to calculation. Among other curious and instructive results to
-be stated hereafter, it was found that the mortality of fever resolves
-itself into the following remarkable progression. Thus suppose 100,000
-patients to be attacked with this disease between the ages of 5 and
-16, of these there would die - 8,266 and of an equal number
-
-    between 15 and 26   there would die  11,494
-            25 and 36      "    "    "   17,071
-            35 and 46      "    "    "   21,960
-            45 and 56      "    "    "   30,493
-            55 and 66      "    "    "   40,708
-            65 and upwards "    "    "   44,643
-
-Thus the risk of life from this malady is twice as great at the age
-of thirty-one as it is at eleven. It is also nearly twice as great
-at forty-one as it is at twenty-one. It is five times as great at
-sixty-one as it is at eleven, and nearly four times as great above
-sixty-five as it is at twenty-one.
-
-From the whole of the foregoing statements, it is manifest that life is
-a fluctuating quantity. In order to compare this fluctuating quantity
-under different circumstances, writers on this branch of statistics use
-several terms, the exact meaning of which it is desirable to explain.
-It is, for example, very important to have a clear understanding of
-what is meant by such expressions as the following: the expectation,
-the probability, the value, the decrement of life, and the law of
-mortality.
-
-1. THE EXPECTATION OF LIFE. It is important to bear in mind that
-several expressions in common use have a signification perfectly
-synonymous with this: namely, _share of existence_; _mean duration of
-life_; _la vie moyenne_.
-
-By these terms is expressed the total number of years, including also
-the fractional parts of a year, ordinarily attained by human beings
-from and after any given age. Suppose, for example, that one thousand
-persons enter on the eighty-sixth year of their age: suppose the
-number of years and days which each one of them lives afterwards be
-observed and recorded; suppose the number ultimately attained by each
-be formed into a sum total; suppose this total be divided equally among
-the thousand, the quotient of this division is said to be each one's
-share of existence, or his mean duration of life, or his expectation
-of life. Thus, of the thousand persons in the present case supposed
-to commence the age of eighty-five, suppose the number of years they
-collectively attain amount to 3,500 years: the one-thousandth part of
-3,500 is three and a half: three years and a half then is said to be
-the expectation of life at the age of eighty-five, because, of all the
-persons originally starting, this is the equal share of existence that
-falls to the lot of each.
-
-2. PROBABILITY OF LIFE; or _the probable duration of life_, _la vie
-probable_. These are synonymous terms, in use chiefly among continental
-writers as an expression of the comparative duration of life. The
-tabular methods of setting forth the duration of life consist, for the
-most part, in assuming that 10,000 infants are born; and that at the
-age of one, two, three, and each successive year of life, there are
-so many still remaining in existence. Fix on any age; observe what
-number remain alive to commence that age; note at what age this number
-decreases to one-half; the age at which they so come to one-half is
-called the probable term of life; because, say the continental writers,
-it is an equal wager whether a person shall or shall not be alive at
-that period. Thus, suppose one thousand males commence together the age
-of eighty-four; suppose the table indicate that there will be alive
-at the age of eighty-five, 817; at the age of eighty-six, 648; at the
-age of eighty-seven, 493; at the age of eighty-eight, 357, and so on.
-In the present case, the probable duration of life at eighty-four is
-said to be very nearly three years, because, at the age of eighty-seven
-there are left alive 493, very nearly one-half of the thousand that
-originally started together.
-
-3. VALUE OF LIFE. This term, when used accurately, expresses the
-duration of life as measured by one or other of the methods already
-expounded. But it is sometimes popularly used in a loose and singularly
-inaccurate sense. Thus it is very commonly said—"Such a man's life
-is not worth ten years' purchase," which is the same thing as to say,
-that an annuity, suppose a hundred pounds a year, payable during the
-life of the person in question, is not worth ten times its magnitude,
-that is one thousand pounds. If a thousand pounds be put into a bank
-at some rate of interest to be agreed upon, and if a hundred pounds be
-drawn every year from the stock, the expression under consideration
-affirms that the person in question will be dead before the principal
-and interest are exhausted. For instance, at four per cent., the value
-of an annuity of one hundred pounds to a man of the age of twenty-five
-is 1694_l._, which is 16-9/10 years' purchase; whereas, his expectation
-of life at that age is 35-9/10 years.
-
-4. LAW OF MORTALITY. By this term is expressed the proportion out of
-any determinate number of human beings who enter on a given year of
-age, that will die in that year. Every observation on the duration of
-life presents certain numbers, which, by recorded facts, are found to
-pass through each year of age, and also shows how many have died or
-failed to pass through every year of age. Those numbers, by the rule
-of three, are converted into the proportions who would die at each
-age out of one million of persons, if such a number had commenced it.
-Suppose, then, a million of persons to be in existence at the first
-year of age; suppose a million to be in existence at the second year
-of age; suppose a million to be in existence at the third year of
-age; and in this manner suppose an equal number to be in existence at
-the commencement of each and every year to the extreme term of human
-life. Now, the proportions that by actual observation are found to
-die at each and every year out of the million that were alive at the
-commencement of it, form separately the law of mortality for each year,
-and collectively for the whole of life.
-
-5. DECREMENT OF LIFE. Assuming, as before, that a million of male
-children are born alive (for the still-born must be excluded from
-the calculation) if it be found that 180,492 would die in the first
-year, it follows that the difference, namely, 819,508, will enter upon
-the age of one year. Suppose the law of mortality indicate that the
-proportion that will die, out of a million, between the age of one
-and two, is 30,000; it is plain that the number who would die out of
-819,508 will by the rule of three be 27,863, and consequently that the
-residue, namely, 791,615, will remain alive, and so enter on the age
-of two years. This method being pursued through each and every age to
-the extreme term of life, when none of the original million survive,
-the result is a table of mortality in the form in which it is commonly
-presented in the works of writers on this branch of science. In the
-table thus constructed there is a column containing the number of
-living persons who, out of the original million, lived to enter upon
-each and every year. Of this rank of numbers the difference between
-each term and its next succeeding one, is the number who die in that
-particular interval: that number is the measure of what is technically
-called the decrement of life for that particular year, and the whole
-of the decrements for each and every year taken collectively is termed
-the decrement of life. The decrement of life, then, is not only not
-the same as the law of mortality, but is carefully to be distinguished
-from it. The law of mortality is derived from observing the number
-who die out of one and the same number which is always supposed to
-enter on each and every year. The decrement of life constitutes a
-rank of numbers arising out of the successive deaths; that is, out of
-the original million in the first year; out of the survivors of that
-million in the second year; out of the survivors of those survivors in
-the third year, and so on. In the first case the number of the living
-is always the same; the number that die is the variable quantity: in
-the second case the number of the living is the variable quantity,
-while the number that die may remain pretty much the same for a
-succession of years; and on casting the eye on the tables constructed
-in the ordinary mode, it will be seen that the number often does remain
-the same for a considerable series of years.
-
-We have said that life is a fluctuating quantity. It fluctuates
-in different countries at the same period; in the same country at
-different periods; in the same country, at the same period, in
-different places; in the same country, at the same period, in the
-same place, among different classes; in the same country, at the same
-period, in the same place, among the same class, at the different
-determinate stages of life. Some few of these fluctuations, and
-more especially the last, depend on the primary constitution of the
-organization in which life itself has its seat, over which man has
-little or no control. The greater part of them depend on external
-and adventitious agencies over which man has complete control. Human
-ignorance, apathy, and indolence, may render the duration of life, in
-regard to large classes and entire countries, short; human knowledge,
-energy and perseverance, may extend the duration of life far beyond
-what is commonly imagined. It will be interesting and instructive to
-select a few of the more striking examples of this from the records we
-possess, few and imperfect as they are, in relation to this subject.
-
-Of the duration of life in the earlier periods of the history of the
-human race we know nothing with exactness, though there are incidental
-statements which afford the means of deducing with some probability
-the rate of mortality in particular situations. There has come down to
-us one document through Domitius Ulpianus, a judge, who flourished in
-the reign of Alexander Severus, which enables us to form a probable
-conjecture at least of the opinion of the Roman people of the value
-of life among the citizens of Rome in that age. It happened at Rome
-as in other countries, that when an estate came into the possession
-of an individual it was burthened with a provision for another person
-during the life of the latter, a younger brother, for example. This
-provision was called by the Romans an aliment. No estate, burthened
-with such a provision, could be sold by the heir in possession, unless
-the purchaser retained in his hands so much of the price as was deemed
-adequate to secure the regular and continuous payment of the aliment.
-This imposed upon the Romans the necessity of considering what the term
-of life would probably be from and after any given age. What they did
-conceive that term to be is stated in a document of Ulpianus, recorded
-by Justinian, and given in the note below.[1] This document imports
-that from infancy up to the age of
-
-                      20       there should be allowed 30 years
-                 From 20 to 25   "     "     "     "   28   "
-                      25 to 30   "     "     "     "   25   "
-                      30 to 35   "     "     "     "   22   "
-                      35 to 40   "     "     "     "   20   "
-                        ————
-                From  50 to 55   "     "     "     "    9   "
-                      55 to 60   "     "     "     "    7   "
-      And at all ages above 60   "     "     "     "    5   "
-
-But between 40 and 50, as many years were to be allowed as the age of
-the party fell short of 60, deducting one year.
-
-No clue has hitherto been obtained to the discovery of the real
-meaning of this document. It is, however, highly probable that the
-Romans had fallen on one of the two methods of measuring the value of
-life already explained; namely, that termed the Probability of Life.
-Of the two modes of determining the value of life, the probability was
-more likely to occur to a Roman judge than the expectation. He had
-no tables, no registers to guide him. What course, then, would he be
-likely to take? Probably he would form a list of his own school-fellows
-and others within his own knowledge, of the age, say, of twenty. By
-prevailing on persons of his own age, on whose correctness he could
-rely, to draw out similar lists, he might accumulate some thousand
-names. In this list it is probable that the male sex alone would be
-included, on account of the greater ease of ascertaining both their
-exact age and the exact date of their death. For the same reason,
-it is probable that the list would consist only of the nobility and
-the inhabitants of towns. Having thus completed his list, the next
-step would be to frame another list of all who died at the age of
-twenty-one; and next, another list of all who died at the age of
-twenty-two, and so on through each and every year of life. Now by
-subtracting the number in the list, No. 1, that is, those who died
-between twenty and twenty-one, from the number who originally started
-at twenty, which, in other words, would be to find the decrement of
-life, in the mode already explained, he would see how many lived to
-commence the age of twenty-one, and so on, through each year of life.
-But this would be to construct a table, showing the probable duration
-of life; that is, a table from which he could observe at what advanced
-age the number originally starting at twenty, and so on, came to
-diminish to one-half, when it would naturally occur to him that it
-is an equal wager whether such younger life would or would not be in
-existence at the advanced age so ascertained. If we suppose this to
-have been the method actually adopted by the Roman judge, and apply
-it to the table of Ulpianus, the result obtained is consistent in an
-extraordinary degree, and is highly interesting.
-
-There is reason to believe that the mortality at present throughout
-Europe, taking all countries together, including towns and villages,
-and combining all classes into one aggregate, is one in thirty-six.
-Süssmilch, a celebrated German writer, who flourished about the middle
-of the last century, estimated it at this average at that period. The
-result of all Mr. Finlaison's investigations is a conviction that the
-average for the whole of Europe does not materially differ at the
-present time. He has ascertained by an actual observation, that in the
-year 1832 it was precisely this in the town of Ostend. Taking this
-town, then, as the subject of comparison, it is found that the probable
-duration of life among the male sex at Ostend exceeds the Roman
-allowance by the following number of years; namely,
-
-  At the age of 17, the excess in round
-                    numbers is    5 years.
-                22     "     "    5
-                27     "     "    5
-                32     "     "    5
-                37     "     "    3
-                42     "     "    3
-                47     "     "    5
-                52     "     "    5
-                57     "     "    4
-                62     "     "    4
-                67     "     "    2
-                72     "     "    1
-                77     "     "    0
-
-But it is not improbable that the Romans made some deduction from
-what they knew to be the real value of life among the citizens of
-Rome, on account of the use of the money appropriated to the aliment,
-which the purchaser of the estate retained in his own hands. It has
-been shown that the average mortality at present at Ostend is one
-in thirty-six; which is the same thing as to assert that a new-born
-child at Ostend has an expectation of thirty-five and a half years
-of life. The Roman allowance from birth, _à primâ ætate_, was thirty
-years. If we suppose the Romans deducted from the real value of life
-five and a half years for the interest of money, it would bring the
-Roman allowance and the duration of life at Ostend to the same. The
-like deduction at the age of seventeen would likewise bring the
-probability of life in both cases to the same. It is not likely that
-the Romans, without any record of the individual facts, and acting
-only on a general principle of utility, the best they could find,
-would make any variation for the intermediate years of childhood and
-youth: consequently the presumption is, that the duration of life at
-Rome, 1300 years ago, was very much the same as it is throughout Europe
-at the present day. This estimate, however, for the reasons already
-assigned, includes only the resident citizens of Rome, the male sex,
-and the higher classes. What the mortality was at Rome among the lower
-class, including the slaves—what it was in the Roman provinces, and in
-the less civilized countries of that age—we have no means of forming
-even a conjecture. What it was in Europe during the succeeding ages
-of barbarism we do not know. In civilized Rome, the value of life
-had probably reached a very high point; in barbarian Europe we may
-be sure it fell to an exceedingly low point. From that low point, in
-civilized Europe, it has been slowly but gradually rising, until, in
-modern times, the whole mass of the European population has, to say
-the very least, reached the highest point attained by the select class
-in ancient Rome. But in some favoured spots in Europe, the whole mass
-has advanced considerably beyond the select class in ancient Rome. In
-England, for example, the expectation of life, at the present day, for
-the mass of the people, as compared with that of the mass at Ostend,
-which, as has been shown, is the same as that of the whole of Europe,
-is as follows:—
-
-  At birth   41½ years.
-  At 12      46¾
-     17      41½
-     22      38⅜
-     27      35¼
-     32      32
-     37      28¾
-     42      25½
-     47      22¼
-     52      19
-     57      16
-     62      13
-     67      10½
-     72       8
-     77       6
-
-It should be borne in mind that the females of the mass exceed in
-duration the lives of the males at every age by two or three years.
-
-The earliest statistical document bearing on the rate of mortality, in
-any European nation, emerging from the state of barbarism, appears to
-be a manuscript of the fourteenth century, relating to the mortality
-of Paris, from which M. Villermé has calculated that the mortality
-of Paris at that period was one in sixteen. How the individual facts
-contained in this manuscript were collected, from which M. Villermé's
-calculation is made, does not appear; and it makes the mortality so
-excessive as to be altogether incredible. Yet a statement scarcely
-less extraordinary is made with regard to Stockholm, in the middle of
-the last century. From a table given by Dr. Price, vol. ii., p. 411,
-it appears that, for all Sweden, between the years 1756 and 1763, the
-expectation of life
-
-  Of males at birth, was      Females,
-        33¼ years.           35¾ years.
-
-while at the same time it was at Stockholm,
-
-  For males at birth,         Females,
-        14¼ years.            18 years.
-
-Whereas, for the twenty years preceding 1800, it was, for all Sweden,
-at birth,
-
-  Males,       Females,
-   34¾.          37½.
-
-Hitherto, in all places which man has made his abode, noxious agents
-have been present which act injuriously upon his body, tending to
-disturb the actions of its economy, and ultimately to extinguish life.
-All these noxious agents, of whatever name or quality, may be included
-under the term Causes of Mortality. Inherent in the constitution of the
-body are conservative powers, the tendency of which is to resist the
-influence of these causes of mortality. The actual mortality at all
-times will of course be according to the relative strength of these
-destructive agents, and the relative weakness of these conservative
-powers. There are states of the system tending to enfeeble these
-conservative powers. Such states become tests, often exceedingly
-delicate, of the presence and power of the destructive agents to which
-the body is exposed; and such, more especially, are, the states of
-parturition, infancy, and sickness. During the prevalence of these
-states, in which the conservative powers of the body are weak, life
-is destroyed by causes which do not prove mortal in other conditions
-of the system. Accordingly, in every age and country, the rate of
-mortality among its lying-in women, its infants and its sick, may
-be taken as a measure of the degree in which the state of the whole
-population is favourable or unfavourable to life.
-
-The change that has taken place in the condition of lying-in women
-during the last century in all the nations of Europe cannot be
-contemplated without astonishment. The mortality of lying-in women in
-France, at the Hôtel Dieu of Paris, in 1780, is stated to have been
-one in 15. In 1817, for the whole kingdom of Prussia, including all
-ranks, it was one in 112. In England, in the year 1750, at the British
-Lying-in Hospital of London, it was one in 42; in 1780, it diminished
-to one in 60; in the years between 1789 and 1798, it further decreased
-to one in 288; in 1822, at the Lying-in Hospital of Dublin, it was no
-more than one in 223; while during the last fifteen years at Lewes, a
-healthy provincial town, out of 2410 cases there have been only two
-deaths, that is, one in 1205. There is no reason to suppose that the
-mortality in the state of parturition is less at Lewes than in any
-other equally healthy country-town in England.
-
-Equally striking is the proof of the diminished violence of the
-prevalent causes of disease and death derived from the diminished
-mortality of children, the vital power of resistance being always
-comparatively weak in the human infant, and consequently, the agents
-that prove destructive to life exerting their main force on the new
-born, and on those of tender age. From mortuary tables, preserved with
-considerable accuracy at Geneva since the year 1566, it appears that at
-the time of the Reformation one-half of the children born died within
-the sixth year; in the seventeenth century, not till within the twelfth
-year; in the eighteenth century, not until the twenty-seventh year;
-consequently, in the space of about three centuries, the probability
-that a child born in Geneva would arrive at maturity has increased
-fivefold. In the present day, at Ostend, only half of the new-born
-children attain the age of thirty; whereas, in England, they attain the
-age of forty-five.
-
-No less remarkable is the progressive diminution of mortality among
-the sick of all ages. Hippocrates has left a statement, which has come
-down to our times, of the history and fate of forty-two cases of acute
-disease. Out of this number, thirty-seven were cases of continued
-fever; of these thirty-seven febrile cases twenty-one died, above half
-of the whole. The remaining five were cases of local inflammation,
-and of these four were fatal; thus, of the whole number of the sick
-(forty-two), twenty-five were lost. Now, even in the Fever Hospital of
-London, to which, for the most part, only the worst cases that occur
-in the metropolis are sent, and even of these many not until so late
-a period of the disease that all hope of recovery is extinct, the
-mortality ranges in different years from one in six to one in twelve;
-and for a period of ten consecutive years, it is no more than one in
-seven; while, in the Dublin Fever Hospital, where most of the cases are
-sent very early, the average mortality from 1804 to 1812 was one in
-twelve. At the Imperial Hospital at Petersburg, the average mortality
-for fourteen years, ending in 1817, was one in four and a half. In the
-Charité of Berlin, on an average of twenty years, from 1796 to 1817,
-it was one in six. At Dresden, it was one in seven; at Munich, it was
-one in nine, the lowest of any hospital of equal size in Germany. In
-the year 1685, the average mortality at St. Bartholomew's and St.
-Thomas's Hospitals was from one in seven to one in ten. During the ten
-years from 1773 to 1783, it decreased to one in fourteen. From 1803 to
-1813, it was one in sixteen. The average for fifty years from 1764 to
-1813, was one in fifteen. In the smaller towns, the mortality is still
-less. It is less in Edinburgh and Dublin than in London; while in the
-hospital at Bath during 1827, even among the physician's patients, the
-mortality was only one in twenty. In the German provincial towns, the
-diminution is still more remarkable. In the hospital at Gottingen, for
-example, it is only one in twenty-one.
-
-If the accuracy of these statements could be relied on, they
-would not only afford striking illustrations of the well-known fact
-that extraordinary differences prevail in the rate of mortality
-in different places, at different periods, and under different
-circumstances; but they would further prove that, during the last
-century, a steady and progressive diminution of mortality has taken
-place in all the countries of Europe. But of the truth of this there
-is much more certain evidence than can be derived from calculations,
-the trustworthiness of the data of which is not established, and
-the correctness of the calculators not known. Both the fluctuations
-of mortality and the increase in the value of life in the different
-countries of Europe, from the earliest period when statistical facts
-began to be collected and compared, are exhibited in a striking
-point of view in the following table, drawn up by Mr. Finlaison. The
-facts relating to selected lives and to the mass of the people are
-distinguished from each other, in order that they may be contrasted.
-The data are derived from the most authentic sources, and the
-calculations are made by men of the highest authority.
-
-
-Let it be conceived, that at each   50  55  60  65  70  75  80  85
-of the following ages, viz.        Yrs.Yrs.Yrs.Yrs.Yrs.Yrs.Yrs.Yrs.
-
-The average duration of Human
-Life of both sexes collectively
-may thenceforward be assumed at
-a maximum of[2]                     23  19  16  13  11   8   6   3
-
-By how many weeks does the
-average duration which results
-from the most authentic Tables
-at present known fall short of
-the maximum Term thus assumed?
-
- Among the higher classes of people exclusively.
-
-     Answer.       Name of the
-                     Observer.   Wks. Wks. Wks. Wks. Wks. Wks. Wks. Wks.
-In England—
-Among the Government
-Annuitants, between
-1775 and 1822
-               John Finlaison.    35    1    7   10   47   11   14   53
-
-Among the Lives assured
-at the Equitable Office,
-between 1760 and 1834
-                Arthur Morgan.   119   83   87   81   96   33   10   27
-
-Among the Nominees of
-the Tontine of 1693--
-between that year
-and 1775
-               John Finlaison.   269  195  170  141  157  110   90   89
-
-In France--
-Among the Nominees of
-the Tontine of 1693--
-between that year and
-1745           M. de Parcieux.   133   88   87   86  118   70   55   65
-
-In Holland--
-Among the Public
-Annuitants, between
-1615 and 1740
-                M. Kersseboom.   186  118  104   75   96   61   48   84
-
-In regard to the mass of the people.
-
-In Breslau in Silesia,
-between 1700 and 1725,
-                   Dr. Halley.   275  211  181  150  166  100   36  137
-
-In Sweden,
-between 1775
-and 1795,         M. Nicander,
-                and Mr. Milne.   207  161  164  146  156   94   60   60
-
-In Northampton,
-in England, between
-1735 and 1780,
-                    Dr. Price.   209  178  145  110  125   76   65   85
-
-In Carlisle,
-in England, between
-1779 and 1787,  Dr. Heysham,
-                and Mr. Milne.    98   74   86   63   94   52   26   46
-
-In all England and
-Wales, between
-1811 and 1831,
-               John Finlaison.   100   59   65   58   87   48   37   49
-
-In the town of Ostend,
-in Flanders, between
-1805 and 1832,
-               John Finlaison.   276  210  184  146  143   76   50   75
-
-In all Belgium, between
-1725 and 1832,
-                  M. Quetelet.   183  133  133  117  112   84   50   61
-
-
-Let us trace from this table the differences that have taken place, in
-different countries at different periods, in the duration of life at
-a given age. Let us take the age given in the first column, namely,
-fifty. Assuming, then, the highest degree of longevity hitherto
-attained at the age of fifty to be twenty-three years, it appears that,
-between the years 1700 and 1725, the mass of the people in Breslau,
-in Silesia, fell short of reaching this period by 275 weeks; the
-inhabitants of the town of Ostend in Flanders, between 1805 and 1832,
-by 276 weeks; the nominees of the tontine of England, between the years
-1693 and 1775, by 269 weeks; the inhabitants of the town of Northampton
-in England, between 1735 and 1780, by 209 weeks; the mass of the people
-in Sweden, between 1775 and 1795, by 207 weeks; the public annuitants
-of Holland, between 1615 and 1740, by 186 weeks; the inhabitants of
-all Belgium, between 1725 and 1832, by 183 weeks; the persons assured
-at the Equitable Office, between 1760 and 1834, by 119 weeks; the
-inhabitants of all England and Wales, between 1811 and 1831, by 100
-weeks; the English government annuitants, between 1775 and 1832, only
-by 35 weeks.
-
-From these statements, it appears that, towards the close of the
-seventeenth century, the duration of life in England was considerably
-less than in France: less even than in Holland nearly a century
-earlier. Thus, the nominees of the tontine of France, between the years
-1693 and 1745, at the age of fifty, according to M. De Parcieux, fell
-short of the maximum longevity by 133 weeks; the public annuitants of
-Holland, seventy-eight years before, namely, between the years 1615 and
-1740, according to M. Kersseboom, fell short of the maximum longevity
-by 186 weeks; whereas, the nominees of the tontine of England, between
-the years 1693 and 1775, according to Mr. Finlaison, fell short of it
-by 269 weeks; a difference nearly double that of Holland, and quite
-double that of France in persons of the corresponding rank in society.
-
-Since that period, surprising changes have taken place in all the
-nations of Europe; but in none has the change been so great as in
-England. From that period, when its mortality exceeded that of any
-great and prosperous European country, its mortality has been steadily
-diminishing, and at the present time the value of life is greater in
-England than in any other country in the world. Not only has the value
-of life been regularly increasing until it has advanced beyond that of
-any country of which there is any record; but the remarkable fact is
-established, that the whole mass of its people now live considerably
-longer than its higher classes did in the seventeenth and eighteenth
-centuries. Thus, by inspecting the preceding table, it will be seen
-that between the years 1693 and 1715, the nominees of the tontine of
-England, at the age of fifty, fell short of the maximum longevity
-by 269 weeks; whereas, the mass of the people in all England and
-Wales, between the years 1811 and 1831, fell short of it only by 100
-weeks; the entire mass having not only reached the select class, but
-absolutely advanced beyond it by 169 weeks.
-
-There cannot be a more interesting and instructive thing than to
-connect these facts with their causes. This will be attempted in a
-subsequent part of this work; but the reader will be incomparably
-better prepared for the investigation when the processes of life have
-been explained, and the influence of physical and moral agents upon
-them traced. And with this exposition we now proceed.
-
-
-
-
-CHAPTER V.
-
-  Ultimate elements of which the body is composed—Proximate
-  principles—Fluids and solids—Primary
-  tissues—Combinations—Results—Organs, systems,
-  apparatus—Form of the body—Division into head, trunk, and
-  extremities—Structure and function of each—Regions—Seats
-  of the more important internal organs.
-
-
-1. The ultimate elements of which the human body is composed are
-azote, oxygen, and hydrogen (gaseous fluids); and carbon, phosphorus,
-calcium, sulphur, sodium, potassium, magnesium, and iron (solid
-substances). These bodies are called elementary and ultimate, because
-they are capable of being resolved by no known process into more simple
-substances.
-
-2. These elementary bodies unite with each other in different
-proportions, and thus form compound substances. A certain proportion
-of azote uniting with a certain proportion of oxygen, hydrogen, and
-carbon, forms a compound substance possessing certain properties.
-Another proportion of azote uniting with a different proportion
-of oxygen, hydrogen, and carbon, forms another compound substance
-possessing properties different from the former. Oxygen, hydrogen, and
-carbon, uniting in still different proportions without any admixture
-of azote, form a third compound possessing properties different from
-either of the preceding. The compounds thus formed by the primary
-combinations of the elementary substances with each other are called
-PROXIMATE PRINCIPLES.
-
-3. Each proximate principle constitutes a distinct form of animal
-matter, of which the most important are named gelatin, albumen, fibrin,
-oily or fatty matter, mucus, urea, pichromel, osmazome, resin, and
-sugar.
-
-4. By chemical analysis it is ascertained that all the proximate
-principles of the body, however they may differ from each other in
-appearance and in properties, are composed of the same ultimate
-elements. Gelatin, for example, consists (in 100 parts) of azote
-16-988/1000, oxygen 27-207/1000, hydrogen 7-914/1000, carbon
-47-881/1000 parts. The elementary bodies uniting in the above
-proportions form an animal substance, soft, tremulous, solid, soluble
-in water, especially when heated, and on cooling, which may be
-considered as its distinctive property, separating from its solution in
-water into the same solid substance, without undergoing any change in
-its chemical constitution.
-
-5. Again, albumen consists of azote 15-705/1000, oxygen 23-872/1000,
-hydrogen 7-540/1000, carbon 52-888/1000, parts. The elementary bodies
-uniting in these different proportions, there results a second
-proximate principle, an adhesive fluid, transparent, destitute of smell
-and taste, miscible in water, but when subjected to a temperature of
-about 165°, converted into a solid substance no longer capable of being
-dissolved in water. This conversion of albumen from a fluid, which is
-its natural state, into a solid, by the application of heat, is called
-coagulation. It is a process familiar to every one. The white of egg is
-nearly pure albumen, naturally a glary and adhesive fluid: by boiling,
-it is coagulated into a white and firm solid.
-
-6. In like manner, fibrin consists of azote 19-934/1000, oxygen
-19-685/1000, hydrogen 7-021/1000, carbon 53-360/1000 parts, forming
-a solid substance of a pale whitish colour and firm consistence, the
-peculiar character of which is its disposition to arrange itself into
-minute threads or fibres.
-
-7. On the other hand, fat or oil, which is a fluid substance of a
-whitish yellow colour, inodorous, nearly insipid, unctuous, insoluble
-in water and burning with rapidity, consists of a larger proportion of
-hydrogen, a small proportion of oxygen, and a still smaller proportion
-of carbon, without any admixture of azote.
-
-8. From this account of the composition of the proximate principles,
-which it is not necessary to extend further, it is manifest that all of
-them consist of the same ultimate elements, and that they derive their
-different properties from the different proportions in which their
-elements are combined.
-
-9. The ultimate elements that compose the body are never found in a
-separate or gaseous state, but always in combination in the form of one
-or other of the proximate principles.
-
-10. In like manner, the proximate principles never exist in a distinct
-and pure state, but each is combined with one or more of the others. No
-part consists wholly of pure albumen, gelatin, or mucus, but albumen is
-mixed with gelatin, or both with mucus.
-
-11. Simple or combined, every proximate principle assumes the form
-either of a fluid or of a solid, and hence the most general and obvious
-division of the body is into fluids and solids. But the terms fluid
-and solid are relative, not positive; they merely express the fact
-that some of the substances in the body are soft and liquid compared
-with others which are fixed and hard; for there is no fluid, however
-thin, which does not hold in solution some solid matter, and no solid,
-however dense, which does not contain some fluid.
-
-12. Fluids and solids are essentially the same in nature; they
-differ merely in their mode of aggregation; hence the easy and rapid
-transition from the one to the other which incessantly takes place in
-the living body, in which no fluid long remains a fluid, and no solid a
-solid, but the fluid is constantly passing into the solid and the solid
-into the fluid.
-
-13. The relative proportion of the fluids in the human body is always
-much greater than that of the solids; hence its soft consistence and
-rounded form. The excess, according to the lowest estimate, is as 6
-to 1, and according to the highest, as 10 to 1. But the proportion is
-never constant; it varies according to age and to the state of the
-health. The younger the age, the greater the preponderance of the
-fluids. The human embryo, when first perceptible, is almost wholly
-fluid: solid substances are gradually but slowly superadded, and even
-after birth the preponderance is strictly according to age; for in
-the infant, the fluids abound more than in the child; in the child,
-more than in the youth; in the youth, more than in the adolescent; in
-the adolescent, more than in the adult; and in the adult, more than
-in the aged. Thus, among the changes that take place in the physical
-constitution of the body in the progress of life, one of the most
-remarkable is the successive increase in the proportion of its solid
-matter: hence the softness and roundness of the body in youth; its
-hard, unequal, and angular surface in advanced life; its progressively
-increasing fixedness and immobility in old age, and ultimate inevitable
-death.
-
-14. The fluids are not only more abundant than the solids, but they
-are also more important, as they afford the immediate material of the
-organization of the body; the media by which both its composition and
-its decomposition are effected. They bear nourishment to every part,
-and by them are carried out of the system its noxious and useless
-matter. In the brain they lay down the soft and delicate cerebral
-substance; in the bone, the hard and compact osseous matter; and the
-worn-out particles of both are removed by their instrumentality. Every
-part of the body is a laboratory in which complicated and transforming
-changes go on every instant; the fluids are the materials on which
-these changes are wrought; chemistry is the agent by which they are
-effected, and life is the governing power under whose control they take
-place.
-
-15. The fluids, composed principally of water holding solid matter in
-solution, or in a state of mechanical division, either contribute to
-the formation of the blood, or constitute the blood, or are derived
-from the blood; and after having served some special office in a
-particular part of the system, are returned to the blood; and according
-to the nature and proportion of the substances they contain, are
-either aqueous, albuminous, mucous, gelatinous, fibrinous, oleaginous,
-resinous, or saline.
-
-16. When the analysis of the different kinds of animal matter that
-enter into the composition of the body has been carried to its ultimate
-point, it appears to be resolvable into two primitive forms: first, a
-substance capable of coagulation, but possessing no determinate figure;
-and secondly, a substance having a determinate figure and consisting of
-rounded particles. The coagulable substance is capable of existing by
-itself; the rounded particles are never found alone, but are invariably
-combined with coagulated or coagulable matter. Alone or combined with
-the rounded particles, the coagulable matter forms, when liquid, the
-fluids, when coagulated, the solids.
-
-17. When solid, the coagulable substance is disposed in one of two
-forms, either in that of minute threads or fibres, or in that of minute
-plates or laminæ; hence every solid of the body is said to be either
-fibrous or laminated. The fibres or laminæ are variously interwoven
-and interlaced, so as to form a net-work or mesh; and the interspaces
-between the fibres or laminæ are commonly denominated areolæ or cells
-(fig. XVII).
-
-18. This concrete substance, fibrous or laminated, is variously
-modified either alone or in combination with the rounded particles.
-These different modifications and combinations constitute different
-kinds of organic substance. When so distinct as obviously to possess a
-peculiar structure and peculiar properties, each of these modifications
-is considered as a separate form of organized matter, and is called a
-PRIMARY TISSUE. Anatomists and physiologists have been at great pains
-to discriminate and classify these primary tissues; for it is found
-that when employed in the composition of the body, each preserves its
-peculiar structure and properties wherever placed, however combined,
-and to whatever purpose applied, undergoing only such modification
-as its local connexions and specific uses render indispensable.
-Considering every substance employed in the construction of the body,
-not very obviously alike, as a distinct form of organized matter, these
-primary tissues may be said to consist of five, namely, the membranous,
-the cartilaginous, the osseous, the muscular, and the nervous.
-
-19. The first primary tissue is the peculiar substance termed MEMBRANE.
-It has been already stated (16) that one of the ultimate forms of
-animal matter is a coagulable substance, becoming concrete or solid
-under the process of coagulation. The commencement of organization
-seems to be the arrangement of this concrete matter into straight
-thready lines, at first so small as to be imperceptible to the naked
-eye. Vast numbers of these threads successively uniting, at length
-form a single thread of sufficient magnitude to be visible, but still
-smaller than the finest thread of the silkworm. If the length of these
-threads be greater than their breadth, they are called fibres; if,
-on the contrary, their breadth exceed their length, they are termed
-plates or laminæ. By the approximation of these fibres or plates in
-every possible direction, and by their accumulation, combination, and
-condensation, is constituted the simplest form of organized substance,
-the primary tissue called membrane.
-
-20. Membrane once formed is extensively employed in the composition
-of the body: it is indeed the material principally used in producing,
-covering, containing, protecting, and fixing every other component
-part of it. It forms the main bulk of the cartilaginous tissue; it
-receives into its cells the earthy matter on which depend the strength
-and hardness of the osseous tissue; it composes the canals or sheaths
-in which are deposited the delicate substance of the muscular, and the
-still more tender pulp of the nervous tissue; it gives an external
-covering to the entire body; it lines all its internal surfaces; it
-envelopes all internal organs; it enters largely as a component element
-into the substance of every organ of every kind; it almost wholly
-constitutes all the internal pouches and sacs, such as the stomach, the
-intestines, the bladder; and all tubes and vessels, such as arteries,
-veins, and lymphatics; it furnishes the common substance in which
-all the parts of the body are, as it were, packed; it fills up the
-interstices between them; it fixes them in their several situations; it
-connects them all together; in a word, it forms the basis upon which
-the other parts are superinduced; or rather the mould into which their
-particles are deposited; so that were it possible to remove every other
-kind of matter, and to leave this primary tissue unaltered in figure
-and undiminished in bulk, the general form and outline of the body, as
-well as the form and outline of all its individual parts, would remain
-unchanged.
-
-21. The properties which belong to membrane are cohesion, flexibility,
-extensibility, and elasticity. By its property of cohesion, the several
-parts of the body are held together; by its combined properties of
-cohesion, flexibility, and extensibility, the body in general is
-rendered strong, light, and yielding, while particular parts of it
-are made capable of free motion. But elasticity, that property by
-which parts removed from their situation in the necessary actions of
-life are restored to their natural position, may be regarded as its
-specific property. The varied purposes accomplished in the economy
-by the property of elasticity will be apparent as we advance in our
-subject. Meantime, it will suffice to observe that it is indispensable
-to the action of the artery in the function of the circulation; to the
-action of the thorax in the function of respiration; to the action of
-the joints in the function of locomotion: in a word, to the working
-of the entire mechanism by which motion of every kind and degree
-is effected. All these properties are physical, not vital; vital
-properties do belong even to this primary form of animal matter; but
-they are comparatively obscure. In the tissue with which organization
-commences, and which is the least removed from an inorganic substance,
-the properties that are prominent and essential are merely physical.
-
-22. By chemical analysis, membrane is found to contain but a small
-proportion of azote, the peculiar element of animal matter. Its
-proximate principles are gelatin, albumen, and mucus. In infancy and
-youth, gelatin is the most abundant ingredient; at a more advanced
-period, albumen predominates[3]. Gelatin differs from albumen in
-containing a less proportion of azote and a greater proportion of
-oxygen; on both accounts it must be regarded as less animalized. Thus
-animalization bears a certain relation to organization. The simplest
-animal tissue is the least animalized, and the least of all at the
-earliest period of life. Not only are the physical and mental powers
-less developed in the young than in the adult, but the very chemical
-composition of the primary tissue of which the body is constructed is
-less characteristic of the perfect animal.
-
-23. Membrane exists under several distinct forms; a knowledge of the
-peculiarities of which will materially assist us in understanding the
-composition of the body. The simplest form of membrane, and that which
-is conceived to constitute the original structure from which all the
-others art produced, is termed the _cellular_. When in thin slices,
-_cellular membrane_ appears as a semi-transparent and colourless
-substance; when examined in thicker masses, it is of a whitish or
-greyish colour. It consists of minute threads, which cross each other
-in every possible direction, leaving spaces between them, and thus
-forming a mesh or net-work (fig. XVII.), not unlike the spider's web.
-The term cells, given to these interspaces, is employed rather in a
-figurative sense than as the expression of the fact; for there are no
-such distinct partitions as the term cell implies. The best conception
-that can be formed of the arrangement of the component parts of
-this structure is, to suppose a substance consisting of an infinite
-number of slender thready lines crossing each other in every possible
-direction (fig. XVII.). The interspaces between these lines during
-life, and in the state of health, are filled with a thin exhalation of
-an aqueous nature, a vapour rather than a fluid, rendering and keeping
-the tissue always moist. This vapour consists of the thinner part of
-the blood, poured into these interstitial spaces by a process hereafter
-to be described, termed secretion. When occupying those spaces, it
-makes no long abode within them, but is speedily removed by the process
-of absorption. In health, these two operations exactly equal each
-other; but if any cause arise to disturb the equilibrium, the vapour
-accumulates, condenses and forms an aqueous fluid, which distends the
-cells and gravitates to the most depending parts. Slightly organized
-as this tissue is, and indistinct as its vita functions may be, it
-is obvious that it must be the seat of at least two vital functions,
-secretion and absorption.
-
-[Illustration: Fig. XVII.
-
-A single film of the cellular tissue lifted up and slightly distended.]
-
-24. It is certain that the interspaces or cells of this membrane have
-no determinate form or size, that they communicate freely with each
-other, and that this communication extends over the whole body; for if
-a limb which has been infiltrated be frozen, a thousand small icicles
-will be formed, assuming the shape of the containing cells, some of
-which are found to be circular and others cylindrical, and so on. If
-air or water escape into any particular part of the body, it is often
-effused over the whole extent of it, and butchers are observed to
-inflate animals by making a puncture in some part where the cellular
-tissue is loose, and from this one aperture the air is forced to the
-most distant parts of the body.
-
-25. Cellular membrane, variously modified and disposed, forms the
-main bulk of all the other solid parts of the body, constituting
-their common envelope and bond of union, and filling up all their
-interstices. It is dense or loose, coarse or fine, according to its
-situation and office. Wherever it is subject to pressure, it is dense
-and firm, as in the palm of the hand and the sole of the foot; around
-the internal organs it is more loose and delicate, and it becomes finer
-and finer as it divides and subdivides, in order to envelope the soft
-and tender structures of the body.
-
-[Illustration: Fig. XVIII.
-
-A portion of cellular tissue, very highly magnified, showing the
-strings of globules of which its ultimate fibres are by some supposed
-to consist.]
-
-26. According to some who have carefully examined with the microscope
-its component threads, they consist of minute particles of a globular
-figure (fig. XVIII.); other microscopical observers regard the cellular
-threads as coagulated or condensed animal substance, perfectly
-amorphous (without form).
-
-27. Every part of this tissue is penetrated by arteries, veins,
-absorbents, and nerves, endowing it with properties truly vital, though
-in a less degree than any of the other primary tissues; and varied and
-important as the uses are which it serves in the economy, the most
-manifest, though certainly not the only ones, are those which depend
-upon its physical properties of cohesion, flexibility, extensibility,
-and elasticity.
-
-[Illustration: Fig. XIX. 1, A portion of adipose tissue; 2, minute bags
-containing the fat; 3, a cluster of the bags, separated and suspended.]
-
-28. The tissue which contains the fat, termed the _adipose_, is
-the second form of membrane; it is obviously a modification of the
-cellular, from which it differs both in the magnitude of its fibres,
-whence it constitutes a tougher and coarser web, and in their
-arrangement; for it is so disposed as to form distinct bags in which
-the fat is contained. Adipose tissue consists of rounded packets,
-separated from each other by furrows (fig. XIX. 2, 2); each packet
-is composed of small spheroidal particles (fig. XIX. 2, 2); each
-particle is again divisible into still smaller grains, which, on minute
-inspection, present the appearance of vesicles filled with the adipose
-matter (fig. XIX. 3).
-
-29. The cells of the cellular tissue, as has been shown (24), are
-continuous over the whole body; but each adipose vesicle is a distinct
-bag, having no communication whatever with any other (fig. XIX. 2, 2).
-The cellular tissue is universally diffused; but the adipose is placed
-only in particular parts of the body; principally beneath the skin, and
-more especially between the skin and the abdominal muscles, and around
-some of the organs contained in the chest and abdomen, as the heart,
-the kidneys, the mesentery, and the omenta. In most of these situations
-some portion of it is generally found, whatever be the degree of
-leanness to which the body may be reduced; while in the cranium, the
-brain, the eye, the ear, the nose, and several other organs, there is
-none, whatever be the degree of corpulency. The uses of the fat, which
-are various, will be stated hereafter.
-
-30. The third form of membrane is termed the
-
-_serous_. Like the adipose, _serous membrane_ is a modification of
-the cellular, and, like it also, it is limited in its situation to
-particular parts of the body, that is, to its three great cavities,
-namely, the head, the chest, and the abdomen. To the two latter it
-affords an internal lining, and to all the organs contained in all
-the three cavities, it affords a covering. By its external surface it
-is united to the wall of the cavity or the substance of the organ it
-invests; by its internal surface it is free and unattached; whence this
-surface is in contact only with itself, forming a close cavity or shut
-sac, having no communication with the external air. Smooth and polished
-(fig. XX.), it is rendered moist by a fluid which is supposed to be
-exhaled in a gaseous state from the serum of the blood; and from this
-serous fluid the membrane derives its name.
-
-[Illustration: Fig. XX.
-
-A portion of intestine, showing its external surface or serous coat.]
-
-31. Though thin, serous membrane is dense, compact, and of great
-strength in proportion to its bulk: it is extensible and elastic;
-extensible, for it expands with the dilatation of the chest in
-inspiration; elastic, for it contracts with the diminished size
-of the chest in expiration. In like manner, it stretches with the
-enlargement of the stomach during a hearty meal, and contracts as
-the stomach gradually diminishes on emptying itself of its contents.
-It is furnished with no blood-vessels large enough to admit the
-colouring matter of the blood; but it is supplied with a great number
-of the colourless vessels termed exhalents, with the vessels termed
-absorbents, and with a few nerves. It indicates no vital properties,
-but those which are common to the simple form of the primary tissue.
-Its specific uses are to afford a lining to the internal cavities; to
-furnish a covering to the internal organs; by its polished and smooth
-surface, to allow a free motion of those organs on each other, and by
-the moisture with which it is lubricated, to prevent them from adhering
-together, however closely, or for however long a period they may be in
-contact.
-
-32. The fourth form of membrane, the _fibrous_, named from the obvious
-arrangement of its component parts, consists of longitudinal fibres,
-large enough to be visible to the naked eye, placed parallel to each
-other, and closely united. Sometimes these fibres are combined in such
-a manner as to form a continuous and extended surface, constituting
-a thin, smooth, dense, and strong membrane, such as that which lines
-the external surface of bones termed PERIOSTEUM, or the internal
-surface of the skull (dura mater). At other times, they form a firm and
-tough expansion (aponeurosis) which descends between certain muscles,
-separating them from each other, and affording a fixed point for the
-origin or insertion of neighbouring muscles; or which is stretched
-over muscles, and sometimes over even an entire limb, in order to
-confine the muscles firmly in their situation, and to aid and direct
-their action (fig. XXVII.). Fibrous membrane also constitutes the
-compact, strong, tough, and flexible bands used for tying parts firmly
-together, termed LIGAMENTS, principally employed in connecting the
-bones with each other, and particularly about the joints; and lastly,
-fibrous membrane forms the rounded white cords in which muscles often
-terminate, called TENDONS (fig. XXV., XXVI.), the principal use of
-which is to connect the muscles with the bones, and to serve as cords
-or ropes to transmit the action of the muscle to a distant point, in
-the accomplishment of which purposes their operation appears to be
-entirely mechanical.
-
-33. The fifth form of membrane, the _mucous_ (fig. XXI.), derives its
-name from the peculiar fluid with which its surface is covered, called
-mucus, and which is secreted by numerous minute glands, imbedded in
-the substance of the membrane. As serous membrane forms a shut sac,
-completely excluding the air, mucous membrane, on the contrary, lines
-the various cavities which are exposed to the air, such as the mouth,
-the nostrils, the wind-pipe, the gullet, the stomach, the intestines,
-the urinary organs, and the uterine system. Its internal surface, or
-that by which it is attached to the passages it lines, is smooth and
-dense; its external surface, or that which is exposed to the contact
-of the air, is soft and pulpy, like the pile of velvet (fig. XXI.). It
-bears a considerable resemblance to the external surface of the rind of
-the ripe peach.
-
-[Illustration: Fig. XXI.
-
-A portion of the stomach, showing its internal surface or mucous coat.]
-
-Unlike all the other tissues of this class, the mucous membranes are
-the immediate seat of some of the most important functions of the
-economy; in the lung, of respiration; in the stomach, of digestion; in
-one part of the intestine, of chylification; in another, of excretion;
-while in the mouth and nose, they are the seat of the animal functions
-of taste and smell; and they are highly organized in accordance with
-the importance of the functions they perform.
-
-34. The last form of membrane which it is necessary to our present
-purpose to particularize, is that which constitutes the external
-covering of the body, and which is called the _skin_. The skin is
-everywhere directly continuous with the mucous membranes that line the
-internal passages, and its structure is perfectly analogous. Both the
-external and the internal surface of the body may be said therefore to
-be covered by a continuous membrane, possessing essentially the same
-organization, and almost identically the same chemical composition.
-The skin is an organ which performs exceedingly varied and important
-functions in the economy, to the understanding of which it is necessary
-to have a clear conception of its structure; some further account of it
-will therefore be required; but this will be more advantageously given
-when the offices it serves are explained.
-
-[Illustration: Fig. XXII. Portions of cartilage, seen in section.]
-
-35. Such is the structure, and such are the properties, of the
-first distinct form of organized matter. The second primary tissue,
-termed the CARTILAGINOUS (fig. XXII.), is a substance intermediate
-between membrane and bone. The nature of its organization is not
-clearly ascertained. By some anatomists, it is regarded as a uniform
-and homogeneous substance, like firm jelly, without fibres, plates,
-or cells; others state that they have been able to detect in it
-longitudinal fibres, interlaced by other fibres in an oblique and
-transverse direction, but without determinate order. All are agreed
-that it is without visible vessels or nerves: not that it is supposed
-to be destitute of them, but that they are so minute as to elude
-observation. Its manifest properties are wholly mechanical. It is
-dense, strong, inextensible, flexible, and highly elastic. It is
-chiefly by its property of elasticity that it accomplishes the various
-purposes it serves in the economy. It is placed at the extremities of
-bones, especially about the joints, where, by its smooth surface, it
-facilitates motion, and, by its yielding nature, prevents the shock or
-jar which would be produced were the same kind and degree of motion
-effected by a rigid and inflexible substance. Where a certain degree
-of strength with a considerable degree of flexibility are required, it
-supplies the place of bone, as in the spinal column, the ribs and the
-larynx.
-
-[Illustration: Fig. XXIII.
-
-Membranous portion of bone; the osseous portion being so completely
-removed, that the bone is capable of being tied in a knot.]
-
-36. The third distinct form of organized matter is termed the
-OSSEOUS tissue. Bone is composed of two distinct substances, an animal
-and an earthy matter: the former organic, the latter inorganic. The
-animal or organic matter is analogous both in its nature and in its
-arrangement to cellular tissue; the earthy or inorganic matter consists
-of phosphoric acid combined with lime, forming phosphate of lime. The
-cellular tissue is aggregated into plates or laminæ, which are placed
-one upon another, leaving between them interspaces or cells, in which
-is deposited the earthy matter (phosphate of lime). If a bone, for
-example, the bone called the radius, one of the bones of the fore-arm,
-be immersed in diluted sulphuric, nitric, muriatic, or acetic acid, it
-retains its original bulk and shape; it loses, however, a considerable
-portion of its weight, while it becomes so soft and pliable, that it
-may be tied in a knot (fig. XXIII.). In this case, its earthy matter
-is removed by the agency of the acid, and is held in solution in the
-fluid; what remains is membranous matter (cellular tissue). If the
-same bone be placed in a charcoal fire, and the heat be gradually
-raised to whiteness, it appears on cooling as white as chalk; it is
-extremely brittle; it has lost much of its weight, yet its bulk and
-shape continue but little changed. In this case, the membraneous matter
-is wholly consumed by the fire, while the earth is left unchanged (fig.
-XXIV.). Every constituent atom of bone consists, then, essentially
-of animal and earthy matter intimately combined. A little more than
-one-third part consists of animal matter (albumen), the remaining
-two-thirds consist of earthy matter (phosphate of lime); other saline
-substances, as the fluate of lime and the phosphate of magnesia, are
-also found in minute quantity, but they are not peculiar to bone.
-
-[Illustration: Fig. XXIV.
-
-Earthy portion of bone.]
-
-37. In general, the osseous tissue is placed in the interior of the
-body. Even when bone approaches the surface, it is always covered
-by soft parts. It is supplied with but few blood-vessels, with
-still fewer nerves, with no absorbents large enough to be visible,
-so that though it be truly alive, yet its vital properties are not
-greatly developed. The arrangement of its component particles is
-highly curious; the structure, the disposition, and the connexion of
-individual bones afford striking examples of mechanism, and accomplish
-most important uses in the economy; but those uses are dependent
-rather upon mechanical than vital properties. The chief uses of bone
-are— 1. By its hardness and firmness to afford a support to the soft
-parts, forming pillars to which the more delicate and flexible organs
-are attached and kept in their relative positions. 2. To defend the
-soft and tender organs by forming a case in which they are lodged and
-protected, as that formed by the bones of the cranium for the lodgment
-and protection of the brain (fig. XLVII.); by the bones of the spinal
-column for the lodgment and protection of the spinal cord (fig.
-XLVIII.); by the bones of the thorax (fig. LIX.), for the lodgment and
-protection of the lungs, the heart, and the great vessels connected
-with it (fig. LIX.). 3. By affording fixed points for the action of the
-muscles, and by assisting in the formation of joints to aid the muscles
-in accomplishing the function of locomotion.
-
-38. All the primary tissues which have now been considered consist of
-precisely the same proximate principles. Albumen is the basis of them
-all; with the albumen is always mixed more or less gelatin, together
-with a minute quantity of saline substance: to the osseous tissue is
-superadded a large proportion of earthy matter. With the exception
-of the mucous, the organization of all these tissues is simple;
-their vital properties are low in kind and in degree; their decided
-properties are physical, and the uses they serve in the economy are
-almost wholly mechanical.
-
-[Illustration: Fig. XXV.
-
-Portion of a muscle; showing (_a_) the muscular fibres and their
-parallel direction; and (_b_) the termination of the fibres in tendon.]
-
-39. But we next come to a tissue widely different in every one of
-those circumstances, a tissue consisting of a new kind of animal
-matter, and endowed with a property not only peculiar to itself,
-but proper to living substance, and characteristic of a high degree
-of vital power. MUSCULAR TISSUE, the fourth distinct form of animal
-matter, commonly known under the name of flesh, is a substance
-resembling no other in nature. It consists of a soft and pulpy
-substance, having little cohesive power, arranged into fibres which
-are distinctly visible to the naked eye, and which are disposed in a
-regular and uniform manner, being placed close and parallel to each
-other (fig. XXV.). These fibres are every where pretty uniformly the
-same in shape, size, and general appearance, being delicate, soft,
-flattened, and though consisting only of a tender pulp, still solid
-(fig. XXV.). When examined under the microscope, fibres, which to the
-naked eye appear to be single threads, are seen to divide successively
-into smaller threads, the minutest or the ultimate division not
-exceeding, as is supposed, the 40,000th part of an inch in diameter. On
-the other hand, the fibres which are large enough to be visible to the
-naked eye, are obviously aggregated into bundles of different magnitude
-in different muscles, but always of the same uniform size in the same
-muscle (fig. XXV.).
-
-[Illustration: Fig. XXVI.
-
-Two portions of muscle; one of which, _a_, is covered with membrane;
-the other, _b_, is uncovered; _c_, the muscular fibres terminating in
-tendon.]
-
-40. The ultimate thread, or the minutest division of which the
-muscular fibre is susceptible, is called a filament; the smallest
-thread which can be distinguished by the naked eye is termed a fibre
-(fig. XXVI.); and the bundle which is formed by the union of fibres
-is denominated a fasciculus. The proper muscular substance is thus
-arranged into three distinct forms progressively increasing in
-size,—the filament, the fibre, and the fasciculus. The filament, the
-fibre, the fasciculus, as well as the muscle itself, formed by the
-aggregation of fasciculi, is each inclosed in its own distinct sheath
-of cellular membrane (fig. XXVI. _a_).
-
-[Illustration: Fig. XXVII.
-
-Portion of a muscle enclosed in a sheath of fascia or aponeurosis.]
-
-41. The composition of the ultimate filament has been very carefully
-examined by many distinguished physiologists with microscopes of high
-magnifying power. Under some of these microscopes the filament appears
-to consist of a series of rounded particles or globules of the same
-size as the particles of the blood when deprived of their colouring
-matter, so that it looks like a string of pearls (fig. XXVIII.), each
-globule being commonly stated to be about the 2000th part of an inch
-in diameter. But it is now pretty generally agreed that this globular
-appearance of the ultimate muscular fibre vanishes under the more
-improved microscopes of the present day, and, as viewed by the latter,
-appears as a peculiar pulpy substance arranged into threads of extreme
-minuteness, placed close and parallel to each other, intersected by a
-great number of delicate lines passing transversely across the muscular
-threads (fig. XXIX.),
-
-[Illustration: Fig. XXVIII.
-
-Ultimate fibres of muscle, very greatly magnified; showing the strings
-of globules of which they are supposed by some to consist.]
-
-42. With the exception of the organs of sense, the muscular tissue is
-more abundantly supplied with arteries, veins, and nerves, than any
-other substance of the body. Every ultimate thread or filament appears
-to be provided with the ultimate branch of an artery, vein, and nerve.
-These vessels are seen ramifying on the surface of the delicate web of
-membrane that incloses the pulp, but cannot be traced into it.
-
-[Illustration: Fig. XXIX.
-
-The appearance of the ultimate muscular fibres and of their transverse
-lines, as seen under the microscope of Mr. Lister, when the object is
-magnified 500 diameters.]
-
-43. The proximate principle of which the muscular pulp is composed
-is fibrin. From the pulp, when inclosed in its sheath of membrane,
-albumen, jelly, various salts, and a peculiar animal extract called
-osmazome, are also obtained; but these substances are probably derived
-from the membranous, not the muscular, matter. Fibrin contains a larger
-proportion of azote, the element peculiar to the animal body, and by
-the possession of which its chemical composition is distinguished from
-that of the vegetable, than any other animal substance.
-
-[Illustration: Fig. XXX.
-
-Portion of the trunk of a nerve; dividing into branches.]
-
-44. Muscular tissue possesses a slight degree of cohesion, a high
-degree of flexibility and extensibility, but no degree of elasticity;
-for although muscle, considered as a compound of muscular substance and
-membrane, be highly elastic, yet this property is probably altogether
-owing to the membranous matter in which it is enveloped. Its peculiar
-and distinctive property is vital, not physical, and consists in the
-power of diminishing its length, or of contracting or shortening itself
-on the application of a stimulus. This property, which is termed
-contractility, is the great, if not the sole source of motion in the
-body. Without doubt, elasticity and gravity, under the generating and
-controlling powder of contractility, aid in accomplishing various
-kinds of motion. Thus membranes, tendons, ligaments, cartilages, and
-bones, by their physical and mechanical properties, modify, economize,
-facilitate, concentrate and direct the motive power generated by the
-pure muscular substance; but still the only real source of motion in
-the body is muscular tissue, and the only mode in which motion is
-generated is by contractility. This will be more fully understood
-hereafter.
-
-[Illustration: Fig. XXXI.
-
-Ultimate fibres of nerve, very highly magnified; showing the strings of
-globules of which they consist.]
-
-45. The last primary tissue, termed the NERVOUS, is equally distinct
-in nature and peculiar in property. It consists of a soft and pulpy
-matter, of a brownish white colour (fig. XXX.). According to some,
-the nervous, like the muscular pulp, is composed of minute globules,
-arranged in the same manner like a string of pearls (fig. XXXI.);
-according to others, it consists of solid elongated threads, of a
-cylindrical form, differing in thickness from that of a hair to the
-finest fibre of silk. The pulp, whatever its form of aggregation, is
-inclosed in a sheath of delicate cellular tissue. This external or
-containing membrane is called the neurilema, or the nerve-coat; the
-internal or contained substance, the proper nervous matter, is termed
-the nerve-string. The nerve-string, enveloped in its nerve-coat,
-constitutes the nervous filament. As in the muscle, so in the nerve,
-many filaments unite to form a fibre, many fibres to form a fasciculus,
-and many fasciculi to form the large cord termed a nerve. Moreover,
-as in the muscle, so in the nerve, the filament, the fibre, the
-fasciculus, the nervous cord itself, are each enveloped in its own
-distinct sheath of cellular membrane; but the arrangement of the
-nervous fibres differs from that of the muscular in this, that though
-the nervous fibres are placed in juxtaposition, yet they do not,
-like the muscular, maintain through their entire course a parallel
-disposition, but cross and penetrate each other, so as to form an
-intimate interlacement (fig. XXXII.).
-
-[Illustration: Fig. XXXII.
-
-Nervous fibres, deprived of their neurilema and unravelled, showing the
-smaller threads, or filaments, of which the fibres consist.]
-
-46. The nervous pulp is at least as liberally supplied with
-blood-vessels as the muscular; the vessels are spread out upon the
-nerve-coat, in which they divide into innumerable branches of extreme
-minuteness, the distribution of which is so perfect, that there is
-not a particle of nervous matter which is not supplied both with an
-arterial and a venous vessel. Hence the neurilema is not merely a
-sheath containing and protecting the nervous pulp, but it affords an
-extended mechanical surface for sustaining the arterial vessels, from
-which the pulp is probably secreted, and certainly nourished.
-
-47. Albumen, in conjunction with a peculiar fatty matter, constitutes
-the chief proximate principles of which the nervous tissue is composed.
-To these are added a small proportion of the animal substance termed
-osmazome, a minute quantity of phosphorus, some salts, and a very large
-proportion of water; for out of one hundred parts of nervous substance,
-water constitutes as much as eighty. Its peculiar vital property is
-sensibility; and as all motion depends on the contractility of the
-muscular fibre, so all sensation depends on the sensibility of the
-nervous substance.
-
-48. Such are the primary tissues, or the several kinds of organized
-matter of which the body is composed; and from this account it is
-obvious that they consist of three only—namely, the concrete matter
-forming the basis of membrane, the pulpy matter forming the proper
-muscular substance, and the pulpy matter forming the proper nervous
-substance. Of these three kinds of animal matter the component parts of
-the body consist. In combining to form the different structures, these
-primary substances are intermixed and arranged in a great variety of
-modes; and from these combinations and arrangements result either an
-organ, a system, or an apparatus.
-
-49. As filaments unite to form fibres, and fibres to form tissues, so
-tissues unite to form organs: that is, bodies having a determinate
-size and figure, and capable of performing specific actions. The
-cellular, the muscular, and the nervous tissues are not organs;
-membranes, muscles, and nerves are organs. The tissue, the simple
-animal substance, is merely one of the elements of which the organ
-is composed; the organ is compounded of several of those simple
-substances, arranged in a determinate manner, and moulded into a given
-shape, and so constituting a specific instrument. The basis of the
-muscle is muscular tissue; but to this are added, invariably, membrane,
-often tendon, and always vessels and nerves. It is this combination
-that forms the specific instrument called a muscle, and that renders it
-capable of performing its specific action. And every such combination,
-with its appropriate endowment, constitutes an organ.
-
-50. Organs are arranged into groups or classes, according as they
-possess an analogous structure, and perform an analogous function; and
-this assemblage constitutes a SYSTEM. All the muscles of the body,
-for example, whatever their size, form, situation, or use, have an
-analogous structure, and perform an analogous function, and hence are
-classed together under the name of the muscular system. All the bones,
-whatever their figure, magnitude, density, position, or office, are
-analogous in structure and function; and hence are classed together
-under the name of the osseous system. For the same reason, all the
-cartilages, ligaments, vessels and nerves, form respectively the
-cartilaginous, ligamentous, vascular and nervous systems.
-
-51. An APPARATUS, on the contrary, is an assemblage of organs, it
-may be differing widely from each other in structure, and exercising
-various and even opposite functions; but all nevertheless concurring
-in the production of some common object. The apparatus of nutrition
-consists of the organs of mastication, deglutition, digestion,
-absorption, and assimilation. Among the individual organs which concur
-in carrying on these functions may be reckoned the lips, the teeth,
-the tongue, the muscles connected with the jaws, the gullet, the
-stomach, the duodenum, the small intestines, the pancreas, the liver,
-the lacteal vessels, the mesenteric glands, and the lungs. Many of
-these organs have no similarity in structure, and few have any thing
-analogous in function; yet all concur, each in its appropriate mode and
-measure, to the conversion of the aliment into blood. In the apparatus
-of respiration, in that of circulation, of secretion, of excretion;
-in the apparatus of locomotion, in the apparatus of sensation, and
-more especially in the apparatus of the specific sensations,—vision,
-hearing, smell, taste, touch, organs are combined which have nothing
-in common but their concurrence in the production of a common end:
-but this concurrence is the principle of their combination; and the
-individual organs having this conjoint operation, taken together,
-constitute an apparatus.
-
-52. A clear idea may now be affixed to the terms structure and
-organization. Structure may be considered as synonymous with
-arrangement; the disposition of parts in a determinate order; that
-which is constructed or built up in a definite mode, according to a
-determinate plan. The arrangement of the threads of the cellular web
-into areolæ or cells; the combination of the primary threads into
-fibres or laminæ; the disposition of the muscular pulp into filaments,
-placed parallel to each other; the investment of the filaments in
-membraneous sheaths; the combination of the filaments, included in
-their sheaths, into fibres; the aggregation of fibres into fasciculi;
-and the analogous arrangement and combination of the nervous pulp,
-are examples of structure. But when those structures are applied to
-particular uses; when they are so combined and disposed as to form
-a peculiar instrument, endowed with a specific function; when the
-cellular fibres, for example, are so arranged as to make a thin, dense,
-and expanded tissue; when to this tissue are added blood-vessels,
-absorbents, and nerves; when, in a word, a membrane is constructed,
-an organ is formed; when, in like manner, to the muscular and the
-nervous fibres, arranged and moulded in the requisite mode, are added
-blood-vessels, absorbents, and nerves, other organs are constructed
-capable of performing specific functions: and this is organization—the
-building up of organs—the combination of definite structures
-into special instruments. Structure is the preparatory process of
-organization; the one is the mere arrangement of the material; the
-other is the appropriation of the prepared material to a specific use.
-
-53. The term organization is employed in reference both to the
-component parts of the body, and to the body considered as a whole. We
-speak of an organized substance and of an organized body. An organized
-substance is one in which there is not only a definite arrangement
-of its component parts (structure), but in which the particular
-arrangement is such as to fit it for accomplishing some special
-use. Every organized substance is therefore essentially a special
-organ; limited in its object it may be, and perhaps only conducive
-to some further object; but still its distinctive character is, that
-it has a peculiar structure, fitting it for the accomplishment of
-some appropriate purpose. On the other hand, an organized body is a
-congeries of organs—the aggregate of the individual organs. Attention
-was directed in the early part of this work to one peculiar and
-essential character, by which such an organized is distinguished from
-an unorganized body. Between the individual parts of the organized body
-there is so close a relation, that no one of them can be removed or
-injured, or in any manner affected without a corresponding affection of
-the whole. The action of the heart cannot cease without the cessation
-of the action of the lung; nor that of the lung without that of the
-brain; nor that of the brain without that of the stomach; in a word,
-there is no organ in whatever distant nook of the system it be placed,
-or however apparently insignificant its function, that is not necessary
-to the perfection of the whole. But into whatever number of portions an
-unorganized body may be divided, each portion retains the properties of
-the mass, and constitutes in itself a perfect existence; there being
-no relation between its individual parts, excepting that of physical
-attraction: on the contrary, each component part of an organized body,
-being endowed with some appropriate and specific power, on the exercise
-of which the powers of all the other parts are more or less dependent,
-the whole must necessarily suffer if but one part fail.
-
-54. From the whole, then, we see that the human body is a congeries of
-organs; that those organs are constructed of a few simple tissues; and
-that all its parts, numerous, diversified, and complex as they are, are
-composed of but three primary forms of animal matter variously modified
-and combined.
-
-[Illustration: Fig. XXXIII.
-
-Muscles of the back and shoulders; showing their symmetrical
-disposition.]
-
-55. But though by the analysis of its component parts, this machine,
-so complex in its construction, and so wonderfully endowed, may be
-reduced to this state of simplicity; and although this analytical view
-of it be highly useful in enabling us to form a clear conception of the
-nature of its composition; yet it is only by considering its individual
-parts such as they actually are, and by studying their situation,
-connexion, structure, and action, that we can understand it as a whole,
-and apply our knowledge of it to any practical use.
-
-56. Viewing then the human body as a complicated whole, as a congeries
-of organs made up of various combinations of simple tissues, it may
-be observed, in reference to its external configuration, that it is
-rounded. This rounded form is principally owing to the large proportion
-of fluids which enter into its composition. The roundness of the face,
-limbs, and entire surface of the child, are in striking contrast to
-the unequal and irregular surface of the old man, whose humours are
-comparatively very much smaller in quantity.
-
-57. The length of the human body exceeds its breadth and thickness;
-the degree of the excess varying at different periods of life, and
-according to the peculiar constitution of the individual. In the
-extremities, the bones, muscles, vessels, and nerves, are especially
-distinguished by their length.
-
-[Illustration: Fig. XXXIV.
-
-Front view of the skeleton. 1. the head; 2. the trunk; 3. the superior
-extremities; 4. the inferior extremities.]
-
-[Illustration: Fig. XXXV.
-
-Back view of the skeleton. 1. the head; 2. the trunk; 3. the superior
-extremities; 4. the inferior extremities.]
-
-58. The form of the human body is symmetrical, that is, it is
-capable of being divided into two lateral and corresponding halves.
-Suppose a median line to pass from the vertex of the head through the
-centre of the spinal column (fig. XXXIV. 1, 2); if the body be well
-formed, it will be divided by this line into two exactly equal and
-corresponding portions (fig. XXXV. 1). This symmetrical disposition
-of the body is not confined to its external configuration. It is
-true of many of the internal organs; but principally, as has been
-already stated, of those that belong to the animal life. The brain and
-the spinal cord are divisible into two exactly equal halves (figs.
-XLVIII. _d_, and XLIX. 1, 2, 3); the organs of sense are double and
-symmetrical: the muscles of one side of the body exactly correspond to
-those of the other (fig. XXXIII.); the two hands and arms and the two
-lower extremities are alike (figs. XXXIV., XXXV.); but for the most
-part, the organs of the organic life, the stomach, the intestines, the
-liver, the spleen, for example, are single, and not symmetrical.
-
-59. The human body is divided into three great portions, the head, the
-trunk, and the extremities (figs. XXXIV. and XXXV. 1, 2, 3, 4).
-
-60. By the HEAD is meant all that part of the body which is placed
-above the first bone of the neck (fig. XXXIV. 1). It is of a spheroidal
-figure, broader and deeper behind than before, somewhat like an egg in
-shape, with the broad end behind; it is flattened at its sides (figs.
-XXXV. 1, and XXXVI. 2, 4). Its peculiar figure renders it at once
-stronger and more capacious than it could have been had it possessed
-any other form. It is supported by its base on the spinal column, to
-which it is attached by the peculiar structure termed a joint (fig.
-XXXIV.), and fastened by ligaments of exceeding strength.
-
-61. The head contains the central organ of the nervous system; the
-organs of the senses, with the exception of that of touch; and the
-organs of mastication. It comprehends the cranium and the face. Both
-are composed partly of soft parts, as the teguments, namely, skin, fat,
-&c., and muscles; and partly of bones.
-
-[Illustration: Fig. XXXVI.
-
-1. Frontal bone; 2. parietal bone; 3. occipital bone; 4. temporal bone;
-5. nasal bone; 6. malar bone; 7. superior maxillary bone; 8. inferior
-maxillary bone.]
-
-[Illustration: Fig. XXXVII.
-
-Bones of the skull, separated; front view. 1. Frontal bone; 2. portions
-of the parietal bones; 3. malar or cheek bones; 4. nasal bones; 5.
-superior maxillary or bones of the upper jaw; 6. the vomer; 7. the
-inferior maxillary or bone of the lower jaw.]
-
-[Illustration: Fig. XXXVIII.
-
-Bones of the skull separated; side view. 1. Frontal bone; 2. parietal
-bone; 3. occipital bone; 4. temporal bone; 5. nasal bone; 6. malar
-bone; 7. superior maxillary bone; 8. the unguis; 9. the inferior
-maxillary bone.]
-
-[Illustration: Fig. XXXIX.
-
-Bones forming the base of the skull; viewed from the inside. 1.
-Occipital bone; 2. temporal bones; 3. sphenoid bone; 4. ethmoid bone;
-5. superior maxillary bones, or bones of the upper jaw; 6. malar or
-cheek bones; 7. foramen magnum.]
-
-62. The bones of the cranium are eight in number, six of which are
-proper to the cranium, and two are common to it and to the face. The
-six bones proper to the cranium are the frontal (fig. XXXVII. 1), the
-two parietal (fig. XXXVI. 2), the two temporal (fig. XXXVIII. 4), and
-the occipital (fig. XXXVIII. 3); the two common to the cranium and face
-are the ethmoidal (fig. XXXIX. 4), and the sphenoidal (fig. XXXIX.
-3). The frontal bone forms the entire forepart of the vault (fig.
-XXXVII. 1); the two parietal form the upper and middle part of it (fig.
-XXXVIII. 2); the two temporal form the lower part of the sides (fig.
-XXXVIII. 4); the occipital forms the whole hinder part, together with a
-portion of the base (figs. XXXVIII. 3, XXXVI. 3, XXXIX. 1); while the
-ethmoidal forms the forepart, and the sphenoidal the middle part of the
-base (fig. XXXIX. 3, 4).
-
-[Illustration: Fig. XL.
-
-2 1
-
-Portions of the bones of the cranium; showing the corresponding
-inequalities in their margins: which margins, when in apposition,
-constitute the mode of union termed suture. 1. External surface of the
-bone; 2. internal surface.]
-
-[Illustration: Fig. XLI.
-
-1
-
-Fig. XLII.
-
-2
-
-1. Side view of the adult skull, showing the several bones united by
-suture; 2. side view of the fœtal skull, showing the bones imperfectly
-ossified, separated to some extent from each other, the interspace
-being occupied by membrane. The small size of the face compared with
-that of the cranium is strikingly apparent.]
-
-63. These bones are firmly united together. The union of bones is
-technically called an _articulation_ or _joint_. All joints are either
-immoveable or moveable. The union of the bones of the cranium affords
-an example of an immoveable articulation. Prominences and indentations,
-like the teeth of a saw, are formed in the margins of the contiguous
-bones (figs. XXXVIII. and XL.). At these inequalities of surface, which
-are exactly adapted to each other (figs. XXXVIII. and XL.), the two
-bones are in immediate apposition in such a manner as to preclude the
-possibility of motion, and even to render the separation extremely
-difficult. This mode of articulation is termed a _suture_. There are
-certain advantages in constructing the cranium of several distinct
-bones, and in uniting them in this peculiar mode. 1. The walls of the
-vault are stronger than they could have been had they been formed of a
-single piece. 2. In the fœtus, the bones are at some distance from each
-other (fig. XLII.); at birth, they yield and overlap one another; and
-in this manner they conduce to the security and ease of that event. 3.
-Minute vessels pass abundantly and securely through the interstices of
-the sutures to and from the interior of the cranium; in this manner,
-a free communication is established between the vessels within and
-without this cavity. 4. It is probable that the shock produced by
-external violence is diminished in consequence of the interruption of
-the vibration occasioned by the suture; it is certain that fracture is
-prevented by it from extending as far as it would do in one continued
-bony substance.
-
-[Illustration: Fig. XLIII.
-
-Section of the skull. 1. Cavity of the cranium occupied by the brain;
-2. cut edge of the bones of the cranium, showing the two tables of
-compact bone and the intervening spongy texture called diploë.]
-
-64. The vault of the cranium forms a cavity which contains the
-brain (fig. XLIII. and XLVIII.) The size of this cavity is invariably
-proportioned to that of the organ it lodges and protects. The form and
-magnitude of the cavity, and consequently the shape and size of the
-cranium, depend upon the brain, and not of the brain upon the cranium.
-The soft parts model and adapt to themselves the hard, and not the hard
-the soft. The formation of the brain in the fœtus is anterior to that
-of the case which ultimately contains it; and the hard bone is moulded
-upon the soft pulp, not the pulp upon the bone. At every period of
-life, on the inner surface of the cranium there are visible impressions
-made by the convolutions of the brain, and the ramifications of the
-arteries (figs. XXXIX. 1, 2, and XL. 2), and on its external surface
-are depressions occasioned by the action of the external muscles. Nor
-does the modifying power of the brain over the bones of the cranium
-terminate at birth. The formation of bone, always a slow process,
-is never completed until the child has attained its third or fourth
-year, and often not until a much later period. At this tender age, the
-bones, which in advanced life are hard and rigid, are comparatively
-soft and yielding, and consequently more readily receive and retain
-the impression of the convolutions and of the other projecting parts
-of the brain, by which they are sometimes so deeply marked, that an
-attentive examination of the inner surface of the cranium is of itself
-sufficient to determine not only that some part, but to indicate the
-very part of the brain which has been preternaturally active. At this
-tender age, pressure, internal or external, general or partial, may
-readily change the form of the cranium. If, by a particular posture,
-the head of a child be unequally balanced on the spine, the brain will
-press more on that side of the cranium than on the other; the organ
-will expand in the direction to which it inclines; that portion of it
-will become preternaturally developed, and consequently the balance of
-its functions will be disturbed. An awkward way of standing or sitting,
-perhaps contracted inadvertently and kept up by habit; a wry neck; any
-cause that keeps the head constantly inclined to one side, may produce
-this result, examples of which and of its consequences will be given
-hereafter.
-
-65. Tracing them from without inwards we see, then, that the various
-coverings afforded to the brain, the central organ of the animal life,
-seated in its vaulted cavity, are: 1. The tegument, consisting of the
-skin and of cellular and adipose membrane. 2. Beneath the tegument,
-muscles, in the forepart and at the vertex, comparatively slender and
-delicate; at the sides and posteriorly, thick, strong, and powerful
-(fig. XLIV.). 3. Beneath the muscles, a thin but dense membrane, termed
-the pericranium, lining the external surface of the cranial bones. 4.
-Beneath the pericranium, the bony substance of the cranium, consisting
-of two firm and hard bony plates, with a spongy, bony structure, called
-diploë, interposed between them (fig. XLIII. 2). 5. Immediately in
-contact with the inner surface of the bony substance of the cranium,
-and forming its internal lining, the dense and strong membrane, called
-the _dura mater_, not only affording a general covering to the brain,
-but sending firm partitions between individual portions of it (fig.
-XLVIII. _c._). 6. A serous membrane lining the internal surface of
-the dura mater, and reflected over the entire surface of the brain,
-termed the arachnoid tunic. 7. A thin and delicate membrane in
-immediate contact with the substance of the brain, descending between
-all its convolutions, lining all its cavities and enveloping all its
-fibres, called the pia mater. 8. An aqueous fluid, contained between
-the arachnoid membrane and the pia mater. Skin, muscle, pericranium,
-bone, dura mater, arachnoid membrane, pia mater, and aqueous fluid,
-superimposed one upon another, form, then, the covering and defence of
-the brain; so great is the care taken to protect this soft and tender
-substance.
-
-66. The bones of the _face_ consist of fourteen, namely, the two
-superior maxillary or jaw-bones (fig. XXXVII. 5), the two malar or
-cheek bones (fig. XXXVII. 3), the two nasal bones (fig. XXXVII. 4),
-the two palate bones, the two ossa unguis (fig. XXXVIII. 8), the two
-inferior turbinated bones, the vomer (fig. XXXVII. 6), and the inferior
-maxilla or the lower jaw (fig. XXXVII. 7.) This irregular pile of bones
-is divided into the superior and inferior maxilla or jaws; the superior
-maxilla being the upper and immoveable portion of the face; the
-inferior maxilla being the lower and moveable portion of it. Besides
-these bones, the face contains thirty-two teeth, sixteen in each
-jaw. The bones of the upper jaw are united together by sutures, and
-the union is so firm, that they have no motion but what they possess
-in common with the cranium. The lower jaw is united by a distinct
-articulation with the cranium (figs. XXXIV. and XXXV.).
-
-67. Besides the bones and the teguments, the face contains a number of
-muscles, which for the most part are small and delicate (fig. XLIV.),
-together with a considerable portion of adipose matter; while, as has
-been stated, the face and head together contain all the senses, with
-the exception of that of touch, which is diffused, more or less, over
-the entire surface of the body.
-
-[Illustration: Fig. XLIV.
-
-Muscles of the face.]
-
-68. The second great division of the body, termed the TRUNK, extends
-from the first bone of the neck to that called the pubis in front, and
-to the lower end of the coccyx behind (fig. XXXIV. 2). It is subdivided
-into the thorax, the abdomen, and the pelvis (fig. XLV.).
-
-69. The _thorax_ or _chest_ extends above from the first bone of
-the neck, by which it is connected with the head, to the diaphragm
-below, by which it is divided from the abdomen (figs. XLV. and LXI.).
-It consists partly of muscles and partly of bones; the muscular and
-the osseous portions being in nearly equal proportions. Both together
-form the walls of a cavity in which are placed the central organs of
-circulation and respiration (fig. LX. 2, 5). The chief boundaries of
-the cavity of the thorax before, behind, and at the sides, are osseous
-(fig. XLV.); being formed before, by the sternum or breast-bone (fig.
-XLV. 6); behind, by the spinal column or back bone (fig. XLV. 2, 4);
-and at the sides, by the ribs (fig. XLV. 7). Below, the boundary is
-muscular, being formed by the diaphragm (fig. LXI. 2), while above the
-thorax is so much contracted (fig. XLV.), that there is merely a space
-left for the passage of certain parts which will be noticed immediately.
-
-70. The figure of the thorax is that of a cone, the apex being above
-(fig. XLV.), through the aperture of which pass the tubes that lead
-to the lungs and stomach, and the great blood-vessels that go to and
-from the heart (fig. LX.). The base of the cone is slanting, and is
-considerably shorter before than behind, like an oblique section of the
-cone (fig. XLV.).
-
-71. The osseous portion of the walls of the thorax is formed behind by
-the spinal column, a range of bones common indeed to all the divisions
-of the trunk; for it constitutes alike the posterior boundary of the
-thorax, abdomen, and pelvis (fig. XLV. 2, 4, 6). It is composed of
-thirty distinct bones, twenty-four of which are separate and moveable
-on one another, and on this account are called true vertebræ (fig. XLV.
-2, 4); the other five, though separate at an early period of life, are
-subsequently united into a single solid piece, called the sacrum (fig.
-XLV. 5). The bones composing this solid piece, as they admit of no
-motion on each other, are called false vertebræ (fig. XLV. 5). To the
-extremity of the sacrum is attached the last bone of the series, termed
-the coccyx (fig. XXXV.).
-
-72. From above downwards, that is, from the first bone of the neck to
-the first bone of the sacrum, the separate bones forming the column
-progressively increase in size; for this column is the chief support
-of the weight of the head and trunk, and this weight is progressively
-augmenting to this point (fig. XLV. 2, 4). From the sacrum to the
-coccyx, the bones successively diminish in size, until, at the
-extremity of the coccyx, they come to a point (fig. XXXV.). The spinal
-column may therefore be said to consist of two pyramids united at their
-base (fig. XLV. 4, 5). The superior pyramid is equal in length to about
-one third of the height of the body, and it is this portion of the
-column only that is moveable.
-
-73. The two surfaces of the spinal column, the anterior and the
-posterior, present a striking contrast (figs. XXXIV. and XXXV.). The
-anterior surface, which in its whole extent is rounded and smooth, is
-broad in the region of the neck, narrow in the region of the back, and
-again broad in the region of the loins (fig. XLV. 2, 4.). It presents
-three curvatures (fig. XLV. 2, 4); the convexity of that of the neck
-being forwards, that of the back backwards, and that of the loins again
-forwards (fig. XLV. 2, 4).
-
-74. From the posterior surface of the column, which is every where
-irregular and rough, spring, along the median line, in regular series,
-strong, sharp, and pointed projections of bone (fig. XXXV.), which
-from being sharp and pointed, like elongated spines, are called
-spinous processes, and have given name to the whole chain of bones.
-These processes afford fixed points for the action of powerful
-muscles. Extending the whole length of the column, from the base of
-the skull to the sacrum, on each side of the spinous processes, are
-deep excavations, which are filled up with the powerful muscles that
-maintain the trunk of the body erect.
-
-75. From the lateral surfaces of the column likewise spring short but
-strong projections of bone, termed transverse processes, which also
-give attachment to powerful muscles (fig. XLVI.).
-
-[Illustration: Fig. XLV.
-
-Bones of the trunk. 1. Spinal column; 2. the seven cervical vertebræ;
-3. the twelve dorsal vertebræ; 4. the five lumbar vertebræ; 5. the
-sacrum; 6. the sternum; 7. the true ribs; 8. the false ribs; 9. the
-clavicle; 10. the scapula; 11. the ilium; 12. the ischium; 13. the
-pubes; 14. the acetabulum; 15. the brim of the pelvis.]
-
-76. The separate bones of the series have a kind of turning motion on
-each other; hence each is called a vertebra, and the name of vertebral
-column is often given to the entire series, as well as that of spinal
-column. That portion of the column which forms the neck consists of
-seven distinct bones, called cervical vertebræ (fig. XLV. 2); that
-portion which forms the back consists of twelve, called dorsal vertebræ
-(fig. XLV. 3); that portion which forms the loins consists of five,
-called lumbar vertebræ (fig. XLV. 4). Between each of these classes of
-vertebræ there are specific differences, but they need not be described
-here: all that is necessary to the present purpose is an account of the
-structure which is common to every vertebra.
-
-77. By inspecting fig. XLVI. 1, it will be seen that the upper and
-under edges of each vertebra consist of a ring of bone, of a firm
-and compact texture, rendering what may be called the body of the
-vertebra exceedingly strong (fig. XLVI. 3). This ring of bone forms a
-superficial depression (fig. XLVI. 2), for the reception of a peculiar
-substance, immediately to be described, which is interposed between
-each vertebra (fig. XLVII. 2).
-
-78. The anterior surface of the body of the vertebra is convex (fig.
-XLVI. 3); its posterior surface is concave (fig. XLVI. 4); from the
-posterior surface springs a bony arch (figs. XLVI. 5 and LIII. 1),
-which, together with the posterior concavity, forms an aperture of
-considerable magnitude (fig. XLVI. 6), a portion of the canal for the
-passage of the spinal cord (figs. XLVII. 3, and XLIX. 3).
-
-[Illustration: Fig. XLVI.
-
-View of some of the vertebræ, which by their union form the spinal
-column.
-
-_a._ A vertebra of the neck; _b._ a vertebra of the back; a vertebra of
-the loins.
-
-1. Ring of compact bone forming, 3, the body of the vertebra; 2.
-superficial depression for the reception of the intervertebral
-cartilage; 3. anterior surface of the body of the vertebra; 4.
-posterior surface; 5. bony arch; 6. opening for the passage of the
-spinal cord; 7. opening for the passage of the spinal nerves; 8.
-articulating processes by which the vertebræ are joined to each other;
-9. two dorsal vertebræ united, showing the arrangement of, 10, the
-spinous processes; 11. a portion of a rib articulated with the side of
-the vertebra.]
-
-79. Both the upper and under edges of the arch form a notch (fig. XLVI.
-7.), which, together with a corresponding notch in the contiguous
-vertebra, completes another aperture rounder and smaller than the
-former, but still of considerable size (fig. XLVI. 7.), the passage of
-the spinal nerves (fig. XLVII. 3).
-
-80. From both the upper and under sides of the arch proceed two short
-but strong projections of bone (fig. XLVI. 8.), termed the articulating
-processes, because it is chiefly by these processes that the vertebræ
-are connected together. From the beginning to the end of the series,
-the two upper processes of the one vertebra are united with the two
-lower processes of the vertebra immediately above it (fig. XLVI. 9),
-and around the edges of all the articulating processes are visible
-rough lines, which mark the places to which the articulating ligaments
-are attached.
-
-81. No vertebra, except the first, rests immediately upon its
-contiguous vertebra (fig. XLV. 2, 4). Each is separated from its fellow
-by a substance of a peculiar nature interposed between them, termed the
-intervertebral substance (figs. XLVII. 2, and L. 2). This substance
-partakes partly of the nature of cartilage, and partly of that of
-ligament. It is composed of concentric plates, formed of oblique fibres
-which intersect each other in every direction. This substance, for
-about a quarter of an inch from its circumference towards its centre,
-is tough, strong, and unyielding; then it becomes softer, and is
-manifestly elastic; and so it continues until it approaches the centre,
-when it becomes pulpy, and is again inelastic. The exterior tough and
-unyielding matter is for the firmness of the connexion of the several
-vertebræ with each other; the interior softer and elastic matter is for
-the easy play of the vertebræ upon each other; the one for security,
-the other for pliancy. And the adjustment of the one to the other is
-such as to combine these properties in a perfect, manner. The quantity
-of the unyielding substance is not so great as to produce rigidity;
-the quantity of the elastic substance is not so great as to occasion
-insecurity. The firm union of its solid matter renders the entire
-column strong; the aggregate elasticity of its softer substance renders
-it springy.
-
-[Illustration: Fig. XLVII.
-
-1. One of the Lumbar vertebræ. 2. Intervertebral substance. 3. A
-portion of the spinal cord in its canal.]
-
-82. The column is not constructed in such a manner as to admit of an
-equal degree of motion in every part of it. Every thing is contrived
-to give to that portion which belongs to the neck freedom of motion,
-and, on the contrary, to render that portion which belongs to the back
-comparatively fixed. In the neck the mechanism of the articulating
-processes is such as to admit of an equal degree of sliding motion
-forwards, backwards, and from side to side, together with a turning
-motion of one bone upon another; at the same time, the intervertebral
-substance between the several vertebræ is thick. In consequence of this
-mechanism, we can touch the breast with the chin, the back with the
-hind head, and the shoulders with the ear, while we can make the head
-describe more than a semicircle. But, in the back, the articulating
-processes are so connected as to prevent the possibility of any motion,
-either forwards or backwards, or any turning of one vertebra upon
-another, while the intervertebral substance is comparatively thin (fig.
-XLV. 2, 4). That portion of the column which belongs to the back is
-intended to afford a fixed support for the ribs, a support which is
-indispensable to their action in the function of respiration. In the
-loins, the articulating processes are so connected as to admit of a
-considerable degree of motion in the horizontal direction, and from
-side to side, and the intervertebral substance here progressively
-increases in thickness to the point at which the upper portion of the
-column is united to the sacrum (fig. XLV. 2, 4), where the degree of
-motion is extensive.
-
-83. The canal for the spinal cord, formed partly by the concavity in
-the posterior surface of the vertebra, and partly by the arch that
-springs from it (fig. XLVI. 6.), is lined by a continuation of the
-dense and strong membrane that constitutes the internal periosteum
-of the cranium, the dura mater (fig. XLVIII. _c_), which, passing
-out of the opening in the occipital bone, called the foramen magnum
-(figs. XXXIX. 7, and XLIX. 3), affords a smooth covering to the canal
-throughout its whole extent.
-
-[Illustration: Fig. XLVIII.
-
-_a._ The scalp, turned down.
-
-_b._ The cut edge of the bones of the skull.
-
-_c._ The external strong membrane of the brain (Dura Mater) suspended
-by a hook.
-
-_d._ The left hemisphere of the brain, showing its convolutions.
-
-_e._ The superior edge of the right hemisphere.
-
-_f._ The fissure between the two hemispheres.]
-
-
-[Illustration: Fig. XLIX.
-
-1. Hemispheres of the brain proper, or cerebrum; 2. hemispheres of the
-smaller brain, or cerebellum; 3. spinal cord continuous with the brain,
-and the spinal nerves proceeding from it on each side.]
-
-84. The spinal cord itself, continuous with the substance of the
-brain, passes also out of the cranium through the foramen magnum into
-the spinal canal (fig. XLIX. 3), enveloped in the delicate membranes
-that cover it, and surrounded by the aqueous fluid contained between
-those membranes. The size of the spinal canal, accurately adapted
-to that of the spinal cord, which it lodges and protects, is of
-considerable size, and of a triangular shape in its cervical portion
-(fig. XLIX. 3), smaller and rounded in its dorsal portion (fig. XLIX.
-3), and again large and triangular in its lumbar portion (fig. XLIX. 3).
-
-85. The spinal column performs several different, and apparently
-incompatible, offices.
-
-First, it affords a support and buttress to other bones. It sustains
-the head (fig. XXXIV. 1); it is a buttress to the ribs (fig. XLVI. 7);
-through the sternum and ribs it is also a buttress to the superior, and
-through the pelvis, to the lower, extremities (fig. XXXIV. 2, 3, 4).
-
-Secondly, it affords a support to powerful muscles, partly to those
-that maintain the trunk of the body in the erect posture against the
-force of gravitation, and partly to those that act upon the superior
-and inferior extremities in the varied, energetic, and sometimes
-long-continued movements they execute.
-
-Thirdly, it forms one of the boundaries of the great cavities that
-contain the chief organs of the organic life. To the support and
-protection of those organs it is specially adapted; hence the surface
-in immediate contact with them is even and smooth; hence its different
-curvatures, convexities, and concavities, have all reference to their
-accommodation; hence in the neck it is convex (fig. XLV. 2), in order
-to afford a firm support to the esophagus, the wind-pipe, the aorta,
-and the great trunks of the venous system (fig. LX. 3, 4); in the back
-it is concave, in order to enlarge the space for the dilatation of
-the lung in the act of inspiration (figs. XLV. 3, and LX. 5); in the
-loins it is convex, in order to sustain and fix the loose and floating
-viscera of the abdomen (figs. XLV. 4, and LX. 6, 7, 8, 9); in the
-pelvis it is concave, in order to enlarge the space for lodging the
-numerous delicate and highly-important organs contained in that cavity
-(fig. XLV. 5).
-
-Fourthly, it forms the osseous walls of a canal (figs. XLVI. 6, and
-XLVII. 3) for the lodgment and protection of the soft and tender
-substance of the spinal cord, one of the great central masses of the
-nervous system, the seat of the animal life (fig. XLIX. 3).
-
-Fifthly, it affords in its osseous walls secure apertures for the
-passage of the spinal nerves (figs. XLVI. 7, and XLIX. 3), by which
-impressions are transmitted from the organs to the spinal cord and
-brain, in the function of sensation; and from the spinal cord and brain
-to the organs in the function of volition.
-
-86. For the due performance of these offices, it is indispensable that
-it should be firm, rigid, strong, and yet to a certain extent readily
-flexible in every direction. By what mechanism is it endowed with these
-apparently incompatible properties?
-
-87. By means of the ring of compact bone, which forms so large a part
-of its body (fig. XLVI. 1) it is rendered firm, rigid, and strong. By
-means of its numerous separate pieces, exactly adjusted to each other,
-and dove-tailed into one another, an increase of strength is gained,
-such as it would not have been possible to communicate to a single
-solid piece. By the same mechanism, some degree of flexibility is also
-obtained; each separate bone yielding to some extent, which, though
-slight in a single bone, becomes considerable in the twenty-four.
-
-88. But the flexibility required is much greater than could be
-obtained by this expedient alone. A rigid and immoveable pile of bones,
-in the position of the spinal column, on which all the other parts of
-the body rest, and to which they are directly or indirectly attached,
-would necessarily have rendered all its movements stiff and mechanical;
-and every movement of every kind impossible, but in a given direction.
-That the movements of the body may be easy, free, and varied; that it
-may be possible to bring into play new and complex combinations of
-motion at any instant, with the rapidity of the changes of thought,
-at the command of the impulses of feeling, it is indispensable that
-the spinal column be flexible in every direction, forwards, backwards,
-and at the sides: it is equally indispensable that it be thus capable
-of yielding, without injuring the spinal cord; without injuring the
-spinal nerves; without injuring the thoracic and abdominal viscera; and
-without injuring the muscles of the trunk and extremities. The degree
-in which it possesses this power of flexibility, and the extent to
-which, by the cultivation of it, it is sometimes actually brought, is
-exemplified in the positions and contortions of the posture-master and
-the tumbler. It is acquired by means of the intervertebral substance,
-the compressible and elastic matter interposed between the several
-vertebræ. So compressible is this substance, that the human body is
-half an inch shorter in the evening than in the morning, having lost
-by the exertions of the day so much of its stature; yet, so elastic is
-this matter, that the stature lost during the day is regained by the
-repose of the night. The weight of the body pressing in all directions
-upon the spinal column; muscles, bones, cartilages, ligaments,
-membranes, with all their vessels and all the fluids contained in
-them; the weight of all these component parts of the head, trunk, and
-extremities, pressing, without the cessation of an instant, during all
-the hours of vigilance, upon the intervertebral substance, compresses
-it; but this weight, being taken off during the night, by the recumbent
-posture of the body, the intervertebral substance, in consequence of
-its elasticity, regains its original bulk, and of course the spinal
-column its original length.
-
-89. But the flexibility acquired through the combined properties of
-compressibility and elasticity is exceedingly increased by the action
-of the pulpy and inelastic matter in the centre of the intervertebral
-substance; this matter serving as a pivot to the vertebræ, facilitating
-their motion on each other. Its effect has been compared to that of
-a bladder partly filled with water, placed between two trenchers; in
-this case, the approximation of the circumference of the two trenchers
-on one side, would instantly displace a portion of the water on that
-side, which would occupy the increasing space on the other, with the
-effect of facilitating the change, in every possible direction, of
-the position of the two trenchers in relation to each other. To this
-effect, however, it is indispensable that the matter immediately around
-this central pivot should be, not like itself, rigid and unyielding,
-but compressible and elastic. It is an interesting fact, that since
-this illustration was suggested, it has been discovered that this
-very arrangement is actually adopted in the animal body. In certain
-animals, in the very centre of their intervertebral substance, there
-has been actually found a bag of water, with a substance immediately
-surrounding the bag, so exceedingly elastic, that when the bag is cut,
-the fluid contained in it is projected to the height of several feet in
-a perpendicular stream.
-
-90. But besides securing freedom and extent of motion, the
-intervertebral substance serves still another purpose, which well
-deserves attention.
-
-Firmness and strength are indispensable to the fundamental offices
-performed by the column; and to endow it with these properties, we
-have seen that the external concentric layers of the intervertebral
-substance are exceedingly tough and that they are attached to the
-bodies of the vertebræ, which are composed of dense and compact bone.
-But than dense and compact bone, nothing can be conceived better
-calculated to receive and transmit a shock or jar on the application
-of any degree of force to the column. Yet such force must necessarily
-be applied to it in every direction, from many points of the body,
-during almost every moment of the day; and did it actually produce a
-corresponding shock, the consequence would be fatal: the spinal cord
-and brain would be inevitably killed; for the death of these tender and
-delicate substances may be produced by a violent jar, although not a
-particle of the substances themselves be touched. A blow on the head
-may destroy life instantaneously, by what is termed concussion; that
-is, by the communication of a shock to the brain through the bones of
-the cranium. The brain is killed; but on careful examination of the
-cerebral substance after death, not the slightest morbid appearance
-can be detected: death is occasioned merely by the jar. A special
-provision is made against this evil, in the structure of the bones
-of the cranium, by the interposition between its two compact plates
-of the spongy substance called diploë (fig. XLIII. 2); and this is
-sufficient to prevent mischief in ordinary cases. A great degree of
-violence applied directly to the head is not common: when it occurs
-it is accidental: thousands of people pass through life without ever
-having suffered from it on a single occasion: but every hour, in the
-ordinary movements of the body, and much more in the violent movements
-which it occasionally makes, a degree of force is applied to the spinal
-column, and through it transmitted to the head, such as, did it produce
-a proportionate shock, would inevitably and instantly destroy both
-spinal cord and brain. The evil is obviated partly by the elastic, and
-partly by the non elastic properties of the matter interposed between
-the several layers of compact bone. By means of the elastic property
-of this matter, the head rides upon the summit of the column as upon a
-pliant spring, while the canal of the spinal cord remains secure and
-uninvaded. By means of the soft and pulpy portion of this matter, the
-vibrations excited in the compact bone are absorbed point by point as
-they are produced: as many layers of this soft and pulpy substance, so
-many points of absorption of the tremors excited in the compact bone;
-so many barriers against the possibility of the transmission of a shock
-to the delicate nervous substance.
-
-91. Alike admirable is the mechanism by which the separate pieces
-of the column are joined together. If but one of the bones were to
-slip off its corresponding bone, or to be displaced in any degree,
-incurable paralysis, followed ultimately by death, or instantaneous
-death, would happen; for pressure on the spinal cord in a certain part
-of its course is incompatible with the power of voluntary motion, and
-with the continuance of life for any protracted term; and in another
-part of its course, with the maintenance of life beyond a few moments.
-To prevent such consequences, so great is the strength, so perfect the
-attachment, so unconquerable the resistance of that portion of the
-intervertebral substance which surrounds the edge of the bodies of the
-vertebræ, that it will allow the bone itself to give way rather than
-yield. Yet such is the importance of security to this portion of the
-frame, that it is not trusted to one expedient alone, adequate as that
-might seem. Besides the intervertebral substance, there is another
-distinct provision for the articulation of the bodies of the vertebræ.
-Commencing at the second cervical vertebra, in its fore part, and
-extending the whole length of the column to the sacrum, is a powerful
-ligament, composed of numerous distinct longitudinal fibres (fig. L.),
-which are particularly expanded over the intervals between the bones
-occupied by the intervertebral substance (figs. L. 1, and LI. 2, 2).
-This ligament is termed the _common anterior vertebral_, beneath which,
-if it be raised from the intervertebral substance, may be seen small
-_decussating_ fibres, passing from the lower edge of the vertebra
-above, to the upper edge of the vertebra below (fig. L. 3), from which
-circumstance these fibres are termed _crucial_.
-
-[Illustration: Fig. L.
-
-1. Common anterior ligament; 2. intervertebral substance. The anterior
-ligament is removed to exhibit (3.) the crucial fibres passing over it.]
-
-[Illustration: Fig. LI.
-
-1. Portion of the occipital bone; 2. common anterior ligament.]
-
-92. Corresponding with the ligament on the anterior, is another on
-the posterior part of the spine (fig. LII. 1), which takes its origin
-from the foramen magnum (fig. LII. 1); descends from thence, within the
-vertebral canal, on the posterior surface of the bodies of the vertebra
-(fig. LII. 1), and extends to the sacrum. This ligament is termed the
-_common posterior vertebral_, which, besides adding to the strength of
-the union of the bodies of the vertebræ, prevents the column itself
-from being bent too much forward.
-
-[Illustration: Fig. LII.
-
-1. Posterior vertebral ligament.]
-
-93. Moreover, the bony arches of the vertebræ (fig. LIII. 1) are
-connected by means of a substance partly ligamentous, and partly
-cartilaginous (fig. LIII. 2), which, while it is extremely elastic, is
-capable of resisting an extraordinary degree of force.
-
-[Illustration: Fig. LIII.
-
-1. Arches of the vertebræ seen from within; 2. ligaments connecting
-them.]
-
-94. And in the last place, the articular processes form so many
-distinct joints, each being furnished with all the apparatus of a
-moveable joint, and thus possessing the ordinary provision for the
-articulation of bones, in addition to the whole of the foregoing
-securities.
-
-95. "In the most extensive motion of which the spinal column is
-capable, that of flexion, the common anterior ligament is relaxed; the
-fore part of the intervertebral substance is compressed, and its back
-part stretched; while the common posterior ligament is in a state of
-extension. In the _extension_ of the column the state of the ligaments
-is reversed; those which were extended being in their turn relaxed,
-while the common anterior vertebral is now put upon the stretch. In the
-_lateral inclination_ of the column, the intervertebral substance is
-compressed on that side to which the body is bent. In the _rotatory_
-motion of the column, which is very limited in all the vertebræ, but
-more particularly in the dorsal, in consequence of their attachment to
-the ribs, the intervertebral substance is contorted, as are likewise
-all the ligaments. All the motions of the column are capable of being
-aided to a great extent by the motion of the pelvis upon the thighs."
-
-96. "The number and breadth of the attachments of these bones,"
-says an accomplished anatomist and surgeon,[4] "their firm union by
-ligament, the strength of their muscles, the very inconsiderable
-degree of motion which exists between any two of them, and lastly, the
-obliquity of their articular processes, especially in the dorsal and
-lumbar vertebræ, render dislocation of them, at least in those regions,
-impossible without fracture; and I much doubt whether dislocation even
-of the cervical vertebræ ever occurs without fracture, either through
-their bodies or their articular processes. The effects of each of these
-accidents would produce precisely the same injury to the spinal marrow,
-and symptoms of greater or less importance, according to the part of
-the spinal column that is injured. Death is the immediate consequence
-if the injury be above the third cervical vertebra, the necessary
-paralysis of the parts to which the phrenic and intercostal nerves
-are distributed causing respiration instantly to cease. If the injury
-be sustained below the fourth cervical vertebra, the diaphragm is
-still capable of action, and dissolution is protracted. The symptoms,
-in fact, are less violent in proportion as the injury to the spinal
-marrow is further removed from the brain; but death is the inevitable
-consequence, and that in every case at no very distant period."
-
-97. So the object of the construction of the spinal column being
-to combine extent and freedom of motion with strength, and it being
-necessary to the accomplishment of this object to build up the column
-of separate pieces of bone, the connecting substances by which the
-different bones are united are constituted and disposed in such a
-manner as to prove absolutely stronger than the bones themselves. Such
-is the structure of this important portion of the human body considered
-as a piece of mere mechanism; but our conception of its beauty and
-perfection would be most inadequate if we did not bear in mind, that
-while the spinal column performs offices so varied and apparently so
-incompatible, it forms an integrant portion of a living machine: it is
-itself alive: every instant, blood-vessels, absorbents and nerves, are
-nourishing, removing, renewing, and animating every part and particle
-of it.
-
-98. The anterior boundary of the thorax is formed by the bone called
-the sternum, or the breast-bone, which is broad and thick at its upper,
-and thin and elongated at its lower extremity (figs. XLV. 6, and
-LIV.), where it gives attachment to a cartilaginous appendix, which
-being pointed and somewhat like a broadsword, is called the ensiform
-cartilage.
-
-[Illustration: Fig. LIV.
-
-Anterior view of the sternum.]
-
-99. Its position is oblique, being near the vertebral column at the
-top, and distant from it at the bottom (fig. XLV. 6). Its margins
-are thick, and marked by seven depressions, for the reception of the
-cartilages of the seven true ribs (fig. LIV). Its anterior surface is
-immediately subjacent to the skin, and gives attachment to powerful
-muscles, which act on the superior extremities: its posterior surface
-is slightly hollowed in order to enlarge the cavity of the thorax (fig.
-LV.).
-
-[Illustration: Fig. LV.
-
-Posterior view of the sternum.]
-
-100. The thorax is bounded at the sides by the ribs, which extend like
-so many arches between the spinal column and the sternum (fig. XLV. 7,
-8). They are in number twenty-four, twelve on each side, of which the
-seven upper are united to the sternum by cartilage, and are called true
-ribs (fig. XLV. 7); the cartilages of the remaining five are united
-with each other and are not attached to the sternum; these are called
-false ribs (fig. XLV. 8): all of them are connected behind to the
-spinal column (fig. XXXV.).
-
-101. The ribs successively and considerably increase in length as far
-as the seventh, by which the cavity they encompass is enlarged; from
-the seventh they successively diminish in length, and the capacity of
-the corresponding part of the cavity is lessened. The direction of the
-ribs from above downwards is oblique (fig. XLV. 7, 8). Their external
-or anterior surface is convex (fig. XLV. 7, 8); their internal or
-posterior surface is concave: by the first their strength is increased;
-by the second the general cavity of the thorax is enlarged (fig. XLV.
-7, 8). Their upper margin is smooth and rounded, and gives attachment
-to a double layer of muscles, called the intercostal, placed in the
-intervals that separate the ribs from each other (fig. LIX.). Along
-the lower margin is excavated a deep groove, for the lodgment and
-protection of the intercostal vessels.
-
-102. The ribs are connected with the spinal column chiefly by what is
-termed the _anterior ligament_ (fig. LVI. 1), which is attached to the
-head of the rib (fig. LVI.), and which, dividing into three portions
-(fig. LVI. 1), firmly unites every rib to two of the vertebræ, and
-to the intervertebral substance (fig. LVI. 1). This articulation is
-fortified by a second ligament (fig. LVI. 2), also attached to a head
-of the rib, termed the _interarticular_ (fig. LVI. 2), and by three
-others, one of which is attached on the fore part, and the two others
-in the back part, to the neck of the rib (fig. LVII. 1).
-
-[Illustration: Fig. LVI.
-
-Ligaments connecting the ribs to the spinal column. 1. anterior
-ligaments; 2. interarticular ligament; 3. ligaments of the necks of the
-ribs.]
-
-The cartilages of the seven superior ribs are attached to the sternum
-by a double layer of ligamentous fibres, termed the _anterior and the
-posterior ligaments of the sternum_ (fig. LVIII.). So strong are the
-bands which thus attach the ribs to the spinal column and the sternum,
-that the ribs cannot be dislocated without fracture. "Such at least is
-the case in experiments upon the dead body, where, though the rib be
-subjected to the application of force by means of an instrument best
-calculated to detach its head from the articulation, yet it is always
-broken."
-
-[Illustration: Fig. LVII.
-
-1, &c. Ligaments connecting the ribs to the vertebræ behind.]
-
-While thus firmly attached to their points of support, the ligaments,
-which fix them, are so disposed as to render the ribs capable of being
-readily moved upwards and downwards: upwards in inspiration; downwards
-in expiration; and it is by this alternate action that they enlarge and
-diminish the cavity of the thorax in the function of respiration.
-
-[Illustration: Fig. LVIII.
-
-Ligaments joining the cartilages of the ribs to the sternum.]
-
-103. Such are the boundaries of the cavity of the thorax as far as
-its walls are solid. The interspaces between these solid portions at
-the sides are filled up by muscles, principally by those termed the
-intercostal (fig. LIX.); below, the boundary is formed by the diaphragm
-(fig. LXI. 2); while above, as has been already stated (69), the cavity
-is so contracted as only to leave an opening for the passage of certain
-parts to and from the chest.
-
-[Illustration: Fig. LIX.
-
-A view of the muscles called _Intercostals_, filling up the spaces
-between the ribs.]
-
-104. The inner surface of the walls of the thorax, in its whole
-extent, is lined by a serous membrane, exceedingly thin and delicate,
-but still firm, called the pleura. The same membrane is reflected over
-the organs of respiration contained in the cavity, so as to give them
-an external coat. The membrane itself is every where continuous, and
-every where the same, whether it line the containing or the contained
-parts; but it receives a different name as it covers the one or the
-other: that portion of it which lines the walls of the cavity being
-called the costal pleura (fig. LXI. _a_), while that which covers the
-organs contained in the cavity is termed the pulmonary pleura (fig. LX.
-5, 1).
-
-105. A fold of each pleura passes directly across the central part
-of the cavity of the thorax; extending from the spinal column to the
-sternum, and dividing the general cavity into two. This portion of the
-pleura is called the mediastinum, from its situation in the centre
-of the thorax, and it so completely divides the thoracic cavity into
-two, that the organs on one side of the chest have no communication
-with those of the other; so that there may be extensive disease in one
-cavity (for example, a large accumulation of water,) while the other
-may be perfectly sound.
-
-106. The main organs contained in the cavity of the thorax are the
-lungs with their air tube; the heart with its great vessels; and the
-tube passing from the mouth to the stomach (fig. LX.).
-
-107. The two lungs occupy the sides of the chest (fig. LX. 5). They
-are completely separated from each other by the membranous partition
-just described, the mediastinum. Between the two folds of the
-mediastinum, namely, in the middle of the chest, but inclining somewhat
-to the left side, is placed the heart, enveloped in another serous
-membrane, the pericardium (fig. LX. 2, 1).
-
-108. The lungs are moulded to the cavities they fill; whence their
-figure is conical, the base of the cone being downwards, resting on the
-diaphragm (fig. LX. 5, _b_); and the apex upwards, towards the neck
-(fig. LX. 5).
-
-109. That surface of each lung which corresponds to the walls of the
-chest is convex in its whole extent (fig. LX. 5); on the contrary, that
-surface which corresponds to the mediastinum is flattened (fig. LX.
-5). The basis of the lung is concave, adapted to the convexity of the
-diaphragm on which it rests (fig. LX. 5).
-
-110. The air-vessel of the lungs, termed the bronchus, together with
-the blood-vessels and nerves, enter the organ at its flattened side,
-not exactly in the middle, but rather towards the upper and back part.
-This portion is termed the root of the lung.
-
-111. The lungs are attached to the neck by the trachea (fig. LX. 4),
-the continuation of which forms the bronchus; to the spinal column by
-the pleura, and to the heart by the pulmonary vessels (fig. LX. 3,
-_d_): their remaining portion is free and unattached.
-
-112. In the living body, the lungs on each side completely fill the
-cavity of the chest, following passively the movements of its walls,
-and accurately adapting themselves to its size, whether its capacity
-enlarge in inspiration, or diminish in expiration, so that the external
-surface of the lung (the pulmonary pleura) is always in immediate
-contact with the lining membrane of the walls of the cavity (the costal
-pleura); consequently, during life, there is no cavity, the chest being
-always completely full.
-
-[Illustration: Fig. LX.
-
-_a._ The cut edges of the ribs, forming the lateral boundaries of the
-cavity of the thorax.
-
-_b._ The diaphragm, forming the inferior boundary of the thorax, and
-the division between the thorax and the abdomen.
-
-_c._ The cut edges of the abdominal muscles, turned aside, exposing the
-general cavity of the abdomen.
-
-1. The cut edge of the pericardium turned aside.
-
-2. The heart.
-
-3. The great vessels in immediate connexion with the heart.
-
-4. The trachea, or wind-pipe.
-
-5. The lungs.
-
-6. The liver.
-
-7. The stomach.
-
-8. The large intestine.
-
-9. The small intestines.
-
-10. The urinary bladder.]
-
-113. The anterior surface of the pericardium, the bag which envelopes
-the heart, lies immediately behind the sternum, and the cartilages of
-the second, third, fourth, and fifth ribs, covered at its sides by the
-pleura, and firmly attached below to the diaphragm (fig. LX. 1).
-
-114. Surrounded by its pericardium, within the mediastinum, the heart
-is placed nearly in the centre of the chest, but its direction is
-somewhat oblique, its apex being directly opposite to the interval
-between the fifth and sixth ribs on the left side (fig. LX. 2); while
-its basis is directed upwards, backwards, and towards the right (fig.
-LX. 2). That portion of its surface which is presented to view on
-opening the pericardium is convex (fig. LX. 2); but its opposite
-surface, namely, that which rests upon the part of the pericardium
-which is attached to the diaphragm, is flattened (fig. LX. 1). It is
-fixed in its situation partly by the pericardium and partly by the
-great vessels that go to and from it. But under the different states
-of expiration and inspiration, it accompanies, in some degree, the
-movements of the diaphragm; and in the varied postures of the body,
-the heart deviates to a certain extent from the exact position here
-described.
-
-115. The second division of the trunk, the _abdomen_, is bounded above
-by the diaphragm (fig. LXI. 2), below by the pelvis (fig. LXI. 3),
-behind and at the sides by the vertebræ and muscles of the loins (fig.
-LXIII.), and before by the abdominal muscles (fig. LXIII. 9).
-
-116. The organ which forms the superior boundary of the abdomen, the
-diaphragm (midriff), is a circular muscle, placed transversely across
-the trunk, nearly at its centre (fig. LXI. 2). It forms a vaulted
-partition between the thorax and the abdomen (fig. LXI. 2). All around
-its border it is fleshy (fig. LXI. 2); towards its centre it is
-tendinous (fig. LXI. 2); the surface towards the abdomen is concave
-(fig. LXI. 2); that towards the thorax convex (fig. LXI. 2); while its
-middle tendinous portion ascends into the thorax as high as the fourth
-rib (fig. LXI. 2).
-
-[Illustration: Fig. LXI.
-
-View of the diaphragm. 1. Cavity of the thorax; 2. diaphragm separating
-the cavity of the thorax from that of the abdomen; 3. cavity of the
-pelvis.]
-
-117. The diaphragm is perforated by several apertures, for the
-transmission of tubes and vessels, which pass reciprocally between the
-thorax and abdomen (fig. LXII.).
-
-1. A separate aperture is formed to afford an exit from the thorax
-of the aorta, the common source of the arteries (fig. LXII. 2), and
-an entrance into the thorax of the thoracic duct, the tube that bears
-the digested aliment to the heart. 2. A little to the left of the
-former, there is another aperture, through which passes the esophagus
-or gullet (fig. LXII. 3), the tube that conveys the food from the mouth
-to the stomach. 3. On the right side, in the tendinous portion of the
-diaphragm, very carefully constructed, is a third aperture for the
-passage of the vena cava (fig. LXII. 4), the great vessel that returns
-the blood to the heart from the lower parts of the body.
-
-[Illustration: Fig. LXII.
-
-View of the diaphragm with the tubes that pass through it. 1. Arch
-of the diaphragm; 2. the trunk of the aorta passing from the chest
-into the abdomen; 3. the esophagus passing from the chest through the
-diaphragm to the stomach; 4. the vena cava, the great vein that returns
-the blood to the heart from the lower parts of the body, passing from
-the abdomen, into the chest, in its way to the right side of the heart;
-5. 6. muscles that arise in the interior of the trunk and that act upon
-the thigh; 5. the muscle called psoas; 6. the muscle called iliacus.]
-
-118. The partition formed by the diaphragm between the thorax and
-abdomen, though complete, is moveable; for as the diaphragm descends in
-inspiration and ascends in expiration, it proportionally enlarges or
-diminishes the cavities between which it is placed; consequently, the
-actual magnitude of these cavities varies every moment, and the size of
-the one is always in the inverse ratio of that of the other.
-
-119. Between the abdomen and the pelvis there is no separation; one
-cavity is directly continuous with the other (fig. LXI. 3); but along
-the inner surface of the expanded bones, which form a part of the
-lateral boundary of the abdomen, there is a prominent line, termed
-the brim of the pelvis (fig. XLV. 15), marking the point at which the
-abdomen is supposed to terminate and the pelvis to commence.
-
-120. Behind and at the sides the walls of the abdomen are completed
-partly by the lumbar portion of the spinal column and partly by the
-lumbar muscles (fig. XLV. 4), and before by the abdominal muscles (fig.
-LXIII. 9).
-
-121. The inner surface of the walls of the abdomen is lined throughout
-by a serous membrane, termed the peritoneum (fig. LXIII.). From the
-walls of the abdomen, the peritoneum is reflected upon the organs
-contained in the cavity, and is continued over them so as to form their
-external coat. The peritoneum also descends between the several organs,
-connecting them together, and holding them firmly in their situation;
-and it likewise forms numerous folds, in which are embedded the vessels
-and nerves that supply the organs. It secretes a serous fluid, by
-which its own surface and that of the organs it covers is rendered
-moist, polished, and glistening, and by means of which the organs
-glide smoothly over it, and over one another in the various movements
-of the body, and are in constant contact without growing together. In
-structure, distribution, and function, the peritoneum is thus perfectly
-analogous to the pleura.
-
-122. Like the thorax, the abdomen is always completely full. When
-the diaphragm is in action, it contracts. When the diaphragm is
-in the state of contraction, the abdominal and lumbar muscles are
-in the state of relaxation. By the contraction of the diaphragm,
-the organs contained in the abdomen are pushed downwards, and the
-anterior and lateral walls of the cavity being at this moment in
-a state of relaxation, they readily yield, and, consequently, the
-viscera are protruded forwards and at the sides. But the abdominal
-and lumbar muscles in their turn contract, the diaphragm relaxing;
-and, consequently, the viscera, forced from the front and sides of the
-abdomen, are pushed upwards, together with the diaphragm, into the
-cavity of the thorax. A firm and uniform pressure is thus at all times
-maintained upon the whole contents of the abdomen: there is an exact
-adaptation of the containing to the contained parts, and of one organ
-to another. No space intervenes either between the walls of the abdomen
-and the organs they enclose, or between one organ and another: so that
-the term cavity does not denote a void or empty space, but merely the
-extent of the boundary within which the viscera are contained.
-
-123. The contents of the abdomen consist of the organs which belong to
-the apparatus of digestion, and of those which belong to the apparatus
-of excretion.
-
-124. The organs which belong to the apparatus of digestion are—1. The
-stomach (fig. LXIII. 2) 2. The duodenum (fig. LXIII. 4). 3. The jejunum
-(fig. LXIII. 5). 4. The ilium (fig. LXIII. 5). The three last organs
-are called the small intestines, and their office is partly to carry on
-the digestion of the aliment commenced in the stomach, and partly to
-afford an extended surface for the absorption of the nutriment as it is
-prepared from the aliment. 5. The pancreas (fig. LXIV. 5). 6. The liver
-(fig. LXIV. 2). 7. The spleen (fig. LXIV. 4). The three last organs
-truly belong to the apparatus of digestion, and their office is to
-co-operate with the stomach and the small intestines in the conversion
-of the aliment into nutriment.
-
-[Illustration: Fig. LXIII.
-
-1. Esophagus; 2. stomach; 3. liver raised, showing its under surface;
-4. duodenum; 5. small intestines; 6. cæcum; 7. colon; 8. urinary
-bladder; 9. gall bladder; 10. abdominal muscles divided and reflected.]
-
-125. The organs which belong to the apparatus of excretion are—1. The
-large intestines consisting of the cæcum (fig. LXIII. 6). 2. The colon
-(fig. LXIII. 7). 3. The rectum (fig. LXIV. 10). It is the office of
-these organs, which are called the large intestines, to carry out of
-the system that portion of the alimentary mass which is not converted
-into nourishment. 4. The kidneys (fig. LXIV. 6), the organs which
-separate in the form of the urine an excrementitious matter from the
-blood, in order that it may be conveyed out of the system.
-
-[Illustration: Fig. LXIV.
-
-General view of the viscera of the abdomen. 1. Stomach raised; 2. under
-surface of liver; 3. gall bladder; 4. spleen; 5. pancreas; 6. kidneys;
-7. ureters; 8. urinary bladder; 9. portion of the intestine called
-duodenum; 10. portion of the intestine called rectum; 11. the aorta.]
-
-126. The last division of the trunk, called the pelvis (fig. LXI. 3),
-consists of a circle of large and firm bones, interposed between the
-lower portion of the trunk and the inferior extremities (fig. XLV.).
-The bones that compose the circle, distinct in the child, are firmly
-united in the adult into a single piece; but as the original separation
-between each remains manifest, they are always described as separate
-bones. They are the sacrum (fig. XLV. 5), the coccyx (fig. XXXV.), the
-ilium (fig. XLV. 11), the ischium (fig. XLV. 12), and the pubis (fig.
-XLV. 13).
-
-127. The sacrum, placed like a wedge between the moveable portion
-of the spinal column and the lower extremities, forms the posterior
-boundary of the pelvis. The figure of this bone is triangular (fig.
-XLV. 5); its anterior surface is concave and smooth, for enlarging the
-cavity of the pelvis and sustaining the organs contained in it (fig.
-XLV. 5); its posterior surface is convex, irregular, and rough (fig.
-XXXV.), giving origin to the great muscles that form the contour of the
-hip, and to the strong muscles of the back and loins that raise the
-spine and maintain the trunk of the body erect.
-
-128. The base or upper part of the sacrum receives the last vertebra
-of the loins on a large and broad surface (fig. XLV. 4), forming a
-moveable joint; and the degree of motion at this point is greater than
-it is at the higher points of the spinal column. Firmly united at its
-sides with the haunch bones, it admits there of no degree of motion.
-
-129. The coccyx, so named from its resemblance to the beak of the
-cuckoo, when elongated by a succession of additional bones, forms the
-tail in quadrupeds; but in man it is turned inwards to support the
-parts contained in the pelvis, and to contract the lower opening of
-the cavity. By means of a layer of cartilage, the medium by which this
-bone is connected with the sacrum, it forms a moveable articulation,
-continuing moveable in men until the age of twenty-five, and in women
-until the age of forty-five; continuing moveable in women thus long, in
-order that by yielding to the force which tends to push it backwards
-during the period of labour, it may enlarge the lower aperture of the
-pelvis, and so facilitate the process of parturition and diminish its
-suffering.
-
-130. The lateral boundaries of the pelvis are formed by the ilium,
-the haunch bone (fig. XLV. 11), and by the ischium, the hip bone (fig.
-XLV. 12). The ilium forms the lower part of the abdomen and the upper
-part of the pelvis (fig. XLV. 11); its broad expanded wing supports the
-contents of the abdomen, and gives attachment to the muscles that form
-the anterior portion of its walls (figs. XLV. 11, and LXIII. 9); its
-external convex surface sustains the powerful muscles that extend the
-thigh; and along its internal surface is the prominent line which marks
-the brim of the pelvis (fig. XLV. 15), and which divides this cavity
-from that of the abdomen.
-
-131. The ischium or hip bone is the lower part of the pelvis (fig.
-XLV. 12); at its undermost portion is a rounded prominence called
-the tuberosity (fig. XLV. 12), in its natural condition covered with
-cartilage, upon which is superimposed a cushion of fat. It is this part
-on which the body is supported in a sitting posture.
-
-132. The pubis or share bone forms the upper and fore part of the
-pelvis (fig. XLV. 13), and together with the two former bones,
-completes the large and deep socket, termed the acetabulum (fig. XLV.
-14), into which is received the head of the thigh-bone (fig. XXXIV.
-4). The margin of the acetabulum and the greater part of its internal
-surface is lined with cartilage, so that in its natural condition it is
-much deeper than it appears to be when the bones alone remain.
-
-133. The lower aperture of the pelvis, which appears large when all
-the soft parts are removed, is not really large, for in its natural
-state it is filled up partly by muscles and partly by ligaments, which
-sustain and protect the pelvic organs, leaving only just space enough
-for the passage to and from those which have their opening on the
-external surface.
-
-134. The cavity of the pelvis, together with all the organs contained
-in it, are lined by a continuation of the membrane that invests the
-abdomen and its contents.
-
-135. The organs contained in the pelvis are the rectum (fig. LXIV. 9),
-which is merely the termination of the large intestines, the urinary
-bladder (fig. LXIV. 8), and the internal part of the apparatus of
-reproduction.
-
-136. The large and strong bones of the pelvis not only afford lodgment
-and protection to the tender organs contained in its cavity, but
-sustain the entire weight of the body, the trunk resting on the sacrum
-as on a solid basis (fig. XLV. 5), and the lower extremities being
-supported in the sockets in which the heads of the thigh-bones play, in
-the varied movements of locomotion (fig. XXXIV. 4).
-
-137. The last division of the body comprehends the superior and the
-inferior extremities.
-
-138. The superior extremities consist of the shoulder, arm, fore-arm,
-and hand.
-
-139. The soft parts of the SHOULDER are composed chiefly of muscles;
-its bones are two, the scapula or the _blade bone_, and the clavicle or
-the _collar bone_ (fig. LXV. 2, 4).
-
-[Illustration: Fig. LXV.
-
-1. Sternum; 2. clavicle; 3. ribs; 4. anterior surface of scapula; 5.
-coracoid process of scapula; 6. acromion process of scapula; 7. margin
-of glenoid cavity of scapula; 8. body of the humerus or bone of the
-arm; 9. head of the humerus.]
-
-140. The SCAPULA is placed upon the upper and back part of the thorax,
-and occupies the space from the second to the seventh ribs (fig. LXV. 4)
-
-[Illustration: Fig. LXVI.
-
-1. Posterior surface of scapula; 2. margin of scapula; 3. acromion
-process; 4. margin of glenoid cavity; 5. clavicle; 6. body of humerus;
-7. head of humerus.]
-
-Unlike that of any other bone of the body, it is embedded in muscles,
-without being attached to any bone of the trunk, excepting at a single
-point. From the bones of the thorax it is separated by a double layer
-of muscles, on which it is placed as upon a cushion, and over the
-smooth surface of which it glides. Originally, like the bones of the
-skull, it consisted of two tables of compact bone, with an intermediate
-layer of spongy bony substance (diploë); but, by the pressure of the
-muscles that act upon it, it gradually grows thinner and thinner,
-until, as age advances, it becomes in some parts quite transparent and
-as thin as a sheet of paper.
-
-141. The figure of the scapula is that of an irregular triangle (fig.
-LXVI.). Its anterior surface is concave (fig. LXV. 4), corresponding to
-the convexity of the ribs (fig. XLV. 7); its posterior surface is very
-irregular (fig. LXVI. 1), being in some parts concave and in others
-convex, giving origin especially to two large processes (figs. LXV. 5,
-and LXVI. 3); one of which is termed the _acromion_ (fig. LXVI. 3),
-and the other the _coracoid_ process of the scapula (fig. LXV. 5). The
-margins of the bone, whatever the thinness of some portions of it, are
-always comparatively thick and strong (fig. LXVI. 2), affording points
-of origin or of insertion to powerful muscles. At what is called the
-anterior angle of the bone there is a shallow oval depression covered
-with cartilage and deepened by a cartilaginous margin, called the
-_glenoid_ cavity of the scapula (figs. LXV. 7, and LXVI. 4), which
-receives the head of the humerus or bone of the arm (figs. LXV. 9, and
-LXVI. 7, 6).
-
-142. The clavicle, the second bone of the shoulder, is a long and
-slender bone, of the form of an italic [Illustration], projecting
-a little forwards towards its middle, so as to give a slight convexity
-of outline to the top of the chest and the bottom of the neck (fig.
-LXV. 2). It is attached by one extremity to the sternum (fig. LXV. 2)
-and by the other to the scapula (fig. LXV. 2), by moveable joints. The
-nature of an immoveable joint has been explained (63). In the connexion
-of the bones of the trunk, while the main object is to secure firmness
-of attachment, some degree of motion is at the same time obtained (81
-et seq.): but the mode in which the several bones of the extremities
-are connected with each other and with the trunk, admits of so great a
-degree of motion, that these articulations are pre-eminently entitled
-to the name of moveable joints. The component parts of all moveable
-joints are bone, cartilage, synovial membrane, and ligament. The great
-character of a moveable joint is the approximation of two or more
-bones; yet these bony surfaces are never in actual contact, but are
-invariably separated from each other by cartilage. The cartilage either
-covers the entire extent of the articulating surface of the bones,
-as in the shoulder-joint, where both the head of the humerus and the
-cavity of the scapula that receives it are enveloped in this substance
-(fig. LXV. 7. 9), or a portion of it is placed between the articulating
-surfaces of the bones, as in the joint between the clavicle and sternum
-(fig. LXVII. _a_); which, when so placed, is termed an interarticular
-cartilage (fig. LXVII. _a_). By its smooth surface cartilage lessens
-friction; while by its elasticity it facilitates motion and prevents
-concussion. Slightly organized cartilage is provided with comparatively
-few blood-vessels and nerves. Had it been vascular and sensible like
-the skin and the muscle, the force applied in the movements of the
-joint would have stimulated the blood-vessels to inordinate action, and
-the sensibility of the nerves would have been the source of constant
-pain: every motion of every joint would have been productive of
-suffering, and have laid the foundation of disease. The facility and
-ease of motion obtained by the smoothness, elasticity, and comparative
-insensibility of cartilage are still further promoted by the fluid
-which lubricates it, termed synovia, secreted by a membrane called
-synovial, which lines the internal surface of the joint, and which
-bears a close resemblance to the serous (30). Synovia is a viscid
-fluid of the consistence of albumen (5). It is to the joint what oil
-is to the wheel, preventing abrasion and facilitating motion; but it
-is formed by the joint itself, at the moment when needed, and in the
-quantity required. The motion of the joint stimulates the synovial
-membrane to secretion, and hence the greater the degree of motion, the
-larger the quantity of lubricating fluid that is supplied. The several
-parts of the apparatus of moveable joints are retained in their proper
-position by ligamentous substance, which, as has been shown (96 and
-97), is oftentimes so strong that it is easier to fracture the bone
-than to tear the ligament, and in every case the kind and extent of
-motion possessed by the joint are dependent mainly on the form of
-the articulatory surfaces of the bones and on the disposition of the
-ligaments.
-
-143. In the joint formed by the clavicle and the sternum (fig. LXVII.
-_a_) an interarticular cartilage is placed between the two bones which
-are united, first by a strong fibrous ligament, which envelops them
-as in a capsule (fig. LXVII. 1); by a second ligament, which extends
-from the cartilage of the first rib to the clavicle (fig. LXVII. 4),
-by which the attachment of the clavicle to the sternum is materially
-strengthened; and by a third ligament which passes transversely from
-the head of one clavicle to that of the other (fig. LXVII. 3). The
-joint thus formed, though so strong and firm that the dislocation of
-it is exceedingly rare, yet admits of some degree of motion in every
-direction, upwards, downwards, forwards, and backwards; and this
-articulation is the sole point by which the scapula is connected with
-the trunk, and consequently by which the upper extremity can act, or be
-acted upon, by the rest of the body.
-
-[Illustration: Fig. LXVII.
-
-1. The fibrous capsule of the sternum and clavicle; 2. the same laid
-open, showing _a_, the interarticular cartilage; 3. the ligament
-connecting the two clavicles; 4. the ligament joining the clavicle to
-the first rib; 5. ligaments passing down in front of the sternum.]
-
-144. The scapular extremity of the clavicle (fig. LXVIII. 6) is
-attached to the processes of the scapula (fig. LXVIII. 4. 3) by several
-ligaments of great strength (fig. LXVIII. 7, 8, 9). First by very
-strong fasciculi which pass from the upper surface of the clavicle
-to the acromion of the scapula (fig. LXVIII. 6); and secondly by two
-ligaments which unite the clavicle with the coracoid process of the
-scapula (fig. LXVIII. 8, 9). These ligaments are so powerful that they
-resist a force capable of fracturing the clavicle; and they need to be
-thus strong, for the clavicle is a shaft which sustains the scapula,
-and through the scapula the whole of the upper extremity; and the main
-object of the joint by which these bones are united, is to afford a
-firm attachment of the scapula to its point of support.
-
-[Illustration: Fig. LXVIII.
-
-1. The clavicle; 2. the anterior part of the scapula; 3. the coracoid
-process; 4. the acromion process; 5. the humerus; 6. ligaments binding
-the scapular end of the clavicle to the acromion; 7. 8. 9. ligaments
-passing from one process of the scapula to the other; 10. the fibrous
-capsule of the shoulder-joint.]
-
-145. The clavicle serves the following uses: it sustains the upper
-extremity; it connects the upper extremity with the thorax; it prevents
-the upper extremity from falling forwards upon the thorax; and it
-affords a fixed point for steadying the extremity in the performance of
-its various actions.
-
-146. The glenoid cavity of the scapula (fig. LXV. 7) receives the head
-of the humerus, the bone of the arm (fig. LXV. 9), and the two bones
-being united by ligament form the shoulder-joint (fig. LXVIII.). This
-joint is what is termed a ball and socket joint, the peculiarities
-of which are two: first, beyond all others this mode of articulation
-admits of free and extensive motion; in the present case, there is
-the utmost freedom of motion in every direction, upwards, downwards,
-backwards, and forwards. In the second place, this mode of articulation
-admits of the motion of the limb without that of the body, or of the
-motion of the body without that of the limb. When at rest, the arm may
-be moved in almost any direction without disturbing the position of any
-other part of the frame; the manifold advantages of which are obvious.
-On the other hand, by careful management, very considerable variations
-in the posture of the body may be effected without the communication
-of any degree of motion to the limb; an unspeakable advantage when the
-limb has sustained injury, or is suffering from disease.
-
-147. It does not seem possible to construct a joint of great strength,
-capable, at the same time, of the degree of motion possessed by the
-joint of the shoulder. So shallow is the socket of the scapula, and
-so large the head of the humerus, that it seems as if the slightest
-movement must dislodge it from its cavity (fig. LXVI. 4. 7). For
-sustaining heavy weights or resisting a great amount of pressure,
-applied to it suddenly and in various directions, the arm is obviously
-unfitted. But this is not its office. The superior extremities are the
-organs of apprehension—the instruments by which the mind executes
-the commands of the will. They do not need the strength required by
-the organs that sustain the weight of the body and that perform the
-function of locomotion; but they do need freedom and extent of motion:
-to this strength may be sacrificed, and so it is; yet what can be
-done to combine strength with mobility is effected. Large and strong
-processes of bone, proceeding as has been shown (141), from the convex
-surface of the scapula (figs. LXV. and LXVI.), overhang, and to a
-considerable extent surround, the head of the arm-bone, especially
-resisting the force that would dislodge it from its socket and drive
-it upwards, inwards, and backwards (fig. LXV.), the directions in
-which force is most commonly applied to it. By these processes of bone
-the joint is greatly strengthened, especially in those directions.
-Moreover, a strong ligament, termed the fibrous capsule (fig. LXVIII.
-10) envelops the joint. This ligament, arising from the neck of
-the scapula (fig. LXVIII. 10), expands itself in such a manner as
-completely to surround the head of the humerus (fig. LXVIII. 10); and
-then again contracts in order to be inserted into the neck of the bone
-(fig. LXVIII. 10). This ligament is strengthened by the tendons of no
-less than four muscles which are expanded over it, as well as by the
-powerful substance termed fascia which is reflected upon it from both
-the processes and ligaments of the scapula. In addition to all these
-expedients for fortifying the joint, it receives a further security
-in the position of the scapula, which is loose and unattached; which
-slides easily over the ribs upon its cushion of flesh; which thus
-obtains, by its facility of yielding, some compensation for its want of
-strength, eluding the force which it cannot resist.
-
-148. The arm consists of numerous and powerful muscles, and of a
-single bone, the humerus, which belongs to the class of bones termed
-cylindrical (185).
-
-149. The upper end of the humerus terminates in a circular head
-(fig. LXV. 9), which is received into the socket of the scapula (fig.
-LXV. 9. 7) termed, as has been stated (141), its glenoid cavity. The
-middle portion of the bone, or what is termed its shaft (fig. LXV. 8),
-diminishes considerably in magnitude, and becomes somewhat rounded
-(fig. LXV. 8), while its lower end again enlarges, and is spread out
-into a flattened surface of great extent (fig. LXIX. 1, 3, 2, 4). Of
-this broad flattened surface, the middle portion is grooved (fig. LXIX.
-2): it is covered with cartilage; it forms the articulating surface
-by which the arm is connected with the fore-arm. On each side of this
-groove there is a projection of bone or tubercle, termed condyle (fig.
-LXIX. 3, 4), the inner (fig. LXIX. 3) being much larger than the outer
-(fig. LXIX. 4). The inner condyle gives origin to the muscles that
-bend, the outer to those that extend the fore-arm and the fingers
-(figs. LXXXIV. 1, 2, and LXXXV. 1).
-
-[Illustration: Fig. LXIX.
-
-1. Lower extremity of the humerus; 2. grooved surface; 3. internal
-condyle; 4. external condyle; 5. the upper part of the ulna; 6. the
-head; 7. the neck; 8. the tubercle of the radius.]
-
-150. The muscles that act upon the arm arise from the back (fig.
-LXXII. 2), the chest (fig. LXXI. 1), the clavicle (fig. LXXI. 1), and
-the scapula (fig. LXXI. 3); and they move the arm with freedom and
-power upwards, downwards, forwards, backwards, inwards, and outwards.
-The chief muscle that raises the arm is the deltoid (fig. LXXI. 3),
-which arises partly from the clavicle and partly from the scapula
-(fig. LXXI. 3). It has the appearance of three muscles proceeding in
-different directions, the different portions being separated by slight
-fissures (figs. LXXI. 3, and LXXII. 3). The fibres converging unite
-and form a powerful muscle which covers the joint of the humerus (fig.
-LXXI. 3). It is implanted by a short and strong tendon into the middle
-of the humerus (fig. LXXI. 4). Its manifest action is to pull the arm
-directly upwards. Its action is assisted by the muscles that cover
-the back of the scapula, which are in like manner inserted into the
-humerus, and which, at the same time that they elevate the arm, support
-it when raised.
-
-[Illustration: Fig. LXXI.
-
-View of the muscles on the fore part of the chest that act upon the
-arm. 1. The muscle called the great pectoral; 2. the small pectoral; 3.
-the deltoid; 4. the humerus.]
-
-151. The principal muscle that carries the arm downwards is the
-latissimus dorsi (fig. LXXII. 2), the broadest muscle of the body,
-which, after having covered all the lower part of the back and loins,
-terminates in a thin but strong tendon which stretches to the arm, and
-is implanted into the humerus (fig. LXXII. 2), near the tendon of a
-muscle immediately to be described,—the great pectoral. When the arm
-is raised by the deltoid and its assistant muscles, the latissimus
-dorsi carries it downwards with force, and its powerful action is
-increased by that of other muscles which arise from the scapula and are
-inserted into the arm.
-
-152. The principal muscle that carries the arm forwards towards the
-chest, is the great pectoral (fig. LXXI. 1), which, arising partly from
-the clavicle (fig. LXXI. 1), partly from the sternum (fig. LXXI. 1),
-and partly from the cartilages of the second, third, fourth, fifth, and
-sixth ribs (fig. LXXI. 1), covers the greater part of the breast (fig.
-LXXI. 1). Its fibres, converging, terminate in a strong tendon, which
-is inserted near the tendon of the longissimus dorsi into the humerus,
-about four inches below its head (fig. LXXI. 1). These two muscles form
-the axilla or armpit, the anterior border of the axilla consisting of
-the pectoral muscle. Though each of these muscles has its own peculiar
-office, yet they often act in concert, thereby greatly increasing their
-power, and the result of their combined action is to carry the arm
-either directly downwards or to the side of the chest.
-
-[Illustration: Fig. LXXII.
-
-View of the muscles seated on the back part of the trunk that act
-upon the shoulder and arm. 1. The muscle called the trapezius; 2. the
-latissimus dorsi; 3. the deltoid.]
-
-153. Some of the muscles that elevate the arm carry it inwards, and
-others outwards; the muscles that carry it forwards likewise carry it
-inwards; while of the muscles that pull it downwards, some direct it
-forwards and inwards, and others backwards and outwards (151 and 152).
-
-154. It has been already stated that the shoulder-joint is completely
-surrounded by the muscular fibres or the tendinous expansions of
-several of these powerful muscles, which have a far greater effect in
-maintaining the head of the humerus in its socket than the fibrous
-capsule of the joint; the latter being necessarily loose, in order
-to allow of the extended and varied motions of the arm, whereas the
-muscles that encompass the joint adhere closely and firmly to it.
-Moreover, by virtue of their vital power these muscles act with an
-efficiency which a mere ligamentous band is incapable of exerting; for
-they apportion the strength of resistance to the separating force, and
-react with an energy proportioned to the violence applied.
-
-155. The bones of the fore-arm are two, the ulna and the radius (figs.
-LXIX. and LXXIII.). The ulna is essentially the bone of the elbow
-(figs. LXIX. 5, and LXXIII. 3); the radius that of the hand (fig.
-LXXV.). Supposing the arm to hang by the side of the body, and the palm
-of the hand to be turned forwards, the ulna, in apposition with the
-little finger, occupies the inner; and the radius, in apposition with
-the thumb, occupies the outer part of the fore-arm (fig. XXXIV. 3).
-
-[Illustration: Fig. LXXIII.
-
-  1. The internal condyle of the humerus; 2. the external
-  condyle of the humerus; 3. the olecranon process of the ulna;
-  4. the head of the radius.]
-
-156. The upper end of the ulna belonging to the elbow is large (figs.
-LXIX. 5, and LXXIII. 3). It sends backwards the large projection
-commonly named the elbow or _olecranon_ (fig. LXXII. 3), in the centre
-of which there is a smooth and somewhat triangular surface (fig.
-LXXIII. 3) which is always covered by skin of a coarse texture, like
-that placed over the lower part of the knee-pan, as if nature intended
-this for a part on which we may occasionally lean and rest. Large at
-the elbow, the ulna gradually grows smaller and smaller as it descends
-towards the wrist, where it ends in a small round head (fig. LXXXII.
-2), beyond which, on the inner side, or that corresponding to the
-little finger, it projects downwards a small rounded point, termed
-the styloid process (fig. LXXXII. 3). As the styloid process and the
-olecranon, the two extremities of the ulna (figs. LXXIII. 3, and
-LXXII. 3), are easily and distinctly felt, the length of this bone was
-primitively used as a measure, called a cubit, which was the ancient
-name of the bone.
-
-157. The radius, the second bone of the fore-arm, placed along its
-outer part next the thumb, is small at its upper end (figs. LXIX. 6,
-and LXXIII. 4); but its body is larger than that of the ulna; while its
-lower end, next the wrist to which it properly belongs, is very bulky
-(fig. LXXXII. 1). Its upper end is formed into a small circular head,
-which is united by distinct joints both to the humerus and to the ulna
-(fig. LXIX. 6). The top of its rounded head is excavated into a shallow
-cup (figs. LXIX. 6, and LXXIII. 4) which receives a corresponding
-convexity of the humerus (fig. LXIX. 2), and its lower extremity is
-excavated into an oblong cavity, which receives two of the bones of the
-wrist (fig. LXXXIII. 1. 4).
-
-158. The joint of the elbow is composed above of the condyles of the
-humerus (fig. LXIX. 3. 2), and below by the heads of the ulna and
-radius (fig. LXIX. 5. 6).
-
-159. The upper surface of the ulna is so accurately adapted to the
-lower surface of the humerus that the one seems to be moulded on
-the other (figs. LXIX. 5, and LXXIII. 3), and the form of these
-corresponding surfaces, which are everywhere covered with cartilage,
-is such as to admit of free motion backwards and forwards, that is,
-of extension and flexion; but to prevent any degree of motion in any
-other direction. The joint is therefore a hinge-joint, of which the two
-motions of flexion and extension are the proper motions. This hinge is
-formed on the part of the humerus by a grooved surface, with lateral
-projections (fig. LXIX. 2, 3, 4), and on the part of the ulna by a
-middle projection with lateral depressions (fig. LXIX. 5): the middle
-projection of the ulna turning readily on the grooved surface of the
-humerus (fig. LXIX. 2).
-
-160. The bones are held in their proper situation, first, by a
-ligament on the fore part of the arm, called the anterior (fig. LXXIV.
-6), which arises from the lower extremity of the humerus, and is
-inserted into the upper part of the ulna and the coronary ligament of
-the radius (fig. LXXIV. 6. 8); secondly, by another ligament on the
-back part of the arm, called the posterior ligament (fig. LXXV. 8),
-placed in the cavity of the humerus that receives the olecranon of the
-ulna (fig. LXXV. 8); and thirdly, by two other ligaments at the sides
-of the ulna (fig. LXXV. 6, 7). The ulna and radius are united, first,
-by a ligament called the coronary, which, arising from the ulna, passes
-completely around the head of the radius (fig. LXXVI. 3), and the
-attachment of which, while sufficiently close to prevent the separation
-of the two bones, is yet not adherent to the radius, for a reason
-immediately to be assigned; secondly, by another ligament which passes
-in an oblique direction from one bone to the other (fig. LXXVI. 4);
-and thirdly, by a dense and broad ligament, termed the _interosseous_
-(figs. LXXIV. 10, and LXXVI. 5), which fills up the space between the
-two bones nearly in their whole extent. This ligament serves other
-offices besides that of forming a bond of union, affording, more
-especially, a greater extent of surface for the attachment of muscles,
-and separating the muscles on the anterior from those on the posterior
-part of the limb.
-
-[Illustration: Fig. LXXIV.
-
-  Anterior view of the ligaments of the elbow-joint. 1. The
-  lower portion of the humerus; 2. the upper portion of the
-  radius; 3. the upper portion of the ulna; 4. the internal
-  condyle; 5. the external condyle; 6. the anterior ligament;
-  7. portion of the internal lateral ligament; 8. portion of
-  the coronary ligament; 9. the oblique ligament; 10. upper
-  portion of the interosseous ligament.]
-
-[Illustration: Fig. LXXV.
-
-  Posterior view of the ligaments of the elbow-joint. 1. Lower
-  end of the humerus; 2. internal condyle; 3. external condyle;
-  4. the olecranon process of the ulna; 5. the upper portion of
-  the radius; 6. the internal lateral ligament; 7. the external
-  lateral ligament; 8. the posterior ligament.]
-
-[Illustration: Fig. LXXVI.
-
-View of the ligaments connecting the ulna and radius at their upper
-part. 1. The radius; 2. the ulna; 3. the coronary ligament surrounding
-the head of the radius; 4. the oblique ligament passing from the ulna
-to the tubercle of the radius; 5 the upper portion of the interosseous
-ligament.]
-
-161. At their inferior extremities the ulna and radius are united
-partly by the interosseous ligament (fig. LXXVII. 1) and partly by
-ligamentous fibres which pass transversely from one bone to the other
-(fig. LXXVII. 2) on the anterior and the posterior surface of the
-fore-arm.
-
-[Illustration: Fig. LXXVII.
-
-1. Interosseous ligament; 2. transverse fibres passing between the
-radius and ulna, and uniting the two bones; 3. 4. 5. posterior and
-lateral ligaments of the wrist joint; 6. ligaments uniting the bones of
-the wrist with one another; 7. 8. ligaments which attach the metacarpal
-to the carpal bones; 9. transverse ligaments for the attachment of the
-phalanges of the fingers; 10. lateral ligaments for the attachment of
-the phalanges of the fingers 11. ligaments of the thumb.]
-
-162. The lower extremity of the radius is also united to the wrist;
-and the hand being attached to the wrist, the junction of the hand and
-the fore-arm is effected by the articulation of the wrist with the
-radius (fig. LXXVII.). The ligaments which connect the bones of the
-wrist with the radius are bands of exceeding strength (fig. LXXVII. 3).
-
-163. The muscles that act upon the fore-arm are placed upon the arm
-(fig. LXXVIII.). The joint of the elbow being a hinge-joint, the
-fore-arm can admit only of two motions, namely, flexion and extension.
-The muscles by which these motions are effected are four, two for each;
-the two flexors being placed on the fore part (fig. LXXVIII. 2. 4), and
-the two extensors on the back part of the arm (fig. LXXIX. 5).
-
-164. The two flexor muscles of the fore-arm are termed the biceps and
-the brachialis (fig. LXXVIII. 2, 4). The biceps is so called because
-it has two distinct heads or points of origin (fig. LXXVIII. 2), both
-of which arise from the scapula (fig. LXXVIII. 2). About a third part
-down the humerus the two heads meet, unite and form a bulky muscle
-(fig. LXXVIII. 2), which, when it contracts, may be felt like a firm
-ball on the fore part of the arm, the upper part of the ball marking
-the point of union of the two heads (fig. LXXVIII. 2). The muscle
-gradually becoming smaller, at length terminates in a rounded tendon
-(fig. LXXVIII. 3), which is implanted into the tubercle of the radius
-a little below its neck (fig. LXXVIII. 3). It is an exceedingly thick
-and powerful muscle, and its manifest action is to bend the fore-arm
-with great strength. But since its tendon is inserted into the radius,
-besides bending the fore-arm, it assists other muscles that also act
-upon the radius in the performance of a function to be described
-immediately (168).
-
-[Illustration: Fig. LXXVIII.
-
-View of the flexor muscles of the fore-arm. 1. The anterior surface
-of the scapula; 2. the muscle called biceps; 3. tendon of the biceps
-passing to the tubercle of the radius; 4. the muscle called brachialis.]
-
-165. The second flexor of the fore-arm, termed the brachialis, is
-placed immediately under the biceps, and is concealed by it for a
-considerable part of its course (fig. LXXVIII. 4). Arising from the
-humerus, on each side of the insertion of the deltoid, it continues its
-attachment to the bone all the way down the fore part of the humerus,
-to within inch of the joint; it then passes over the joint, adhering
-firmly to the anterior ligament (fig. LXXVIII. 4), and is inserted by a
-strong tendon into the ulna (fig. LXXVIII. 4). It is a thick and fleshy
-muscle, powerfully assisting the action of the biceps.
-
-166. The two extensor muscles are named the triceps and the anconeous
-(fig. LXXIX.). The triceps, seated on the back part of the arm, derives
-its name from having three distinct points of origin, or three separate
-heads (fig. LXXIX. 5); one of which arises from the scapula and two
-from the humerus (fig. LXXIX. 5). All these heads adhere firmly to the
-humerus, as the brachialis does on the fore part of the arm, down to
-within an inch of the joint (fig. LXXIX. 5), where they form a strong
-tendon, which is implanted into the olecranon of the ulna (fig. LXXIX.
-3); the projection of which affords a lever for increasing the action
-of the muscle. In all animals that leap and bound, this process of the
-ulna is increased in length in proportion to their power of performing
-these movements. The triceps forms an exceedingly thick and strong
-muscle, which envelops the whole of the back part of the arm (fig.
-LXXIX.); its action is simple and obvious; it powerfully extends the
-fore-arm. The anconeous, a small muscle of a triangular form, arising
-from the external condyle of the humerus, and inserted into the ulna a
-little below the olecranon, assists the action of the triceps.
-
-[Illustration: Fig. LXXIX.
-
-View of the extensor muscles of the fore-arm. 1. The scapula; 2. the
-upper part of the humerus; 3. upper end of the ulna; 4. upper end
-of the radius; 5. the muscle called _triceps_, the extensor of the
-fore-arm.]
-
-167. Such are the motive powers which act upon the fore-arm, and
-which produce all the motions of which the hinge-joint of the elbow
-renders it capable. But besides flexion and extension, the fore-arm is
-capable of the motion of rotation, which is accomplished by means of
-the radius. It has been shown (157) that the top of the rounded head of
-the radius is excavated into a shallow cup (figs. LXIX. 6, and LXXIII.
-4) which receives a corresponding convexity of the humerus (figs.
-LXIX. 2, and LXXIII. 2). In consequence of this articulation with the
-humerus, the radius, like the ulna, can move backwards and forwards
-in flexion and extension, the proper movements of the hinge-joint;
-but that portion of the margin of the hinge of the radius which is in
-apposition with the ulna is convex (fig. LXIX. 6), and is received into
-a semilunar cavity hollowed out in the ulna (fig. LXIX. 5). In this
-cavity the rounded head of the radius revolves, the two bones being
-held together by the ligament already described (160), which surrounds
-the head of the radius (fig. LXXVI. 3), and which holds it firmly
-without being adherent to it, and without impeding in any degree the
-rotatory motion of the radius. Below, the surface of the radius next
-the ulna is hollowed out into a semilunar cavity (fig. LXXXII. 1),
-which receives a corresponding convex surface of the ulna (fig. LXXXII.
-2), upon which convex surface the radius rolls (fig. LXXXII. 1). Thus,
-by the mode in which it is articulated with the ulna above, the radius
-turns upon its own axis. By the mode in which it is articulated with
-the ulna below, the radius revolves upon the head of the ulna; and, in
-consequence of both articulations, is capable of performing the motion
-of rotation. Moreover, the hand being attached to the radius through
-the medium of the wrist (figs. LXXXII. 1. 4. and LXXXIII. 1. 4) must
-necessarily follow every movement of the radius; the rotation of which
-brings the hand into two opposite positions. In the one, the palm of
-the hand is directed upwards (fig. LXXXII.); in the other, it is turned
-downwards (fig. LXXXIII.). When the hand is turned upwards, it is said
-to be in the state of _supination_ (fig. LXXXII.); when downwards, in
-that of _pronation_ (fig. LXXXIII.). A distinct apparatus of muscles
-is provided for effecting the rotation of the radius, in order to
-bring the hand into these opposite states: one set for producing its
-supination, and another its pronation.
-
-168. The principal supinators arise from the external condyle of the
-humerus (fig. LXXX.), and are called long and short (fig. LXXX. 4, 5).
-The long supinator extends as far as the lower end of the radius, into
-which it is inserted (fig. LXXX. 4): the short supinator surrounds the
-upper part of the radius, and is attached to it in this situation (fig.
-LXXX. 5.). Moreover, the triceps, being inserted into the radius (164),
-often cooperates with the supinators and powerfully assists their
-action.
-
-169. The principal pronators are also two, called the round and the
-square (figs. LXXXI. and LXXXVI. 1). The round pronator arises from the
-internal condyle, and passing downwards, is inserted into the middle
-of the radius (fig. LXXXI. 4); the square pronator is a small muscle
-between the radius and ulna, at their lower extremities being attached
-to each (fig. LXXXVI. 1).
-
-[Illustration: Fig. LXXX.
-
-View of the supinators of the radius and hand. 1. The humerus; 2. the
-ulna; 3. the radius; 4. the muscle called the long supinator passing to
-be inserted into the lower portion of the radius; 5. the muscle, called
-the short supinator, surrounding the upper part of the radius.]
-
-170. The action of these muscles in producing the rotation of the
-radius, and so rendering the hand supine or prone, is sufficiently
-manifest from the mere inspection of the diagrams (fig. LXXXI. 4).
-
-[Illustration: Fig. LXXXI.
-
-View of the pronators of the hand. 1. Lower end of the humerus; 2. the
-radius; 3. the ulna; 4. the muscle called the round _pronator_, one of
-the powerful pronators of the hand.]
-
-171. The hand is composed of the carpus, metacarpus, and fingers.
-
-172. The carpus (fig. LXXXII. 4) consists of eight small wedge-shaped
-bones, placed in a double row, each row containing an equal number, and
-the whole disposed like stones in an arch (fig. LXXXII. 4). They do in
-fact form an arch, the convexity of which is upwards, on the dorsal
-surface (fig. LXXXIII. 4); and the concavity downwards, on the palmar
-surface (fig. LXXXII. 4). But they differ from the stones of an arch
-in this, that each bone is joined to its fellow by a distinct moveable
-joint, each being covered with a smooth articulating cartilage. At the
-same time all of them are tied together by ligaments of prodigious
-strength, which cross each other in every direction (fig. LXXVII. 6),
-so that the several separate joints are consolidated into one great
-joint. The consequence of this mechanism is that some degree of motion
-is capable of taking place between the several bones, which, when
-multiplied together, gives to the two rows of bones such an extent of
-motion, that when the wrist is bent the arch of the carpus forms a kind
-of knuckle. By this construction a facility and ease of motion, and
-a power of accommodation to motion and force, are obtained, such as
-belong to no arch contrived by human ingenuity.
-
-[Illustration: Fig. LXXXII.
-
-1. Lower extremity of the radius; 2. lower extremity of the ulna;
-3. styloid process of the ulna; 4. bones of the carpus or wrist;
-5. metacarpal bones; 6. first phalanges of the fingers; 7. second
-phalanges of the fingers; 8. third phalanges of the fingers.]
-
-173. The metacarpus (fig. LXXXII. 5), the middle portion of the hand,
-interposed between the wrist and the fingers, is composed of five
-bones, which are placed parallel to each other (fig. LXXXII. 5). They
-are convex outwardly, forming the back (fig. LXXXIII. 5), and concave
-inwardly, forming the hollow of the hand (fig. LXXXII. 5). They are
-large at each end, to form the joints by which they are connected with
-the wrist and fingers (figs. LXXXII. and LXXXIII.): they are small in
-the middle, in order to afford room for the lodgment and arrangement
-of the muscles, that move the fingers from side to side (fig. LXXXVI.
-2). Their ends, which are joined to the carpus, are connected by nearly
-plane surfaces (figs. LXXXII. and LXXXIII.): their ends, which support
-the fingers, are formed into rounded heads, which are received into
-corresponding cup-shaped cavities, excavated in the top of the first
-bones of the fingers (fig. LXXXII. 5.). The powerful ligaments that
-unite these bones pass, both on the dorsal and the palmar surface, from
-the inferior extremity of the second row of the carpal to the bases of
-the metacarpal bones (fig. LXXVII, 7, 8). The ligaments are arranged in
-such a manner as to limit the motions of the joints chiefly to those
-of flexion and extension, allowing, however, a slight degree of motion
-from side to side.
-
-174. Each of the fingers is composed of three separate pieces of bone,
-called phalanges; the thumb has only two (fig. LXXXII. 6, 7, 8): the
-phalanges are convex outwardly (fig. LXXXII. 6, 7, 8) for increasing
-their strength, and flattened inwardly (fig. LXXXIII. 6, 7, 8) for
-the convenience of grasping. The last bones of the fingers, which are
-small, terminate at their under ends, in a somewhat rounded and rough
-surface (fig. LXXXIII. 8), on which rests the vascular, pulpy, and
-nervous substance, constituting the special organ of touch, placed at
-the points of the fingers, and guarded on the upper surface by the nail
-(fig. LXXXII. 8).
-
-[Illustration: Fig. LXXXIII.
-
-1. Lower extremity of the radius; 2. lower extremity of the ulna; 3.
-styloid process of the ulna; 4. bones of the carpus; 5. metacarpal
-bones; 6. 7. 8. first, second, and third phalanges of the fingers.]
-
-175. The round inferior extremity of the metacarpus is admitted into
-the cavity of the superior extremity of the first phalanx of the five
-fingers (figs. LXXXII. and LXXXIII.), and their joints are connected by
-lateral and transverse ligaments of great strength (fig. LXXVII. 9).
-The situation and direction of the ligaments which unite the several
-phalanges of the fingers (fig. LXXVII. 9) are precisely the same as
-those of the articulation of the phalanges with the metacarpus (fig.
-LXXVII. 7, 8); and the articulation of these bones with one another is
-such as to admit only of the motions of flexion and extension.
-
-176. The muscles which perform these motions are seated for the most
-part on the fore-arm. Independently of the supinators and pronators
-which have been already described (167 et seq.), there are distinct
-sets of muscles for bending and extending the wrist and the fingers.
-The flexors arise from the internal, and the extensors from the
-external, condyle of the humerus (fig. LXIX. 3, 4). The internal
-condyle is larger and longer than the external (fig. LXIX. 3, 4); for
-the flexors require a larger point of origin and a longer fulcrum
-than the extensor muscles; because to the actions of flexion, such as
-grasping, bending, pulling, more power is necessary than to the action
-of extension, which consists merely in the unfolding or the opening of
-the hand previously to the renewal of the grasp.
-
-177. For the same reason, two muscles are provided for flexing,
-while only one is provided for extending the fingers. The flexors,
-bulky, thick, and strong, are placed on the fore part of the fore-arm
-(fig. LXXXIV.). The first, named the superficial flexor (fig. LXXXIV.
-1), about the middle of the arm, divides into four fleshy portions,
-each of which ends in a slender tendon (fig. LXXXIV. 1). As these
-tendons approach the fingers they expand (fig. LXXXIV. 1), and when
-in apposition with the first phalanx, split and form distinct sheaths
-for the reception of the tendons of the second flexor (fig. LXXXIV.
-3). After completing the sheath, the tendons proceed forward along the
-second phalanx, into the fore part of which they are implanted, and
-the chief office of this powerful muscle is to bend the second joint
-of the fingers upon the first, and the first upon the metacarpal bone.
-Its action is assisted by a second muscle, called the deep or profound
-flexor (fig. LXXXIV. 2), because it lies beneath the former; or the
-perforans, because it pierces it. Bulky and fleshy, this second flexor,
-like the first, about the middle of the arm, divides into four tendons,
-which, entering the sheaths prepared for them in the former muscle
-(where the tendons are small and rounded for their easy transmission
-and play), pass to the root of the third phalanx of the fingers into
-which they are implanted (fig. LXXXIV. 3).
-
-[Illustration: Fig. LXXXIV.
-
-View of the flexor muscles of the fingers. 1. The superficial flexor,
-divided and turned aside, to show, 2. the deep flexor; 3. sheaths for
-the tendons of the deep flexor, formed by the splitting of the tendons
-of the superficial flexor; 4. the anterior annular ligament, divided
-and turned aside.]
-
-118. The muscle that extends the fingers, called the common extensor,
-is placed on the back part of the fore-arm (fig. LXXXV.), about the
-middle of which it divides into four portions which terminate in
-so many tendons (fig. LXXXV. 2). When they reach the back of the
-metacarpal bones, these tendons become broad and flat, and send
-tendinous expansions to each other, forming a strong tendinous sheath
-which surrounds the back of the fingers (fig. LXXXV. 2). These
-tendinous expansions are inserted into the posterior part of the bones
-of the four fingers (fig. LXXXV. 2); and their office is powerfully to
-extend all the joints of all the fingers (fig. LXXXV. 2).
-
-179. On both the palmar and dorsal regions of the wrist are placed
-ligaments for tying down these tendons, and preventing them from
-starting from their situation during the action of the muscles (figs.
-LXXXIV. and LXXXV.). On the palmar region an exceedingly strong
-ligament passes anteriorly to the concave arch of the carpus (fig.
-LXXXIV. 4) for the purpose of tying down the tendons of the flexor
-muscles. On the dorsal surface (fig. LXXXV.), a similar ligament,
-passing in an oblique direction from the styloid process of the radius
-to the styloid process of the ulna (fig. LXXXV. 3), performs the same
-office in tying down the tendons of the extensor muscle. Both these
-ligaments are called annular.
-
-[Illustration: Fig. LXXXV.
-
-View of the extensor muscles of the fingers. 1. The common extensor,
-sending (2 2 2 2) tendons to each finger; 3. the posterior annular
-ligament.]
-
-180. In the palm of the hand are placed additional muscles which
-assist the flexors of the fingers (fig. LXXXVI. 2), being chiefly
-useful in enabling the fingers to perform with strength and precision
-short and quick motions. There are especially four small and rounded
-muscles (fig. LXXXVI. 2), resembling the earth worm in form and size,
-and hence called lumbricales; but as their chief use is to assist the
-fingers in executing short and rapid motions, they have also received
-the better name of the musculi fidicinales.
-
-[Illustration: Fig. LXXXVI.
-
-1. The muscle called the square pronator; 2. muscles seated in the palm
-of the hand, by which, chiefly, the fingers execute short and rapid
-motions.]
-
-181. The thumb, in consequence of the comparative looseness of its
-ligaments, is capable of a much greater extent of motion than the
-fingers, and can be applied to any part of each of the fingers, to
-different parts of the hand, and in direct opposition to the power
-exerted by the whole of the fingers and hand, in the act of grasping.
-The muscles which enable it to perform these varied motions, and which
-act powerfully in almost every thing we do with the hand, form a mass
-of flesh at the ball of the thumb (fig. LXXXVII. 1), almost entirely
-surrounding it. The little finger is also provided with a distinct
-apparatus of muscles (fig. LXXXVII. 2), which surrounds its root, just
-as those of the thumb surround its ball, in order to keep it firm in
-opposition to the power of the thumb in the act of grasping, and in
-various other motions.
-
-[Illustration: Fig. LXXXVII.
-
-1. The mass of muscles forming the ball of the thumb; 2. the mass of
-muscles forming the ball of the little finger; 3. tendons of one of the
-flexor muscles of the fingers; 4. sheaths formed by the tendons of the
-superficial flexor for the reception of the tendons of the deep flexor.]
-
-182. The upper extremity is covered by a tendinous expansion or fascia
-which envelopes the whole arm, encloses its muscles as in a sheath,
-and affords them, in their strong actions, "that kind of support which
-workmen feel in binding their arms with thongs." This fascia likewise
-descends between many of the muscles, forming strong partitions between
-them, and affording points of origin to many of their fibres, scarcely
-less fixed than bone itself.
-
-183. From the whole, it appears, that the first joint of the upper
-extremities, that of the shoulder, is a ball and socket joint, a joint
-admitting of motion in every direction; that the second joint, that of
-the elbow, is partly a hinge-joint, admitting of flexion and extension,
-and partly a rotation joint, admitting of a turning or rotatory motion;
-and that the joints of the wrist and of the fingers are likewise
-hinge-joints, admitting at the same time of some degree of lateral
-motion. When these various motions are combined, the result is that
-the hand can apply itself to bodies in almost every direction, in any
-part of the area described by the arm, when all the joints are moved to
-their utmost extent. There is thus formed an instrument of considerable
-strength, capable of a surprising variety and complexity of movements,
-capable of seizing, holding, pulling, pushing and striking with great
-power, yet at the same time capable of apprehending the minutest
-objects, and of guiding them with the utmost gentleness, precision, and
-accuracy, so that there are few conceptions of the designing mind which
-cannot be executed by the skilful hand.
-
-184. The lower extremities consist of the thigh, leg, and foot.
-
-185. The osseous part of the thigh consists of a single bone, called
-the femur (fig. XXXIV. 4), the longest, thickest, and strongest bone in
-the body. It sustains the entire weight of the trunk, and occasionally
-much heavier loads superimposed upon it. It is constructed in such
-a manner as to combine strength with lightness. This is effected by
-rendering the bone what is technically called cylindrical; that is, a
-bone in which the osseous fibres are arranged around a hollow cylinder.
-There are two varieties of osseous matter,—the compact, in which the
-fibres are dense and solid (fig. LXXXVIII. 1), and the spongy, in which
-the fibres are comparatively tender and delicate (fig. LXXXVIII. 2).
-Both varieties are, indeed, combined, more or less, in every bone,
-the compact substance being always external, and the spongy internal;
-but in the cylindrical bones the arrangement is peculiar. Every long
-or cylindrical bone consists of a body or shaft (fig. LXXXVIII. 4.),
-and of two extremities (fig. LXXXVIII. 5). The body is composed
-principally of compact substance, which on the external surface is so
-dense and solid, that scarcely any distinct arrangement is visible;
-but towards the interior this density diminishes; the fibres become
-distinct (fig. LXXXVIII. 5), and form an expanded tissue of a cellular
-appearance (fig. LXXXVIII. 5), the cells being called cancelli, and
-the structure cancellated. In the centre of the bone even the cancelli
-disappear; the osseous fibres terminate; and a hollow space is left
-filled up, in the natural state, by an infinite number of minute
-membranous bags which contain the marrow (fig. LXXXVIII. 3). In the
-body of the bone, to which strength is requisite, that part being the
-most exposed to external violence, the compact matter is arranged
-around a central cavity. By this means strength is secured without
-any addition of weight; for the resisting power of a cylindrical body
-increases in proportion to its diameter; consequently the same number
-of osseous fibres placed around the circumference of a circle produce
-a stronger bone than could have been constructed had the fibres been
-consolidated in the centre, and had the diameter been proportionally
-diminished. The hollow space thus gained in its centre, renders the
-bone lighter by the subtraction of the weight of as many fibres as
-would have gone to fill up that space; while its strength is not only
-not diminished by this arrangement, but positively increased. On the
-other hand, at the extremities of the bone, space, not strength, is
-required; required for the attachment and arrangement of the tendons
-of the muscles that act upon it, and for the formation of joints (fig.
-LXXXVIII. 5). Accordingly, at its extremities the bone swells out into
-bulky surfaces; but these surfaces are composed, not of dense and solid
-substance, but of spongy tissue, covered by an exceedingly thin crust
-of compact matter, and so, as by the former expedient strength is
-secured without increase of weight, by this, space is obtained without
-increase of weight.
-
-[Illustration: Fig. LXXXVIII.
-
-A section of the femur, showing, 1. the compact bony substance; 2. the
-spongy or cancellated structure; 3. the internal cavity containing the
-marrow; 4. body; 5, extremities of the bone.]
-
-186. The thigh-bone, placed at the under and outer part of the pelvis,
-has an oblique direction, the under being considerably nearer its
-fellow than the upper end (fig. XXXIV. 4), in order to afford space for
-the passages at the bottom of the pelvis, and also to favour the action
-of walking. The body of the bone, which is of a rounded form (fig.
-XXXIV. 4), is smooth on its anterior surface (fig. XXXIV. 4), where it
-is always slightly convex, the convexity being forwards (fig. XXXIV.
-4), while its posterior surface is irregular and rough, and forms a
-sharp prominent line, termed the linea aspera (fig. XXXV. 4), giving
-attachment to numerous muscles.
-
-187. The superior extremity of the femur terminates in a large ball or
-head, which forms nearly two-thirds of a sphere (fig. LXXXIX. 4.). It
-is smooth, covered with cartilage, and received into the socket of the
-ilium called the acetabulum, which, deep as it is, is still further
-deepened by the cartilage which borders the brim (fig. LXXXIX. 3). The
-brim is particularly high in the upper and outer part, because it is in
-this direction that the reaction of the ground against the descending
-weight of the trunk tends to dislodge the ball from its socket.
-
-188. Passing obliquely downwards and outwards from the ball, is that
-part of the femur which is called the neck (fig. LXXXIX. 5). It spreads
-out archlike between the head and the body of the bone, and is more
-than an inch in length (fig. LXXXIX. 5). It is thus long in order
-that the head of the bone may be set deep in its socket, and that its
-motions may be wide, free, and unembarrassed.
-
-[Illustration: Fig. LXXXIX.
-
-1. Lower portion of the ilium; 2. tuberosity of the ischium: 3. socket
-for the head of the femur, or thigh-bone; 4. head of the femur; 5. neck
-of the femur; 6. the great process of the femur called the trochanter
-major; 7. the body of the femur.]
-
-189. From the external surface of the femur, nearly in a line with
-its axis, proceeds the largest and strongest bony process of the body
-which gives insertion to its most powerful muscles, namely, those that
-extend the thigh and that turn it upon its axis (fig. LXXXIX. 6).
-Because, from its oblique direction, it rotates the thigh, this process
-is called the trochanter, and, from its size, the trochanter major. At
-the under and inner part of the neck on the posterior surface of the
-bone, is a similar process, but much smaller, called the trochanter
-minor (fig. XXXV. 4), into which are inserted the muscles that bend the
-thigh.
-
-190. The inferior extremity of the femur, much broader and thicker
-than the superior (fig. XC. 1), is terminated by two eminences, with
-smooth surfaces, termed condyles (fig. XC. 2), which, articulated with
-the tibia, and the patella, form the joint of the knee (figs. XC. 2, 4,
-5, and XCI. 1, 2, 3).
-
-[Illustration: Fig. XC.
-
-1. Lower end of the femur; 2. condyles of the femur; 3. upper end of
-the tibia; 4. articular surfaces on the head of the tibia on which the
-thigh-bone plays; 5. the patella, or knee-pan; 6. upper end of the
-fibula, not entering into the knee-joint.]
-
-[Illustration: Fig. XCI.
-
-Posterior view of the bones forming the knee-joint. 1. Lower end of the
-femur; 2. upper end of the tibia; 3. articular surfaces on the head of
-the tibia, on which the thigh-bone plays; 4. upper end of the fibula,
-not entering into the knee joint.]
-
-191. The bones of the leg, two in number, consist of the tibia (fig.
-XC. 3) and fibula (fig. XC. 6). The tibia, next to the femur, the
-longest bone in the body, is situated at the inner side of the leg
-(fig. XC. 3). Its superior extremity is bulky and thick (fig. XC. 3).
-The top of it forms two smooth and slightly concave surfaces, adapted
-to the convex surfaces of the condyles of the femur (fig. XC. 4, 2).
-On its outer side there is a smooth surface, to which the head of the
-fibula is attached (fig. XC. 6). Its lower extremity, which is small,
-forms a concavity adapted to the convexity of the bone of the tarsus,
-called the astragalus, with which it is articulated (fig. XCII. 4.)
-Its inner part is produced so as to form the inner ankle (figs. XCII.
-2, and XCIII. 3): its outer side is excavated into a semilunar cavity,
-for receiving the under end of the fibula, which forms the outer ankle
-(figs. XCII. 3, and XCIII. 4).
-
-192. The fibula, in proportion to its length the most slender bone of
-the body, is situated at the outer side of the tibia (fig. XC. 6). Its
-upper end formed into a head, with a flat surface on its inner side
-(figs. XC. 6, and XCI. 4), is firmly united to the tibia (fig. XC. 4).
-Its lower end forms the outer ankle, which is lower and farther back
-than the inner (fig. XCII. 3, 2).
-
-[Illustration: Fig. XCII.
-
-Anterior view of the bones forming the ankle-joint. 1. Lower end of
-the tibia; 2. production of the tibia, forming the inner ankle; 3.
-lower end of the fibula, forming the outer ankle; 4. upper part of the
-astragalus: these three bones form the ankle-joint; 5 5 5, other bones
-of the tarsus; 6 6 6 6 6 metatarsal bones.]
-
-[Illustration: Fig. XCIII.
-
-Posterior view of the bones forming the ankle-joint. 1. Lower end of
-the tibia; 2. lower end of the fibula; 3. internal malleolus or ankle;
-4. external malleolus or ankle; 5. one of the tarsal bones, called the
-astragalus, with which the tibia and fibula are articulated; 6. the os
-calcis or heel.]
-
-193. The patella, or knee-pan (fig. XC. 5), is a light but strong
-bone, of the figure of the heart as painted on playing-cards, placed
-at the fore part of the joint of the knee, and attached by a strong
-ligament to the tibia, the motions of which it follows (fig. XC. 5). It
-is lodged, when the knee is extended, in a cavity formed for it in the
-femur (fig. XC.); when bent, in a cavity formed for it at the fore part
-of the knee (fig. XC. 5).
-
-194. The foot consists of the tarsus, metatarsus, and toes.
-
-195. The tarsus, or instep, is composed of seven strong,
-irregular-shaped bones, disposed like those of the carpus, in a double
-row (fig. XCII. 4, 5). The arrangement of the tarsal bones is such as
-to form an arch, the convexity of which above, constitutes the upper
-surface of the instep (fig. XCII. 4, 5): in the concavity below are
-lodged the muscles, vessels, and nerves that belong to the sole.
-
-196. The metatarsus consists of five bones, which are placed parallel
-to each other (fig. XCII. 6), and which extend between the tarsus
-and the proper bones of the toes (fig. XCII. 6). Their extremities,
-especially next the tarsus, are large, in order that they may form
-secure articulations with the tarsal bones (fig. XCII. 6). Their
-bodies are arched upwards (fig. XCII. 6), slightly concave below, and
-terminate forwards in small, neat, round heads, which receive the
-first bones of the toes, and with which they form joints, admitting
-of a much greater degree of rotation than is ever actually exercised,
-in consequence of the practice of wearing shoes. The natural, free,
-wide-spreading form of the toes, and the consequent security with
-which they grasp the ground, is greatly impaired by this custom. Taken
-together, the bones of the metatarsus form a second arch corresponding
-to that of the tarsus (fig. XCVIII. 2).
-
-197. Each toe consists of three distinct bones, called, like those
-of the fingers, phalanges (fig. XCVIII.), but the great toe, like
-the thumb, has only two (fig. XCVIII.). That extremity of the first
-phalanges which is next the metatarsal bones is hollowed into a socket
-for the head of the metatarsal bones.
-
-198. Besides the bones already described, there are other small bones,
-of the size and figure of flattened peas, found in certain parts of
-the extremities, never in the trunk, called sesamoid, from their
-resemblance to the seed of the sesamum. They belong rather to the
-tendons of the muscles than to the bones of the skeleton. They are
-embedded within the substance of tendons, are found especially at the
-roots of the thumb and of the great toe, and are always placed in the
-direction of flexion. Their office, like that of the patella, which is,
-in truth, a bone of this class, is to increase the power of the flexor
-muscles by altering the line of their direction, that is, by removing
-them farther from the axis of the bone on which they are intended to
-act.
-
-199. The ligaments which connect the bones of the lower extremities
-are the firmest and strongest in the body. Of these, the fibrous
-capsule of the hip-joint (fig. XCIV. 1), which secures the head of the
-femur in the cavity of the acetabulum (fig. XCIV.), is the thickest and
-strongest. It completely surrounds the joint (fig. XCIV. 1). It arises
-from the whole circumference of the acetabulum, and, proceeding in a
-direction outwards and backwards, is attached below to the neck of the
-femur (fig. XCIV. 1). It is thicker, stronger, and much more closely
-attached to the bones than the fibrous capsule of the shoulder-joint
-(144), because the hip-joint is formed, not like the shoulder-joint,
-for extent of motion, but for strength. Its internal surface is
-lined by synovial membrane, and its external surface is covered and
-strengthened by the insertion of muscles that move the thigh-bone.
-The joint is strengthened by another ligament, which passes from the
-inner and fore part of the cavity of the acetabulum (fig. XCV.) to be
-inserted into the head of the femur (fig. XCIV.), called the round
-ligament, the office of which obviously is to hold the head of the
-femur firmly in its socket.
-
-[Illustration: Fig. XCIV.
-
-1. The fibrous capsule of the hip-joint, laid open and turned aside to
-show, 2. the round ligament in its natural position.]
-
-[Illustration: Fig. XCV.
-
-A view of the head of the femur drawn out of its socket, and suspended
-by the round ligament, to show more clearly the action of the ligament
-in retaining the head of the femur in its socket.]
-
-200. Numerous and complicated ligaments connect the bones that form
-the knee-joint (fig. XCVI.), and the strength of these powerful bands
-is greatly increased by the tendons that move the leg (fig. XCVI. 5),
-which pass over, and more or less surround, the joint.
-
-[Illustration: Fig. XCVI.
-
-General view of the ligaments of the knee-joint. 1. Lower end of the
-femur; 2. upper end of the tibia; 3. upper end of the fibula; 4. the
-patella; 5. united tendons of the extensor muscles; 6. ligaments of
-the patella; 7. the capsular investment of the knee; 8. the internal
-lateral ligament; 9. the external lateral ligaments; 10. the posterior
-ligament; 11. the ligament connecting the tibia and fibula; 12. a
-portion of the interosseous ligament.]
-
-201. Strong ligaments maintain in their proper position the bones that
-form the ankle-joint (fig. XCVII.), connect the bones of the tarsus
-and metatarsus with one another (fig. XCVIII. 1), and articulate the
-several phalanges of the toes (fig. XCVIII. 2).
-
-[Illustration: Fig. XCVII.
-
-General view of the posterior ligaments of the ankle-joint. 1. Lower
-end of the tibia; 2. lower end of the fibula; 3. astragalus; 4. os
-calcis; 5. ligament between the tibia and fibula; 6. ligament passing
-from the fibula to the astragalus; 7. ligament passing from the fibula
-to the os calcis; 8. ligament passing from the tibia to the astragalus.]
-
-[Illustration: Fig. XCVIII.
-
-General view of the ligaments of the sole of the foot. 1. Ligaments
-connecting the bones of the tarsus; 2. ligaments connecting the bones
-of the toes.]
-
-202. The joint of the hip, like that of the shoulder, is capable of
-flexion, extension, and rotation; but its rotatory motions are to a
-much less extent, on account of the greater depth of the acetabulum and
-the stronger and shorter fibrous capsule. When the femur is flexed, the
-thigh is bent upon the pelvis, and its inferior extremity is carried
-forwards. When it is extended, the thigh is carried backwards. The
-two thighs may be separated from each other laterally (abduction), or
-brought near to each other (adduction), or the one may be made to cross
-the other, and they may be rotated outwards or inwards.
-
-203. The apparatus of muscles that produces these varied motions is
-seated partly on the trunk and partly on the pelvis. Thus, the powerful
-muscle that flexes the thigh, or that carries it forwards, termed
-the psoas (fig. XCIX. 1), arises from the last vertebra of the back,
-and successively from each vertebra of the loins (fig. XCIX. 1), and
-is inserted into the lesser trochanter of the femur (fig. XCIX. 3).
-Its action is assisted first by a large and strong muscle named the
-iliacus (fig. XCIX. 2), which occupies the whole concavity of the ilium
-(fig. XCIX. 2), and which, like the psoas, is inserted into the lesser
-trochanter of the femur (fig. XCIX. 3).
-
-[Illustration: Fig. XCIX.
-
-View of the muscles that bend the thigh. 1. The muscle called psoas;
-2. the muscle called iliacus; 3. tendons of these muscles, going to be
-inserted into the trochanter minor of the femur.]
-
-204. The muscles that extend the thigh, or that carry it backwards,
-named the glutæi, the most powerful muscles of the body, are placed
-in successive layers, one upon the other, on the back part of the
-ilium (fig. C. 1, 2, 3), and are inserted into the linea aspera of the
-femur. They constitute the mass of flesh which forms the hip, and their
-powerful action in drawing the thigh backwards is assisted by several
-other muscles (fig. C. 4, 5, 6). Their action is never perfectly simple
-and direct; for those which move the thigh forwards sometimes carry it
-inwards, and sometimes outwards; and in like manner, those which move
-it backwards, at one time carry it inwards and at another outwards,
-according to the direction of the fibres of the muscle and the position
-of the limb when those fibres act; while some of them, and more
-especially those which carry it backwards, at the same time rotate it,
-or roll it upon its axis.
-
-[Illustration: Fig. C.
-
-View of the muscles that extend the thigh. 1. The muscle called glutæus
-maximus, removed from its origin, 2, 2, to show the muscles which lie
-beneath it; 2. cut edge showing the origin of the same muscle; 3. the
-muscle called glutæus medius; 4, 5, 6. smaller muscles, assisting the
-action of the glutæi.]
-
-205. The knee is a hinge-joint, admitting only of flexion and
-extension, and is therefore provided only with two sets of muscles, one
-for bending and the other for extending the leg. The flexors of the leg
-arise from the under and back part of the pelvis, are seated on the
-back part of the thigh, and are inserted into the upper part either of
-the tibia or of the fibula (fig. CI). They consist for the most part of
-three muscles, named the semi-tendinosus, the semi-membranosus (fig.
-CI. 3), and the biceps of the leg (fig. CI. 1). The tendons of the two
-former muscles, in passing to be inserted into the leg, form the inner,
-and that of the latter the outer, hamstrings (fig. CI. 4, 5).
-
-[Illustration: Fig. CII.
-
-View of the flexor and extensor muscles of the leg. 1. The biceps of
-the leg; 2. tendon of the biceps, inserted into the head of the fibula;
-3. the semi-membranosus, passing to be inserted into the head of the
-fibula; 4. tendon of the semi-membranosus forming the inner, and 5.
-tendon of the biceps forming the outer, hamstring; 6. upper part of the
-gastrocnemius muscle; 7. the four large muscles which unite to form the
-great extensor muscle of the leg, inserted into 8. the patella; 9. a
-portion of the glutæus maximus concealing the other muscles of the hip.]
-
-206. Four large muscles, blended together in such a manner as to form
-one muscle of prodigious size, termed the quadriceps cruris (fig. CI.
-7), occupying nearly all the forepart and the sides, and a considerable
-portion of the back part of the thigh, constitute the great flexor of
-the thigh. This enormous mass of muscle arises partly from the ischium,
-and partly from the upper part of the femur (fig. CI. 7), and is all
-inserted into the patella (fig. CI. 8), which constitutes a pulley for
-the purpose of assisting the action of these powerful muscles.
-
-207. The muscles which bend the toes and extend the foot, termed the
-gastrocnemii (fig. CII. 1, 2), are placed on the back part of the leg,
-and form the mass of muscle which constitutes the calf of the leg (fig.
-CII. 1, 2). They arise partly from the lower extremity of the femur
-(fig. CII.) and partly from the upper and back part of the fibula and
-tibia; and they form the largest and strongest tendon in the body,
-termed the tendo achillis (fig. CII. 3), which is implanted into the
-heel (fig. CII. 4).
-
-[Illustration: Fig. CII.
-
-View of the muscles which bend the toes, and which, by lifting the
-heel, extend the foot. 1. The muscle called gastrocnemius externus,
-which, uniting with 2. the gastrocnemius internus, forms 3. the tendo
-achillis, which is inserted into 4. the heel.]
-
-[Illustration: Fig. CIII.
-
-View of the muscles which extend the toes and bend the foot. 1. The
-common extensor; 2. the tendons of the same muscle inserted into the
-toes; 3. the anterior annular ligament of the foot.]
-
-[Illustration: Fig. CIV.
-
-View of the muscles in the sole of the foot. 1 The muscle which draws
-the great toe from the other toes; 2. the muscle which draws the little
-toe from the other toes; 3. the muscle called the short flexor of the
-toes, which assists in bending the four smaller toes.]
-
-208. The muscles which extend the toes and bend the foot are seated
-on the fore part of the leg (fig. CIII.); split into tendons like the
-analogous muscles of the fingers (fig. CIII. 2); and are bound down
-by a ligament (fig. CIII. 3), exactly the same in name, disposition,
-and office, as that which belongs to the hand (fig. CIII. 3). Numerous
-minute muscles are placed in the sole of the foot (fig. CIV.), which
-act on the toes as the small muscles in the palm of the hand act on the
-fingers (fig. LXXXVI.).
-
-209. Such are the moving powers which put in action the complicated
-mechanism provided for the function of locomotion. And these powers are
-adequate to their office; but they are what may be termed expensive
-powers; agents requiring a high degree, of organization and the utmost
-resources of the economy to support and maintain them. Hence in the
-construction of the framework of the machine which they have to move,
-whatever mechanical contrivance may economize their labour, is adopted.
-The construction, form, and disposition of the several parts of that
-framework have all reference to two objects: first, the combination
-of strength with lightness; and secondly, security to tender organs,
-with the power of executing rapid, energetic, and, sometimes, violent
-motions. The combination is effected and the object attained in a mode
-complicated in the detail, simple in the design, and perfect in the
-result. The weight of the body transmitted from the arch of the pelvis
-to a second arch, formed by the neck of the thigh-bone, and from this,
-in a perpendicular direction, to a third arch formed by the foot, is
-ultimately received by the heel behind, and by the metatarsal bones
-and the first phalanges of the toes before, and more especially by the
-metatarsal joints belonging to the great and little toe, which have a
-special apparatus of muscles, for the purpose of preserving steadily
-their relative situation to the heel. The weight of the body is thus
-sustained on a series of arches, from which it is, in succession,
-transmitted to the ground, where it ultimately rests upon a tripod:
-forms known and selected as the best adapted to afford support, and to
-give security of position. Columns of compact bone superimposed one
-upon another, and united at different points by bands of prodigious
-strength, form the pillars of support. But these bony columns never
-touch each other; are never in actual contact; are all separated by
-layers of elastic matter which, while they assist in binding the
-columns together, enable them to move one upon another, as upon so many
-pliant springs. The layers of cartilage interposed between the several
-vertebræ; the layer of cartilage interposed between the vertebral
-column and the pelvis; the layer of cartilage that lines the acetabulum
-and that covers the head of the femur; the layer of cartilage that
-covers the lower extremity of the femur and the upper extremity of the
-tibia and fibula and the tarsus; the successive layers of cartilage
-interposed between the several bones of the tarsus; and finally,
-the layer of cartilage that covers both the tarsal and the digital
-extremities of the metatarsal bones; are so many special provisions to
-prevent the weight of the body from being transmitted to the ground
-with a shock; and, at the same time, so many barriers established
-between the ground and the spinal cord, the brain and the soft and
-tender organs contained in the thoracic and abdominal cavities, to
-prevent these organs from being injured by the reaction of the ground
-upon the body. The excellence of this mechanism is seen in its results;
-in contemplating "from what heights we can leap—to what heights we can
-spring—to what distances we can bound—how swiftly we can run—how
-firmly we can stand—how nimbly we can dance—and yet how perfectly we
-can balance ourselves upon the smallest surfaces of support!"
-
-210. It is necessary, in order to complete this general view of the
-structure of the human body, and of the combination and arrangement
-of its various parts, to denote the several regions into which, for
-the purpose of describing with accuracy the situation and relation of
-its more important organs, the body is divided. It is not needful to
-the present purpose to describe the regions of the head, because its
-internal cavity contains only one organ, the brain, and its external
-divisions do not differ materially from those which are common
-and familiar; but the chest, the abdomen, and the upper and lower
-extremities are mapped out into regions, of which it is very important
-to have an exact knowledge, which may be acquired by the study of the
-annexed diagrams.
-
-[Illustration: Fig. CV.
-
-Anterior view of the regions of the body. 1. Region of the neck; 2.
-region of the chest or thorax. Abdominal regions: 3. epigastric; 4.
-umbilical; 5. hypogastric region. Regions of the upper extremities. 6.
-shoulder; 7. arm; 8. elbow; 9. fore-arm; 10. wrist; 11. ball of thumb;
-12. the axilla or armpit. Regions of the lower extremities: 13. thigh;
-14. knee; 15. leg; 16. ankle; 17. instep and foot.]
-
-[Illustration: Fig. CVI.
-
-Posterior view of the regions of the body: 18. region to the scapula;
-19. of the back; 20. of the loins; 21. of the hips; 22. of the ham; 23.
-of the calf of the leg; 24. of the heel and foot.]
-
-[Illustration: Fig. CVII.
-
-Lateral view of the regions of the body: 25. arch of the foot.]
-
-[Illustration: Fig. CVIII.
-
-Anterior view of the situation of the more important internal organs:
-1. lungs, right and left; 2. heart; 3. line representing the edge of
-the diaphragm; 4. liver; 5. stomach; 6. small intestines; 7. colon; 8.
-urinary bladder.]
-
-[Illustration: Fig. CIX.
-
-Posterior view of the situation of the more important internal organs:
-9. kidnies, right and left; 10. the course of the spinal cord.]
-
-[Illustration: Fig. CX.
-
-Lateral view of the situation of the more important internal organs.]
-
-
-
-
-CHAPTER VI.
-
-OF THE BLOOD.
-
-  Physical characters of the blood: colour, fluidity,
-  specific gravity, temperature: quantity—Process
-  of coagulation—Constituents of the blood:
-  proportions—Constituents of the body contained in the
-  blood—Vital properties of the blood—Practical applications.
-
-
-211. Supposing the human body to have been built up in the manner now
-described, and to be in the full exercise of all its functions, the
-integrity of its various structures is maintained, and their due action
-excited by the blood. Out of this substance is formed the blandest
-fluid, as the milk, and the firmest solid, as the compact bone. The
-heart, capable of untiring action, as long as the blood is in contact
-with its internal surface, becomes immovable soon after the supply of
-this fluid is withdrawn; and in less than one minute from the time
-it ceases to flow in due quantity and of proper quality through the
-vessels of the brain, the eye is no longer capable of seeing, nor the
-ear of hearing, nor the brain of carrying on any intellectual operation.
-
-212. At the moment, and for some time after it has issued from its
-vessel, the appearance of the blood is that of a thick, viscid, and
-tenacious fluid; yet it is essentially a solid, composed of several
-substances, each possessing its own distinct and peculiar properties,
-the relation and combination of which cannot be considered without
-exciting the feeling that our admiration of the structure of the animal
-frame ought not to be confined to the mechanism of its solid parts, but
-that the whole is admirable, from the common material of which it is
-composed, to its most delicate and elaborate instrument.
-
-213. The colour of redness is universally associated with the idea of
-blood; but redness of colour is not essential to blood. There are many
-animals with true, yet without red, blood; and there is no animal in
-which the blood is red in all the parts of its body. The blood of the
-insect is transparent; that of the reptile is of a yellowish colour;
-that of the fish, in the greater part of its body, is colourless. Even
-the red blood of the human body is not equally red in every part of it,
-there being two distinct systems of blood-vessels, distinguished from
-each other by carrying blood of different colours.
-
-214. In the state of health, the specific gravity of human blood, water
-being 1000, is 1080; from which standard it is capable of varying from
-1120, the maximum, to 1026, the minimum.
-
-215. The natural temperature of the human blood is 98°. From this it
-is capable of varying from 104°, the maximum, to 86°, the minimum;
-these changes being always the effect of disease.
-
-216. It is estimated that the fluids circulating in the adult
-man amount to about fifty pounds; of these it is calculated that
-twenty-eight consist of red blood.
-
-217. Fluid and homogeneous as the blood appears while flowing in its
-vessel, when a mass of it is collected and allowed to stand at rest, it
-soon undergoes a very remarkable change. First, a thin film is formed
-upon its surface; this is followed by the conversion of the whole mass
-into a soft jelly: this jelly separates into two portions, a fluid and
-a solid portion. The solid portion again separates into two parts, into
-a substance of a yellowish-white colour, occupying the upper surface,
-and into a red mass always found at the under surface.
-
-218. The process by which the constituents of the blood are thus
-spontaneously disunited, and afforded in a separate form, is
-denominated COAGULATION; the fluid portion separated by the process is
-termed the SERUM; the solid portion the COAGULUM or CLOT; the white
-substance forming the upper part of the clot, the FIBRIN; and the red
-mass forming the under part of it, the RED PARTICLES.
-
-219. Probably the process of coagulation commences the moment the
-blood leaves its living vessel. In three minutes and a half it is
-visible to the eye; in seven minutes the mass is formed into a jelly;
-in from ten to twelve minutes the serum separates from the clot; in
-about twenty the clot is divided into fibrin and red particles, when
-the coagulation is complete; but occasionally the clot continues to
-grow firmer and firmer for the space of twenty-four hours.
-
-220. As soon as the coagulation commences, and during all the time the
-blood preserves its heat, an aqueous vapour arises from it, termed
-the HALITUS. The halitus consists of water holding in solution a
-small quantity of animal and saline matter, which communicate to it a
-fœtid odour of a strong and peculiar nature, manifest on approaching
-a slaughter-house, and still more manifest in the slaughter-house of
-human beings, a field of battle.
-
-221. During the process of coagulation, as in every other in which a
-fluid is converted into a solid, caloric is evolved.
-
-222. During the process of coagulation carbonic acid is also extricated.
-
-223. The process of coagulation affords three distinct substances,
-the chief constituents of the blood, namely, serum, fibrin, and red
-particles.
-
-224. The serum, the fluid portion of the blood, when obtained
-perfectly pure, is of a light straw colour, tinged with green.
-Its taste is saline, and its consistence adhesive. It is composed
-principally of water holding in solution animal and saline matter.
-The animal matter gives it its adhesive consistence, and the saline
-its peculiar salt taste. The chief animal matter contained in it is
-the proximate principle termed albumen, which may be separated from
-the water that holds it in solution by the application of heat and
-by certain chemical agents. Heat being applied, when the temperature
-reaches 160°, fluid serum is converted into a white opaque solid
-substance of firm consistence. This is found to be albumen, which may
-be also separated from the watery portion by the application of spirits
-of wine, acids, oxymuriate of mercury, and several other chemical
-substances. The quantity of albumen contained in 1000 parts of serum
-varies from about 78, the maximum, to 58, the minimum.
-
-225. If the albumen yielded by the serum be subjected to pressure, or
-be cut into small pieces, there flows from it a watery fluid which is
-termed the serosity. In meat dressed for the table, the serum of the
-blood contained in the blood-vessels is converted by the heat into
-solid albumen, from which, when cut, the serosity flows in the form of
-gravy.
-
-226. Besides albumen, serum holds in solution both a fatty and an oily
-matter, in the proportion of about one part of each to 1000 parts of
-serum. The proportion of its saline substances is about ten in 1000
-parts. According to M. le Canu, who has made the most recent chemical
-analysis of serum, 1000 parts contain, of
-
-  Water                                     906·00
-  Albumen                                    78·00
-  Animal matter, soluble in water
-    and alcohol                               1·69
-  Albumen combined with soda                  2·10
-  Crystallizable fatty matter                 1·20
-  Oily matter                                 1·00
-  Hydrochlorate of soda and
-    potash                                    6·00
-  Subcarbonate and phosphate of
-    soda, and sulphate of potash              2·10
-  Phosphate of lime, magnesia,
-    and iron, with subcarbonate
-    of lime and magnesia                       ·91
-  Loss                                        1·00
-
-227. All the animal and saline matter held in solution in the serum
-being removed, the fluid that remains is water, the proportion of which
-in 1000 parts varies from 853, the maximum, to 779, the minimum.
-
-228. The second constituent of the blood, the fibrin, is the most
-essential portion of it, being invariably present, whatever other
-constituent be absent. While circulating in the living vessel,
-fibrin is fluid and transparent; by the process of coagulation, it
-is converted into a solid and opaque substance of a yellowish white
-colour, consisting of stringy fibres, disposed in striæ, which
-occasionally form a complete net-work (fig. CXI.). These fibres are
-exceedingly elastic. In their general aspect and their chemical
-relations they bear a close resemblance to pure muscular fibre, that
-is, to muscular fibre deprived of its enveloping membrane and of its
-colouring matter, and they form the basis of muscle. According to M.
-le Canu, the proportion of the fibrin varies from seven parts in 1000,
-the maximum, to one part in 1000, the minimum, the medium of twenty
-experiments being four parts in 1000.
-
-[Illustration: Fig. CXI.
-
-A portion of the fibrin of the blood, showing its fibrous structure and
-the striated or net-like arrangement of its fibres.]
-
-229. The third constituent of the blood, the matter upon which its red
-colour depends, though, as has been stated, entirely absent in certain
-classes of animals, and in all animals in some parts of their body,
-seems to be essential, at least to the organic organs, whenever they
-perform their functions with a high degree of perfection. Thus in the
-lowest class of vertebrated animals, the fish, while the principal part
-of its body receives only a colourless fluid, its organic organs, as
-the heart, the gills, the liver, are provided with red blood.
-
-230. The red matter, wherever present, is invariably heavier than
-the fibrin, and consequently, during the process of coagulation, it
-gradually subsides to the lower surface, and is always found forming
-the bottom of the clot. Its proportion to the other constituents varies
-very remarkably, the maximum being 148, the minimum 68, and the medium
-108, in 1000 parts of blood.
-
-231. All observers are agreed that the red matter of the blood consists
-of minute particles, having a peculiar and definite structure; but in
-regard to the nature of that structure, there is considerable diversity
-of opinion, which is not wonderful, since the particles in question
-are so minute that they can be distinguished only by the microscope,
-and since, of all microscopical objects, they are perhaps the most
-difficult to examine, because, being soft and yielding, their figure
-is apt to change, and because there is reason to suppose that their
-substance is not uniform in its refractive power.
-
-232. The earlier observers describe the red particles as being of
-a globular figure, and accordingly name them globules. They conceive
-that each globule consists of a central solid particle, enveloped in a
-transparent vesicle. Recently, Sir Everard Home and Mr. Bauer in this
-country, and MM. Prevost and Dumas on the continent, have revived this
-opinion, and describe the red particle as consisting of a central solid
-white corpuscle contained in an external envelop of a red colour. When
-the blood is observed with the microscope in a living animal, flowing
-in its vessels, only two substances can be distinguished, namely,
-a transparent fluid and the red corpuscles. MM. Prevost and Dumas
-contend that these two substances are the only component parts of the
-blood. When the blood coagulates, they conceive that the red envelop
-separates from the central white corpuscle; that these white corpuscles
-unite together; that the aggregates resulting from this combination
-are disposed in the form of filaments, which filaments constitute the
-fibrin, while the red matter at the bottom of the clot is nothing but
-the disintegrated envelops of the central particle. But this view is
-not the common one. In general, physiologists conceive the fibrin to
-be one constituent and the red particles to be another constituent of
-the blood. Mr. Lister, who has successfully laboured to improve the
-microscope, and who, together with his friend Dr. Hodgkin, have very
-carefully examined with their improved instrument the red particles,
-contend that the figure of these bodies is not globular, although
-they state that the instant the particles are removed from the living
-blood-vessels many things are capable of making them assume a globular
-appearance; such, for example, as the application of water. With a
-rapidity which, in spite of every precaution, the eye in vain attempts
-to follow, the particles change their real figure for a globular form
-on the application of the smallest quantity of pure water; while,
-if the water contain a solution of saline matter, little alteration
-is occasioned in the figure of the particles. According to these
-observers, the red particles are flattened cakes, having rounded and
-very slightly thickened margins (fig. CXII. 1). The thickness of the
-margin gives to both surfaces the appearance of a slight depression
-in the middle (fig. CXII. 1), so that the particles bear a close
-resemblance to a penny piece. There is no appearance of an external
-envelop. The circular and flattened cake is transparent; when seen
-singly it is nearly if not quite colourless (fig. CXII. 1); it assumes
-a reddish tinge only when aggregated in considerable masses.
-
-[Illustration: Fig. CXII.
-
-1. A particle of the human blood as it appears when transparent and
-floating; 2. the same dry, seen as opaque, illuminated by a leiberkuhn;
-3. the same as it appears when half the leiberkuhn is darkened; 4. a
-particle of the frog's blood floating; 5. the same seen on its edge.
-All the above objects are magnified 500 diameters[5].]
-
-233. The red particle of the human blood is circular (fig. CXII. 1, 2,
-3). It is circular also in all animals belonging to the class mammalia;
-but in the three lower classes of vertebrated animals, the bird, the
-reptile, and the fish, it is elliptical (fig. CXII. 4, 5).
-
-234. The magnitude of the red particle of the human blood is variously
-estimated from the two-thousandth to the six-thousandth part of an inch
-in diameter. Bauer estimates it at the two-thousandth, Hodgkin and
-Lister at the three-thousandth, Kater at the four-thousandth, Wollaston
-at the five-thousandth, and Young at the six-thousandth part of an
-inch. Its magnitude is uniformly the same in all individuals of the
-same species, but differs exceedingly in the different classes. The
-elliptical particles are larger than the circular, but proportionally
-thinner; larger in fishes than in any other class of animals, and
-largest of all in the skate.
-
-235. When perfect and entire, the red particles indicate a disposition
-to arrange themselves in a definite mode. They combine spontaneously
-into columns of variable length (fig. CXIII.). In order to observe this
-tendency, a small quantity of blood, the moment it is taken from its
-living vessel, should be placed between two strips of glass or covered
-with a bit of talc and placed under the microscope. When thus arranged,
-a considerable agitation at first takes place among the particles.
-As soon as this motion subsides, the particles apply themselves to
-each other by their broad surfaces, and thus form piles or columns of
-Considerable length (fig. CXIII.). The columns often again combine one
-among another, the end of one being attached to the side of another,
-sometimes producing very curious ramifications (fig. CXIII.). In
-like manner, the elliptical particles apply themselves to each other
-by their broad surfaces, but they are not so exactly matched as the
-circular, one particle partially overlapping another, so that they form
-less regular columns than the circular.
-
-[Illustration: Fig. CXIII.
-
-Columnar arrangement which the particles of the human blood assume
-immediately after it is drawn from its vessel.]
-
-236. The red particles, as far as is known, constitute a distinct and
-peculiar form of animal matter: the red colour, according to some,
-depending on an impregnation of iron; according to others, on an animal
-substance of a gelatinous nature.
-
-237. The exact proportion of the different substances contained in the
-blood, according to the most recent analysis of it, that by M. le Canu,
-is as follows, namely,
-
-  Water                                786·500
-  Albumen                               69·415
-  Fibrin                                 3·565
-  Colouring matter                     119·626
-  Crystallizable fatty matter            4·300
-    Oily matter                          2·270
-  Extractive matter, soluble in
-    alcohol and water                    1·920
-  Albumen combined with soda             2·010
-  Chloruret of sodium and potassium,
-    alkaline phosphate,
-    sulphate, and subcarbonates          7·304
-  Subcarbonate of lime and magnesia,
-    phosphates of lime,
-    magnesia and iron, peroxide
-    of iron                              1·414
-  Loss                                   2·586
-                                      --------
-                                      1000·
-
-238. From the results of this analysis it is manifest that all the
-proximate principles of which the different tissues are composed exist
-in the blood, namely, albumen, the proximate principle forming the
-basis of membrane; fibrin, the proximate principle forming the basis
-of muscle; fatty matter, forming the basis of nerve and brain; and
-various saline and mineral substances, forming a large part of bone,
-and entering more or less into the composition of every fluid and solid.
-
-239. The blood, which contains all the proximate constituents of the
-body, and which, by distributing them to the various tissues and
-organs, maintains their integrity and life, is itself alive. The
-vitality of the blood is proved,—
-
-240. i. By its undergoing the process of death, which it does just as
-much as the heart or the brain, every time it is removed from the body.
-While flowing in its living vessel, the blood is permanently fluid.
-Its fluidity depends on a force of mutual repulsion exerted by its
-particles on each other. That repulsive force is a vital endowment,
-probably derived from the organic nerves so abundantly distributed
-to the inner coat of the blood-vessels. When this vital influence
-is withdrawn, which happens on the removal of the blood from its
-vessel, the mass is no longer capable of remaining fluid; the fibrin
-is converted into a solid; the red particles, instead of repelling,
-attract each other, forming the crude aggregate at the bottom of
-the clot; coagulation is thus a process of death; its commencement
-indicates a diminution of the vital energy of the blood; during its
-progress that energy is constantly growing less and less; the blood is
-dying; and when complete, the blood is dead.
-
-241. Hence in every state of the system in which the vital energy of
-the blood is preternaturally increased, coagulation is proportionably
-slow; in every state in which its energy is diminished, coagulation
-is rapid. By copious and repeated blood-letting, the vital energy
-is rapidly exhausted. The effect of blood-letting on coagulation
-is determined by experiments instituted for the express purpose of
-ascertaining it. Blood was received from a horse at four periods, about
-a minute and a half intervening between the filling of each cup.
-
-                                      Minutes.   Seconds.
-
-  In cup No. 1. coagulation began in     11         10
-       "     2.     "     "     "        10          5
-       "     3.     "     "     "         9         55
-       "     4.     "     "     "         3         10
-
-242. In like manner three cups were filled with the blood of a sheep,
-at the interval of half a minute.
-
-                                      Minutes.   Seconds.
-
-  In cup No. 1. coagulation began in      2         10
-       "     2.     "     "     "         1         45
-       "     3.     "     "     "         0         55
-
-The same result was obtained in blood taken from a human subject. A
-pound and a half of blood was removed from the arm of a woman labouring
-under fever, a portion of which, received into a tea-cup on the first
-effusion, remained fluid for the space of seven minutes; a similar
-quantity, taken immediately before tying up the arm, was coagulated
-in three minutes thirty seconds. These experiments demonstrate that
-coagulation is rapid or slow as the vital energy of the blood is
-exhausted or unexhausted, or that in proportion to the degree of life
-possessed by the blood is the space of time it takes in dying.
-
-243. This result is referable to the principle already shown to be
-characteristic of living substance,—namely, the power of resisting,
-within a certain range, the ordinary influence of physical agents.
-The operation of this power is illustrated in a beautiful manner in
-a series of experiments performed by Mr. Hunter on the egg and on
-blood. This physiologist exposed a live, that is, a fresh egg to the
-temperature of the 17th and the 15th degrees of Fahrenheit; it took
-half an hour to freeze it. The egg was then thawed and exposed to 10°
-less cold, namely, to the 25th degree of Fahrenheit; it was now frozen
-in a quarter of an hour. A living egg and one that had been killed by
-having been first frozen and then thawed, were put together into a
-freezing mixture at 15°: the dead was frozen twenty-five minutes sooner
-than the living egg. The undiminished vitality of the fresh egg enabled
-it to resist the low temperature for the space of twenty-five minutes;
-the vitality of the frozen egg having been destroyed, it yielded at
-once to the influence of the physical agent. On subjecting blood to
-analogous experiments, the result was found to be the same. Blood
-immediately taken from the living vessel, and blood previously frozen
-and then thawed, being exposed to a freezing mixture, a much shorter
-period and a much less degree of cold were required to freeze the
-latter than the former.
-
-244. ii. The vitality of the blood is proved by the change it
-undergoes in becoming a constituent part of an organized tissue.
-The blood conveys to the several tissues the constituents of which
-they are composed; each tissue selects from the mass of blood its
-own constituents and converts them into its own substance, in which
-conversion, since the blood always goes to the tissue in a fluid
-form, the blood must necessarily pass from a fluid into a solid. In
-the vessels the vital endowment of the blood maintains it permanently
-fluid; in the structures the same power makes it and keeps it
-solid. One and the same substance in one and the same body, in one
-part is always fluid, in another always solid; the fluid is every
-moment passing into the solid and the solid into the fluid, without
-intermixture and without interference. Nothing analogous to this is
-ever witnessed in inorganic matter, in physical mechanism; it is
-peculiar to the organized body and distinctive of the mechanism of
-life. Sometimes in physical mechanism we can perceive the mechanical
-arrangements and distinctly trace them from beginning to end: in vital
-mechanism, even when we can discern the mechanical arrangements, we can
-seldom trace them beyond a step or two, and never from beginning to
-end; but arrangement and adaptation we know there must be in that which
-goes beyond, no less than in that which keeps within, our perception,
-and we ought scarcely to question the existence of adjustments, because
-they elude our sense, when probably the very reason why they do so is
-that their delicacy and perfection immeasurably exceed any with which
-sense has made us acquainted.
-
-245. iii. The vitality of the blood is proved by the process of
-organization. We can trace only a few steps of this process, but these
-are sufficient to establish the point in question. Blood effused from
-living vessels into the substance, or upon the surface of living
-organs, solidifies without losing vitality. If a clot of blood be
-examined some time after it has thus become solid, it is found to
-abound with blood-vessels. Some of these vessels are obviously derived
-from the surrounding living parts. The minute vessels of these parts,
-as can be distinctly traced, elongate and shoot into the clot. The
-clot thus acquires blood-vessels of its own. By degrees a complete
-circulation is established within it. The blood-vessels of the clot act
-upon the blood they receive just as the vessels of any other part act
-upon their blood, that is transform it into the animal matter it is
-their office to elaborate. In this manner a clot of blood is converted
-into a component part of the body, and acquires the power of exercising
-its own peculiar and appropriate functions in the economy.
-
-246. But while, in this process, some of the vessels of the clot can
-be distinctly traced from the surrounding living parts, others appear
-to have no communication with those parts, at all events no such
-communication can be traced. These vessels, the origin of which cannot
-be found external to the clot, are supposed by some physiologists to
-be formed within it. Within the living egg, during incubation, certain
-motions or actions are observed spontaneously to arise, which terminate
-in the development of the chick. Analogous motions arising within the
-clot terminate, it is conceived, in the development of blood-vessels.
-According to this view, a simultaneous action takes place in the clot,
-and in the living part with which it is in contact; each shooting out
-vessels which elongate, approximate, unite, and thus establish a direct
-vital communication. Whether this view of the process of organization
-be the correct one or not does not affect the present argument. It
-is certain that a clot of blood surrounded by living parts becomes
-organized; it is certain that no dead substance surrounded by living
-parts becomes organized; it follows that the blood possesses life.
-
-247. Health and life depend on the quantity, quality, and distribution
-of the blood. The chief source from which the blood itself is derived
-is the chyle: hence too much or too little food, or too great or too
-little activity of the organs that digest it, may render the quantity
-of the blood preternaturally abundant or deficient; or though there be
-neither excess nor deficiency in the quantity of nourishment formed,
-parts of the blood which ought to be removed may be retained, or
-parts which ought to be retained may be removed, and hence the actual
-quantity in the system may be superabundant or insufficient.
-
-248. The relative proportion of every constituent of the blood
-is capable of varying; and of course in the degree in which the
-healthy proportion is deranged, the quality of the mass must undergo
-a corresponding deterioration. The watery portion is sometimes so
-deficient, that the mass is obviously thickened; while at other times
-the fluid preponderates so much over the solid constituents, that the
-blood is thin and watery. The albumen, the quantity of which varies
-considerably even in health, in disease is sometimes twice as great,
-and at other times is less than half its natural proportion. In some
-cases the fibrin preponderates so much, that the coagulum formed by
-the blood is exceedingly coherent, firm and dense; in other cases the
-quantity of fibrin is so small, that the coagulation is imperfect,
-forming only a soft, loose and tender coagulum, and in extreme cases
-the blood remains wholly fluid. When the vital energy of the system
-is great, the red particles abound; when it is depressed, they are
-deficient. In the former state, they are of a bright red colour; in
-the latter, dusky, purple, or even black. When the depression of
-the vital energy is extreme, the power of mutual repulsion exerted
-by the particles would seem to be so far destroyed as to admit of
-their adhering to each other partially in certain organs; while in
-other cases they seem to be actually disorganised, and to have their
-structures so broken up, that they escape from the current of the
-circulation as if dissolved in the serum, through the minute vessels
-intended only for the exhalation of the watery part of the blood.
-This fearful change is conceived to have an intimate connexion with
-a diminution of the proportion of the saline constituents. Out of
-the body, as has been shown, the red particles change their figure
-instantaneously, and are rapidly dissolved when in contact with
-pure water; while they undergo little change of form if the water
-hold saline matter in solution. It would seem that one use of the
-saline constituents of the blood is to preserve entire the figure and
-constitution of the red particles. It is certain that any change in the
-proportion of the saline constituents produces a most powerful effect
-on the condition of the red particles. It is no less certain that
-changes do take place in the proportion of the saline constituents.
-In the state of health, the taste of the blood is distinctly salt,
-depending chiefly on the quantity of muriate of soda contained in
-it. In certain violent and malignant diseases, such, for example, as
-the malignant forms of fever, and more especially that form of it
-termed pestilential cholera, this salt taste is scarcely, if at all,
-perceptible; and it is ascertained that, in such cases, the proportion
-of saline matter is sensibly diminished.
-
-249. The quality of the blood may be also essentially changed
-by the disturbance of the balance of certain organic functions:
-digestion, absorption, circulation, respiration, are indispensable
-to the formation of the blood and to the nourishment of the tissues.
-Absorption, nutrition, secretion, circulation, render the blood impure,
-either by directly communicating to it hurtful ingredients, or by
-allowing noxious matters to accumulate in it, or by destroying the
-relative proportion of its constituents. Organs are specially provided,
-the main function of which is to separate and remove from the blood
-these injurious substances. Organs of this class are called depurating,
-and the process they carry on is denominated that of depuration. The
-lungs, the liver, the kidneys, are depurating organs, and one result at
-least of the functions they perform is the purification or depuration
-of the blood. If the lung fail to eliminate carbon, the liver bile,
-the kidney urine, carbon, bile, urine, or at least the constituents
-of which these substances are composed, must accumulate in the blood,
-contaminate it, and render it incapable of duly nourishing and
-stimulating the organs.
-
-250. But though the blood be good in quality and just in quantity,
-health and life must still depend upon its proper distribution. It
-may be sent out to the system too rapidly or too slowly. It may be
-distributed to different portions of the system unequally; too much may
-be sent to one organ, and too little to another: consequently, while
-the latter languishes, the former may be oppressed, overwhelmed or
-stimulated to violent and destructive action. In either case health is
-disturbed and life endangered.
-
-251. Of the mode and degree in which food, air, moisture, temperature,
-repletion, abstinence, exercise, indolence, influence the quantity,
-quality, and distribution of the blood; of the mode in which the
-condition of the blood modifies the actions both of the organic and
-the animal organs; of the reason why health and disease are wholly
-dependent on those states and actions, a clear and just conception
-may be formed when the several functions have been described, and the
-precise office of each is understood.
-
-
-
-
-CHAPTER VII.
-
-OF THE CIRCULATION.
-
-  Vessels connected with the heart: chambers of the
-  heart—Position of the heart—Pulmonic circle:
-  systemic circle—Structure of the heart, artery, and
-  vein—Consequences of the discovery of the circulation to the
-  discoverer—Action of the heart: sounds occasioned by its
-  different movements—Contraction: dilatation—Disposition
-  and action of the valves—Powers that move the blood—Force
-  of the heart—Action of the arterial tubes: the pulse:
-  action of the capillaries: action of the veins—Self-moving
-  power of the blood—Vital endowment of the capillaries:
-  functions—Practical applications.
-
-
-252. The blood, being necessary to nourish the tissues and to
-stimulate the organs, must be in motion in order to be borne to them.
-An apparatus is provided partly for the purpose of originating an
-impelling force to put the blood in motion, and partly for the purpose
-of conveying the blood when in motion to the different parts of the
-body.
-
-253. The heart is the impelling organ; the great vessels in immediate
-connexion with it are the transmitting organs (fig. CXIV. 1, 2). The
-heart is divided into two sets of chambers (fig. CXIV. 3, 4, 10, 11),
-one for the reception of the blood from the different parts of the body
-(fig. CXIV. 3, 10); the other for the communication of the impulse
-which keeps the blood in motion (fig. CXIV. 4, 11). The chamber which
-receives the blood is termed an auricle (fig. CXIV. 3, 10), and is
-connected with a vessel termed a vein (fig. CXIV. 1, 2, 9); that which
-communicates impulse to the blood is termed a ventricle (fig. CXIV. 4,
-11), and is connected with a vessel termed an artery (fig. CXIV. 7,
-12). The vein carries blood to the auricle; the auricle transmits it to
-the ventricle; the ventricle propels it into the artery; the artery,
-carrying it out from the ventricle, ultimately sends it again into the
-vein, the vein returns it to the auricle, the auricle to the ventricle,
-the ventricle to the artery, and thus the blood is constantly moving in
-a circle; hence the name of the process, the circulation of the blood.
-
-[Illustration: Fig. CXIV.
-
-View of the heart with its several chambers exposed, and the great
-vessels in connection with them. 1. The superior vena cava; 2. the
-inferior vena cava; 3. the chamber called the right auricle; 4. the
-chamber called the right ventricle; 5. the line marking the passage
-between the two chambers, and the points of attachment of one margin of
-the valve; 6. the septum between the two ventricles; 7. the pulmonary
-artery arising from the right ventricle, and dividing at 8, into right
-and left for the corresponding lungs; 9. the four pulmonary veins
-bringing the blood from the lungs into 10, the left auricle; 11. the
-left ventricle; 12. the aorta arising from the left ventricle, and
-passing down behind the heart to distribute blood, by its divisions and
-subdivisions, to every part of the body.]
-
-254. In nourishing the tissues and stimulating the organs, the blood
-parts with its nutritive and stimulating constituents, and receives in
-return some ingredients which can no longer be usefully employed in the
-economy, and others which are positively injurious. An apparatus is
-established for its renovation and depuration; this organ is termed the
-lung (fig. LIX. 5), and to this organ the blood must in like manner be
-conveyed. Thus the blood moves in a double circle, one from the heart
-to the body and from the body back to the heart, termed the systemic
-circle; the other from the heart to the lung and from the lung back
-to the heart, termed the pulmonic circle. Hence in the human body the
-heart is double, consisting of two corresponding parts precisely the
-same in name, in nature, and in office; the one appropriated to the
-greater, or the systemic, and the other to the lesser, or the pulmonic
-circulation (fig. CXIV.).
-
-255. There is a complete separation between these two portions of the
-heart (fig. CXIV. 6), formed by a strong muscular partition which
-prevents any communication between them except through the medium of
-vessels.
-
-256. The heart is situated between the two lungs (fig. LIX. 2, 5),
-in the lower and fore part of the chest, nearly in the centre, but
-inclining a little to the left side. Its position is oblique (fig.
-LIX. 2, 5). Its basis is directed upwards, backwards, and towards the
-right (fig. LIX. 2); its apex is directed downwards, forwards, and
-towards the left, opposite to the interval between the cartilages
-of the fifth and sixth ribs (fig. LIX. 2). It is inclosed in a bag
-termed the pericardium (fig. CXV.), which consists of serous membrane.
-The pericardium is considerably larger than the heart, allowing
-abundant space for the action of the organ (fig. CXV.). One part of
-the pericardium forms a bag around the heart (fig. CXV.); the other
-part is reflected upon the heart so as to form its external covering
-(fig. CXV.), and is continued for a considerable distance upon the
-great vessels that go to and from the heart in such a manner that this
-bag, like all the serous membranes, constitutes a shut sac. Both that
-portion of the pericardium which is reflected upon the heart, and that
-which forms the internal surface of the bag around it, is moistened
-during life by a serous fluid, which, after death, is condensed into a
-small quantity of transparent water. That portion of the pericardium
-which rests on the diaphragm (fig. LXX. 1) is so firmly attached to it
-that it cannot be separated without laceration, and by this attachment,
-together with the great vessels at its base, the heart is firmly held
-in its situation, although in the varied movements of the body it is
-capable of deviating to a slight extent from the exact position here
-described.
-
-[Illustration: Fig. CXV.
-
-View of the heart enveloped in its pericardium, the fore part of the
-latter being cut open and reflected back.]
-
-257. When the interior of the heart is laid open there are brought
-into view four chambers (fig. CXIV. 3, 4, 10, 11), two for each circle.
-Those belonging to the pulmonic circle are on the right (fig. CXIV. 3,
-4), those to the systemic on the left side of the body (fig. CXIV. 10,
-11); hence the terms right and left are applied to these respective
-parts of the heart.
-
-258. The veins which carry the blood to the right or the pulmonic
-chambers are two, one of which brings it from the upper, and the other
-from the lower parts of the body: the first is called the superior and
-the second the inferior vena cava (fig. CXIV. 1, 2). Both pour their
-blood into the first chamber, termed the right auricle (fig. CXIV.
-3); from the right auricle the blood passes into the second chamber,
-denominated the right ventricle (fig. CXIV. 4): from which springs
-the artery which carries the blood from the heart to the lung, the
-pulmonary artery (fig. CXIV. 7). This is the pulmonic circle. From
-the lung the blood is returned to the heart by four veins, termed the
-pulmonary veins (fig. CXIV. 9), which pour the blood into the third
-chamber of the heart, the left auricle (fig. CXIV. 10). From the left
-auricle it passes into the fourth chamber, the left ventricle (fig.
-CXIV. 11), from which springs the artery which carries out the blood
-to the system, termed the aorta (figs. CXIV. 12, and CXVII. 11). This
-is the systemic circle. In the system the minute branches of the aorta
-unite with the minute branches that form the venæ cavæ, which return
-the blood to the right auricle of the heart, and thus the double circle
-is completed.
-
-259. The two chambers called the auricles occupy the basis of the
-heart (fig. CXIV. 3, 10). The right auricle is situated at the basis
-of the right ventricle (figs. CXIV. 3, and CXVI. 4). It is partly
-membranous and partly muscular. At its upper and back part is the
-opening of the vena cava superior (fig. CXVI. 1), which returns the
-blood to the heart from the head, neck, and all the upper parts of the
-body. At its lower part is the opening of the vena cava inferior (fig.
-CXVI. 2), which returns the blood from all the lower parts of the body.
-
-[Illustration: Fig. CXVI.
-
-View of the heart with the great vessels in connection with it, on the
-right side, its different chambers being laid open and its structure
-shown. 1. The vena cava superior; 2. the vena cava inferior; 3. cut
-edge of the right auricle turned aside to show, 4. the cavity of the
-right auricle into which the two venæ cavæ pour the blood returned
-from all parts of the body; 5. hook suspending the reflected portion
-of the wall of the auricle; 6. the right ventricle; 7. cut edge of the
-wall of the ventricle, a portion of which has been removed to show 8.
-the cavity of the ventricle; 9. situation of the opening between the
-auricle and ventricle, called the auricular orifice of the ventricle;
-10. valve placed between the auricle and ventricle, one margin being
-firmly attached to the auriculo-ventricular opening in its entire
-extent, the other lying loose in the cavity of the ventricle; 11.
-probe passed from the auricle into the ventricle underneath the valve,
-showing the course of the blood from the former chamber to the latter;
-12. the columnæ carneæ attached by one extremity to the walls of the
-ventricle, the other extremity ending in tendinous threads attached to
-the loose margin of the valve; 13. passage to the pulmonary artery;
-14. the three semilunar valves placed at the commencement of 15. the
-pulmonary artery; 16. the two great branches into which the trunk of
-the pulmonary artery divides, one branch going to each lung.]
-
-260. The auricle communicates with its corresponding ventricle by a
-large opening, termed the auricular orifice of the ventricle (figs.
-CXIV. 5, and CXVI. 9). All around the opening is placed a thin but
-strong membrane (fig. CXVI. 10), one margin of which is firmly attached
-to the wall of the ventricle (figs. CXIV. 5, and CXVI. 9), while the
-other is free (fig. CXVI. 10). This membrane receives the name, and, as
-will be seen immediately, performs the office of a valve.
-
-261. The ventricle is much thicker and proportionally stronger than the
-auricle (fig. CXVI. 3, 6). It is composed almost entirely of muscular
-fibre. Over nearly the whole extent of its internal surface are placed
-irregular masses of muscular fibres, many of which stand out from the
-wall of the ventricle like columns or pillars (fig. CXVI. 12); hence
-they are called fleshy columns (columnæ carneæ). Some of these fleshy
-columns are adherent by one extremity to the wall of the ventricle,
-while the other extremity terminates in tendinous threads which are
-attached to the membrane that forms the valve (fig. CXVI. 12).
-
-262. From the upper and right side of this chamber springs the
-pulmonary artery (fig. CXVI. 15); at the entrance of which are placed
-three membranes of a crescent or semilunar shape, termed the semilunar
-valves (fig. CXVI. 14).
-
-263. The structure of the left side of the heart is perfectly analogous
-to that of the right. Its auricle, like that on the left side, is
-placed at the base of the ventricle (figs. CXIV. 10, and CXVII. 2), and
-like it also is thin, being composed chiefly of membrane. At its upper
-and back part (figs. CXIV. 9, and CXVII. 1) are the openings of the
-four pulmonary veins, two from the right, and two from the left lung.
-
-264. At the passage of communication between the left auricle and
-ventricle is placed a valve analogous to that on the right side (fig.
-CXVII. 7).
-
-[Illustration: Fig. CXVII.
-
-View of the heart with the great vessels in connection with it, on the
-left side, its chambers being laid open as in the preceding figure.
-1. The four pulmonary veins opening into, 2. the cavity of the left
-auricle; 3. the cut edge of the wall of the auricle; 4. the appendix
-of the auricle; 5. the cavity of the left ventricle; 6. the cut edge
-of the wall of the ventricle, the greater portion of the wall having
-been removed to show the interior of the chamber; 7. valve placed
-between the auricle and ventricle; 8. columnæ carneæ terminating in
-tendinous threads attached to the loose margin of the valve; 9. probe
-passed underneath the valve and its tendinous threads, raising them
-from the wall of the ventricle similar to a refluent current of blood;
-10. passage to 11. the aorta; 12. two of the semilunar valves placed
-at the mouth of the aorta, the third having been cut away; 13. arch of
-the aorta; 14. the three semilunar valves at the commencement of the
-pulmonary artery seen in action, completely closing the mouth of the
-vessel.]
-
-265. The walls of the left ventricle are nearly as thick again as those
-of the right, and its fleshy columns are much larger and stronger. From
-the upper and back part of this fourth chamber (fig. CXVII. 11) springs
-the great systemic artery, the aorta, around the mouth of which are
-placed three semilunar valves (fig. CXVII. 12), similar to those at the
-mouth of the pulmonary artery.
-
-266. The partition which divides the two sets of chambers from each
-other (fig. CXIV. 6) is wholly composed of muscular fibres, and is
-called the septum of the heart.
-
-267. The external surface of the heart is covered by a thin but
-strong membrane continued over it from the pericardium. Between this
-membranous covering and its fleshy substance is lodged, even when the
-body is reduced to the greatest degree of thinness, a quantity of
-fat. Immediately beneath this fat are the fleshy fibres that compose
-the main bulk of the organ. These fibres are arranged in a peculiar
-manner. The arrangement is not perceptible when the heart is examined
-in its natural state, but after it has been subjected to long-continued
-boiling, which, besides separating extraneous matters from the fibres,
-hardens and loosens without displacing them, the manner in which they
-are disposed is manifest. Just at the point where the muscular fibres
-that constitute the septum of the auricles are set upon those which
-form the septum of the ventricles, and parallel with the origin of the
-aorta, the heart is not muscular but tendinous. The substance called
-tendon, it has been shown, is often employed in the body to afford
-origin or insertion to muscular fibres, performing, in fact, the
-ordinary office of bone, and substituted for it in situations where
-bone would be inconvenient. From the tendinous matter just indicated
-most of the fibres that constitute the muscular walls of the heart
-take their origin. From this point the fibres proceed in different
-directions: those which go to form the wall of the auricles ascend;
-those which form the wall of the ventricles pursue an oblique course
-downwards, and the arrangement of the whole is such, that a general
-contraction of the fibres must necessarily bring all the parts of the
-heart towards this central tendinous point. The object and the result
-of this arrangement will be manifest immediately.
-
-268. The internal surface of the chambers of the heart, in its whole
-extent, is lined by a fine transparent serous membrane, which renders
-it smooth and moist; and, like all other organs which have important
-functions to perform, it is plentifully supplied with blood-vessels and
-nerves.
-
-269. Such is the structure of the organ that moves the blood. The
-artery, the tube that carries it out from the heart, is a vessel
-composed of three distinct layers of membrane superimposed one upon
-another, and intimately united by delicate cellular tissue. These
-layers are termed tunics or coats. The external coat (fig. CXVIII. 3),
-which is also called the cellular, consists of minute whitish fibres,
-which are dense and tough, and closely interlaced together in every
-direction. They form a membrane of great strength, the elasticity of
-which, especially in the longitudinal direction, is such that, in
-addition to its other names, it has received that of the elastic coat.
-
-[Illustration: Fig. CXVIII.
-
-Portion of an artery, showing the several coats of which it is composed
-separated from each other. 1. The internal or serous coat; 2. the
-middle or fibrous coat; 3. the external or cellular coat.]
-
-270. The middle or the fibrous tunic is composed of yellowish
-flattened fibres which pass in an oblique direction around the calibre
-of the vessel, forming segments of circles, which, uniting, produce
-complete rings (fig. CXVIII. 2). This tunic is thick, consisting of
-several layers of fibres which it is easy to peel off in succession.
-They form a firm, solid, elastic, but, at the same time, brittle
-membrane.
-
-271. The inner tunic, thin, colourless, nearly transparent, and
-perfectly smooth, is moistened by a serous fluid, and is thence called
-the serous coat (fig. CXVIII. 1). To the naked eye it presents no
-appearance of fibres, yet notwithstanding its extreme delicacy, it is
-so strong that, after the other coats of the artery have been entirely
-removed in a living animal, it is capable of resisting the impetus of
-the circulation, and of preventing the dilatation of the artery. The
-arteries themselves are supplied with arteries, vessels that nourish
-their tissues, and which are sent to them from neighbouring branches,
-seldom or never from the vessel itself to which they are distributed.
-Each individual part of an artery is supplied by its own appropriate
-vessels, which form but few communications above and below, so that
-if care be not taken in surgical operations to disturb these nutrient
-arteries very little, the vessel will perish for want of sustenance.
-
-272. The vein, the tube that carries back the blood to the heart,
-is composed of the same number of tunics as the artery, which, with
-the exception of the middle, are essentially the same in structure,
-but they are all much thinner. The external tunic consists of a less
-dense and strong cellular membrane; the middle tunic, instead of being
-formed of elastic rings, is composed of soft and yielding fibres,
-disposed in a longitudinal direction; while the inner coat, which is
-still more delicate than that of the artery, is arranged in a peculiar
-manner. The inner coat of most veins, at slight intervals, is formed
-into folds (fig. CXX. 5), one margin of which is firmly adherent to
-the circumference of the vessel, while the other margin is free and
-turned in the direction of the heart. These membranous folds are termed
-valves. In all veins the diameter of which is less than a line the
-valves are single; in most veins of greater magnitude they are placed
-in pairs, while in some of the larger trunks they are triple, and in
-a few instances quadruple, and even quintuple. The veins, like the
-arteries, are supplied with nutrient vessels and nerves.
-
-273. All the arteries of the body proceed from the two trunks already
-described; that connected with the pulmonic circle, the pulmonary
-artery, and that connected with the systemic circle, the aorta. These
-vessels, as they go out from the heart and proceed to their ultimate
-termination, are arborescent, that is, they successively increase in
-number and diminish in size, like the branches of a tree going off from
-the trunk (fig. CXIX. 1, 2, 3). Each trunk usually ends by dividing
-into two or more branches (fig. CXIX. 1, 2), the combined area of which
-is always greater than that of the trunk from which they spring, in
-the proportion of about one and a half to one. As the branch proceeds
-to its ultimate termination it divides and subdivides, until at length
-the vessel becomes so minute, that it can no longer be distinguished
-by the eye. These ultimate branches are called capillary vessels,
-from their hair-like smallness (fig. CXIX. 4); but this term does not
-adequately express their minuteness. It has been stated (234) that the
-red particle of the blood, at the medium calculation, is not more than
-the three-thousandth part of an inch in diameter; yet vast numbers of
-the capillary vessels are so small that they are incapable of admitting
-one of these particles, and receive only the colourless portion of the
-blood.
-
-[Illustration: Fig. CXIX.
-
-View of the manner in which an artery divides and subdivides into its
-ultimate branches. 1. Trunk of the artery; 2. large branches into which
-it subdivides; 3. small branches, successively becoming smaller and
-smaller until they terminate in 4. the capillary branches.]
-
-274. Every portion of an artery, by reason of the elasticity of its
-coats, preserves nearly a cylindrical form, and as the area of the
-branches is greater than that of the trunks, the blood, in proceeding
-from the heart to the capillaries, though passing through a series of
-descending cylinders, is really flowing through an enlarging space.
-
-275. The disposition of the veins, like that of the arteries, is
-arborescent, but in an inverse order; for the course of the veins is
-from capillary vessels to visible branches, and from visible branches
-to large trunks (fig. CXX. 1, 2, 3). In every part of the body where
-the capillary arteries terminate the capillary veins begin, and
-the branches uniting to form trunks, and the small to form large
-trunks, and the trunks always advancing towards the heart, and always
-increasing in magnitude as they approach it, form at length the two
-veins which it has been stated (258) return all the blood of the body
-to the right auricle of the heart.
-
-[Illustration: Fig. CXX.
-
-View of the manner in which the minute branches of the vein unite to
-form the larger branches and the trunks. 1. Capillary venous branches;
-2. small branches formed by the union of the capillary; 3. larger
-branches formed by the union of the smaller and gradually increasing in
-size, to form the great trunk, 4. a portion of which is laid open to
-show its inner surface and the arrangement of 5. the valves formed by
-its inner coat.]
-
-276. The veins are very much more numerous than the arteries, for
-they often consist of double sets, and they are at the same time
-more capacious and more extensible. Reckoning the whole of the blood
-at one-fifth of the weight of the body, it is estimated that, of
-this quantity, about one-fourth is in the arterial and the remaining
-three-fourths in the venous system. The combined area of the branches
-of the veins is much greater than that of the two trunks in which they
-terminate (fig. CXX. 1, 2, 3, 4): the blood, therefore, in returning to
-the heart, is always flowing from a large into a smaller space.
-
-277. The divisions and subdivisions of the artery freely communicate
-in all parts of the body by means of what are called anastomosing
-branches, and this communication of branch with branch and trunk with
-trunk is termed anastomosis. The same intercommunication, but with
-still greater freedom and frequency, takes place among the branches
-of veins. In both orders of vessels the communication is frequent in
-proportion to the minuteness of the branch and its distance from the
-heart. It is also more frequent in proportion as a part is exposed
-to pressure; hence the minute arteries and veins about a joint are
-distinguished for the multitude of their anastomosing branches; and
-above all, it is frequent in proportion to the importance of the organ;
-hence the most remarkable anastomosis in the body is in the brain. By
-this provision care is taken that no part be deprived of its supply of
-blood; for if one channel be blocked up, a hundred more are open to the
-current, and the transmission of it to any particular region or organ
-by two or more channels, instead of through one trunk, is a part of the
-same provision. Thus the fore-arm possesses four principal arteries
-with corresponding veins, and the brain receives its blood through four
-totally independent canals[6].
-
-278. That the blood is really a flowing stream, and that it pursues the
-course described (258), is indubitable. For,
-
-(1.) With the microscope, in the transparent parts of animals, the
-blood can be seen in motion (fig. CXXI.); and if its course be
-attentively observed, its route may be clearly traced.
-
-[Illustration: Fig. CXXI.
-
-View of the circulation of the blood as seen under the microscope in
-the web of the frog's foot.]
-
-(2.) The membranes termed valves are so placed as to allow of the
-freest passage to the blood in the circle described, while they either
-altogether prevent or exceedingly impede its movement in any other
-direction.
-
-(3.) The effect of a ligature placed around a vein and an artery, and
-of a puncture made above the ligature in the one vessel and below it in
-the other, demonstrate both the motion of the blood and the course of
-it. When a ligature is placed around a vein, that part of the vessel
-which is most distant from the heart becomes full and turgid on account
-of the accumulation of blood in it; while the part of the vessel which
-is between the ligature and the heart becomes empty and flaccid,
-because it has carried on its contents to the heart, and it can receive
-no fresh supply from the body. When, on the contrary, a ligature is
-placed around an artery, that portion of the vessel which lies between
-the ligature and the heart becomes full and turgid, and the other
-portion empty and flaccid. This can only be because the contents of
-the two vessels move in opposite directions,—from the heart to the
-artery, from the artery to the vein, and from the vein to the heart.
-At the same time, if the vein be punctured above the ligature, there
-will be little or no loss of blood; while if it be punctured below
-the ligature, the blood will continue to flow until the loss of it
-occasions death, which could not be unless the blood were in motion,
-nor unless the direction of its course were from the artery to the vein
-and from the vein to the heart.
-
-(4.) If fluids be injected into the veins or arteries, whether of the
-dead or of the living body, they readily make their way and fill the
-vessels, if thrown in the direction stated to be the natural course
-of the circulation; but they are strongly resisted if forced in the
-opposite direction.
-
-279. Such is the description, and with the exception of the first
-proof, such the evidence of the circulation of the blood in the
-human body, pretty much as it was given by the discoverer of it, the
-illustrious Harvey. Before the time of Harvey, a vague and indistinct
-conception that the blood was not without motion in the body had been
-formed by several anatomists. It is analogous to the ordinary mode
-in which the human mind arrives at discovery (chap. iii., p. 103),
-that many minds should have an imperfect perception of an unknown
-truth, before some one mind sees it in its completeness and fully
-discloses it. Having, about the year 1620, succeeded in completely
-tracing the circle in which the blood moves, and having at that
-time collected all the evidence of the fact, with a rare degree of
-philosophical forbearance, Harvey still spent no less than eight years
-in re-examining the subject, and in maturing the proof of every point,
-before he ventured to speak of it in public. The brief tract which at
-length he published was written with extreme simplicity, clearness,
-and perspicuity, and has been justly characterised as one of the most
-admirable examples of a series of arguments deduced from observation
-and experiment that ever appeared on any subject.
-
-280. Cotemporaries are seldom grateful to discoverers. More than one
-instance is on record in which a man has injured his fortune and lost
-his happiness through the elucidation and establishment of a truth
-which has given him immortality. It may be that there are physical
-truths yet to be brought to light, to say nothing of new applications
-of old truths, which, if they could be announced and demonstrated
-to-day, would be the ruin of the discoverer. It is certain that there
-are moral truths to be discovered, expounded, and enforced, which, if
-any man had now penetration enough to see them, and courage enough to
-express them, would cause him to be regarded by the present generation
-with horror and detestation. Perhaps, during those eight years of
-re-examination, the discoverer of the circulation sometimes endeavoured
-in imagination to trace the effect which the stupendous fact at the
-knowledge of which he had arrived would have on the progress of his
-favourite science; and, it may be, the hope and the expectation
-occasionally arose that the inestimable benefit he was about to confer
-on his fellow men would secure to him some portion of their esteem
-and confidence. What must have been his disappointment when he found,
-after the publication of his tract, that the little practice he had
-had as a physician, by degrees fell off. He was too speculative,
-too theoretical, not practical. Such was the view taken even by his
-friends. His enemies saw in his tract nothing but indications of a
-presumptuous mind that dared to call in question the revered authority
-of the ancients; and some of them saw, moreover, indications of a
-malignant mind, that conceived and defended doctrines which, if not
-checked, would undermine the very foundations of morality and religion.
-When the evidence of the truth became irresistible, then these persons
-suddenly turned round and said, that it was all known before, and
-that the sole merit of this vaunted discoverer consisted in having
-circulated the circulation. The pun was not fatal to the future fame of
-this truly great man, nor even to the gradual though slow return of the
-public confidence even during his own time; for he lived to attain the
-summit of reputation.
-
-281. It is then indubitably established that the whole blood of the
-body in successive streams is collected and concentrated at the heart.
-The object of the accumulation of a certain mass of it at this organ
-is to subject it to the action of a strong muscle, and thereby to
-determine its transmission with adequate force and precision through
-the different sets of capillary vessels.
-
-282. In the accomplishment of this object the heart performs a twofold
-action; that of contraction and that of dilatation. The auricles
-contract and thereby diminish their cavities, then dilate and thereby
-expand them, and the one action alternates with the other. There is the
-like alternate contraction and dilatation of the ventricles. The first
-action is termed systole, the second diastole, and both are performed
-with force.
-
-283. When the heart is laid open to view in a living animal, and its
-movements are carefully observed, it is apparent that the two auricles
-contract together; that the two ventricles contract together; that
-these motions alternate with each other, and that they proceed in
-regular succession. The interval between these alternate movements is,
-however, exceedingly short, and can scarcely be perceived when the
-heart is acting with full vigour; but it is evident when its action is
-somewhat languid.
-
-284. When the ventricles contract, the apex of the heart is drawn
-upwards, and at the same time raised or tilted forwards. It is during
-this systole of the ventricles, and in consequence of this result of
-their action, that the apex of the heart gives that impulse against the
-walls of the chest which is felt in the natural state between the fifth
-and sixth ribs, and which just perceptibly precedes the pulse at the
-wrist.
-
-285. When the ear is applied to the human chest, over the situation of
-the heart, a dull and somewhat prolonged sound is heard, which precedes
-and accompanies the impulse of the heart against the chest. This dull
-sound is immediately succeeded by a shorter and sharper sound: after
-this there is a short pause; and then the dull sound and impulse are
-again renewed. The duller sound and stronger impulse are ascribed to
-the contraction of the ventricles, and the sharper sound and feebler
-impulse to that of the auricles.
-
-286. The movement of the heart is effected by the contraction of its
-muscular fibres. Those fibres rest, as upon a firm support, on the
-tendinous matter to which they are attached, from which they diverge,
-and towards which their contraction must necessarily bring all the
-parts of the heart (267). The result of their contraction is the
-powerful compression of all the chambers of the heart, and thereby the
-forcible ejection of their contents through the natural openings.
-
-287. But the chambers, alternately with forcible contraction, perform
-the action of forcible dilatation. This movement of dilatation is
-effected by the reaction of the elasticity of the tendinous matter on
-which the muscular fibres are supported (267). This highly elastic
-substance, by the contraction of the fibres, is brought into a state of
-extreme tension. The contraction of the fibres ceasing, that moment the
-tense tendon recoils with a force exactly proportionate to the degree
-of tension into which it had been brought. Thus the very agent that is
-employed forcibly to close the chamber is made the main instrument of
-securing its instantaneous re-opening. A vital energy is appointed to
-accomplish what is indispensable, and what nothing else can effect,
-the origination of a motive power; a physical agent is conjoined to
-perform the easier task to which it is competent; and the two powers,
-the vital and the physical, work in harmony, each acting alternately,
-and each, with undeviating regularity and unfailing energy, fulfilling
-its appropriate office.
-
-288. When the chambers of the heart which open into each other, and
-which as freely communicate with the great vessels that enter and
-proceed from them, are forcibly closed, and the blood they contain is
-projected from them, how is one uniform forward direction given to the
-current? Why, when the right ventricle contracts, is the blood not sent
-back into the right auricle, as well as forward into the pulmonary
-artery? There is but one mode of preventing such an event, which is to
-place a flood-gate between the two chambers; and there a flood-gate
-is placed, and that flood-gate is the valve. As long as the blood
-proceeds onwards in the direct course of the circulation, it presses
-this membrane close to the side of the heart, and thereby prevents it
-from occasioning any impediment to the current. When, on the contrary,
-the blood is forced backwards, and attempts to re-enter the auricle,
-being of course driven in all directions, some of it passes between the
-wall of the ventricle and the valve. The moment it is in this situation
-it raises up the valve, carries it over the mouth of the passage, and
-shuts up the channel. There cannot be a more perfect flood-gate.
-
-289. This is beautiful mechanism; but there is another arrangement
-which surpasses mere mechanism, however beautiful. It has been shown
-(260) that one edge of the membrane that forms the valve is firmly
-adherent to the wall of the ventricle, while the other edge, when not
-in action, appears to lie loosely in the ventricle (fig. CXVI. 10).
-Were this edge really loose the refluent current would carry it back
-completely into the auricle, and so counteract its action as a valve;
-but it is attached to the tendinous threads proceeding from the fleshy
-columns that stand along the wall of the ventricle (fig. CXVI. 12). By
-these tendinous threads, as by so many strings, the membrane is firmly
-held in its proper position (fig. CXVI. 10, 12); and the refluent
-current cannot carry it into the auricle. Thus far the arrangement is
-mechanical. But each of these fleshy columns is a muscle, exerting
-a proper muscular action. Among the stimulants which excite the
-contractility of the muscular fibre, one of the most powerful is
-distension. The refluent current distends the membrane; the distension
-of the membrane stretches the tendinous threads attached to it; the
-stretching of its tendinous threads stretches the fleshy column; by
-this distension of the column it is excited to contraction; by the
-contraction of the column its thread is shortened; by the shortening
-of the thread the valve is tightened, and that in the exact degree
-in which the thread is shortened. So, the greater the impetus of the
-refluent blood, the greater the distension of the membrane; and the
-greater the distension of the membrane, the greater the excitement of
-the fleshy column; the greater the energy with which it is stimulated
-to act, the greater, therefore, the security that the valve will be
-held just in the position that is required, with exactly the force that
-is needed. Here, then, is a flood-gate not only well constructed as far
-as regards the mechanical arrangement, but so endowed as to be able to
-act with additional force whenever additional force is requisite; to
-put forth on every occasion, as the occasion arises, just the degree of
-strength required, and no more.
-
-290. The contraction of the heart is the power that moves the blood;
-and this contraction generates a force which is adequate to impel it
-through the circle. From experiments performed by Dr. Hales it appears
-that if the artery of a large animal, such as the horse, be made to
-communicate with an upright tube, the blood will ascend in the tube to
-the height of about ten feet above the level of the heart, and will
-afterwards continue there rising and falling a few inches with each
-pulsation of the heart. In this animal, then, the heart acts with a
-force capable of maintaining a column of ten feet. Now a column of ten
-feet indicates a pressure of about four pounds and a half in a square
-inch of surface. Suppose the human heart to be capable of supporting
-a column of blood eight feet high, this will indicate a pressure of
-four pounds to the square inch; but the left ventricle of the heart,
-while it injects its column of blood into the aorta, has to overcome
-the inertia of the quantity of blood projected; of the mass already
-in the artery, and of the elasticity of the vessel yielding to a
-momentary increase of pressure: it is probable, therefore, that the
-heart acts with a force of six pounds on the inch. The left ventricle,
-when distended, has about ten square inches of internal surface;
-consequently the whole force exerted by it may be about sixty pounds.
-According to the calculation of Hales, it is fifty-one and a half.
-Now, it is proved by numerous experiments, that, after death, a slight
-impulse with the syringe, certainly much less than that which is acting
-upon the blood in the same artery during life, is sufficient to propel
-a solution of indigo, or fresh drawn blood, from a large artery into
-the extreme capillary. If, therefore, after death, a slight force will
-fill the capillaries, a force during life equal to sixty pounds must be
-adequate to do so.
-
-291. The heart, with a force equal to the pressure of sixty pounds,
-propels into the artery two ounces of blood at every contraction. It
-contracts four thousand times in an hour. There passes through the
-heart, therefore, every hour, eight thousand ounces or seven hundred
-pounds of blood. It has been stated (216) that the whole mass of blood
-in an adult is about twenty-eight pounds: on an average the entire
-circulation is completed in two minutes and a half; consequently a
-quantity of blood equal to the whole mass passes through the heart
-from twenty to twenty-four times in an hour. But though the average
-space of time requisite to accomplish a complete circulation may be
-two minutes and a half, yet when a stream of blood leaves the heart,
-different portions of it must finish their circle at very different
-periods, depending in part upon the length of the course which they
-have to go, and in part upon the degree of resistance that obstructs
-their passage. A part of the stream, it is obvious, finishes its course
-in circulating through the heart itself; another portion takes a longer
-circuit through the chest; another extends the circle round the head;
-and another visits the part placed at the remotest distance from the
-central moving power. Such is the velocity with which the current
-sometimes goes, that, in the horse, a fluid injected into the great
-vein of the neck, on one side, has been detected in the vein on the
-opposite side, and even in the vein of the foot, within half a minute.
-
-292. It has been shown (282) that the different chambers of the
-heart have a tendency to perform their movements in a uniform manner,
-and in a successive order; that they contract and dilate in regular
-alternation, and at equal intervals; but, moreover, they continue
-these movements equally without rest and without fatigue. On go the
-motions, night and day, for eighty years together, at the rate of
-a hundred thousand strokes every twenty-four hours, alike without
-disorder, cessation, or weariness. The muscles of the arm tire after
-an hour's exertion, are exhausted after a day's labour, and can by no
-effort be made to work beyond a certain period. There is no appreciable
-difference between the muscular substance of the heart and that of the
-arm. It is true that the heart is placed under one condition which
-is peculiar. Muscles contract on the application of stimuli; and
-different muscles are obedient to different stimuli,—the voluntary
-muscles to the stimulus of volition, and the heart to that of the
-blood. The exertion of volition is not constant, but occasional; the
-muscle acts only when it is excited by the application of its stimulus:
-hence the voluntary muscle has considerable intervals of rest. The
-blood, on the contrary, is conveyed to the heart without ceasing, in a
-determinate manner, in a successive order; and this is the reason why
-through life its action is uniform: it uniformly receives a due supply
-of its appropriate stimulus. But why it is unwearied, why it never
-requires rest, we do not know. We know the necessities of the system
-which render it indispensable that it should be capable of untiring
-action, for we know that the first hour of its repose would be the
-last of life; but of the mode in which this wonderful endowment is
-communicated, or of the relations upon which it is dependent, we are
-wholly ignorant.
-
-293. The force exerted by the heart is vital. It is distinguished from
-mechanical force in being produced by the very engine that exerts it.
-In the best-constructed machinery there is no real generation of power.
-There is merely concentration and direction of it. In the recoil of the
-spring, in the reaction of condensed steam, the energy of the expansive
-impulse is never greater than the force employed to compress or
-condense, and the moment this power is expended all capacity of motion
-is at an end. But the heart produces a force equal to the pressure of
-sixty pounds by the gentlest application of a bland fluid. Here no
-force is communicated to be again given out, as in every mechanical
-moving power; but it is new power, power really and properly generated;
-and this power is the result of vital action, and is never in any case
-the result of action that is not vital.
-
-294. The heart projects the blood with a given force into the arterial
-tubes. The arteries in the living body are always filled to distension,
-and somewhat beyond it, by the quantity of blood that is in them. It
-has been shown that the elasticity of their coats is such as to give
-to them, even after death, the form of open hollow cylinders (274).
-During life they are kept in a state of distension by the quantity of
-blood they contain. By virtue of their elasticity they react upon
-their contents with a force exactly proportioned to the degree of their
-distension, that is, with a force at least adequate to keep them always
-open and rigid.
-
-295. These open and rigid tubes, already filled to distension, and
-somewhat beyond it, receive at every contraction of the heart a
-forcible injection of a new wave of blood. The first effect of the
-injection of this new wave into a tube previously full to distension,
-is to cause the current to proceed by jerks or jets, each jerk or
-jet corresponding to the contraction of the heart. And, accordingly,
-by this jet-like motion, the flow of the blood in the artery is
-distinguished from that in the vein, in which latter vessel the current
-is an equal and tranquil stream.
-
-296. The second effect of this new wave is to occasion some further
-distension of the already distended artery, and accordingly, when
-the vessel is exposed in a living animal, and its action carefully
-observed, a slight augmentation of its diameter is distinguishable at
-every contraction of the heart. This new wave while it distends must at
-the same time slightly elongate the vessel; cause its straight portions
-to bend a little, and its curved portions to bend still more; and,
-consequently, in some situations, to lift it a little from its place,
-giving it a slight degree of locomotion;—and these two causes combined
-produce the pulse. When the finger is pressed gently on an artery, at
-the instant of the contraction of the heart, the vessel is felt to
-bound against the finger with a certain degree of force: this, as just
-stated, is owing to a slight distension of the vessel by the new wave
-of blood, together with a slight elongation of it, and a gentle rising
-from its situation.
-
-297. The blood, in flowing through the arterial trunks and branches
-to the capillaries, through the arterial to the venous capillaries, and
-through the venous branches and trunks back to the heart, is exposed
-to numerous and powerful causes of retardation: such, for example,
-as the friction between the blood and the sides of the vessels, the
-numerous curves and angles formed by the branches in springing from the
-trunks, the tortuous course of the vessels in many parts of the body,
-and the increasing area of the arterial branches as they multiply and
-subdivide. Yet the extraordinary fact has been recently discovered,
-that the blood moves with the same momentum or force in every part of
-the arterial system, in the aorta, in the artery in the neck which
-carries the blood to the head (the carotid artery), in the artery of
-the arm (the humeral artery), in the artery of the lower extremity
-(the femoral artery); in a word, in the minute and remote capillary,
-and in the large trunk near the heart. Having contrived an instrument
-by which the force of the blood as it flows in its vessel could be
-accurately indicated by the rise of mercury in a tube, M. Poiseuille
-found that the elevation of the mercury is uniformly the same in the
-different arteries of the same animal, whatever the size of the artery
-and its distance from the heart. This tube was inserted, for example,
-into the common carotid artery of a horse: the diameter of the vessel
-was 34/100ths of an inch; its distance from the heart was thirty-nine
-inches; the height to which the mercury rose in the graduated tube was
-accurately marked. The tube was then inserted into a muscular branch of
-the artery in the thigh: the diameter of this vessel was 7/100ths of an
-inch, and its distance from the heart 67½ inches. According to the mean
-of nine observations, the mercury rose in both tubes to precisely the
-same elevation. Here is another instance of the beautiful adjustments
-everywhere established in the living economy. The blood is sent by a
-living engine, moving under laws peculiar to the state of life, into
-living vessels, which in their turn acting under laws peculiar to the
-state of life, so accommodate themselves to the current as absolutely
-to offer no resistance to its progress; so accommodate themselves to
-the moving power, as completely and everywhere to obviate the physical
-impediments to motion inseparable from inorganic matter.
-
-298. That the arterial tubes do possess and exert a truly vital power,
-modifying the current of the blood they contain, is indubitably
-established.
-
-1. If in a living animal the trunk of an artery be laid bare, the mere
-exposure of it to the atmospheric air causes it to contract to such a
-degree, that its size becomes obviously and strikingly diminished. This
-can result only from the exertion of a vital property, for no dead tube
-is capable in such a manner of diminishing its diameter.
-
-2. If during life an artery be opened and the animal be largely bled,
-the arteries become progressively smaller and smaller as the quantity
-of blood in the body diminishes. If the bleeding be continued until the
-animal dies, and the arteries of the system be immediately examined,
-they are found to be reduced to a very small size; if again examined
-some time after death, they are found to have become larger, and they
-go on growing successively larger and larger until they regain nearly
-their original magnitude, which they retain until they are decomposed
-by putrefaction.
-
-3. M. Poiseuille distended with water the artery of an animal just
-killed. This water was urged by the pressure of a given column of
-mercury. The force of the reaction of the artery was now measured by
-the height of a column of mercury which the water expelled from the
-artery could support. It was found that the artery reacted with a
-force greater than that employed to distend it, and greater than the
-same artery could exert some time after death; but since mechanical
-reaction can never be greater than the force previously exerted upon
-it (293), it follows that the excess of the reaction indicated in this
-case was vital.
-
-4. If an artery be exposed and a mechanical or chemical stimulus be
-applied to it, its diameter is altered, sometimes becoming larger and
-sometimes smaller, according to the kind of agent employed.
-
-299. Any one of these facts, taken by itself, affords a demonstration
-that the arterial trunks and branches are capable of enlarging and
-diminishing their diameter by virtue of a vital endowment. There is
-complete evidence that the exertion of this vital power on the part
-of the arterial trunk is not to communicate to the blood the smallest
-impulsive force; the engine constructed for the express purpose of
-working the current generates all the force that is required; but the
-labour of the engine is economized by imparting to the tubes that
-receive the stream a vital property, by which they wholly remove the
-physical obstructions to its motion.
-
-300. Driven by the heart through the arterial branches into the
-capillaries, the blood courses along these minute vessels urged by the
-same power. The most careful observers, from Haller and Spalanzani
-down to the present time, concur in stating that the pulsatory
-movement communicated by the heart to the blood in the great arteries
-is distinctly visible under the microscope in the capillaries. "I
-have often observed in frogs and tadpoles, and once in the bat," says
-Wedemeyer, "that when the circulation was becoming feeble, the blood
-in the finest capillaries advanced by jerks, corresponding with the
-contractions of the heart. I remarked the same appearance in the fine
-veins several times in the toad and tadpole, and once in the frog." If
-an experimenter so dispose the circulation of the limb of an animal
-that the flow of blood be confined to the branches of a single artery,
-and a corresponding vein, it is found that the blood stagnates in the
-vein whenever the current in the artery is stopped by a ligature, but
-no sooner is the ligature removed from the artery, than the blood
-begins again to flow freely along the vein, the capillaries of the
-artery which have to send on the current to those of the vein being
-now again within the influence of the heart. And if the impulse of
-the heart be removed from the capillary system, by placing a ligature
-around the aorta, the capillary circulation is uniformly and completely
-stopped.
-
-301. It was found by Dr. Hales, that, under ordinary circumstances,
-the blood rises in a tube connected with a vein to the height only of
-six inches, while it has been shown (290) that in the artery it ascends
-as high as ten feet. This prodigious difference between the venous and
-the arterial tension led to the conclusion that the impulsive force of
-the heart was all but exhausted before the blood reached the veins, and
-set physiologists on the search for other powers to carry on the venous
-circulation. It was overlooked that the blood has an open and ready
-escape from the great trunks of the veins through the right chambers of
-the heart, and that in consequence of this free escape of their fluid,
-these vessels indicate no greater tension than is just sufficient to
-lift the blood to the heart, and to overcome friction[7]. M. Magendie
-having laid bare the chief artery and vein of a living limb, and having
-raised the vessels in such a manner that he could place a ligature
-around the former, without including the latter, found that the flow
-of blood from a puncture made below a ligature on the vein, was rapid
-or slow, according as the heart was allowed to produce a greater or
-less degree of tension in the artery, which tension was regulated by
-compressing the artery between the fingers. After a similar preparation
-of a limb, a ligature was placed around the vein; a tube was then
-inserted into it; it was found that the blood ascended in the tube from
-the obstructed vein just as high as from the artery.
-
-302. Thus we are able to trace the action of the heart from the
-beginning to the end of the circle. Of this circle it is the sole
-moving power; but it is a living engine acting in combination with
-living vessels. The force it exerts is a vital force, economized by the
-agency of a vital property communicated to the vessels, by virtue of
-which they spontaneously and completely remove all physical obstruction
-to the progress of the stream through its channels.
-
-303. Some German physiologists of great eminence, after a careful and
-patient observation of the blood, have satisfied themselves that in
-addition to the contraction of the heart, it is necessary to admit a
-second original and independent motive force, namely, a self-moving
-power inherent in the particles of the blood itself. The blood we
-know is a living substance. No reason can be assigned why the power
-of originating motion should not be communicated to such a substance
-as well as to the muscular fibre, of which, indeed, one constituent
-of the blood affords the basis. Such a power, if found to be inherent
-in the particles of the blood, would explain some phenomena connected
-with the circulation not yet clearly elucidated; but the proof of the
-self-moving power of the blood does not yet seem to be complete. It
-is, however, impossible to explain the phenomena of the circulation,
-or to obtain a satisfactory view of some of the other functions of the
-economy, without supposing the particles of the blood to be endowed
-with a vital power of repulsion, in consequence of which they are
-prevented from uniting when in contact, and the fluidity of the mass is
-maintained.
-
-In this account of the powers that move the blood, no notice has been
-taken of the physical agents supposed to act as auxiliaries to the
-heart, in carrying on the circulation, such as the suction power of the
-thorax, and of the auricles of the heart, and the capillary attraction
-of the vessels; because, without questioning the existence of such
-agents, or denying that advantage may be taken of them, it seems pretty
-clear that their influence is but trivial, and they assumed importance
-only when the vital endowments of the tissues were not well understood.
-
-304. The ultimate end for which the apparatus of the circulation is
-constructed, and for which all its action is exerted, is to convey
-arterial blood to the capillary arteries. These vessels are totally
-distinct in structure and in office from the larger arterial tubes. All
-the tunics of these minute vessels diminish in thickness and strength
-as the tubes lessen in size, but more especially the middle or the
-fibrous coat; which, according to Wedemeyer, may still be distinguished
-by its colour in the transverse section of any vessel whose internal
-diameter is not less than the tenth of a line; but that it entirely
-disappears in vessels too small and too remote to receive the wave of
-blood in a manifest jet. But while the membranous tunics diminish,
-the nervous filaments distributed to them increase: the smaller and
-thinner the capillary, the greater the proportionate quantity of its
-nervous matter; and this is most manifest in organs of the greatest
-irritability. The coats of the capillaries successively becoming
-thinner and thinner, at length disappear altogether, and the vessels
-ultimately terminate in membraneless canals formed in the substance of
-the tissues. "The blood in the finest capillaries," says Wedemeyer,
-"no longer flows within actual vessels; it is not contained in tubes
-whose parietes are formed by a membranous substance distinguishable by
-its texture and compactness from the adjoining cellular tissue: it is
-contained in the different tissues in channels which it forms in them
-for itself; and, under the microscope, the stream is seen easily and
-rapidly to work out for itself a new passage in the tissues which it
-penetrates."
-
-305. Some of these fine capillaries, before they entirely lose their
-membranous tunics, communicate directly with veins. Of the capillaries
-which terminate by direct communication with veins, some are large
-enough to admit of three or four of the red particles of the blood
-abreast; the diameter of others is sufficient to admit only of one;
-while others are so small that they can transmit nothing but the serum
-of the blood. As long as the capillary is of sufficient magnitude
-to receive three or four of the particles abreast, it is evident
-that it possesses regular parietes; but by far the greater number,
-before they communicate with veins, lose altogether their membranous
-coats. There are no visible openings or pores in the sides or ends
-of the capillaries by means of which the blood can be extravasated,
-preparatory to its being imbibed by the veins. There is nowhere
-apparent a sudden passage of the arterial into the venous stream; no
-abrupt boundary between the division of the two systems. The arterial
-streamlet winds through long routes, and describes numerous turns
-before it assumes the nature and takes the direction of a venous
-streamlet. The ultimate capillary rarely passes from a large arterial
-into a large venous branch.
-
-306. The vital power which it has been shown (298) is possessed by
-the arterial trunks and branches, is still more intense in the minute
-capillaries. If alcohol, strong acetic acid, naphtha, and other
-stimulating fluids, be injected into the arteries of a living animal,
-it is found that they are not transmitted through the capillaries
-at all, or, at all events, that they make their way through them
-with extreme difficulty; whereas mild, unirritating fluids pass with
-rapidity and ease. Wedemeyer exposed and divided the main artery in
-the fore-leg of a horse, together with the corresponding vein in the
-shoulder. Several syringes-full of tepid water were now injected into
-the lower end of the artery. The gentlest pressure was sufficient to
-force the fluid through the capillaries. At each injection the water
-issued in a full stream from the aperture of the vein, the flow of the
-fluid ceasing as soon as the injection was stopped. Next, instead of
-water, four syringes-full of pure cold brandy were injected. To propel
-this fluid through the capillaries, so as to render its smell and taste
-perceptible at the aperture of the vein, required a great degree of
-pressure; and when at last the fluid issued from the vein, it merely
-trickled in a feeble stream.
-
-The experiment being repeated on another horse with vinegar, six
-syringes-full of which being injected in rapid succession, at first
-this fluid passed as easily as water, afterwards it flowed with greater
-difficulty and in a small stream; before long the force required to
-propel it was extreme, and at last the obstruction to its passage
-became complete, so that no fluid whatever issued from the vein.
-
-These experiments, whenever repeated, afforded the same result, and
-they demonstrate that the capillaries are capable of being stimulated
-to contract upon their contents, and that they can contract with such
-force as to stop the current. It is manifest that the power by which
-they do this is vital, because after death all fluids, the mildest and
-the most acrid, pass through them with equal facility.
-
-307. Drs. Thompson, Philip, Hastings, and others in this country,
-have applied stimulants of various kinds to the capillary arteries,
-in order to observe with the microscope the changes which the vessels
-undergo. The results of these experiments, performed independently,
-agree with each other; and all the observers concur in stating that
-those results are so obvious and decisive as to admit of no question.
-Wedemeyer, fully aware of all that had been done on this subject by
-the English physiologists, repeated their experiments with his usual
-patience and care, vigilantly watching the effects with his microscope.
-His observations completely coincide with those of our countrymen. The
-circulation being observed in the mesentery of the frog and in the web
-of its foot, it was apparent that no change whatever took place in
-the diameter of the small arteries, nor in that of the capillaries,
-as long as the circulation was allowed to go on in its natural state;
-but as soon as stimulants were applied to them, an alteration of their
-diameter was visible. Alcohol, without much apparent contraction of the
-vessels, stopped the flow of the blood. Muriate of soda, in the course
-of three or four minutes, caused the vessels to contract one-fifth of
-their calibre, which contraction was followed by dilatation and gradual
-retardation and stoppage of the blood. Ammonia caused immediate and
-direct dilatation, and the effect of galvanism was still more striking.
-In a space of time varying from ten to thirty seconds, nay, sometimes
-immediately after the completion of the galvanic circle, the vessels
-contracted, some a fourth, others half, and others three-fourths, of
-their calibre. The flow of the blood through the contracted vessels
-was accelerated. The contraction sometimes lasted a considerable time,
-occasionally several hours; in other instances the contraction ceased
-in ten minutes, and the vessels resumed their natural diameter. A
-second application of galvanism to the same capillaries seldom caused
-any material contraction.
-
-308. The evidence, then, is abundant that stimulants are capable of
-modifying to a great extent the action of the capillary arteries,
-sometimes causing them to contract, at other times to dilate; sometimes
-quickening the flow of blood through them, at other times retarding it,
-and frequently altogether arresting its motion. This contractile power
-of the capillaries must be a vital endowment, for no such property is
-possessed by any substance destitute of life, and there is satisfactory
-evidence that it is communicated, regulated, and controlled by the
-organic nerves, which, as has been shown, increase as the size of the
-vessels and the thickness of their membranous tunics diminish. The
-powerful influence of these nerves upon the capillary vessels is placed
-beyond doubt or controversy by the obvious local changes produced in
-the capillary circulation by sudden, and even by mental, impressions,
-by the flush of the cheek and the sparkle of the eye, at a thought
-conceived or a sound heard; changes which can be effected, as far as we
-have any knowledge, by no medium excepting that of the nerves. The part
-performed by electricity, the physical agent by which it is conceived
-the nerves operate, will be considered hereafter.
-
-309. Exerting upon each other a vital force of repulsion, under a
-vital influence derived from the organic nerves, urged by the vital
-contraction of the heart, the particles of the blood reach the extreme
-capillaries. Most of these capillaries terminate (304) in canals, which
-they work out for themselves in the substance of the tissues. The
-tissues are endowed with a vital attractive force, which they exert
-upon the blood—an elective as well as an attractive force: for in
-every part of the body, in the brain, the heart, the lung, the muscle,
-the membrane, the bone, each tissue attracts only those constituents
-of which it is itself composed. Thus the common current, rich in all
-the proximate constituents of the tissues, flows out to each. As the
-current approaches the tissue, the particles appropriate to the tissue
-feel its attractive force, obey it, quit the stream, mingle with the
-substance of the tissue, become identified with it, and are changed
-into its own true and proper nature. Meantime, the particles which are
-not appropriate to that particular tissue, not being attracted by it,
-do not quit the current, but passing on, are borne by other capillaries
-to other tissues, to which they are appropriate, and by which they
-are apprehended and assimilated, When it has given to the tissues the
-constituents with which it abounded, and received from them particles
-no longer useful, and which would become noxious, the blood flows into
-the veins to be returned by the pulmonic heart to the lung, where,
-parting with the useless and noxious matter it has accumulated, and,
-replenished with new proximate principles, it returns to the systemic
-heart, by which it is again sent back to the tissues.
-
-310. Particles of blood are seen to quit the current and mingle with
-the tissues; particles are seen to quit the tissues and mingle with
-the current. But all that we can see, with the best aid we can get,
-does but bring us to the confines of the grand operations that go on,
-of which we are altogether ignorant. Arterial blood is conveyed by
-the arteries to the capillaries; but before it has passed from under
-the influence of the capillaries it has ceased to be arterial blood.
-Arterial blood is conveyed by the carotid artery to the brain; but
-the cerebral capillaries do not deposit blood, but brain. Arterial
-blood is conveyed by its nutrient arteries to bone, but the osseous
-capillaries do not deposit blood, but bone. Arterial blood is conveyed
-by the muscular arteries to muscle, but the muscular capillaries do not
-deposit blood, but muscle. The blood conveyed by the capillaries of
-brain, bone, and muscle is the same, all comes alike from the systemic
-heart, and is alike conveyed to all tissues; yet in the one it becomes
-brain, in the other bone, and in the third muscle. Out of one and the
-same fluid these living chemists manufacture cuticle, and membrane, and
-muscle, and brain, and bone; the tears, the wax, the fat, the saliva,
-the gastric juice, the milk, the bile, all the fluids, and all the
-solids of the body.
-
-311. And they do still more; for they are architects as well as
-chemists; after they have manufactured the tissue, they construct the
-organ. The capillaries of the eye not only form its different membranes
-and humours, but arrange them in such a manner as to constitute the
-optical instrument; and the capillaries of the brain not only form
-cerebral matter, but build it up into the instrument of sensation,
-thought, and motion.
-
-312. The practical applications of these phenomena are numerous and
-most important; but they can be clearly and impressively stated
-only when the operation of the physical agents which influence the
-circulation, and which proportionally affect life and health, has been
-explained.
-
-
-
-
-FOOTNOTES.
-
-
-[1] Computationi in alimentis faciendæ hanc formam esse Ulpianus
-scribit, ut _à primâ ætate_ usque ad annum vicesimum quantitas
-alimentorum triginta annorum computetur, ejusque quantitatis Falcidia
-præstetur: _ab annis verò viginti_ usque ad annum vicesimumquintum
-annorum viginti octo: _ab annis vigintiquinque_ usque ad annos
-triginta, annorum vigintiquinque: _ab annis triginta_ usque ad annos
-trigintaquinque annorum viginti duo; _ab annis trigintaquinque_
-usque ad annos quadraginta annorum viginti: _ab annis quadraginta_
-usque ad annos quinquaginta tot annorum computatio fit quot ætate
-ejus ad annum sexagesimum deerit, remisso uno anno: _ab anno verò
-quinquagesimo_ usque ad annum quinquagesimumquintum annorum novem:
-_ab annis quinquagintaquinque_ usque ad annum sexagesimum annorum
-septem: _ab annis sexaginta_, cujuscunque ætatis sit, annorum quinque;
-eoque nos jure uti Ulpianus ait, et circa compu tationem ususfructus
-faciendam. Solitum est tamen _à primâ ætate_ usque ad annum trigesimum
-computationem annorum triginta fieri: _ab annis verò triginta_ tot
-annorum computationem inire, quot ad annum sexagesimum deesse videntur;
-nunquam ergo amplius quam triginta aunorum computatio initur. Sic
-denique, et si Reipublicæ ususfructus egetur, sive simpliciter, sive
-ad ludos, triginta annorum computatio fit. Si quis ex heredibus rem
-propriam esse contendat, deinde hereditariam esse convincatur: quidem
-putant ejus quoque Falcidiam non posse retineri; quià nihil intersit,
-subtraxerit an hereditariam esse negaverit. Quod Ulpianus rectè
-improbat. (Vide Justin. Pandect. lib. 35, tit. 2, ad Legem Falcidiam.)
-
-[2] Which maximum is a little above the highest point hitherto any
-where attained.
-
-[3] Hence in the preparation of jelly as an article of diet, the parts
-of young animals, as the feet of the calf, are principally employed;
-whereas soups made from beef contain a large proportion of albumen,
-while in those made from veal the proportion of jelly preponderates.
-
-[4] Treatise on Ligaments, by Bransby B. Cooper, Esq.
-
-[5] For these illustrations I am indebted to Mr. Lister, who has been
-so kind as to make drawings of the objects for me.
-
-[6] Whenever there is any interruption to the ordinary flow of the
-circulating fluids, the powers of the anastomosing circulation are
-capable of being increased to a surprising extent. The aorta itself
-has frequently been tied in animals of considerable size without
-destroying life; in the human body it has also been found obliterated
-by disease in different parts of its course, in one case as high
-as the termination of its curvature. In the cure for aneurism the
-external iliac artery has been tied by Mr. Abernethy with success; the
-subclavian artery below the clavicle by Mr. Keate; the common carotid
-by Sir Astley Cooper; the subclavian artery above the clavicle by
-Mr. Ramsden; the internal iliac artery by Dr. Stevens; the arteria
-innominata by Dr. Mott, of New York; and lastly, the abdominal aorta
-itself, by Sir A. Cooper. Mr. Grainger tied the abdominal aorta of a
-dog; when the animal had recovered from that operation, the carotids
-and the great trunks of the anterior extremities were tied: in this
-manner the whole course of the circulation was altered. The dog, which
-was of very large size, survived all these operations, and appeared to
-enjoy its ordinary health. Grainger's General Anatomy, p. 251-253.
-
-[7] See this matter very ably discussed in Dr. Arnott's excellent work
-on the Elements of Physics, vol. i.
-
-
-END OF VOL. I.
-
-
-London: Printed by W. CLOWES and SONS, Stamford Street.
-
-
-
-
-TRANSCRIBER'S NOTES.
-1. (Figure LXXIV.) was incorrectly labeled as (Figure LXXVI.).
-     This has been corrected.
-2. No Figure LXX in original book.
-
-
-
-
-
-End of the Project Gutenberg EBook of The Philosophy of Health; Volume 1 (of
-2), by Thomas Southwood-Smith
-
-*** END OF THIS PROJECT GUTENBERG EBOOK PHILOSOPHY OF HEALTH, VOLUME 1 ***
-
-***** This file should be named 60773-0.txt or 60773-0.zip *****
-This and all associated files of various formats will be found in:
-        http://www.gutenberg.org/6/0/7/7/60773/
-
-Produced by Chris Curnow, Brian Wilsden and the Online
-Distributed Proofreading Team at http://www.pgdp.net (This
-file was produced from images generously made available
-by The Internet Archive)
-
-Updated editions will replace the previous one--the old editions will
-be renamed.
-
-Creating the works from print editions not protected by U.S. copyright
-law means that no one owns a United States copyright in these works,
-so the Foundation (and you!) can copy and distribute it in the United
-States without permission and without paying copyright
-royalties. Special rules, set forth in the General Terms of Use part
-of this license, apply to copying and distributing Project
-Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm
-concept and trademark. Project Gutenberg is a registered trademark,
-and may not be used if you charge for the eBooks, unless you receive
-specific permission. If you do not charge anything for copies of this
-eBook, complying with the rules is very easy. You may use this eBook
-for nearly any purpose such as creation of derivative works, reports,
-performances and research. They may be modified and printed and given
-away--you may do practically ANYTHING in the United States with eBooks
-not protected by U.S. copyright law. Redistribution is subject to the
-trademark license, especially commercial redistribution.
-
-START: FULL LICENSE
-
-THE FULL PROJECT GUTENBERG LICENSE
-PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK
-
-To protect the Project Gutenberg-tm mission of promoting the free
-distribution of electronic works, by using or distributing this work
-(or any other work associated in any way with the phrase "Project
-Gutenberg"), you agree to comply with all the terms of the Full
-Project Gutenberg-tm License available with this file or online at
-www.gutenberg.org/license.
-
-Section 1. General Terms of Use and Redistributing Project
-Gutenberg-tm electronic works
-
-1.A. By reading or using any part of this Project Gutenberg-tm
-electronic work, you indicate that you have read, understand, agree to
-and accept all the terms of this license and intellectual property
-(trademark/copyright) agreement. If you do not agree to abide by all
-the terms of this agreement, you must cease using and return or
-destroy all copies of Project Gutenberg-tm electronic works in your
-possession. If you paid a fee for obtaining a copy of or access to a
-Project Gutenberg-tm electronic work and you do not agree to be bound
-by the terms of this agreement, you may obtain a refund from the
-person or entity to whom you paid the fee as set forth in paragraph
-1.E.8.
-
-1.B. "Project Gutenberg" is a registered trademark. It may only be
-used on or associated in any way with an electronic work by people who
-agree to be bound by the terms of this agreement. There are a few
-things that you can do with most Project Gutenberg-tm electronic works
-even without complying with the full terms of this agreement. See
-paragraph 1.C below. There are a lot of things you can do with Project
-Gutenberg-tm electronic works if you follow the terms of this
-agreement and help preserve free future access to Project Gutenberg-tm
-electronic works. See paragraph 1.E below.
-
-1.C. The Project Gutenberg Literary Archive Foundation ("the
-Foundation" or PGLAF), owns a compilation copyright in the collection
-of Project Gutenberg-tm electronic works. Nearly all the individual
-works in the collection are in the public domain in the United
-States. If an individual work is unprotected by copyright law in the
-United States and you are located in the United States, we do not
-claim a right to prevent you from copying, distributing, performing,
-displaying or creating derivative works based on the work as long as
-all references to Project Gutenberg are removed. Of course, we hope
-that you will support the Project Gutenberg-tm mission of promoting
-free access to electronic works by freely sharing Project Gutenberg-tm
-works in compliance with the terms of this agreement for keeping the
-Project Gutenberg-tm name associated with the work. You can easily
-comply with the terms of this agreement by keeping this work in the
-same format with its attached full Project Gutenberg-tm License when
-you share it without charge with others.
-
-1.D. The copyright laws of the place where you are located also govern
-what you can do with this work. Copyright laws in most countries are
-in a constant state of change. If you are outside the United States,
-check the laws of your country in addition to the terms of this
-agreement before downloading, copying, displaying, performing,
-distributing or creating derivative works based on this work or any
-other Project Gutenberg-tm work. The Foundation makes no
-representations concerning the copyright status of any work in any
-country outside the United States.
-
-1.E. Unless you have removed all references to Project Gutenberg:
-
-1.E.1. The following sentence, with active links to, or other
-immediate access to, the full Project Gutenberg-tm License must appear
-prominently whenever any copy of a Project Gutenberg-tm work (any work
-on which the phrase "Project Gutenberg" appears, or with which the
-phrase "Project Gutenberg" is associated) is accessed, displayed,
-performed, viewed, copied or distributed:
-
-  This eBook is for the use of anyone anywhere in the United States and
-  most other parts of the world at no cost and with almost no
-  restrictions whatsoever. You may copy it, give it away or re-use it
-  under the terms of the Project Gutenberg License included with this
-  eBook or online at www.gutenberg.org. If you are not located in the
-  United States, you'll have to check the laws of the country where you
-  are located before using this ebook.
-
-1.E.2. If an individual Project Gutenberg-tm electronic work is
-derived from texts not protected by U.S. copyright law (does not
-contain a notice indicating that it is posted with permission of the
-copyright holder), the work can be copied and distributed to anyone in
-the United States without paying any fees or charges. If you are
-redistributing or providing access to a work with the phrase "Project
-Gutenberg" associated with or appearing on the work, you must comply
-either with the requirements of paragraphs 1.E.1 through 1.E.7 or
-obtain permission for the use of the work and the Project Gutenberg-tm
-trademark as set forth in paragraphs 1.E.8 or 1.E.9.
-
-1.E.3. If an individual Project Gutenberg-tm electronic work is posted
-with the permission of the copyright holder, your use and distribution
-must comply with both paragraphs 1.E.1 through 1.E.7 and any
-additional terms imposed by the copyright holder. Additional terms
-will be linked to the Project Gutenberg-tm License for all works
-posted with the permission of the copyright holder found at the
-beginning of this work.
-
-1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm
-License terms from this work, or any files containing a part of this
-work or any other work associated with Project Gutenberg-tm.
-
-1.E.5. Do not copy, display, perform, distribute or redistribute this
-electronic work, or any part of this electronic work, without
-prominently displaying the sentence set forth in paragraph 1.E.1 with
-active links or immediate access to the full terms of the Project
-Gutenberg-tm License.
-
-1.E.6. You may convert to and distribute this work in any binary,
-compressed, marked up, nonproprietary or proprietary form, including
-any word processing or hypertext form. However, if you provide access
-to or distribute copies of a Project Gutenberg-tm work in a format
-other than "Plain Vanilla ASCII" or other format used in the official
-version posted on the official Project Gutenberg-tm web site
-(www.gutenberg.org), you must, at no additional cost, fee or expense
-to the user, provide a copy, a means of exporting a copy, or a means
-of obtaining a copy upon request, of the work in its original "Plain
-Vanilla ASCII" or other form. Any alternate format must include the
-full Project Gutenberg-tm License as specified in paragraph 1.E.1.
-
-1.E.7. Do not charge a fee for access to, viewing, displaying,
-performing, copying or distributing any Project Gutenberg-tm works
-unless you comply with paragraph 1.E.8 or 1.E.9.
-
-1.E.8. You may charge a reasonable fee for copies of or providing
-access to or distributing Project Gutenberg-tm electronic works
-provided that
-
-* You pay a royalty fee of 20% of the gross profits you derive from
-  the use of Project Gutenberg-tm works calculated using the method
-  you already use to calculate your applicable taxes. The fee is owed
-  to the owner of the Project Gutenberg-tm trademark, but he has
-  agreed to donate royalties under this paragraph to the Project
-  Gutenberg Literary Archive Foundation. Royalty payments must be paid
-  within 60 days following each date on which you prepare (or are
-  legally required to prepare) your periodic tax returns. Royalty
-  payments should be clearly marked as such and sent to the Project
-  Gutenberg Literary Archive Foundation at the address specified in
-  Section 4, "Information about donations to the Project Gutenberg
-  Literary Archive Foundation."
-
-* You provide a full refund of any money paid by a user who notifies
-  you in writing (or by e-mail) within 30 days of receipt that s/he
-  does not agree to the terms of the full Project Gutenberg-tm
-  License. You must require such a user to return or destroy all
-  copies of the works possessed in a physical medium and discontinue
-  all use of and all access to other copies of Project Gutenberg-tm
-  works.
-
-* You provide, in accordance with paragraph 1.F.3, a full refund of
-  any money paid for a work or a replacement copy, if a defect in the
-  electronic work is discovered and reported to you within 90 days of
-  receipt of the work.
-
-* You comply with all other terms of this agreement for free
-  distribution of Project Gutenberg-tm works.
-
-1.E.9. If you wish to charge a fee or distribute a Project
-Gutenberg-tm electronic work or group of works on different terms than
-are set forth in this agreement, you must obtain permission in writing
-from both the Project Gutenberg Literary Archive Foundation and The
-Project Gutenberg Trademark LLC, the owner of the Project Gutenberg-tm
-trademark. Contact the Foundation as set forth in Section 3 below.
-
-1.F.
-
-1.F.1. Project Gutenberg volunteers and employees expend considerable
-effort to identify, do copyright research on, transcribe and proofread
-works not protected by U.S. copyright law in creating the Project
-Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm
-electronic works, and the medium on which they may be stored, may
-contain "Defects," such as, but not limited to, incomplete, inaccurate
-or corrupt data, transcription errors, a copyright or other
-intellectual property infringement, a defective or damaged disk or
-other medium, a computer virus, or computer codes that damage or
-cannot be read by your equipment.
-
-1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right
-of Replacement or Refund" described in paragraph 1.F.3, the Project
-Gutenberg Literary Archive Foundation, the owner of the Project
-Gutenberg-tm trademark, and any other party distributing a Project
-Gutenberg-tm electronic work under this agreement, disclaim all
-liability to you for damages, costs and expenses, including legal
-fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT
-LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE
-PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE
-TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE
-LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR
-INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH
-DAMAGE.
-
-1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a
-defect in this electronic work within 90 days of receiving it, you can
-receive a refund of the money (if any) you paid for it by sending a
-written explanation to the person you received the work from. If you
-received the work on a physical medium, you must return the medium
-with your written explanation. The person or entity that provided you
-with the defective work may elect to provide a replacement copy in
-lieu of a refund. If you received the work electronically, the person
-or entity providing it to you may choose to give you a second
-opportunity to receive the work electronically in lieu of a refund. If
-the second copy is also defective, you may demand a refund in writing
-without further opportunities to fix the problem.
-
-1.F.4. Except for the limited right of replacement or refund set forth
-in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO
-OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
-LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE.
-
-1.F.5. Some states do not allow disclaimers of certain implied
-warranties or the exclusion or limitation of certain types of
-damages. If any disclaimer or limitation set forth in this agreement
-violates the law of the state applicable to this agreement, the
-agreement shall be interpreted to make the maximum disclaimer or
-limitation permitted by the applicable state law. The invalidity or
-unenforceability of any provision of this agreement shall not void the
-remaining provisions.
-
-1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the
-trademark owner, any agent or employee of the Foundation, anyone
-providing copies of Project Gutenberg-tm electronic works in
-accordance with this agreement, and any volunteers associated with the
-production, promotion and distribution of Project Gutenberg-tm
-electronic works, harmless from all liability, costs and expenses,
-including legal fees, that arise directly or indirectly from any of
-the following which you do or cause to occur: (a) distribution of this
-or any Project Gutenberg-tm work, (b) alteration, modification, or
-additions or deletions to any Project Gutenberg-tm work, and (c) any
-Defect you cause.
-
-Section 2. Information about the Mission of Project Gutenberg-tm
-
-Project Gutenberg-tm is synonymous with the free distribution of
-electronic works in formats readable by the widest variety of
-computers including obsolete, old, middle-aged and new computers. It
-exists because of the efforts of hundreds of volunteers and donations
-from people in all walks of life.
-
-Volunteers and financial support to provide volunteers with the
-assistance they need are critical to reaching Project Gutenberg-tm's
-goals and ensuring that the Project Gutenberg-tm collection will
-remain freely available for generations to come. In 2001, the Project
-Gutenberg Literary Archive Foundation was created to provide a secure
-and permanent future for Project Gutenberg-tm and future
-generations. To learn more about the Project Gutenberg Literary
-Archive Foundation and how your efforts and donations can help, see
-Sections 3 and 4 and the Foundation information page at
-www.gutenberg.org
-
-
-
-Section 3. Information about the Project Gutenberg Literary Archive Foundation
-
-The Project Gutenberg Literary Archive Foundation is a non profit
-501(c)(3) educational corporation organized under the laws of the
-state of Mississippi and granted tax exempt status by the Internal
-Revenue Service. The Foundation's EIN or federal tax identification
-number is 64-6221541. Contributions to the Project Gutenberg Literary
-Archive Foundation are tax deductible to the full extent permitted by
-U.S. federal laws and your state's laws.
-
-The Foundation's principal office is in Fairbanks, Alaska, with the
-mailing address: PO Box 750175, Fairbanks, AK 99775, but its
-volunteers and employees are scattered throughout numerous
-locations. Its business office is located at 809 North 1500 West, Salt
-Lake City, UT 84116, (801) 596-1887. Email contact links and up to
-date contact information can be found at the Foundation's web site and
-official page at www.gutenberg.org/contact
-
-For additional contact information:
-
-    Dr. Gregory B. Newby
-    Chief Executive and Director
-    gbnewby@pglaf.org
-
-Section 4. Information about Donations to the Project Gutenberg
-Literary Archive Foundation
-
-Project Gutenberg-tm depends upon and cannot survive without wide
-spread public support and donations to carry out its mission of
-increasing the number of public domain and licensed works that can be
-freely distributed in machine readable form accessible by the widest
-array of equipment including outdated equipment. Many small donations
-($1 to $5,000) are particularly important to maintaining tax exempt
-status with the IRS.
-
-The Foundation is committed to complying with the laws regulating
-charities and charitable donations in all 50 states of the United
-States. Compliance requirements are not uniform and it takes a
-considerable effort, much paperwork and many fees to meet and keep up
-with these requirements. We do not solicit donations in locations
-where we have not received written confirmation of compliance. To SEND
-DONATIONS or determine the status of compliance for any particular
-state visit www.gutenberg.org/donate
-
-While we cannot and do not solicit contributions from states where we
-have not met the solicitation requirements, we know of no prohibition
-against accepting unsolicited donations from donors in such states who
-approach us with offers to donate.
-
-International donations are gratefully accepted, but we cannot make
-any statements concerning tax treatment of donations received from
-outside the United States. U.S. laws alone swamp our small staff.
-
-Please check the Project Gutenberg Web pages for current donation
-methods and addresses. Donations are accepted in a number of other
-ways including checks, online payments and credit card donations. To
-donate, please visit: www.gutenberg.org/donate
-
-Section 5. General Information About Project Gutenberg-tm electronic works.
-
-Professor Michael S. Hart was the originator of the Project
-Gutenberg-tm concept of a library of electronic works that could be
-freely shared with anyone. For forty years, he produced and
-distributed Project Gutenberg-tm eBooks with only a loose network of
-volunteer support.
-
-Project Gutenberg-tm eBooks are often created from several printed
-editions, all of which are confirmed as not protected by copyright in
-the U.S. unless a copyright notice is included. Thus, we do not
-necessarily keep eBooks in compliance with any particular paper
-edition.
-
-Most people start at our Web site which has the main PG search
-facility: www.gutenberg.org
-
-This Web site includes information about Project Gutenberg-tm,
-including how to make donations to the Project Gutenberg Literary
-Archive Foundation, how to help produce our new eBooks, and how to
-subscribe to our email newsletter to hear about new eBooks.
-
diff --git a/old/60773-0.zip b/old/60773-0.zip
deleted file mode 100644
index 8bf58bf..0000000
--- a/old/60773-0.zip
+++ /dev/null
diff --git a/old/60773-h.zip b/old/60773-h.zip
deleted file mode 100644
index 9dded61..0000000
--- a/old/60773-h.zip
+++ /dev/null
diff --git a/old/60773-h/60773-h.htm b/old/60773-h/60773-h.htm
deleted file mode 100644
index 05c1797..0000000
--- a/old/60773-h/60773-h.htm
+++ /dev/null
@@ -1,13949 +0,0 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
-    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
-  <head>
-    <meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1" />
-    <meta http-equiv="Content-Style-Type" content="text/css" />
-    <title>
-      The Project Gutenberg eBook of The PHILOSOPHY OF HEALTH, Vol I., by SOUTHWOOD SMITH, M.D..
-    </title>
-    <link rel="coverpage" href="images/cover.jpg" />
-    <style type="text/css">
-
-body {
-    margin-left: 10%;
-    margin-right: 10%;
-}
-
-    h1,h2 {
-    text-align: center; /* all headings centered */
-    clear: both;
-}
-
-.half-title {margin-top: 2em; margin-bottom: 2em;
-             text-align: center;
-             font-size: x-large;
-             font-weight: normal;
-             line-height: 1.6;}
-
-p {
-    margin-top: .51em;
-    text-align: justify;
-    margin-bottom: .49em;}
-
-div.chapter {page-break-before: always;}
-
-.mortality  {line-height: 75%; font-size: 75%;}
-
-.smaller     {font-size: 90%;}
-.large       {font-size: 120%;}
-.xlarge      {font-size: 150%;}
-.xxlarge     {font-size: 175%;}
-
-hr.chap {width: 65%}
-hr.full {width: 95%;}
-hr.r5   {width: 5%; margin-top: 1em; margin-bottom: 1em;}
-
-.sig5        {text-align:right; padding-right: 5%;}
-.topspace1   {margin-top:1em;}
-.topspace2   {margin-top:2em;}
-.topspace4   {margin-top:4em;}
-.romanindent {text-indent:14.5em}
-
-table {
-    margin-left: auto;
-    margin-right: auto;
-}
-
-.tdl      {text-align: left;}
-.tdr      {text-align: right;}
-.tdc      {text-align: center;}
-.tdmort   {text-align: center; width: 100px;}
-.tdchap   {text-align: center; padding-top: 2em;}
-
-.pagenum { /* uncomment the next line for invisible page numbers */
-    /*  visibility: hidden;  */
-    position: absolute;
-    left: 92%;
-    font-size: smaller;
-    text-align: right;
-}
-
-.center   {text-align: center;}
-
-.smcap    {font-variant: small-caps;}
-
-/* Images */
-.figcenter   {margin: auto;
-              text-align: center;
-}
-
-.caption {text-align: center; font-weight: bold; margin-top: 1em; margin-bottom: 2em;}
-
-img      {border: none; max-width: 100%;}
-
-/* Footnotes */
-.footnotes        {border: dashed 1px;}
-
-.footnote         {margin-left: 10%; margin-right: 10%; font-size: 0.9em;}
-
-.footnote .label  {position: absolute; right: 84%; text-align: right;}
-
-.fnanchor {
-    vertical-align: super;
-    font-size: .8em;
-    text-decoration:
-    none;
-}
-
-.covernote {
-     visibility: visible;
-     display: block;
-}
-
-/* Transcriber's notes */
-.transnote {background-color: #E6E6FA;
-    color: black;
-     font-size:smaller;
-     padding:0.5em;
-     margin-bottom:5em;
-     font-family:sans-serif, serif; }
-
-    </style>
-  </head>
-<body>
-
-
-<pre>
-
-The Project Gutenberg EBook of The Philosophy of Health; Volume 1 (of 2), by 
-Thomas Southwood-Smith
-
-This eBook is for the use of anyone anywhere in the United States and most
-other parts of the world at no cost and with almost no restrictions
-whatsoever.  You may copy it, give it away or re-use it under the terms of
-the Project Gutenberg License included with this eBook or online at
-www.gutenberg.org.  If you are not located in the United States, you'll have
-to check the laws of the country where you are located before using this ebook.
-
-Title: The Philosophy of Health; Volume 1 (of 2)
-       or, an exposition of the physical and mental constitution of man
-
-Author: Thomas Southwood-Smith
-
-Release Date: November 23, 2019 [EBook #60773]
-
-Language: English
-
-Character set encoding: ISO-8859-1
-
-*** START OF THIS PROJECT GUTENBERG EBOOK PHILOSOPHY OF HEALTH, VOLUME 1 ***
-
-
-
-
-Produced by Chris Curnow, Brian Wilsden and the Online
-Distributed Proofreading Team at http://www.pgdp.net (This
-file was produced from images generously made available
-by The Internet Archive)
-
-
-
-
-
-
-</pre>
-
-
-<div class="figcenter">
-<img src="images/cover.jpg" alt="Cover" />
-</div>
-
-<div class="topspace2">
-<div class="transnote covernote">
-<p class="center">The cover image was created by the transcriber and is placed in the public domain.</p>
-</div>
-</div>
-
-<hr class="chap" />
-
-<p><span class="pagenum"><a name="Page_i" id="Page_i">[Pg i]</a></span></p>
-
-<h1>
-THE<br />
-
-<span class="xlarge center">PHILOSOPHY OF HEALTH;</span><br /></h1>
-
-<p class="center">OR,</p>
-
-<p class="center xxlarge">AN EXPOSITION</p>
-
-<p class="center">OF THE</p>
-
-<p class="center xlarge">PHYSICAL AND MENTAL CONSTITUTION OF MAN,</p>
-
-<p class="center">WITH A VIEW TO THE PROMOTION OF</p>
-
-<p class="center xlarge">HUMAN LONGEVITY AND HAPPINESS.</p>
-
-<p class="center">BY</p>
-
-<p class="center">SOUTHWOOD SMITH, M.D.,<br /></p>
-
-<p class="center smaller"><i>Physician to the London Fever Hospital, to the Eastern Dispensary,
-and to the Jews' Hospital.</i></p>
-
-<p class="center">IN TWO VOLUMES. <span class="smcap">Vol. I.</span></p>
-
-<p class="center large"><i>THIRD EDITION.</i></p>
-
-<p class="center xlarge">LONDON:</p>
-<p class="center large">C. COX, 12, KING WILLIAM STREET, STRAND.</p>
-<hr class="r5" />
-<p class="center large">1847.</p>
-
-<hr class="chap" />
-
-<p><span class="pagenum"><a name="Page_ii" id="Page_ii">[Pg ii]</a></span></p>
-
-<p class="center">London: Printed by <span class="smcap">W. Clowes</span> and <span class="smcap">Sons</span>, Stamford Street.</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_iii" id="Page_iii">[Pg iii]</a></span></p>
-<h2>CONTENTS OF VOL. I.</h2>
-</div>
-
-<table summary="contents">
-<tr>
-<td class="tdl"><span class="smcap">Introduction</span></td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_1">Page 1</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">
-CHAPTER I.</td>
-</tr>
-<tr>
-<td class="tdl">Characters by which living beings are distinguished from
-inorganic bodies&mdash;Characters by which animals are
-distinguished from plants&mdash;Actions common to plants and
-animals&mdash;Actions peculiar to animals&mdash;Actions included
-in the <span class="smcap">ORGANIC</span> circle&mdash;Actions included in the <span class="smcap">ANIMAL</span>
-circle&mdash;Organs and functions defined&mdash;Action of physical
-agents on organized structures&mdash;Processes of supply, and
-processes of waste&mdash;Reasons why the structure of the
-animal is more complex than that of the plant</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_13">13</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">
-CHAPTER II.</td>
-
-</tr>
-<tr>
-<td class="tdl">Two distinct lives combined in the animal&mdash;Characters of
-the apparatus of the organic life&mdash;Characters of the
-apparatus of the animal life&mdash;Characteristic differences
-in the action of each&mdash;Progress of life&mdash;Progress of
-death</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_51">51</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">CHAPTER III.</td>
-</tr>
-<tr>
-<td class="tdl">Ultimate object of organization and life&mdash;Sources</td>
-</tr>
-<tr>
-<td class="tdl">of pleasure&mdash;Special provision by which the organic
-organs influence consciousness and afford pleasure&mdash;Point
-at which the organic organs cease to affect consciousness
-<span class="pagenum"><a name="Page_iv" id="Page_iv">[Pg iv]</a></span>
-and why&mdash;The animal appetites: the senses: the intellectual
-faculties: the selfish and sympathetic affections: the moral
-faculty&mdash;Pleasure the direct, the ordinary, and the
-gratuitous result of the action of the organs&mdash;Pleasure
-conducive to the development of the organs, and to
-the continuance of their action&mdash;Progress of human
-knowledge&mdash;Progress of human happiness</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_73">73</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">CHAPTER IV.</td>
-</tr>
-<tr>
-<td class="tdl">Relation between the physical condition and happiness, and
-between happiness and longevity&mdash;Longevity a good, and
-why&mdash;Epochs of life&mdash;The age of maturity the only one
-that admits of extension&mdash;Proof of this from physiology&mdash;Proof
-from statistics&mdash;Explanation of terms&mdash;Life a fluctuating
-quantity&mdash;Amount of it possessed in ancient Rome: in modern
-Europe: at present in England among the mass of the people
-and among the higher classes</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_106">106</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">CHAPTER V.</td>
-</tr>
-<tr>
-<td class="tdl">Ultimate elements of which the body is composed&mdash;
-Proximate principles&mdash;Fluids and solids&mdash;Primary tissues&mdash;
-Combinations&mdash;Results&mdash;Organs, systems, apparatus&mdash;
-Form of the body&mdash;Division into head, trunk, and
-extremities&mdash;Structure and function of each&mdash;Regions&mdash;
-Seats of the more important internal organs</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_148">148</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">CHAPTER VI.</td>
-</tr>
-<tr>
-<td class="tdl">Of the blood&mdash;Physical characters of the blood: colour, fluidity,
-specific gravity, temperature; quantity&mdash;Process of coagulation
-&mdash;Constituents of the blood; proportions&mdash;Constituents of the
-body contained in the blood&mdash;Vital properties of the blood
-&mdash;Practical applications</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_334">334</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">CHAPTER VII.<span class="pagenum"><a name="Page_v" id="Page_v">[Pg v]</a></span></td>
-</tr>
-<tr>
-<td class="tdl">Of the circulation&mdash;Vessels connected with the heart;
-chambers of the heart&mdash;Position of the heart&mdash;Pulmonic
-circle; systemic circle&mdash;Structure of the heart, artery, and
-vein&mdash;Consequences of the discovery of the circulation
-to the discoverer&mdash;Action of the heart; sounds occasioned
-by its different movements&mdash;Contraction; dilatation&mdash;Disposition
-and action of the valves&mdash;Powers that move the blood
-&mdash;Force of the heart&mdash;Action of the arterial tubes; the pulse;
-action of the capillaries; action of the veins&mdash;Self-moving
-power of the blood&mdash;Vital endowment of the capillaries;
-functions&mdash;Practical applications</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_357">357</a></td>
-</tr>
-
-<tr>
-<td class="tdchap">FOOTNOTES.</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr"><a href="#Page_408">408</a></td>
-</tr>
-</table>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_1" id="Page_1">[Pg 1]</a></span></p>
-<h2>INTRODUCTION.</h2>
-</div>
-
-<hr class="r5" />
-
-<p>The object of the present work is to give a brief
-and plain account of the structure and functions
-of the body, chiefly with reference to health and
-disease. This is intended to be introductory to
-an account of the constitution of the mind, chiefly
-with reference to the development and direction of
-its powers. There is a natural connexion between
-these subjects, and an advantage in studying them
-in their natural order. Structure must be known
-before function can be understood: hence the
-science of physiology is based on that of anatomy.
-The mind is dependent on the body: hence an
-acquaintance with the physiology of the body
-should precede the study of the physiology of the
-mind. The constitution of the mind must be understood
-before its powers and affections can be
-properly developed and directed: hence a knowledge
-of the physiology of the mind is essential
-to a sound view of education and morals.</p>
-
-<p>In the execution of the first part of this work,
-that which relates to the organization of the body,
-
-<span class="pagenum"><a name="Page_2" id="Page_2">[Pg 2]</a></span>
-
-a formidable difficulty presents itself at the outset.
-The explanation of structure is easy when the
-part described can be seen. The teacher of anatomy
-finds no difficulty in communicating to the
-student a clear and exact knowledge of the structure
-of an organ; because, by the aid of dissection,
-he resolves the various complex substances, of
-which it is built up, into their constituent parts,
-and demonstrates the relation of these elementary
-parts to each other. But the case is different with
-him who attempts to convey a knowledge of the
-structure of an organ merely by the description of
-it. The best conceived and executed drawing is
-a most inadequate substitute for the object itself.
-It is impossible wholly to remove this difficulty:
-what can be done, by the aid of plates, to lessen
-it, is here attempted. A time may come when the
-objects themselves will be more generally accessible:
-meanwhile, the description now given of
-the chief organs of the body may facilitate the
-study of their structure to those who have an
-opportunity of examining the organs themselves,
-and will, it is hoped, enable every reader at once
-to understand much of their action.</p>
-
-<p>Physical science has become the subject of
-popular attention, and men of the highest endowments,
-who have devoted their lives to the cultivation
-
-<span class="pagenum"><a name="Page_3" id="Page_3">[Pg 3]</a></span>
-
-of this department of knowledge, conceive
-that they can make no better use of the treasures
-they have accumulated, than that of diffusing
-them. Of this part of the great field of knowledge,
-to make "the rough places plain, and the crooked
-places straight," is deemed a labour second in
-importance only to that of extending the boundaries
-of the field itself. But no attempt has hitherto
-been made to exhibit a clear and comprehensive
-view of the phenomena of life; the organization
-upon which those phenomena depend; the physical
-agents essential to their production, and the
-laws, as far as they have yet been discovered, according
-to which those agents act. The consequence
-is, that people in general, not excepting
-the educated class, are wholly ignorant of the
-structure and action of the organs of their own
-bodies, the circumstances which are conducive to
-their own health, the agents which ordinarily produce
-disease, and the means by which the operation
-of such agents may be avoided or counteracted;
-and they can hardly be said to possess
-more information relative to the connexion between
-the organization of the body and the qualities of the
-mind, the physical condition and the mental state;
-the laws which regulate the production, combination,
-and succession of the trains of pleasurable
-
-<span class="pagenum"><a name="Page_4" id="Page_4">[Pg 4]</a></span>
-
-and painful thought, and the rules deducible from
-those laws, having for their object such a determination
-of voluntary human conduct, as may
-secure the pleasurable and avoid the painful.</p>
-
-<p>Yet nothing would seem a fitter study for man
-than the nature of man in this sense of the term.
-A knowledge of the structure and functions of the
-body is admitted to be indispensable to whoever
-undertakes, as the business of his profession, to
-protect those organs from injury, and to restore
-their action to a sound state when it has become
-disordered; but surely some knowledge of this
-kind may be useful to those who have no intention
-to practise physic, or to perform operations in
-surgery; may be useful to every human being, to
-enable him to take a rational care of his health, to
-make him observant of his own altered sensations,
-as indications of approaching sickness; to give
-him the power of communicating intelligibly with
-his medical adviser respecting the seat and the
-succession of those signs of disordered function,
-and to dispose and qualify him to co-operate with
-his physician in the use of the means employed to
-avert impending danger, or to remove actual
-disease.</p>
-
-<p>But if to every human being occasions must
-continually occur, when knowledge of this kind
-
-<span class="pagenum"><a name="Page_5" id="Page_5">[Pg 5]</a></span>
-
-would be useful, the possession of it seems peculiarly
-necessary to those who have the exclusive
-care of infancy, almost the entire care of childhood,
-a great part of the care of the sick, and whose
-ignorance, not the less mischievous because its activity
-is induced by affection, constantly endangers,
-and often defeats, the best concerted measures of
-the physician.</p>
-
-<p>The bodily organization and the mental powers
-of the child depend mainly on the management of
-the infant; and the intellectual and moral aptitudes
-and qualities of the man have their origin in
-the predominant states of sensation, at a period
-far earlier in the history of the human being than
-is commonly imagined. The period of infancy
-is divided by physiologists into two epochs; the
-first, commencing from birth, extends to the seventh
-month: the second, commencing from the
-seventh month, extends to the end of the second
-year, at which time the period of infancy ceases,
-and that of childhood begins. The first epoch of
-infancy is remarkable for the rapidity of the development
-of the organs of the body: the processes
-of growth are in extreme activity; the formative
-predominates over the sentient life, the chief object
-of the action of the former being to prepare
-the apparatus of the latter. The second epoch of
-
-<span class="pagenum"><a name="Page_6" id="Page_6">[Pg 6]</a></span>
-
-infancy is remarkable for the development of the
-perceptive powers. The physical organization
-of the brain, which still advances with rapidity,
-is now capable of a greater energy, and
-a wider range of function. Sensation becomes
-more exact and varied; the intellectual faculties
-are in almost constant operation; speech commences,
-the sign, and, to a certain extent, the
-cause of the growing strength of the mental
-powers; the capacity of voluntary locomotion is
-acquired, while passion, emotion, affection, come
-into play with such constancy and energy, as to
-exert over the whole economy of the now irritable
-and plastic creature a prodigious influence for
-good or evil. If it be, indeed, possible to make
-correct moral perception, feeling, and conduct, a
-part of human nature, as much a part of it as any
-sensation or propensity&mdash;if this be possible for
-every individual of the human race, without exception,
-to an extent which would render <em>all</em> more
-eminently and consistently virtuous than <em>any</em> are
-at present (and of the possibility of this, the conviction
-is the strongest in the acutest minds which
-have studied this subject the most profoundly),
-preparation for the accomplishment of this object
-must be commenced at this epoch. But if preparation
-for this object be really commenced, it
-
-<span class="pagenum"><a name="Page_7" id="Page_7">[Pg 7]</a></span>
-
-implies, on the part of those who engage in the
-undertaking, some degree of knowledge; knowledge
-of the physical and mental constitution of
-the individual to be influenced; knowledge of the
-mode, in which circumstances must be so modified
-in adaptation to the nature of the individual
-being, as to produce upon it, with uniformity and
-certainty, a given result. The theory of human
-society, according to its present institutions, supposes
-that this knowledge is possessed by the
-mother; and it supposes, further, that this adaptation
-will actually take place in the domestic
-circle through her agency. Hence the presumed
-advantage of having the eye of the mother always
-upon the child; hence the apprehension of evil
-so general, I had almost said instinctive, whenever
-it is proposed to take the infant, for the purpose
-of systematic physical and mental discipline, from
-beyond the sphere of maternal influence. But
-society, which thus presumes that the mother will
-possess the power and the disposition to do this,
-what expedients has it devised to endow her with
-the former, and to secure the formation of the
-latter? I appeal to every woman whose eye may
-rest on these pages. I ask of you, what has
-ever been done for you to enable you to understand
-the physical and mental constitution of that
-
-<span class="pagenum"><a name="Page_8" id="Page_8">[Pg 8]</a></span>
-
-human nature, the care of which is imposed upon
-you? In what part of the course of your education
-was instruction of this kind introduced?
-Over how large a portion of your education did
-it extend? Who were your teachers? What have
-you profited by their lessons? What progress
-have you made in the acquisition of the requisite
-information? Were you at this moment to undertake
-the guidance of a new-born infant to
-health, knowledge, goodness, and happiness, how
-would you set about the task? How would you
-regulate the influence of external agents upon its
-delicate, tender, and highly-irritable organs, in
-such a manner as to obtain from them healthful
-stimulation, and avoid destructive excitement?
-What natural and moral objects would you select
-as the best adapted to exercise and develope its
-opening faculties? What feelings would you
-check, and what cherish? How would you excite
-aims; how would you apply motives? How would
-you avail yourself of pleasure as a final end, or
-as the means to some further end? And how
-would you deal with the no less formidable instrument
-of pain? What is your own physical, intellectual,
-and moral state, as specially fitting you
-for this office? What is the measure of your own
-self-control, without a large portion of which no
-
-<span class="pagenum"><a name="Page_9" id="Page_9">[Pg 9]</a></span>
-
-human being ever yet exerted over the infant
-mind any considerable influence for good? There
-is no philosopher, however profound his knowledge,
-no instructor, however varied and extended
-his experience, who would not enter upon this
-task with an apprehension proportioned to his
-knowledge and experience; but knowledge which
-men acquire only after years of study, habits which
-are generated in men only as the result of long-continued
-discipline, are expected to come to you
-spontaneously, to be born with you, to require on
-your part no culture, and to need no sustaining
-influence.</p>
-
-<p>But, indeed, it is a most inadequate expression
-of the fact, to say that the communication of the
-knowledge, and the formation of the habits which
-are necessary to the due performance of the duties
-of women, constitute no essential part of their
-education: the direct tendency of a great part of
-their education is to produce and foster opinions,
-feelings, and tastes, which positively disqualify
-them for the performance of their duties. All
-would be well if the marriage ceremony, which
-transforms the girl into the wife, conferred upon
-the wife the qualities which should be possessed
-by the mother. But it is rare to find a person
-capable of the least difficult part of education,
-
-<span class="pagenum"><a name="Page_10" id="Page_10">[Pg 10]</a></span>
-
-namely, that of communicating instruction, even
-after diligent study, with a direct view to teaching;
-yet an ordinary girl, brought up in the ordinary
-mode, in the ordinary domestic circle, is
-intrusted with the direction and control of the
-first impressions that are made upon the human
-being, and the momentous, physical, intellectual,
-and moral results that arise out of those impressions!</p>
-
-<p>I am sensible of the total inadequacy of any
-remedy for this evil, short of a modification of our
-domestic institutions. Mere information, however
-complete the communication of it, can do
-little beyond affording a clearer conception of the
-end in view, and of the means fitted to secure it.
-Even this little, however, would be something
-gained; and the hope of contributing, in some
-degree, to the furtherance of this object, has supplied
-one of the main motives for undertaking the
-present work. Meantime, women are the earliest
-teachers; they must be nurses; they can be neither,
-without the risk of doing incalculable mischief,
-unless they have some understanding of the subjects
-about to be treated of. On these grounds I
-rest their <em>obligation</em> to study them; and I look
-upon that notion of delicacy, which would exclude
-them from knowledge calculated, in an extraordinary
-
-<span class="pagenum"><a name="Page_11" id="Page_11">[Pg 11]</a></span>
-
-degree, to open, exalt, and purify their
-minds, and to fit them for the performance of
-their duties, as alike degrading to those to whom
-it affects to show respect, and debasing to the mind
-that entertains it.</p>
-
-<p>Though each part of this work will be made as
-complete in itself as the author is capable of rendering
-it, and to that extent independent of any
-other part, yet there will be found to be a strict
-connexion between the several portions of the
-whole; and greatly as the topics included in the
-latter differ from those which form the earlier
-subjects, the advantage of having studied the former
-before the latter are entered on, will be felt
-precisely as the word <em>study</em> can be justly applied
-to the operation of the mind on such matters.</p>
-
-<p>In the expository portion of the work I have
-not been anxious to abstain from the employment
-of technical terms, when a decidedly useful purpose
-was to be obtained by the introduction of
-them; but I have been very careful to use no
-such term without assigning the exact meaning of
-it. A technical term unexplained is a dark spot
-on the field of knowledge; explained, it is a clear
-and steady light.</p>
-
-<p>In order really to understand the states of health
-and disease, an acquaintance with the nature of
-
-<span class="pagenum"><a name="Page_12" id="Page_12">[Pg 12]</a></span>
-
-organization, and of the vital processes of which it
-is the seat and the instrument, is indispensable: it
-is for this reason that the exposition of structure
-and function, attempted in this first part of the work,
-is somewhat full; but there cannot be a question
-that, if it accomplish its object, it will not only
-enable the account of health and disease in the
-subsequent part of it to be much more brief, but
-that it will, at the same time, render that account
-more intelligible, exact, and practical.</p>
-
-<p class="sig5">S. S.</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_13" id="Page_13">[Pg 13]</a></span></p>
-<p class="half-title">THE<br />
-<span class="large">PHILOSOPHY OF HEALTH.</span></p>
-</div>
-
-<hr class="r5" />
-
-<h2>CHAPTER I.</h2>
-
-<blockquote>
-
-<p>Characters by which living beings are distinguished from
-inorganic bodies&mdash;Characters by which animals are distinguished
-from plants&mdash;Actions common to plants and
-animals&mdash;Actions peculiar to animals&mdash;Actions included
-in the organic circle&mdash;Actions included in the animal
-circle&mdash;Organs and functions defined&mdash;Action of physical
-agents on organized structures&mdash;Processes of supply,
-and processes of waste&mdash;Reasons why the structure of
-the animal is more complex than that of the plant.</p>
-</blockquote>
-
-<p>The distinction between a living being and an
-inorganic body, between a plant and a stone, is,
-that the plant carries on a number of processes
-which are not performed by the stone. The
-plant absorbs food, converts its food into its own
-proper substance, arranges this substance into
-bark, wood, vessels, leaves, and other organized
-structures; grows, arrives at maturity, and decays;
-generates and maintains a certain degree of
-heat; derives from a parent the primary structure
-and the first impulse upon which these varied
-
-<span class="pagenum"><a name="Page_14" id="Page_14">[Pg 14]</a></span>
-
-actions depend; gives origin to a new being similar
-to itself, and, after a certain time, terminates
-its existence in death.</p>
-
-<p>No such phenomena are exhibited by the stone;
-it neither absorbs food, nor arranges the matter
-of which it is composed into organized structure;
-nor grows, nor decays, nor generates heat, nor
-derives its existence from a parent, nor gives
-origin to a new being, nor dies. Nothing analogous
-to the processes by which these results are produced,
-is observable in any body that is destitute of life;
-all of them are carried on by every living creature.
-These processes are, therefore, denominated
-vital, and, being peculiar to the state of life, they
-afford characters by which the living being is
-distinguished from the inorganic body.</p>
-
-<p>In like manner the distinction between an animal
-and a plant is, that the animal possesses properties
-of which the plant is destitute. It is
-endowed with two new and superior powers, to
-which there is nothing analogous in the plant;
-namely, the power of sensation, and the power of
-voluntary motion; the capacity of feeling, and the
-capacity of moving from place to place as its feeling
-prompts. The animal, like the plant, receives
-food, transforms its food into its own proper substance,
-builds this substance up into structure,
-generates, and maintains a certain temperature,
-derives its existence from a parent, produces an
-offspring like itself, and terminates its existence in
-
-<span class="pagenum"><a name="Page_15" id="Page_15">[Pg 15]</a></span>
-
-death. Up to this point the vital phenomena exhibited
-by both orders of living creatures are alike:
-but at this point the vital processes of the plant
-terminate, while those of the animal are extended
-and exalted by the exercise of the distinct and
-superior endowments of sensation and voluntary
-motion. To feel, and to move spontaneously, in
-accordance with that feeling, are properties possessed
-by the animal, but not by the plant; and
-therefore these properties afford characters by
-which the animal is distinguished from the plant.</p>
-
-<p>The two great classes of living beings perform,
-then, two distinct sets of actions: the first set is
-common to all living creatures; the second is peculiar
-to one class: the first set is indispensable to life;
-the second is necessary only to one kind of life,
-namely, the animal. The actions included in the
-first set, being common to all living or organized
-creatures, are called <span class="smcap">ORGANIC</span>; the actions included
-in the second class, belonging only to one
-part of living or organized creatures, namely, animals,
-are called <span class="smcap">ANIMAL</span>. The <span class="smcap">ORGANIC</span> actions
-consist of the processes by which the existence of
-the living being is maintained, and the perpetuation
-of its species secured: the <span class="smcap">ANIMAL</span> actions
-consist of the processes by which the living being
-is rendered percipient, and capable of spontaneous
-motion. The <span class="smcap">ORGANIC</span> processes comprehend
-those of nutrition, respiration, circulation, secretion,
-excretion, and reproduction; the first five
-
-<span class="pagenum"><a name="Page_16" id="Page_16">[Pg 16]</a></span>
-
-relate to the maintenance of the life of the individual
-being; the last to the perpetuation of its
-species. The <span class="smcap">ANIMAL</span> processes comprehend those
-of sensation and of voluntary motion, often denominated
-processes of relation, because they put
-the individual being in communication with the
-external world. There is no vital action performed
-by any living creature which may not be
-included in one or other of these processes, or in
-some modification of some one of them. There
-is no action performed by any inorganic body
-which possesses even a remote analogy to either
-of these vital processes. The line of demarcation
-between the organic and the inorganic world is,
-therefore, clear and broad; and the line of demarcation
-between the two great divisions of the
-organic world, between the inanimate and the
-animate, that is, between plants and animals, is
-no less decided: for, of the two sets of actions
-which have been enumerated, the one, as has just
-been stated, is common to the whole class of
-living beings, while the second set is peculiar to
-one division of that class. The plant performs
-only the organic actions: all the vital phenomena
-it exhibits are included in this single circle; it is,
-therefore, said to possess only organic life: but
-the animal performs both organic and animal
-actions, and is therefore said to possess both
-organic and animal life.</p>
-
-<p>Both the organic and the animal actions are
-
-<span class="pagenum"><a name="Page_17" id="Page_17">[Pg 17]</a></span>
-
-accomplished by means of certain instruments,
-that is, organized bodies which possess a definite
-structure, and which are moulded into a peculiar
-form. Such an instrument is called an organ,
-and the action of an organ is called its function.
-The leaf of the plant is an organ, and the conversion
-of sap by the leaf into the proper juice of the
-plant, by the process called respiration, is the
-function of this organ. The liver of the animal
-is an organ; and the conversion of the blood that
-circulates through it into bile, by the process of
-secretion, is its function. The brain is an organ;
-the sentient nerve in communication with it is
-also an organ. The extremity of the sentient
-nerve receives an impression from an external
-object, and conveys it to the brain, where it becomes
-a sensation. The transmission of the impression
-is the function of the nerve; the conversion
-of the impression into a sensation is the
-function of the brain.</p>
-
-<p>The living body consists of a congeries of these
-instruments or organs: the constituent matter of
-these organs is always partly in a fluid and partly
-in a solid state. Of the fluids and solids which
-thus invariably enter in combination into the composition
-of the organs, the fluids may be regarded
-as the primary and essential elements, for they
-are the source and the support of the solids. There
-is no solid which is not formed out of a fluid; no
-solid which does not always contain, as a constituent
-
-<span class="pagenum"><a name="Page_18" id="Page_18">[Pg 18]</a></span>
-
-part of it, some fluid, and none which is
-capable of maintaining its integrity without a
-continual supply of fluids.</p>
-
-<p>Whatever be the intimate composition of the
-fluids out of which the solids are formed, the investigation
-of which is more difficult than that of
-the solids and the nature of which is therefore
-less clearly ascertained, it is certain that all the
-matter which enters into the composition of the
-solid is disposed in a definite order. It is this
-disposition of the constituent matter of the living
-solid in a definite order that constitutes the
-arrangement so characteristic of all living substance.
-Definite arrangements are combined in
-definite modes, and the result is what is termed
-organization. From varied arrangements result
-different kinds of organized substances, each endowed
-with different properties, and exhibiting
-peculiar characters. By the recombination of
-these several kinds of organized substances, in different
-proportions and different modes, are formed
-the special instruments, or organs, of which we
-have just spoken; while it is the combining, or
-the building up of these different organized substances
-into organs, that constitutes structure.</p>
-
-<p>In the living body, not only is each distinct
-organ alive, but, with exceptions so slight that
-they need not be noticed here, every solid which
-enters into the composition of the organ is endowed
-with vital properties. This is probably the
-
-<span class="pagenum"><a name="Page_19" id="Page_19">[Pg 19]</a></span>
-
-case with the primary substances or tissues which
-compose the several organs of the plant; but that
-the animal solids are alive is indubitable; nay,
-the evidence is complete, that many even of the
-animal fluids possess vitality. The blood in the
-animal is as truly alive as the brain, and the bone
-as the flesh. The organized body, considered as
-a whole, is the seat of life; but life also resides
-in almost every component part of it.</p>
-
-<p>Yet the matter out of which these living substances
-is formed is not alive. By processes of
-which we know nothing, or, at least, of which we
-see only the first steps,&mdash;matter, wholly destitute of
-life, is converted into living substance. The inorganic
-matter, which is the subject of this wonderful
-transformation, is resolvable into a very
-few elementary substances. In the plant, these
-substances consist of three only, namely, oxygen,
-hydrogen, and carbon. The first two are aëriform
-or gaseous bodies; the last is a solid substance,
-and it is of this that the plant is chiefly composed:
-hence the basis of the plant is a solid.
-The elementary bodies, into which all animal substance
-is resolvable, are four, namely, azote,
-oxygen, hydrogen, and carbon. Into every animal
-fluid and solid this new substance azote enters
-so largely, that it may be considered as the fundamental
-and distinctive element of the animal organization:
-hence the basis of the animal is an
-aëriform or gaseous fluid. The animal is composed
-
-<span class="pagenum"><a name="Page_20" id="Page_20">[Pg 20]</a></span>
-
-of air, the plant of solid matter; and this
-difference in their elementary nature gives origin
-to several distinctive characters between the plant
-and the animal, in addition to those which have
-been already stated.</p>
-
-<p>Thus the characters of the plant are solidity,
-hardness, fixedness, and durability; while the
-animal is comparatively fluid, soft, volatile, and
-perishable; and the reason is now manifest. The
-basis of the animal being an aëriform fluid, its
-consistence is softer than that of the plant, the
-basis of which is a firm solid; and, at the same
-time, the component elements of the animal being
-more numerous than those of the plant, and the
-fluidity of these elements, and of the compounds
-they form, greatly favouring their action and reaction
-on each other and on external agents, the
-animal body is more volatile and perishable during
-life, and more readily decomposed after death.</p>
-
-<p>It has been stated, that the object of every
-structure or organ of the living body, is the performance
-of some special action or function,&mdash;the
-ultimate object of the fluids being the production
-of the solids; the ultimate object of the
-solids being the formation of organs; the ultimate
-object of organs being the performance of actions
-or functions; while it is in the performance of
-actions or functions that life consists. Functions
-carried on by organs; organs in action; special
-organs performing definite actions, this it is that
-
-<span class="pagenum"><a name="Page_21" id="Page_21">[Pg 21]</a></span>
-
-constitutes the state of life. Every particle of
-matter which enters into the composition of the
-living body has thus its own place, forming, or
-destined to form, a constituent part of some organ;
-every organ has its own action; all the organs of
-the body form the body; and all the actions of all
-the organs constitute the aggregate of the vital
-phenomena.</p>
-
-<p>Every organ is excited to action, or its function
-is called into operation by means of some
-external body. The external bodies capable of
-exciting and maintaining the functions of living
-organs, consist of a definite class. Because these
-bodies belong to that department of science which
-is called physical, they are termed physical agents.
-They are air, water, heat, cold, electricity, and
-light. Without the living organ, the physical
-agent can excite no vital action: without the physical
-agent, the living organ can carry on no vital
-process. The plant cannot perform the vital process
-of respiration without the leaf, nor, with the
-leaf, without air. The physical agent acts upon
-the living organ; the living organ reacts upon
-the physical agent, and the action between both is
-definite. In the lung of the animal a certain
-principle of the air unites, in definite proportions,
-with a certain principle of the blood; the oxygen
-of the air combines with the carbon of the blood;
-the air is changed by the abstraction of its oxygen;
-the blood is changed by the abstraction of
-
-<span class="pagenum"><a name="Page_22" id="Page_22">[Pg 22]</a></span>
-
-its carbon. Atmospheric air goes to the lung,
-but atmospheric air does not return from the lung;
-it is converted into a new substance by the action
-of the organ: it is changed into carbonic acid by
-the union of a given quantity of oxygen, which
-it transmits to the organ, with a given quantity
-of carbon which the organ conveys to it. Venous
-blood goes to the lung, but venous blood does not
-return from the lung; it is converted, by the instrumentality
-of the organ, into a new substance,
-into arterial blood, by giving to the air carbon,
-and by receiving from the air oxygen. In this
-manner the change in the physical agent is definite
-and uniform; and the change in the living
-substance is equally definite and uniform.</p>
-
-<p>It is this determinate interchange of action
-between the living organ and the physical agent
-that constitutes what is termed a vital process.
-All vital processes are carried on by living organs;
-the materials employed in all vital processes are
-physical agents; the processes themselves are
-vital functions. All the changes produced by all
-the organs of the plant upon physical agents, and
-all the changes produced by all physical agents
-upon the organs of the plant, constitute all the
-vital processes of the plant&mdash;comprehend the
-whole sum of its vital phenomena. The root, the
-trunk, the woody substance, the bark, the ascending
-vessels bearing sap, the descending vessels
-bearing secreted fluids, the leaves, the flowers,
-
-<span class="pagenum"><a name="Page_23" id="Page_23">[Pg 23]</a></span>
-
-these are the living organs of the plant. Air,
-water, heat, cold, electricity, light, these are the
-physical agents which produce in these organs definite
-changes, and which are themselves changed
-by them in definite modes; and the whole of these
-changes, taken together, comprehend the circle of
-actions, or the range of functions performed by
-this living being.</p>
-
-<p>In the state of life, during the interchange of
-action which thus incessantly goes on between
-physical agents and vital organs, the laws to
-which inorganic matter is subject are resisted,
-controlled, and modified. Physical and chemical
-attractions are brought under the influence of a
-new and superior agency, with the laws of which
-we are imperfectly acquainted, but the operation
-of which we see, and which we call the agency
-of life. Air, water, heat, electricity, are physical
-agents, which subvert the most intimate combinations
-of inorganic bodies, resolving them into their
-simple elements, and recombining these elements
-in various modes, and thus forming new
-bodies, endowed with totally different properties;
-but the physical and chemical agencies by which
-these changes are wrought in the inorganic, are
-resisted, controlled, and modified by the living
-body: resisted, for these physical agents do not
-decompose the living body; controlled and modified,
-for the living body converts these very agents
-into the material for sustaining its own existence
-
-<span class="pagenum"><a name="Page_24" id="Page_24">[Pg 24]</a></span>
-
-Of all the phenomena included in that circle of
-actions which we designate by the general term
-life, this power of resisting the effects universally
-produced by physical agents on inorganic matter,
-and of bringing these very agents under subjection
-to a new order of laws, is one of the most
-essential and distinctive.</p>
-
-<p>All vital processes are processes of supply, or
-processes of waste. By every vital action performed
-by the organized body, some portion of its
-constituent matter is expended. Numerous vital
-actions are constantly carried on for the sole purpose
-of compensating this expenditure. Every
-moment old particles are carried out of the system;
-every moment new particles are introduced
-into it. The matter of which the organized, and
-more especially the animal, body is composed, is
-thus in a state of perpetual flux; and in a certain
-space of time it is completely changed, so that of
-all the matter that constitutes the animal body at a
-given point of time, not a single particle remains
-at another point of time at a given distance.</p>
-
-<p>All the wants of the economy of the plant are
-satisfied by a due supply of air, water, heat, cold,
-electricity, and light. Some of these physical
-agents constitute the crude aliment of the plant;
-others produce in this aliment a series of changes,
-by which it is converted from crude aliment into
-proper nutriment, while others act as stimulants,
-by which movements are excited, the ultimate
-
-<span class="pagenum"><a name="Page_25" id="Page_25">[Pg 25]</a></span>
-
-object of which is the distribution of the nutriment
-to the various parts of the economy of the
-plant.</p>
-
-<p>The same physical agents are indispensable to
-the support of the animal body; but the animal
-cannot be sustained by these physical agents
-alone; for the maintenance of animal life, in
-some shape or other, vegetable or animal matter,
-or both in a certain state of combination, must be
-superadded: hence another distinction between the
-plant and the animal,&mdash;the necessity, on the part
-of the animal, of an elaborated aliment to maintain
-its existence. By the vital processes of its economy,
-the plant converts inorganic into organic
-matter; by the vital processes of its economy, the
-animal converts matter, already rendered organic,
-into its own proper substance. The plant is thus
-purveyor to the animal: but it is more than purveyor
-to it; for while it provides, it also prepares
-its food; it saves the animal one process, that of
-the transmutation of inorganic into organic matter.
-The ultimate end, or the final cause of the vital
-processes performed by the first class of living
-beings, is thus the elaboration of aliment for the
-second: the inferior life is spent in ministering,
-and the great object of its being is to minister to
-the existence of the superior.</p>
-
-<p>At the point at which organization commences
-structure is so simple that there is no manifest distinction
-of organs. Several functions are performed
-
-<span class="pagenum"><a name="Page_26" id="Page_26">[Pg 26]</a></span>
-
-apparently by one single organized substance. The
-lowest plants and the lowest animals are equally
-without any separate organs, as far as it is in our
-power to distinguish them, for carrying on the vital
-actions they perform. An organized tissue, apparently
-of an homogeneous nature, containing fluid
-matter, is all that can be made out by which the
-most simply-constructed plant carries on its single
-set, and by which the most simply-constructed
-animal carries on its double set, of actions. But
-this simplicity of structure exists only at the very
-commencement of the organized world. Every advancement
-in the scale of organization is indicated
-by the construction of organs manifestly separate
-for the performance of individual functions; and,
-invariably, the higher the being, the more complete
-is this separation of function from function,
-and, consequently, the greater the multiplication
-of organs, and the more elaborate and complex
-the structure;&mdash;and hence another distinction between
-the plant and the animal. The simplicity
-of the structure of the plant is in striking contrast
-to the complexity of the structure of the
-animal; and this difference is not arbitrary; it is
-a matter of absolute necessity, and the reason of
-this necessity it will be instructive to contemplate.</p>
-
-<p>The plant, as has been shown, performs only
-one set of functions, the organic; while the animal
-performs two sets of functions, the organic and
-the animal. The animal, then, performs more
-
-<span class="pagenum"><a name="Page_27" id="Page_27">[Pg 27]</a></span>
-
-functions than the plant, and functions of a higher
-order; it carries on its functions with a greater
-degree of energy; its functions have a more extended
-range, and all its functions bear a certain
-relation to each other, maintaining an harmonious
-action. The number, the superiority, the
-relation, the range, and the energy of the functions
-performed by the animal are, then, so many conditions,
-which render it absolutely indispensable
-that it should possess a greater complexity of
-structure than the plant.</p>
-
-<p>1. To build up structure is to create, to arrange,
-and to connect organs. Organs are the instruments
-by which functions are performed, and
-without the instrument there can be no action.
-With as many more organs than the plant possesses
-the animal must, therefore, be provided, as
-are necessary to carry on the additional functions
-it performs. Organs, for its organic functions, it
-must have as well as the plant; but to these must
-be superadded organs of another class, for which
-the plant has no need, namely, organs for its animal
-functions. Two sets of organs must, therefore,
-be provided for the animal, while the plant
-requires but one.</p>
-
-<p>2. Some functions performed by the animal are
-of a higher order than any performed by the plant,
-and the superior function requires a higher organization.
-The construction of an organ is complex
-as its action is elevated; the instrument is
-
-<span class="pagenum"><a name="Page_28" id="Page_28">[Pg 28]</a></span>
-
-elaborately prepared in proportion to the nobleness
-of its office.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_029.png" alt="Fig. I." />
-</div>
-<div class="topspace4"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_030.png" alt="Fig. II. Fig. III. Fig. IV." />
-</div>
-<div class="topspace2"></div>
-
-<p>3. But this is not all; for the addition of a
-superior function requires not only the addition of
-an organ having a corresponding superiority of
-structure, but it requires, further, that a certain
-elevation of structure should be communicated to
-all the organs of all the inferior functions, on account
-of the relation which it is necessary to establish
-between function and function. Unless the
-organ of an inferior function be constructed with
-a perfection corresponding to that of the organ of
-a superior function, the inferior will be incapable
-of working in harmony with the superior. Take,
-for example, the inferior function of nutrition:
-nutrition is an organic function equally necessary
-to the plant and to the animal, and requiring in
-both organs for performing it; but this function
-cannot be performed in the animal by organs as
-simple as suffice for the plant. Nutrition, in the
-plant, is carried on in the following mode:&mdash;The
-root of the plant is divided, like the trunk, into
-numerous branches (fig. I. 1). These branches
-divide and subdivide into smaller and smaller
-branches, until at last they reach an extreme degree
-of minuteness (fig. I. 2 2). The smallest of
-these divisions, called, from their hair-like tenuity,
-<i>capillary</i> (fig. I. 2 2), are provided with a peculiar
-structure, which is endowed with a specific
-function. In most plants this peculiar structure
-
-<span class="pagenum"><a name="Page_29" id="Page_29">[Pg 29]</a></span>
-
-is found at the terminal point of the rootlet (fig. I.
-2 2); but in some plants the capillary branches
-of the rootlets are provided with distinct bodies
-(fig. II. 1 2), scarcely to be discerned when the
-root has been removed some time from the soil,
-and has become dry (fig. II. 2 2); but which, in a
-few minutes after the root has been plunged in
-water, provided the plant be still alive, become
-turgid with fluid, and, consequently, distinctly
-visible (fig. II. 1 1 1). These bodies, when they
-exist, or the terminal point of the rootlet when
-these bodies are absent, are termed <i lang="la">spongeolæ</i>, or
-spongeoles; and the structure and function of the
-organ, in both cases, are conceived to be precisely
-the same. In both the organ consists of a minute
-
-<span class="pagenum"><a name="Page_30" id="Page_30">[Pg 30]</a></span>
-
-cellular structure. Fig. III. 1, shows this structure
-as it appears when the object is magnified.
-The office of this organ is to absorb the aliment of
-the plant from the soil; and so great is its absorbing
-power, that, as is proved by direct experiment,
-it absorbs the colouring molecules of liquids,
-though these molecules will not enter the ordinary
-pores, which are of much greater magnitude.
-With the spongeoles are connected vessels which
-pass through the substance of the stem or trunk
-to the leaf. Fig. III. 2, shows these tubes
-springing from the cellular structure of the spongeole,
-and passing up to the stem or trunk. Fig.
-IV. 2, exhibits a magnified view of the appearance
-of the mouths of these tubes on making an
-horizontal section of the spongeole. Fig. V.
-1 1 1, exhibits a view of these tubes passing to
-the leaf. Figs. VI. and VII. 1 1 1 1, show these
-vessels spread out upon, and ramifying through,
-the leaf. The crude aliment, borne by these tubes
-to the leaf, is there converted into proper nutriment;
-and from the leaf, when duly elaborated,
-
-<span class="pagenum"><a name="Page_31" id="Page_31">[Pg 31]</a></span>
-
-this proper nutriment is carried out by ducts to
-the various organs of the plant, in order to supply
-them with the aliment they need.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_031.png" alt="Fig. V." />
-</div>
-<div class="topspace2"></div>
-
-<p>Now, for carrying on the process of nutrition in
-this mode, there must be organs to absorb the
-crude aliment, organs to convey the crude aliment
-to the laboratory, the leaf, in which it is converted
-into proper nutriment; and, finally, organs for
-carrying out this proper nutriment to the system.
-Complication of structure, to this extent, is indispensable;
-and, accordingly, with spongeolæ, with
-sap-vessels, with leaves, with distributive ducts,
-the plant is provided. Without all the parts of
-this apparatus it could not carry on its function:
-any further complication would be useless.</p>
-
-<p><span class="pagenum"><a name="Page_32" id="Page_32">[Pg 32]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_032.png" alt="Fig. VI." />
-</div>
-
-<p>But, suppose a new and superior function to
-be added to the plant; suppose it to be endowed
-with the power of locomotion, what would be the
-consequence of communicating to it this higher
-power? That its former state of simplicity would
-<span class="pagenum"><a name="Page_33" id="Page_33">[Pg 33]</a></span>
-no longer suffice for the inferior function. Why?
-because the exercise of the superior would interrupt
-the action of the inferior function. Nutrition
-by imbibition, and the exercise of locomotion, cannot
-go on simultaneously in the same being. The
-plant is fixed in the soil by its roots; and from
-this, its state of immobility, results this most important
-consequence, that its spongeolæ are always
-in contact with its food.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_033.png" alt="Fig. VII." />
-</div>
-<div class="topspace2"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_034.png" alt="Fig. VIII." />
-</div>
-
-<p>But we may imagine a plant not fixed to the
-soil; a plant so constituted as to be capable of
-moving from place to place; such a plant would
-not be always in contact with its food, and therefore,
-as it exercised its faculty of locomotion, it
-
-<span class="pagenum"><a name="Page_34" id="Page_34">[Pg 34]</a></span>
-
-could not but interrupt or suspend its function of
-nutrition. In a being capable of carrying on these
-two functions simultaneously, the entire apparatus
-of the function of nutrition must then be modified.
-Instead of having spongeolæ fixed immovably
-in the earth, and spread out in a soil adapted
-to transmit to these organs nutrient matter in a
-state fitted for absorption, it must be provided with
-a reservoir for containing its food, in order that it
-may carry its aliment about with it in all its changes
-of place. And such is the modification uniformly
-found in all animals: an internal reservoir for
-containing its food is provided, perhaps, for every
-animal without exception. Even the simplest and
-minutest creatures with which the microscope has
-made us acquainted, the lowest tribes of the Infusoria
-(fig. VIII.), the sentient, self-moving cellules,
-placed at the very bottom of the animal scale, possess
-this modification of structure. For a long
-time it was conceived that these minute and simple
-creatures were without distinction of parts, that
-they had no separate organs for the reception and
-digestion of their food; that they absorbed their
-
-<span class="pagenum"><a name="Page_35" id="Page_35">[Pg 35]</a></span>
-
-aliment through the porous tissue of which their
-body is composed; that thus, instead of having a
-separate stomach, their entire body is a stomach,
-and instead of having even as much as a separate
-organ for absorption, like the more perfect plant,
-the whole body might be considered as a single
-spongeole.</p>
-
-<p>But, by a simple and beautiful experiment, a
-German physiologist has shown the incorrectness
-of this opinion, and has established the fact, that
-the distinction between the plant and the animal,
-here contended for, is found even at the very lowest
-point of the animal scale. Like other physiologists,
-conceiving that the difficulty of discovering
-the structure of the lower tribes of the
-animalculi might be owing to the transparency or
-the tissues of which they are composed, it struck
-Ehrenberg, that if he could feed them with coloured
-substances, he might obtain some insight into
-their organization. In his first endeavours to accomplish
-this object he failed, for he employed
-the pigments in ordinary use; but either the animals
-would not touch aliment thus adulterated, or
-those that did so were instantly killed. It then
-occurred to him, that these colours are adulterated
-with lead and other substances, in all probability
-noxious to the little subjects of his experiment.
-"What I require," said he, "is some vegetable or
-animal colouring matter perfectly pure." He then
-tried perfectly pure indigo and perfectly pure
-
-<span class="pagenum"><a name="Page_36" id="Page_36">[Pg 36]</a></span>
-
-carmine. His success was now complete: in a minute
-or two, after mixing with their food pure vegetable
-colouring matter, he observed in the interior of the
-body of these creatures minute spots of a definite
-figure, and of the colour of the pigment employed
-(fig. VIII. 1 1 1 1). The form and magnitude of
-these spots were different in different tribes, but the
-same in the same individual, and even in the same
-species (fig. IX. 1 1, fig. X. 1 1). No other parts
-of the body were tinged with the colour, though
-the animals remained in the coloured fluid for days
-together. This was decisive. This physiologist
-had now obtained an instrument capable of revealing
-to him the interior organization of a class
-
-<span class="pagenum"><a name="Page_37" id="Page_37">[Pg 37]</a></span>
-
-of beings, the structure of which had heretofore
-been wholly unknown. On applying it to the
-<span class="smcap">Monas Termo</span> (fig. VIII.), the animated point, or
-cellule, which stands at the bottom of the animal
-scale, he discovered, in the posterior portion of its
-body, several coloured spots which constitute its
-stomachs (fig. VIII. 1 1 1 1). The different situations
-
-<span class="pagenum"><a name="Page_38" id="Page_38">[Pg 38]</a></span>
-
-and different forms of the stomach in different
-tribes of these creatures, are represented by the
-coloured portions (fig. VIII. 1, fig. IX. 1, fig. X.
-1), in which the currents of fluid flowing to their
-mouths are seen (fig. IX. 2, fig. X. 2). These experiments
-go far towards establishing the fact,
-that every animal, even the very lowest, has an external
-mouth and an internal stomach, and that it
-takes its food by an act of volition.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_036.png" alt="Fig. IX." />
-</div>
-<div class="topspace2"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_037.png" alt="Fig. X." />
-</div>
-<div class="topspace2"></div>
-
-<p>But if the proof of this must be admitted to be
-still imperfect with regard to the lowest tribes of
-animals, it is certain that, as we ascend in the
-scale of organization, the nutritive apparatus is
-uniformly arranged in this mode. Every animal of
-every class large enough to be distinctly visible,
-and the structure of which is not rendered inappreciable
-by the transparency of its solids and
-fluids, is manifestly provided with a distinct internal
-reservoir for containing its food. On the
-internal surface of this reservoir open the mouths
-of vessels, minute in size but countless in number,
-which absorb the food from the stomach.</p>
-
-<p>Fig. XI. shows these vessels opening on the inner
-surface of the stomach, the white points representing
-their mouths, turgid with the food they have
-absorbed. Fig. XII. exhibits magnified views of
-the same vessels, the points representing their open
-mouths, and the lines the vessels themselves in
-continuation with their mouths. Fig. XIII. shows
-the appearance of the inner surface of the intestine
-
-<span class="pagenum"><a name="Page_39" id="Page_39">[Pg 39]</a></span>
-
-soon after the animal has taken food; the
-smaller white lines (1 1 1 1) representing the absorbent
-vessels full of digested food, and the larger
-lines (2 2 2 2) the trunks of the absorbent vessels
-formed by the union of many of the smaller.</p>
-
-<div class="topspace2">
-<div class="figcenter">
-<img src="images/i_039a.png" alt="Fig. XI." />
-</div>
-</div>
-<div class="topspace2"></div>
-
-<div class="topspace2">
-<div class="figcenter">
-<img src="images/i_039b.png" alt="Fig. XII." />
-</div>
-</div>
-<div class="topspace2"></div>
-
-<p>From this account, it is clear that the absorbing
-vessels of the stomach perform an
-office precisely analogous to that of the spongeoles
-of the root. What the soil is to the
-
-<span class="pagenum"><a name="Page_40" id="Page_40">[Pg 40]</a></span>
-
-plant, the stomach is to the animal. The absorbing
-vessels diffused through the stomach, as long
-as the stomach contains food, are in exactly the
-same condition as the spongeoles of the root spread
-out in the soil; and the absorbing vessels of the
-stomach are as much and as constantly in contact
-with the aliment, which it is their office to take
-into the system, as the spongeoles of the root.
-Such, then, is the expedient adopted to render the
-function of nutrition compatible with the function
-of locomotion. A reservoir of food is placed in the
-interior of the animal, provided with absorbent
-vessels which are always in contact with the aliment.
-In this mode, contact with aliment is not
-disturbed by continual change of place; the organic
-
-<span class="pagenum"><a name="Page_41" id="Page_41">[Pg 41]</a></span>
-
-process is not interrupted by the exercise of
-the animal function.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_040.png" alt="Fig. XIII." />
-</div>
-<div class="topspace2"></div>
-
-<p>But the more elaborate organization which it is
-necessary to impart to the apparatus of the inferior
-function, in consequence of the communication of
-a superior faculty, is not completed simply by the
-addition of this new organ, the stomach. Other
-complications are indispensable; for if food be
-contained in an isolated organ, placed in the interior
-of the body, means must be provided for conveying
-the food into this organ; hence the necessity
-of an apparatus for deglutition. Moreover,
-the food having been conveyed to the stomach,
-and having undergone there the requisite changes,
-means must next be provided for conveying it from
-the stomach to the other parts of the body; hence
-the necessity of an apparatus for the circulation.
-But food, however elaborately prepared by the
-stomach, is incapable of nourishing the body, until
-it has been submitted to the action of atmospheric
-air; hence the necessity of an additional apparatus,
-either for conveying food to the air, or for
-transmitting air to the food, or for bringing both
-the food and the air into contact in the same
-organ. And, when structure after structure has
-been built up, in order to carry on this extended
-series of processes, the number of provisions required
-is not even yet complete; for of the most
-nutritious fond the whole mass is not nutritive;
-and even the whole of that portion of it which is
-
-<span class="pagenum"><a name="Page_42" id="Page_42">[Pg 42]</a></span>
-
-actually applied to the purpose of nutrition, becomes,
-after a time, worn out, and must be removed
-from the system; hence the necessity of a
-further apparatus for excretion.</p>
-
-<p>That nutrition and locomotion may go on together,
-it is clear, then, that there must be provided
-a distinct apparatus for containing food, a distinct
-apparatus for deglutition, a distinct apparatus for
-circulation, a distinct apparatus for respiration,
-a distinct apparatus for excretion, and so on;
-and that, in this manner, the communication of a
-single function of a superior order renders a modification
-not merely of one but of many inferior
-functions absolutely indispensable, in order to
-adjust the one to the other, and to enable them
-to act in harmony.</p>
-
-<p>But the necessary complication of structure
-does not stop even here; for the communication of
-one function of a superior order imposes the necessity
-of communicating still another. Locomotion
-cannot be exercised without perception; sensation
-is indispensable to volition, and volition, of
-course, to voluntary motion. A being endowed
-with the power of moving from place to place,
-without possessing the power of perceiving external
-objects, must be speedily destroyed. The
-communication of sensation to a creature fixed
-immovably to a single spot, conscious of the approach
-of bodies, but incapable of avoiding their
-contact, would be not only useless but pernicious,
-
-<span class="pagenum"><a name="Page_43" id="Page_43">[Pg 43]</a></span>
-
-since it would be to make a costly provision for
-the production of pain, and nothing else; but the
-communication of locomotion without sensation
-would be as unwisely defective, as the former
-would be perniciously expensive; since it would
-be to endow a being with a faculty, the exercise
-of which would be fatal to it for the want of a
-second faculty to guide the first. Nor could the
-possession of locomotion, without the further possession
-of sensation, be otherwise than fatal, for
-another reason. Consciousness is not necessary to
-nutrition as performed by the plant, but it is
-indispensable to nutrition as performed by the
-animal: for if the food of the animal be not always
-on the same spot with itself; if it be under the
-necessity of searching for it, and of conveying it,
-when found, into the interior of its body, it must,
-of course, possess the power of perceiving it when
-within its reach, and of apprehending and appropriating
-it by an act of volition, of none of which
-actions is it capable without the possession of sensation.
-Again, then, we see that, in order to
-secure harmonious action, function must be put in
-relation with function. In order to prevent jarring
-and mutually-destructive action, function
-must be superadded to function, and throughout
-the animal creation the complication of structure,
-which is necessary for the accomplishment of these
-ends, is given without parsimony, but without
-profusion: nothing is given which is not needed,
-nothing is withheld which is required.</p>
-
-<p><span class="pagenum"><a name="Page_44" id="Page_44">[Pg 44]</a></span></p>
-
-<p>4. As we ascend in the scale of organization,
-numerous functions being carried on, and numerous
-organs constructed for performing them, it is
-obvious that the range of each function must be
-proportionally extended; the range necessarily increasing
-with the multiplication of organ and function:
-and this is another cause of the unavoidable
-complication of structure. Slight consideration
-will suffice to show the necessary connexion between
-an extended range of action and complication
-of structure. Take, as an example, the organic
-function of respiration: respiration is the function
-by which air is brought into contact with food; it
-is the completion of digestion. The sole end of
-all the apparatus that belongs to this function is
-to bring the air and the food into a certain degree
-of proximity. Now, when all the substances that
-enter into the composition of the body of an animal
-are slight, delicate, and permeable to air (as
-in fig. XIV.), and when the body is always surrounded
-by air, air must at all times be in contact
-with the particular organ that contains the food,
-no less than with the general system to which the
-food is distributed. In this case, to construct a
-separate apparatus for containing air would be
-useless, because wherever food is, there air must
-be, since it constantly permeates every part of the
-body.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_045.png" alt="Fig. XIV." />
-</div>
-<div class="topspace2"></div>
-
-<p>When, on the other hand, the tissues are so firm
-and dense as to be impermeable; when they are
-folded into bulky and complex organs, and when
-
-<span class="pagenum"><a name="Page_45" id="Page_45">[Pg 45]</a></span>
-
-these organs are placed in situations to which the
-external air cannot reach, the construction of a
-separate apparatus for respiration is indispensable.
-The respiratory apparatus consists either of organs
-for carrying air to the food, or of organs for carrying
-food to the air. The one or the other is
-adopted, according to the nature of the body. If
-the size of the animal be small; if the tissues
-which form the solid portion of its body be delicate
-in texture; if, at the same time, the wants
-of its economy require that its food should be
-highly aërated (for there is the closest connexion
-between energy of function and perfect aëration of
-
-<span class="pagenum"><a name="Page_46" id="Page_46">[Pg 46]</a></span>
-
-the food), an apparatus of sufficient magnitude to
-aërate the food in a high degree would occupy
-the entire bulk of the body. In such a case, it is
-easier to carry air to the food than food to the air;
-it is better to make the entire body a respiratory
-organ, than to construct a respiratory organ disproportioned
-to the magnitude of the body. Air-tubes
-diffused through every part of the body, and
-opening on its external surface, would obviously
-afford to every point of the system an easy access
-of air. By an expedient of this kind the system
-might be highly aërated, while the respiratory
-apparatus would occupy but a comparatively small
-space; the function might be performed on an extended
-scale, while there would be no necessity for
-encumbering a minute body with a bulky organ.
-And this is the mode in which respiration is carried
-on in large tribes of creatures, whose body is
-small in size and delicate in texture, and the functions
-of whose economy are performed with energy
-(fig. XV.).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_047.png" alt="Fig. XV." />
-<div class="caption">
-The Achilles Butterfly of South America (<i>Papilio Achilles</i>),<br />
-showing the tracheæ on the upper and under side of the<br />
-wings.</div>
-</div>
-
-<p>But this contrivance will not do when the animal
-is of large magnitude; when its body is
-divided into numerous compartments; when these
-compartments extend far beneath the external
-surface; when important organs are placed in
-deeply-seated cavities; and when the substances
-that compose the organs are dense, hard, thick,
-and convoluted. To construct air-tubes of the
-requisite diameter and length, always open, always
-
-<span class="pagenum"><a name="Page_47" id="Page_47">[Pg 47]</a></span>
-
-in a condition to permit the ingress and egress of
-an adequate current of air to and from the remotest
-nook and corner of a body such as this, would be
-difficult, if not impossible. At all events, it is
-easier, in such a case, to carry the food to the air,
-than the air to the food. But, for the accomplishment
-
-<span class="pagenum"><a name="Page_48" id="Page_48">[Pg 48]</a></span>
-
-of this purpose, what is necessary? An organ
-for containing food; an organ for containing air;
-vessels to carry food to and from the receptacle of
-the aliment; vessels to carry air to and from the
-receptacle of the air; expedients to expose a stream
-of food to a current of air; and, finally, tubes to
-carry out to the system the product of this complicated
-operation. Accordingly, a reservoir of food
-and a reservoir of air; an apparatus by which both
-are conveyed to their respective receptacles; and an
-apparatus by which both are brought into contact
-sufficiently close to admit of their mutual action,
-are all combined in the lung of the animal, and in
-the mechanism by which its movements are effected.
-The object is accomplished, but the apparatus by
-which it is effected is as complex in structure as
-it is efficient in action; the result simple; the
-means by which the result is secured, highly complicated.</p>
-
-<p>And if this be true of an inferior or organic
-function, it is still more strikingly true of a superior
-or animal function. The relation is still
-stricter between the complexity of the apparatus
-of sensation and the range of feeling, than between
-the complexity of the apparatus of respiration and
-the range of the respiratory process. The greater
-the number of the senses, the greater the number
-of the organs of sense; the more accurate and
-varied the impressions conveyed by each, the more
-complex the structure of the instrument by which
-
-<span class="pagenum"><a name="Page_49" id="Page_49">[Pg 49]</a></span>
-
-they are communicated; the more extended the
-range of the intellectual operations, the larger the
-bulk of the brain, the greater the number of its
-distinct parts, and the more exquisite their organization.
-From the point of the animal scale, at
-which the brain first becomes distinctly visible,
-up to man, the basis of the organ is the same;
-but, as the range of its function extends, part after
-part is superadded, and the structure of each part
-becomes progressively more and more complex.
-The evidence of this, afforded by comparative
-anatomy, is irresistible, and the interest connected
-with the study of it can scarcely be exceeded.</p>
-
-<p>5. In the last place, structure is complex in
-proportion to the energy of function. The greater
-the power with which voluntary motion is capable
-of being exerted, the higher the organization of
-the apparatus by which it is performed; the more
-compact and dense the shell, the cartilage, the
-bone, the firmer the fibre of the muscle, and, in
-general, the greater its comparative bulk. The
-wing of the eagle is as much more developed than
-the wing of the wren, as its flight is higher, and
-its speed swifter. The muscles which give to the
-tiger the rapidity and strength of its spring possess
-a more intense organization than those which
-slowly move on the tardigrade sloth. The structure
-of the brain of man is more exquisite than
-that of the fish, as his perceptions are more acute,
-
-<span class="pagenum"><a name="Page_50" id="Page_50">[Pg 50]</a></span>
-
-and capable of greater combination, comprehension,
-and continuity.</p>
-
-<p>Thus we see that the organization of the animal
-is more complex than that of the plant, not from
-an arbitrary disposition, but from absolute necessity.
-The few and simple functions performed by
-the plant require only the few and simple organs
-with which it is provided: the numerous and
-complicated functions performed by the animal
-require its numerous and complicated organs: the
-plant, simple as it is in structure, is destitute of
-no organ required by the nature of its economy;
-the animal, complex as it is in structure, is in
-possession of no organ which it could dispense
-with: from the one, nothing is withheld which is
-needed; to the other, nothing is given which is superfluous:
-in the one, there is economy without
-niggardliness; in the other, munificence without
-waste.</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_51" id="Page_51">[Pg 51]</a></span></p>
-<h2>CHAPTER II.</h2>
-</div>
-
-<blockquote>
-<p>Two distinct lives combined in the animal&mdash;Characters of
-the apparatus of the organic life&mdash;Characters of the
-apparatus of the animal life&mdash;Characteristic differences
-in the action of each&mdash;Progress of life&mdash;Progress of
-death.</p>
-</blockquote>
-
-<p>Of the two sets of functions carried on by living
-beings, it has been shown, that the plant performs
-only one, while the animal exercises both. The
-two lives thus in continual play in the animal
-differ from each other as much as the process of
-vegetation differs from that of thought, yet they
-are united so closely, and act so harmoniously,
-that their existence as distinct states is not only
-not apparent to ordinary observation, but the very
-discovery of the fact is of recent date, and forms
-one among the splendid triumphs of modern physiology.
-Their action is perfect, yet their separate
-identity is so distinctly preserved, that each has its
-own apparatus and its own action, which are not
-only not the same, but, in many interesting circumstances,
-are in striking contrast to each other.</p>
-
-<p>1. In general the organs that belong to the
-apparatus of the organic life are single, and not
-symmetrical; the organs that belong to the apparatus
-
-<span class="pagenum"><a name="Page_52" id="Page_52">[Pg 52]</a></span>
-
-of the animal life are either double, or
-symmetrical, or both. As will be shown hereafter,
-the heart, the lungs, the stomach, the
-intestines, the liver, the pancreas, the spleen, the
-instruments by which the most important functions
-of the organic life are carried on, are single organs.
-(Chap. 5.) The figure of each is more or less irregular,
-so that if a line were carried through their
-centre, it would not divide them into two equal
-and precisely corresponding portions. On the
-contrary, the organs of the animal life are symmetrical.
-The brain and the spinal cord are
-divisible into two perfectly equal parts. (Chap.
-5.) The nerves which go off from these organs
-for the most part go off in pairs equal in size and
-similar in distribution. (Ibid.) The trunk, so
-important an instrument of voluntary motion,
-when well formed, is divisible into two perfectly
-corresponding portions. (Ibid.) The muscular
-apparatus of one half of the body is the exact
-counterpart of that of the other; while the arms,
-the hands, and the lower extremities are not only
-double, but the organization of the one is precisely
-similar to that of its fellow.</p>
-
-<p>2. In general, the apparatus of the organic life is
-placed in the interior of the body, while that of the
-animal life is placed on the external surface. The
-organic organs are the instruments by which life is
-maintained. There is no action of any one of them
-that can be suspended even for a short space of time
-
-<span class="pagenum"><a name="Page_53" id="Page_53">[Pg 53]</a></span>
-
-without the inevitable extinction of life. But the
-animal organs are not so much instruments of life
-as means by which a certain relation is established
-between the living being and external objects. And
-this difference in their office is the reason of the
-difference in their position. Existence depending
-on the action of the organic organs, they are placed
-in the interior of the body; they are fixed firmly in
-their situation in order that they may not be disturbed
-by the movements of locomotion; they are
-enveloped in membranes, covered by muscles,
-placed under the shelter of bones, and every possible
-care is taken to secure them from accident and
-to shield them from violence. Existence not being
-immediately dependent on the action of the organs
-of the animal life, they do not need to be protected
-from the contact of external objects with extraordinary
-care, but it is necessary to the performance
-of their functions that they should be placed at the
-exterior of the body. And there they are placed, and
-so placed as to afford an effectual defence to the
-organic organs. Thus the groundwork of the animal
-is made the bulwark of the organic life. The
-muscles, the immediate agents by which voluntary
-motion is effected, and the bones, the fixed points
-and the levers by which that motion acquires the
-nicest precision and the most prodigious rapidity
-and power, are so disposed that, while the latter accomplish,
-in the most perfect manner, their primary
-
-<span class="pagenum"><a name="Page_54" id="Page_54">[Pg 54]</a></span>
-
-and essential office in relation to the muscles, they
-serve a secondary but scarcely less important office
-in relation to the internal viscera. As we advance
-in our subject, we shall see that a beautiful illustration
-of this is afforded in the structure and action
-of the trunk; that the trunk is moveable; that
-it is composed of powerful muscles, and of firm and
-compact bones; and that while its movements are
-effected by the action of the muscles which are
-attached to the bones, these bones enclose a
-cavity, in which are placed the lungs, the heart,
-the great trunks of the venous system, the great
-trunks of the arterial system, and the main trunk
-of the thoracic duct, the vessel by which the
-digested aliment is carried into the blood. (Chap.
-5.) Thus, by these strong and firm bones, together
-with the thick and powerful muscles that
-rest upon them, is formed a secure shelter for a
-main portion of the apparatus of the organic
-functions of respiration, circulation, and digestion.
-The bones and muscles of the thorax,
-themselves performing an important part in the
-function of respiration, afford to the lungs the
-chief organ of this function, composed of tender
-and delicate tissues, easily injured, and the
-slightest injury perilling life, a free and secure
-place to act in. The fragile part of the apparatus
-is defended by the osseous portion of it, the play
-of the latter being equally essential to the function
-
-<span class="pagenum"><a name="Page_55" id="Page_55">[Pg 55]</a></span>
-
-as that of the former. In like manner the tender
-and delicate substance of the brain and spinal
-cord, the central seat of the animal life, with
-which all the senses are in intimate communion,
-is protected by bones and muscles which perform
-important voluntary movements while the organs
-of sense which put us in connexion with the external
-world, which render us susceptible of pleasure,
-and which give us notice of the approach of objects
-capable of exciting pain, are placed where external
-bodies may be brought most conveniently and completely
-into contact with them; and where alone
-they can be efficient as the sentinels of the system.
-For this reason, with the exception of the sense of
-touch, which, though placed especially at the extremities
-of the fingers, is also diffused over the
-whole external surface of the frame, all the senses
-have their several seats in the head, the most elevated
-part of the body, of an ovoid figure, capable
-of moving independently of the rest of the fabric,
-and which, being supported on a pivot, is enabled
-to describe at least two-thirds of a circle.</p>
-
-<p>Such is the difference in the structure and position
-of the apparatus of the two lives, but the
-difference in their action is still more striking.</p>
-
-<p>1. The action of the apparatus of the organic
-life when sound is without consciousness; the
-object of the action of the apparatus of the animal
-life is the production of consciousness. The final
-cause of the action of the apparatus of the organic
-
-<span class="pagenum"><a name="Page_56" id="Page_56">[Pg 56]</a></span>
-
-life is the maintenance of existence; the final
-cause of the action of the apparatus of the animal
-life is the production of conscious existence.
-What purpose would be answered by connecting
-consciousness with the action of the organic
-organs? Were we sensible of the organic processes;
-did we know when the heart beats, and
-the lung plays, and the stomach digests, and the
-excretory organ excretes, the consciousness could
-not promote, but might disturb the due and orderly
-course of these processes. Moreover they would
-so occupy and engross our minds that we should
-have little inclination or time to attend to other
-objects. Beneficently therefore are they placed
-equally beyond our observation and control.
-Nevertheless, when our consciousness of these
-processes may be of service; when they are going
-wrong; when their too feeble or too intense action
-is in danger of destroying existence, the animal
-life is made sensible of what is passing in the
-organic, in order that the former may take beneficial
-cognizance of the latter, may do what experience
-may have taught to be conducive to the
-restoration of the diseased organ to a sound state,
-or avoid doing what may conduce to the increase
-or maintenance of its morbid condition.</p>
-
-<p>But while the action of the organic organs is
-thus kept alike from our view and feeling, the sole
-object of the action of the animal organs is to produce
-and maintain a state of varied and extended
-
-<span class="pagenum"><a name="Page_57" id="Page_57">[Pg 57]</a></span>
-
-consciousness. We do not know when the heart
-dilates to receive the vital current, nor when it
-contracts to propel it with renewed impetus
-through the system; nor when the blood rushes
-to the lung to give out its useless and noxious particles;
-nor when the air rushes to the blood
-to take up those particles, to replace them by
-others, and thus to purify and renovate the vital
-fluid. Many processes of this kind are continually
-going on within us during every moment of our
-existence, but we are no more conscious of them
-than we are of the motion of the fluids in the blade
-of grass on which we tread. On the contrary
-when an external object produces, in a sentient
-nerve, that change of state which we denote by
-the words "an impression;" when the sentient
-nerve transmits this impression to the brain; when
-the brain is thereby brought into the state of perception,
-the animal life is in active operation, and
-percipient or conscious existence takes place. Consciousness
-does not belong to the organic, it <em>is</em> the
-animal life.</p>
-
-<p>2. The functions of the organic life are performed
-with uninterrupted continuity; to those of
-the animal life rest is indispensable. The action
-of the heart is unceasing; it takes not and needs
-not rest. On it goes, for the space of eighty or
-ninety years, at the rate of a hundred thousand
-strokes every twenty-four hours, having at every
-stroke a great resistance to overcome, yet it continues
-
-<span class="pagenum"><a name="Page_58" id="Page_58">[Pg 58]</a></span>
-
-this action for this length of time without intermission.
-Alike incessant is the action of the
-lung, which is always receiving and always emitting
-air; and the action of the skin, which is always
-transpiring and always absorbing; and the action of
-the alimentary canal, which is always compensating
-the loss which the system is always sustaining.</p>
-
-<p>But of this continuity of action the organs and
-functions of the animal life are incapable. No
-voluntary muscle can maintain its action beyond a
-given time; no effort of the will can keep it in a
-state of uninterrupted contraction; relaxation must
-alternate with contraction; and even this alternate
-action cannot go on long without rest. No organ
-of sense can continue to receive impression after
-impression without fatigue. By protracted exertion
-the ear loses its sensibility to sound, the eye
-to light, the tongue to savour, and the touch to
-the qualities of bodies about which it is conversant.
-The brain cannot carry on its intellectual operations
-with vigour beyond a certain period; the
-trains of ideas with which it works become, after
-a time, indistinct and confused; nor is it capable
-of reacting with energy until it has remained in a
-state of rest proportioned to the duration of its preceding
-activity.</p>
-
-<p>And this rest is sleep. Sleep is the repose of the
-senses, the rest of the muscles, their support and
-sustenance. What food is to the organic, sleep is
-to the animal life. Nutrition can no more go on
-
-<span class="pagenum"><a name="Page_59" id="Page_59">[Pg 59]</a></span>
-
-without aliment, than sensation, thought, and
-motion without sleep.</p>
-
-<p>But it is the animal life only that sleeps: death
-would be the consequence of the momentary slumber
-of the organic. If, when the brain betook
-itself to repose, the engine that moves the blood
-ceased to supply it with its vital fluid, never again
-would it awake. The animal life is active only
-during a portion of its existence; the activity of
-the organic life is never for a moment suspended;
-and in order to endow its organs with the power
-of continuing this uninterrupted action, they are
-rendered incapable of fatigue: fatigue, on the
-contrary, is inseparable from the action of the
-organs of the animal life; fatigue imposes the
-necessity of rest, rest is sleep, and sleep is renovation.</p>
-
-<p>3. Between all the functions of the organic life
-there is a close relation and dependence. Without
-the circulation there can be no secretion; without
-secretion, no digestion; without digestion, no nutrition;
-without nutrition, no new supply of circulating
-matter, and so through the entire circle. But
-the functions of the animal life are not thus dependent
-on each other. One of the circle may be
-disordered without much disturbance of the rest; and
-one may cease altogether, while another continues
-in vigorous action. Sensation may be lost, while
-motion continues; and the muscle may contract
-though it cannot feel. One organ of sense may
-
-<span class="pagenum"><a name="Page_60" id="Page_60">[Pg 60]</a></span>
-
-sleep while the rest are awake. One intellectual
-faculty may be in operation while others slumber.
-The muscle of volition may act, while there is no
-consciousness of will. Even the organs of the
-voice and of progression may perform their office
-while the sensorium is deeply locked in sleep.</p>
-
-<p>4. The two lives are born at different periods,
-and the one is in active operation before the other
-is even in existence. The first action observable
-in the embryo is a minute pulsating point. It is
-the young heart propelling its infant stream. Before
-brain, or nerve, or muscle can be distinguished,
-the heart is in existence and in action;
-that is, the apparatus of the organic function
-of the circulation is built up and is in operation
-before there is any trace of an animal organ.
-Arteries and veins circulate blood, capillary
-vessels receive the vital fluid, and out of it form
-brain and muscle, the organs of the animal, no
-less than the various substances that compose the
-organs of the organic life. The organic is not only
-anterior to the animal life, but it is by the action of
-the organic that existence is given to the animal life.
-The organic life is born at the first moment of
-existence; the animal life not until a period comparatively
-distant; the epoch emphatically called
-the period of birth, namely, the period when the
-new being is detached from its mother; when it
-first comes into contact with external objects;
-when it carries on all the functions of its economy
-
-<span class="pagenum"><a name="Page_61" id="Page_61">[Pg 61]</a></span>
-
-by its own organs, and consequently enjoys independent
-existence.</p>
-
-<p>5. The functions of the organic life are perfect
-at once. The heart contracts as well, the arteries
-secrete as well, the respiratory organs work as well
-the first moment they begin to act as at any subsequent
-period. They require no teaching from
-experience, and they profit nothing from its lessons.
-On the contrary, the operations of the
-brain, and the actions of the voluntary muscles,
-feeble and uncertain at first, acquire strength
-by slow degrees, and attain their ultimate perfection
-only at the adult age. How indistinct
-and confused the first sensations of the infant!
-Before it acquire accuracy, precision, and truth,
-how immense the labour spent upon perception!
-Sensations are succeeded by ideas; sensations
-and ideas coalesce with sensations and
-ideas; combinations thus formed suggest other
-combinations previously formed, and these a third,
-and the third a fourth, and so is constituted a
-continuous train of thought. But the infantile
-associations between sensation and sensation, between
-idea and idea, and between sensations and
-ideas, are, to a certain extent, incorrect, and to a
-still greater extent inadequate; and the misconception
-necessarily resulting from this early imperfection
-in the intellectual operations is capable of
-correction only by subsequent and more extended
-impressions. During its making hours, a large portion
-
-<span class="pagenum"><a name="Page_62" id="Page_62">[Pg 62]</a></span>
-
-of the time of the infant is spent in receiving
-impressions which come to it every instant from
-all directions, and which it stores up in its little
-treasury; but a large portion is also consumed in
-the far more serious and difficult business of discrimination
-and correction. Could any man, after
-having attained the age of manhood, reverse the
-order of the course through which he has passed;
-could he, with the power of observation, together
-with the experience that belong to manhood, retrace
-with perfect exactness every step of his sentient
-existence, from the age of forty to the moment
-that the air first came into contact with his body
-at the moment of his leaving his maternal dwelling,
-among the truths he would learn, the most
-interesting, if not the most surprising, would be
-those which relate to the manner in which he
-dealt with his earliest impressions; with the mode
-in which he combined them, recalled them, laid
-them by for future use; made his first general
-deduction; observed what subsequent experience
-taught to be conformable, and what not conformable,
-to this general inference; his emotions on
-detecting his first errors, and his contrasted feelings
-on discovering those comprehensive truths,
-the certainty of which became confirmed by every
-subsequent impression. Thus to live backwards
-would be, in fact, to go through the analysis of the
-intellectual combinations, and, consequently, to
-obtain a perfect insight into the constitution of the
-
-<span class="pagenum"><a name="Page_63" id="Page_63">[Pg 63]</a></span>
-
-mind; and among the curious results which would
-then become manifest, perhaps few would appear
-more surprising than the true action of the senses.
-The eye, when first impressed by light, does not
-perceive the objects that reflect it; the ear, when
-first impressed by sound, does not distinguish the
-sonorous body. When the operation for cataract
-has been successfully performed in a person born
-blind, the eye immediately becomes sensible to
-light, but the impression of light does not immediately
-give information relative to the properties of
-bodies. It is gradually, not instantaneously; it is
-even by slow degrees that luminous objects are
-discerned with distinctness and accuracy. To
-see, to hear, to smell, to taste, to touch, are processes
-which appear to be performed instantaneously,
-and which actually are performed with
-astonishing rapidity in a person who observes them
-in himself; but they were not always performed
-thus rapidly: they are processes acquired, businesses
-learnt; processes and businesses acquired
-and learnt, not without the cost of many efforts
-and much labour. But the senses afford merely
-the materials for the intellectual operations of memory,
-combination, comparison, discrimination,
-induction, operations the progress of which
-is so slow, that they acquire precision, energy,
-and comprehensiveness only after the culture of
-years.</p>
-
-<p>And the same is true of the muscles of volition.
-
-<span class="pagenum"><a name="Page_64" id="Page_64">[Pg 64]</a></span>
-
-How many efforts are made before the power of
-distinct articulation is acquired! how many before
-the infant can stand! how many before the child
-can walk! The organic life is born perfect; the
-animal life becomes perfect only by servitude, and
-the aptitude which service gives.</p>
-
-<p>6. The organic life may exist after the animal life
-has perished. The animal life is extinguished when
-sensation is abolished, and voluntary motion can
-be performed no more. But disease may abolish
-sensation and destroy the power of voluntary motion,
-while circulation, respiration, secretion, excretion,
-in a word, the entire circle of the organic
-functions continues to be performed. In a single
-instant apoplexy may reduce to drivelling fatuity
-the most exalted intellect, and render powerless
-and motionless muscles of gigantic strength; while
-the action of the heart and the involuntary contractions
-of the muscles may not only not be weakened,
-but may act with preternatural energy.
-In a single instant, apoplexy may even completely
-extinguish the animal life, and yet the organic may
-go on for hours, days, and even weeks; while catalepsy,
-perhaps the most singular disease to which
-the human frame is subject, may wholly abolish
-sensation and volition, while it may impart to the
-voluntary muscles the power of contracting with
-such unnatural energy and continuity, that the
-head, the trunk, the limbs may become immoveably
-fixed in whatever attitude they happen to be at
-
-<span class="pagenum"><a name="Page_65" id="Page_65">[Pg 65]</a></span>
-
-the moment the paroxysm comes on. In this extraordinary
-condition of the nervous system, however
-long the paroxysm last, and however complete
-the abolition of consciousness, the heart continues
-to beat, and the pulse to throb, and the lungs to
-respire, and all the organic organs to perform
-their ordinary functions. Dr. Jebb gives the following
-description of the condition of a young
-lady who was the subject of this curious malady.</p>
-
-<p>"My patient was seized with an attack just as
-I was announced. At that moment she was employed
-in netting; she was in the act of passing
-the needle through the mesh; in that position she
-became immoveably rigid, exhibiting, in a pleasing
-form, a figure of death-like sleep, beyond the
-power of art to imitate, or the imagination to conceive.
-Her forehead was serene, her features perfectly
-composed. The paleness of her colour, and
-her breathing, which at a distance was scarcely
-perceptible, operated in rendering the similitude to
-marble more exact and striking. The position of
-her fingers, hands, and arms was altered with difficulty,
-but preserved every form of flexure they
-acquired: nor were the muscles of the neck exempted
-from this law, her head maintaining every
-situation in which the hand could place it, as
-firmly as her limbs."</p>
-
-<p>In this condition of the system the senses were
-in a state of profound sleep; the voluntary muscles,
-on the contrary, were in a state of violent action;
-
-<span class="pagenum"><a name="Page_66" id="Page_66">[Pg 66]</a></span>
-
-but this action not being excited by volition, nor
-under its control, the patient remained as motionless
-as she was insensible. The brain was in a
-state of temporary death; the muscle in a state of
-intense life. And the converse may happen: the
-muscle may die, while the brain lives; contractility
-may be destroyed, while sensibility is perfect;
-the power of motion may be lost, while that of
-sensation may remain unaffected. A case is on
-record, which affords an illustration of this condition
-of the system. A woman had been for some
-time confined to her bed, labouring under severe
-indisposition. On a sudden she was deprived of
-the power of moving a single muscle of the body;
-she attempted to speak, but she had no power to
-articulate; she endeavoured to stretch out her
-hand, but her muscles refused to obey the commands
-of her will, yet her consciousness was perfect,
-and she retained the complete possession of
-her intellectual faculties. She perceived that her
-attendants thought her dead, and was conscious of
-the performance upon her own person of the services
-usually paid to the dead; she was laid out,
-her toes were bound together, her chin was tied
-up; she heard the arrangements for her funeral
-discussed, and yet she was unable to make the
-slightest sign that she was still in the possession
-of sense, feeling, and life.</p>
-
-<p>In one form of disease, then, the animal life,
-both the sensitive and the motive portions of it,
-
-<span class="pagenum"><a name="Page_67" id="Page_67">[Pg 67]</a></span>
-
-may perish; and in another form of disease, either
-the one or the other part of it may be suspended,
-while the organic life continues in full operation:
-it follows that the two lives, blended as they are,
-are distinct, since the one is capable of perishing
-without immediately and inevitably involving the
-destruction of the other.</p>
-
-<p>7. And, finally, as the organic life is the first
-born, so it is the last to die; while the animal
-life, as it is the latest born, and the last to attain
-its full development, so it is the earliest to decline
-and the first to perish. In the process of natural
-death, the extinction of the animal is always anterior
-to that of the organic life. Real death is a
-later, and sometimes a much later event than apparent
-death. An animal appears to be dead when,
-together with the abolition of sensation and the loss
-of voluntary motion, respiration, circulation, and
-the rest of the organic functions can no longer be
-distinguished; but these functions go on some
-time after they have ceased to afford external indications
-of their action. In man, and the warmblooded
-animals in general, suspension or submersion
-extinguishes the animal life, at the latest,
-within the space of four minutes from the time that
-the atmospheric air is completely excluded from the
-lung; but did the organic functions also cease at
-the same period, it would be impossible to restore
-an animal to life after apparent death from drowning
-
-<span class="pagenum"><a name="Page_68" id="Page_68">[Pg 68]</a></span>
-
-and the like. But however complete and protracted
-the abolition of the animal functions, re-animation
-is always possible as long as the organic
-organs are capable of being restored to their usual
-vigour. The cessation of the animal life is but the
-first stage of death, from which recovery is possible;
-death is complete only when the organic
-together with the animal functions have wholly
-ceased, and are incapable of being re-established.</p>
-
-<p>In man, the process of death is seldom altogether
-natural. It is generally rendered premature by
-the operation of circumstances which destroy life
-otherwise than by that progressive and slow decay
-which is the inevitable result of the action of organized
-structure. Death, when natural, is the
-last event of an extended series, of which the first
-that is appreciable is a change in the animal life
-and in the noblest portion of that life. The higher
-faculties fail in the reverse order of their development;
-the retrogression is the inverse of the progression,
-and the noblest creature, in returning to
-the state of non-existence, retraces step by step
-each successive stage by which it reached the
-summit of life.</p>
-
-<p>In the advancing series, the animal is superadded
-to the organic life; sensation, the lowest
-faculty of the animal life, precedes ratiocination,
-the highest. The senses called into play at the
-moment of birth soon acquire the utmost perfection
-
-<span class="pagenum"><a name="Page_69" id="Page_69">[Pg 69]</a></span>
-
-of which they are capable; but the intellectual
-faculties, later developed, are still later perfected,
-and the highest the latest.</p>
-
-<p>In the descending series, the animal life fails
-before the organic, and its nobler powers decay
-sooner and more rapidly than the subordinate.
-First of all, the impressions which the organs of
-sense convey to the brain become less numerous
-and distinct, and consequently the material on
-which the mind operates is less abundant and perfect;
-but at the same time, the power of working
-vigorously with the material it possesses more than
-proportionally diminishes. Memory fails; analogous
-phenomena are less readily and less completely
-recalled by the presence of those which
-should suggest the entire train; the connecting
-links are dimly seen or wholly lost; the train itself
-is less vivid and less coherent; train succeeds
-train with preternatural slowness, and the consequence
-of these growing imperfections is that, at
-last, induction becomes unsound just as it was in
-early youth; and for the same reason, namely,
-because there is not in the mental view an adequate
-range of individual phenomena; the only
-difference being that the range comprehended in
-the view of the old man is too narrow, because
-that which he had learnt he has forgotten; while
-in the youth it is too narrow, because that which
-it is necessary to learn has not been acquired.</p>
-
-<p>And with the diminution of intellectual power
-
-<span class="pagenum"><a name="Page_70" id="Page_70">[Pg 70]</a></span>
-
-the senses continue progressively to fail: the eye
-grows more dim, the ear more dull, the sense of
-smell less delicate, the sense of touch less acute,
-while the sense of taste immediately subservient to
-the organic function of nutrition is the last to
-diminish in intensity and correctness, and wholly
-fails but with the extinction of the life it serves.</p>
-
-<p>But the senses are not the only servants of the
-brain; the voluntary muscles are so equally; but
-these ministers to the master-power, no longer kept
-in active service, the former no longer employed to
-convey new, varied, and vivid impressions, the
-latter no longer employed to execute the commands
-of new, varied, and intense desires, become
-successively feebler, slower, and more uncertain in
-their action. The hand trembles, the step totters,
-and every movement is tardy and unsteady. And
-thus, by the loss of one intellectual faculty after
-another, by the obliteration of sense after sense,
-by the progressive failure of the power of voluntary
-motion; in a word, by the declining energy
-and the ultimate extinction of the animal life,
-man, from the state of maturity, passes a second
-time through the stage of childhood back to that
-of infancy; lapses even into the condition of the
-embryo: what the f&oelig;tus was, the man of extreme
-old age is: when he began to exist, he possessed
-only organic life; and before he is ripe for the
-tomb, he returns to the condition of the plant.</p>
-
-<p>And even this merely organic existence cannot
-
-<span class="pagenum"><a name="Page_71" id="Page_71">[Pg 71]</a></span>
-
-be long maintained. Slow may be the waste of
-the organic organs; but they do waste, and that
-waste is not repaired, and consequently their functions
-languish, and no amount of stimulus is
-capable of invigorating their failing action. The
-arteries are rigid and cannot nourish; the veins
-are relaxed and cannot carry on the mass of blood
-that oppresses them; the lungs, partly choked up
-by the deposition of adventitious matter, and partly
-incapable of expanding and collapsing by reason of
-the feeble action of the respiratory apparatus, imperfectly
-aërate the small quantity of blood that
-flows through them; the heart, deprived of its
-wonted nutriment and stimulus, is unable to contract
-with the energy requisite to propel the vital
-current; the various organs, no longer supplied
-with the quantity and quality of material necessary
-for carrying on their respective processes, cease
-to act; the machinery stops, and this is death.</p>
-
-<p>And now the processes of life at an end, the body
-falls within the dominion of the powers which preside
-universally over matter; the tie that linked all
-its parts together, holding them in union and keeping
-them in action, in direct opposition to those
-powers dissolved, it feels and obeys the new attractions
-to which it has become subject; particle after
-particle that stood in beautiful order fall from their
-place; the wonderful structures they composed
-melt away; the very substances of which those
-structures were built up are resolved into their
-
-<span class="pagenum"><a name="Page_72" id="Page_72">[Pg 72]</a></span>
-
-primitive elements; these elements, set at liberty,
-enter into new combinations, and become constituent
-parts of new beings; those new beings in
-their turn perish; from their death springs life,
-and so the changes go on in an everlasting circle.</p>
-
-<p>As far as relates to the organized structures in
-which life has its seat, and to the operations of
-life dependent on those structures, such is its history;
-a history not merely curious, but abounding
-with practical suggestions of the last importance.
-The usefulness of a familiar acquaintance with the
-phenomena which have now been elucidated will
-be apparent at every step as we proceed.</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_73" id="Page_73">[Pg 73]</a></span></p>
-<h2>CHAPTER III.</h2>
-</div>
-
-<blockquote>
-<p>Ultimate object of organization and life&mdash;Sources of pleasure&mdash;Special
-provision by which the organic organs
-influence consciousness and afford pleasure&mdash;Point at
-which the organic organs cease to affect consciousness,
-and why&mdash;The animal appetites: the senses: the intellectual
-faculties: the selfish and sympathetic affections:
-the moral faculty&mdash;Pleasure the direct, the ordinary, and
-the gratuitous result of the action of the organs&mdash;Pleasure
-conducive to the development of the organs, and to
-the continuance of their action&mdash;Progress of human
-knowledge&mdash;Progress of human happiness.</p>
-</blockquote>
-
-<p>The object of structure is the production of function.
-Of the two functions combined in the living
-animal, one is wholly subservient to the other.
-To build up the apparatus of the animal life, and
-to maintain it in a condition fit for performing its
-functions, is the sole object of the existence of the
-organic life. What then is the object of the animal
-life? That object, whatever it be, must be
-the ultimate end of organization, and of all the
-actions of which it is the seat and the instrument.</p>
-
-<p>Two functions, sensation and voluntary motion,
-are combined in the animal life. Of these two
-functions, the latter is subservient to the former:
-voluntary motion is the servant of sensation, and
-exists only to obey its commands.</p>
-
-<p><span class="pagenum"><a name="Page_74" id="Page_74">[Pg 74]</a></span></p>
-
-<p>Is sensation, then, the ultimate object of organization?
-Simple sensation cannot be an ultimate
-object, because it is invariably attended with an
-ultimate result; for sensation is either pleasurable
-or painful. Every sensation terminates in a
-pleasure or a pain. Pleasure or pain, the last
-event in the series, must then be the final end.</p>
-
-<p>Is the production of pain the ultimate object of
-organization? That cannot be, for the production
-of pain is the indirect, not the direct,&mdash;the extraordinary,
-not the ordinary, result of the actions of
-life. It follows that pleasure must be the ultimate
-object, for there is no other of which it is possible
-to conceive. The end of organic existence is animal
-existence; the end of animal existence is sentient
-existence; the end of sentient existence is
-pleasurable existence; the end of life therefore is
-enjoyment. Life commences with the organic
-processes; to the organic are superadded the animal;
-the animal processes terminate in sensation;
-sensation ends in enjoyment; it follows, that enjoyment
-is the final end. For this every organ is constructed;
-to this every action of every organ is subservient;
-in this every action ultimately terminates.</p>
-
-<p>And without a single exception in the entire
-range of the sentient creation, the higher the
-organized structure the greater the enjoyment,
-mediately or immediately, to which it is subservient.
-From its most simple to its most complex
-state, every successive addition to structure, by
-
-<span class="pagenum"><a name="Page_75" id="Page_75">[Pg 75]</a></span>
-
-which function is rendered more elevated and perfect,
-proportionally increases the exquisiteness of
-the pleasure to which the function ministers, and
-in which it terminates.</p>
-
-<p>Pleasure is the result of the action of living organs,
-whether organic or animal; pleasure is the
-direct, the ordinary, and the gratuitous result of
-the action of both sets of organs; the pleasure
-resulting from the action of the organs is conducive
-to their complete development, and thereby to the
-increase of their capacity for affording enjoyment;
-the pleasure resulting from the action of the organs,
-and conducive to their development, is
-equally conducive to the perpetuation of their
-action, and consequently to the maintenance of
-life; it follows not only that enjoyment is the end
-of life, but that it is the means by which life is
-prolonged. Of the truth of each of these propositions,
-it will be interesting to contemplate the
-plenitude of the proof.</p>
-
-<p>1. In the first place, pleasure is the result of the
-action of the organic organs. It has indeed been
-shown that the very character by which the action
-of these organs is distinguished is that they are
-unattended with consciousness. Nevertheless, by
-a special provision, consciousness is indirectly
-connected with the processes of this class, limited
-in extent indeed, and uniformly terminating at a
-certain point; but the extent and the limitation
-alike conducing to the pleasurableness of its nature.
-
-<span class="pagenum"><a name="Page_76" id="Page_76">[Pg 76]</a></span>
-
-And this is an adjustment in the constitution
-of our frame which is well deserving of attention.</p>
-
-<p>Organic processes are dependent on a peculiar
-influence derived from that portion of the nervous
-system distinguished by the term organic. The
-organic nerves, distributed to the organic organs,
-take their origin and have their chief seat in the
-cavities that contain the main instruments of the
-organic life, namely, the chest and abdomen (see
-chap. v.). As will be fully shown hereafter,
-these nerves encompass the great trunks of the
-blood-vessels that convey arterial blood to the
-organic organs. In all its ramifications through
-an organic organ, an arterial vessel is accompanied
-by its organic nerve; so that wherever the capillary
-arterial branch goes, secreting or nourishing,
-there goes, inseparably united with it, an organic
-nerve, exciting and governing.</p>
-
-<p>Among the peculiarities of this portion of the
-nervous system, one of the most remarkable is,
-that it is wholly destitute of feeling. Sensibility
-is inseparably associated with the idea commonly
-formed of a nerve. But the nervous system consists
-of two portions, one presiding over sensation
-and voluntary motion, hence called the sentient
-and the motive portions; the other destitute of
-sensation, but presiding over the organic processes,
-hence called the organic portion. If the communication
-between the organic organ and the organic
-
-<span class="pagenum"><a name="Page_77" id="Page_77">[Pg 77]</a></span>
-
-nerve be interrupted, the function of the
-organ, whatever it be, is arrested. Without its
-organic nerves, the stomach cannot secrete gastric
-juice; the consequence is, that the aliment is undigested.
-Without its organic nerves, the liver
-cannot secrete bile, the consequence is, that the
-nutritive part of the aliment is incapable of being
-separated from its excrementitious portion. The
-organic organ receives from its organic nerve an
-influence, without which it cannot perform its
-function; but the nerve belonging to this class
-neither feels nor communicates feeling, and hence
-it imparts no consciousness of the operation of any
-process dependent upon it. Yet there is not one
-of these processes that does not exert a most important
-influence over consciousness. How? By
-a special provision, as curious in its nature as it is
-important in its result.</p>
-
-<p>Branches of sentient nerves are transmitted from
-the animal to the organic system, and from the organic
-to the animal; and an intimate communication
-is established between the two classes. The
-inspection of fig. XVI. will illustrate the mode in
-which this communication is effected. A B represents
-a portion of the spinal cord (one of the
-central masses of the sentient system), covered
-with its membranes. The part here represented
-is a front view of that portion of the spinal cord
-which belongs to the back, and which is technically
-called the dorsal portion.</p>
-
-<p><span class="pagenum"><a name="Page_78" id="Page_78">[Pg 78]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_078.png" alt="Fig. XVI." />
-</div>
-<div class="topspace2"></div>
-
-<p><span class="pagenum"><a name="Page_79" id="Page_79">[Pg 79]</a></span></p>
-
-<p>1, 2, 3, 4, 5, 6, 7, 8, 9, the second, &amp;c. ribs with
-the corresponding dorsal (sentient) nerves, <i>a</i>, <i>b</i>,
-<i>c</i>, <i>d</i>, <i>e</i>, <i>f</i>, <i>g</i>, <i>h</i>, going out to supply their respective
-organs with sensation.</p>
-
-<p>C D E, a portion of the main trunk of the
-organic (non-sentient) nerve, commonly called the
-Great Sympathetic.</p>
-
-<p>F G H, the membrane of the spinal cord cut
-open and exposing I K, the spinal cord itself,
-L, the anterior branch of one of the dorsal
-nerves, arising from the anterior surface of the
-spinal cord by several bundles of fibres.</p>
-
-<p>M, the posterior branch of the same nerve,
-arising in like manner from the posterior surface
-of the spinal cord by several branches of fibres.</p>
-
-<p>The anterior and posterior branches uniting to
-form one trunk N.</p>
-
-<p>Two branches, P Q, sent off from the spinal
-(sentient) trunk to unite with the organic (non-sentient)
-trunk.</p>
-
-<p>R S T U V W, other branches of the sentient,
-connected with the branches of the non-sentient
-nervous trunks in the same mode.</p>
-
-<p>X Y, the main trunk of the sympathetic (non-sentient)
-nerve cut across and turned aside, in
-order that the parts beneath it (P N) may be more
-distinctly seen.</p>
-
-<p>From this description, it is apparent that each
-sentient nerve, before it goes out to the animal
-organs, to which it is destined to communicate
-
-<span class="pagenum"><a name="Page_80" id="Page_80">[Pg 80]</a></span>
-
-sensation, sends off two branches to the organic or
-the non-sentient. These sentient nerves mix and
-mingle with the insensible nerves; accompany
-them in their course to the organic organs, and
-ramify with them throughout their substance. It
-is manifest, then, that sentient nerves, that nerves
-not necessary to the organic processes, having, as
-far as is known, nothing whatever to do with those
-processes, enter as constituent parts into the composition
-of the organic organs. What is the result?
-That organic organs are rendered sentient;
-that organic processes, in their own nature insensible,
-become capable of affecting consciousness.
-What follows? What is the consciousness excited?
-Not a consciousness of the organic process.
-Of that we still remain wholly insensible.
-Not simple sensation. The result uniformly produced,
-as long as the state of the system is that of
-health, is pleasurable consciousness. The heart
-sends out to the organs its vital current. Each
-organ, abstracting from the stream the particles it
-needs, converts them into the peculiar fluid or solid
-it is its office to form. The stomach, from the
-arterial streamlets circulating through it, secretes
-gastric juice; the liver, from the venous streamlets
-circulating through it, secretes bile. When these
-digestive organs have duly prepared their respective
-fluids, they employ them in the elaboration of the
-aliment. We are not conscious of this elaboration,
-though it go on within us every moment; but is
-
-<span class="pagenum"><a name="Page_81" id="Page_81">[Pg 81]</a></span>
-
-consciousness not affected by the process? Most
-materially. Why? Because sentient mingle with
-organic nerves; because the sentient nerves are
-impressed by the actions of the organic organs.
-And how impressed? As long as the actions of
-the organic organs are sound, that is, as long as
-their processes are duly performed, the impression
-communicated to the sentient nerves is in its nature
-agreeable; is, in fact, <span class="smcap">THE PLEASURABLE
-CONSCIOUSNESS WHICH CONSTITUTES THE FEELING
-OF HEALTH</span>. The state of health is nothing but
-the result of the due performance of the organic
-organs: it follows that the feeling of health, the
-feeling which is ranked by every one among the
-most pleasurable of existence, is the result of the
-action of organs of whose direct operations we are
-unconscious. But the pleasurable consciousness
-thus indirectly excited is really the consequence of
-a special provision, established for the express
-purpose of producing pleasure. Processes, in their
-own nature insensible, are rendered sentient expressly
-for this purpose, that, over and above the
-special object they serve, they may afford enjoyment.
-In this case, the production of pleasure
-is not only altogether gratuitous, not only communicated
-for its own sake, not only rested in as
-an ultimate object, but it is made to commence at
-the very confines of life; it is interwoven with
-the thread of existence: it is secured in and by
-the actions that build up and that support the
-
-<span class="pagenum"><a name="Page_82" id="Page_82">[Pg 82]</a></span>
-
-very framework, the material instrument of our
-being.</p>
-
-<p>But if the communication of sensibility to processes
-in their own nature incapable of exciting
-feeling, for the purpose of converting them into
-sources of pleasurable consciousness, indicate an
-express provision for the production of enjoyment,
-that provision is no less exemplified in the point at
-which this superadded sensibility is made to cease.</p>
-
-<p>Some of the consequences of a direct communication
-of consciousness to an organic process
-have been already adverted to. Had the eye, besides
-transmitting rays of light to the optic nerve,
-been rendered sensible of the successive passage of
-each ray through its substance, the impression excited
-by luminous bodies, which is indispensable to
-vision, the ultimate object of the instrument, if
-not wholly lost, must necessarily have become obscure,
-in direct proportion to the acuteness of this
-sensibility. The hand of the musician could
-scarcely have executed its varied and rapid movements
-upon his instrument, had his mind been
-occupied at one and the same instant with the
-process of muscular contraction in the finger, and
-the idea of music in the brain. Had the communication
-of such a twofold consciousness been possible,
-in no respect would it have been beneficial,
-in many it would have been highly pernicious;
-and the least of the evils resulting from it would
-have been, that the inferior would have interrupted
-
-<span class="pagenum"><a name="Page_83" id="Page_83">[Pg 83]</a></span>
-
-the superior faculty, and the means deteriorated
-the end. But in some cases the evil
-would have been of a much more serious nature.
-Had we been rendered sensible of the flow of the
-vital current through the engine that propels it;
-were the distension of the delicate valves that
-direct the current ever present to our view; by
-some inward feeling were we reminded, minute by
-minute, of the progress of the aliment through the
-digestive apparatus, and were the mysterious operations
-of the organic nerves palpable to sight, the
-terror of the maniac, who conceived that his body
-was composed of unannealed glass, would be the
-ordinary feeling of life. Every movement would
-be a matter of anxious deliberation; and the approach
-of every body to our own would fill us with
-dismay. But adjusted as our consciousness actually
-is, invariably the point at which the organic
-process begins is that at which sensation ends.
-Had sensation been extended beyond this point, it
-would have been productive of pain: at this point
-it uniformly stops. Nevertheless, by the indirect
-connexion of sensation with the organic processes,
-a vast amount of pleasure might be created: a
-special apparatus is constructed for the express
-purpose of establishing the communication. There
-is thus the twofold proof, the positive and the negative,
-the evidence arising as well from what they
-do, as from what they abstain from doing, that the
-organic processes are, and are intended to be,
-sources of enjoyment.</p>
-
-<p><span class="pagenum"><a name="Page_84" id="Page_84">[Pg 84]</a></span></p>
-
-<p>But the production of pleasure, commencing at
-this the lowest point of conscious existence, increases
-with the progressive advancement of organization
-and function.</p>
-
-<p>The appetite for food, and the voluntary actions
-dependent upon it, may be considered as the first
-advancement beyond a process purely organic.
-The function by which new matter is introduced
-into the system and converted into nutriment, is
-partly an animal and partly an organic operation.
-The animal part of it consists of the sensations of
-hunger and thirst, by which we are taught when
-the wants of the system require a fresh supply of
-aliment, together with the voluntary actions by
-which the aliment is introduced into the system.
-The organic part of the function consists of the
-changes which the aliment undergoes after its introduction
-into the system, by which it is converted
-into nutriment. Sensations always of a pleasurable
-nature arise indirectly in the manner already
-explained, from the due performance of the organic
-part of the function; but pleasure is also directly
-produced by the performance of the animal part of
-it. Wholesome food is grateful; the satisfaction
-of the appetite for food is pleasurable. Food is
-necessary to the support of life; but it is not indispensable
-to the maintenance of life that food should
-be agreeable. Appetite there must be, that food
-may be eaten; but the act of eating might have
-been secured without connecting it with pleasure.
-
-<span class="pagenum"><a name="Page_85" id="Page_85">[Pg 85]</a></span>
-
-Pleasure, however, is connected with it, first directly,
-by the gratefulness of food, and secondly
-indirectly, by the due digestion of the food. And
-the annexation of pleasure in this twofold mode
-to the performance of the function of nutrition is
-another case of the gratuitous bestowment of pleasure;
-another instance in which pleasure is communicated
-for its own sake, and rested in as an
-ultimate object. Pleasures of this class are sometimes
-called low; they are comparatively low; but
-they are not the less pleasures, because they are
-exceeded in value by pleasures of a nobler nature.
-Man may regard them with comparative indifference,
-because he is endowed with faculties which
-afford him gratifications superior in kind and larger
-in amount; but it is no mark of wisdom to despise
-and neglect even these: for they are annexed to
-the exercise of a function which is the first to exalt
-us above a merely organic existence; they are the
-first pleasures of which, considered merely as sentient
-creatures, we are susceptible; they amount
-in the aggregate to an immense sum; and they
-mark the depth in our nature in which are laid the
-fountains of enjoyment.</p>
-
-<p>Organs of sense, intellectual faculties, social
-affections, moral powers, are superadded endowments
-of a successively higher order: at the same
-time, they are the instruments of enjoyment of a
-nature progressively more and more exquisite.</p>
-
-<p><span class="pagenum"><a name="Page_86" id="Page_86">[Pg 86]</a></span></p>
-
-<p>An organ of sense is an instrument composed of a
-peculiar arrangement of organized matter, by which
-it is adapted to receive from specific agents definite
-impressions. Between the agent that produces and
-the organ that receives the impression, the adaptation
-is such, that the result of their mutual action
-is, in the first place, the production of sensation,
-and, in the second place, the production of pleasure.
-The pleasure is as much the result as the sensation.
-This is true of the eye in seeing, the ear in
-hearing, the hand in touching, the organ of smell
-in smelling, and the tongue in tasting. Pleasure
-is linked with the sense; but there might have
-been the sense without the pleasure. A slight difference
-in the construction of the organ, or in the
-intensity of the agent, would not merely have
-changed, it would even have reversed the result;
-would have rendered the habitual condition of the
-eye, the ear, the skin, not such as it now is in
-health, but such as it is in the state of inflammation.
-But the adjustment is such as habitually to
-secure that condition of the system in which every
-action that excites sensation produces pleasure as
-its ordinary concomitant; and the amount of enjoyment
-which is thus secured to every man, and
-which every man without exception actually experiences
-in the ordinary course of an ordinary life,
-it would be beyond his power to estimate were he
-always sensible of the boon; but the calculation is
-
-<span class="pagenum"><a name="Page_87" id="Page_87">[Pg 87]</a></span>
-
-altogether impossible, when, as is generally the
-case, he merely enjoys without ever thinking of the
-provisions which enable him to do so.</p>
-
-<p>But if the pleasures that arise from the ordinary
-operations of sense form, in the aggregate, an incalculable
-sum, how great is the accession brought to
-this stock by the endowments next in order in the
-ascending scale, namely, the intellectual faculties!</p>
-
-<p>There is one effect resulting from the operation of
-the intellectual faculties on the senses that deserves
-particular attention. The higher faculties elevate
-the subordinate in such a manner as to make them
-altogether new endowments. In illustration of
-this, it will suffice to notice the change wrought,
-as if in the very nature of sensation, the moment it
-becomes combined with an intellectual operation,
-as exemplified in the difference between the intellectual
-conception of beauty, and the mere perception
-of sense. The grouping of the hills that bound
-that magnificent valley which I behold at this moment
-spread out before my view; the shadow of
-the trees at the base of some of them, stretching
-its deep and varied outline up the sides of others;
-the glancing light now brightening a hundred different
-hues of green on the broad meadows, and
-now dancing on the upland fallows; the ever-moving,
-ever-changing clouds; the scented air;
-the song of birds; the still more touching music
-which the breeze awakens in the scarcely trembling
-branches of those pine trees,&mdash;the elements of
-
-<span class="pagenum"><a name="Page_88" id="Page_88">[Pg 88]</a></span>
-
-which this scene is composed, the mere objects of
-sense, the sun, the sky, the air, the hills, the
-woods, and the sounds poured out from them, impress
-the senses of the animals that graze in the
-midst of them; but on their senses they fall dull
-and without effect, exciting no perception of their
-loveliness, and giving no taste of the pleasures they
-are capable of affording. Nor even in the human
-being, whose intellectual faculties have been uncultivated,
-do they awaken either emotions or ideas;
-the clown sees them, hears them, feels them no
-more than the herds he tends: yet in him whose
-mind has been cultivated and unfolded, how numerous
-and varied the impressions, how manifold
-the combinations, how exquisite the pleasures produced
-by objects such as these!</p>
-
-<p>And from the more purely intellectual operations,
-from memory, comparison, analysis, combination,
-classification, induction, how still nobler
-the pleasure! Not to speak of the happiness of
-him who, by his study of natural phenomena, at
-length arrived at the stupendous discovery that the
-earth and all the stars of the firmament move, and
-that the feather falls to the ground, by the operation
-of one and the same physical law; nor of the
-happiness of him who sent his kite into the cloud,
-and brought down from its quiet bed the lightning
-which he suspected was slumbering there; nor of
-the happiness of him who concentrated, directed,
-and controlled that mighty power which has enabled
-
-<span class="pagenum"><a name="Page_89" id="Page_89">[Pg 89]</a></span>
-
-the feeble hand of man to accomplish works
-greater than have been feigned of fabled giant;
-which has annihilated distance; created, by economizing
-time; changed in the short space in which
-it has been in operation the surface of the habitable
-globe; and is destined to work upon it more and
-greater changes than have been effected by all
-other causes combined; nor of the happiness of
-him who devoted a longer life with equal success
-to a nobler labour, that of <span class="smcap">REARING THE FABRIC
-OF FELICITY BY THE HAND OF REASON AND OF LAW</span>.
-The intellectual pleasures of such men as Newton,
-Franklin, Watt, and Bentham, can be <em>equalled</em>
-only by those who possess equal intellectual power,
-and who put forth equal intellectual energy: to be
-greatly happy as they were, it were necessary to be
-as highly endowed; but to be happy, it is not necessary
-to be so endowed. In the ordinary intellectual
-operations of ordinary men, in their ordinary
-occupations, there is happiness. Every human
-being whose moments have passed with winged
-speed, whose day has been short, whose year is
-gone almost as soon as it seemed commenced, has
-derived from the exercise of his intellectual faculties
-pleasures countless in number and inestimable
-in value.</p>
-
-<p>But the sympathetic pleasures, out of which
-grow the social, are of a still higher order even than
-the intellectual. The pleasures that result from
-the action of the organic organs, from the exercise
-
-<span class="pagenum"><a name="Page_90" id="Page_90">[Pg 90]</a></span>
-
-of the several senses, and from the operation of the
-intellectual faculties, like the sensations in which
-they arise, belong exclusively to the individual being
-that experiences them, and cannot be communicated
-to another. Similar sensations and pleasures
-may be felt by beings similarly constituted; but
-the actual sensations and pleasures afforded by the
-exercise of a person's own organs and faculties are
-no more capable of becoming another's than his
-existence. These, then, are strictly the selfish
-pleasures; and the provision that has been made
-for securing them has been shown.</p>
-
-<p>But there are pleasures of another class, pleasures
-having no relation whatever to a person's
-own sensation or happiness; pleasures springing
-from the perception of the enjoyment of others.
-The sight of pleasure not its own affects the human
-heart, provided its state of feeling be natural and
-sound, just as it would be affected were it its own.
-Not more real is the pleasure arising from the gratification
-of appetite, the exercise of sense, and the
-operation of intellect, than that arising from the
-consciousness that another sentient being is happy.
-Pleasures of this class are called sympathetic, in
-contradistinction to those of the former class, which
-are termed selfish.</p>
-
-<p>There are then two principles in continual operation
-in the human being, the selfish and the sympathetic.
-The selfish is productive of pleasure of a
-certain kind; the sympathetic is productive of pleasure
-
-<span class="pagenum"><a name="Page_91" id="Page_91">[Pg 91]</a></span>
-
-of another kind. The selfish is primary and
-essential; the sympathetic, arising out of the selfish,
-is superadded to it. And so precisely what the animal
-life is to the organic, the sympathetic principle
-is to the selfish; and just what the organic life gains
-by its union with the animal, the mental constitution
-gains by the addition of the sympathetic to the
-selfish affection. The analogy between the combination
-in both cases is in every respect complete.
-As the organic life produces and sustains the animal,
-so the sympathetic principle is produced and
-sustained by the selfish. As the organic life is
-conservative of the entire organization of the body,
-so the selfish principle is conservative of the entire
-being. As the animal life is superadded to the
-organic, extending, exalting, and perfecting it, so
-the sympathetic principle is superadded to the selfish,
-equally extending, exalting, and perfecting it.
-The animal life is nobler than the organic, whence
-the organic is subservient to the animal; but there
-is not only no opposition, hostility, or antagonism
-between them, but the strictest possible connexion,
-dependence, and subservience. The sympathetic
-principle is nobler than the selfish, whence
-the selfish is subservient to the sympathetic; but
-there is not only no opposition, hostility, or antagonism
-between them, but the strictest possible
-connexion, dependence, and subservience. Whatever
-is conducive to the perfection of the organic,
-is equally conducive to the perfection of the animal
-
-<span class="pagenum"><a name="Page_92" id="Page_92">[Pg 92]</a></span>
-
-life; and whatever is conducive to the attainment
-of the true end of the selfish is equally conducive
-to the attainment of the true end of the sympathetic
-principle. The perfection of the animal life
-cannot be promoted at the expense of the organic,
-nor that of the organic at the expense of the animal;
-neither can the ultimate end of the selfish
-principle be secured by the sacrifice of the sympathetic,
-nor that of the sympathetic by the sacrifice
-of the selfish. Any attempt to exalt the animal
-life beyond what is compatible with the healthy
-state of the organic, instead of accomplishing that
-end, only produces bodily disease. Any attempt
-to extend the selfish principle beyond what is compatible
-with the perfection of the sympathetic, or
-the sympathetic beyond what is compatible with
-the perfection of the selfish, instead of accomplishing
-the end in view, only produces mental disease.
-Opposing and jarring actions, antagonizing and
-mutually destructive powers, are combined in no
-other work of nature; and it would be wonderful
-indeed were the only instance of it found in man,
-the noblest of her works, and in the mind of man,
-the noblest part of her noblest work.</p>
-
-<p>No one supposes that there is any such inharmonious
-combination in the organization of his
-physical frame, and the notion that it exists in his
-mental constitution, as it is founded in the grossest
-ignorance, so it is productive of incalculable mischief.
-In both, indeed, are manifest two great
-
-<span class="pagenum"><a name="Page_93" id="Page_93">[Pg 93]</a></span>
-
-powers, each distinct; each having its own peculiar
-operation; and the one being subservient to the
-other, but both conducing alike to one common end.
-By the addition of the apparatus of the animal to
-that of the organic life, a nobler structure is built up
-than could have been framed by the organic alone:
-by the addition of the sympathetic to the selfish part
-of the mental constitution, a happier being is formed
-than could have been produced by the selfish alone.
-And as the organic might have existed without the
-animal life, but by the addition of the animal a
-new and superior being is formed, so might the
-selfish part of the mental constitution, and the
-pleasures that flow from it, have existed alone;
-but by the addition of the sympathetic, a sum is
-added to enjoyment, of the amount of which some
-conception may be formed by considering what human
-life would be, with every selfish appetite and
-faculty gratified in the fullest conceivable degree,
-but without any admixture whatever of sympathetic
-or social pleasure. Selfish enjoyment is not common.
-If any one set himself to examine what at
-first view might seem a purely selfish pleasure, he
-will soon be sensible that, of the elements composing
-any given state of mind to which he would
-be willing to affix the term pleasurable, a vast preponderance
-consists of sympathetic associations.
-The more accurately he examine, and the farther
-he carry his analysis, the stronger will become
-his conviction, that a purely selfish enjoyment, that
-
-<span class="pagenum"><a name="Page_94" id="Page_94">[Pg 94]</a></span>
-
-is, a truly pleasurable state of mind, in no degree,
-mediately or immediately, connected with the
-pleasurable state of another mind, is exceedingly
-rare.</p>
-
-<p>But if the constitution of human nature and
-the structure of human society alike render it
-difficult for the human heart to be affected with a
-pleasure in no degree derived from&mdash;absolutely and
-totally unconnected with sympathetic association,
-of that complex pleasure which arises out of social
-intercourse, partly selfish and partly sympathetic,
-how far sweeter the sympathetic than the selfish
-part; and as the sympathetic preponderates over
-the selfish, how vast the increase of the pleasure!
-And when matured, exalted into affection&mdash;affection,
-that holy emotion which exerts a transforming
-influence over the selfish part of human nature,
-turning it into the sympathetic; affection, which
-renders the happiness of the beloved object inexpressibly
-dearer to the heart than its own; affection,
-among the benignant feelings of which as
-there is none sweeter so there is none stronger
-than that of self-devotion, nay, sometimes even of
-self-sacrifice; affection, which is sympathy pure,
-concentrated, intense&mdash;Oh how beautiful is the
-constitution of this part of our nature, by which
-the most transporting pleasures the heart receives
-are the direct reflection of those it gives!</p>
-
-<p>Nor ought it to be overlooked, that, while nearly
-all the selfish, like all the sensual pleasures, cannot
-
-<span class="pagenum"><a name="Page_95" id="Page_95">[Pg 95]</a></span>
-
-be increased beyond a fixed limit, cannot be protracted
-beyond a given time, are short-lived in proportion
-as they are intense, and satiate the appetite
-they gratify, the sympathetic pleasures are capable
-of indefinite augmentation; are absolutely inexhaustible;
-no limit can be set to their number,
-and no bound to their growth; they excite the
-appetite they gratify; they multiply with and by
-participation, and the more is taken from the fountain
-from which they flow, the deeper, the broader,
-and the fuller the fountain itself becomes.</p>
-
-<p>But not only is the mental state of affection in
-all its forms and degrees highly pleasurable, but
-the very consciousness of being the object of affection
-is another pleasure perfectly distinct from that
-arising immediately from the affection itself. It
-has been said of charity, that it is twice blessed,
-that it blesses alike him that gives and him that
-receives; but love has in it a threefold blessing:
-first, in the mental state itself; secondly, in the
-like mental state which the manifestation of it produces
-in another; and thirdly, in the mental state
-inseparable from the consciousness of being the
-object of affection. And this reflex happiness,
-this happiness arising from the consciousness of
-being the object, is even sweeter than any connected
-with being the subject of affection.</p>
-
-<p>In like manner there is pleasure in the performance
-of beneficent actions; in energetic, constant,
-and therefore ultimately successful exertions to
-
-<span class="pagenum"><a name="Page_96" id="Page_96">[Pg 96]</a></span>
-
-advance the great interests of human kind, in art,
-in science, in philosophy, in education, in morals,
-in legislation, in government; whether those exertions
-are put forth in the study, the school, the
-senate, or any less observed though perhaps not
-less arduous nor less important field of labour.
-Exertions of this kind beget in those for whom, towards
-those by whom, they are made, benignant
-feelings&mdash;respect, veneration, gratitude, love. With
-such feelings the philosopher, the instructor, the
-legislator, the statesman, the philanthropist, knows
-that he is, or that, sooner or later, he will be regarded
-by his fellow men; and in this consciousness
-there is happiness: but this is another source
-of happiness perfectly distinct from that arising
-from the performance of beneficent actions; it is
-a new happiness superadded to the former, and, if
-possible, still more exquisite. Thus manifold is the
-beneficent operation of the sympathetic affection:
-thus admirable is the provision made in the constitution
-of our nature for the excitement and extension
-of this affection, and, through its instrumentality,
-for the multiplication and exaltation of
-enjoyment!</p>
-
-<p>In affections and actions of the class just referred
-to, and in the pleasures that result from them,
-there is much of the nature which is commonly
-termed moral. And the power to which the moral
-affections and actions are referred is usually and
-justly considered as the supreme faculty of the
-
-<span class="pagenum"><a name="Page_97" id="Page_97">[Pg 97]</a></span>
-
-mind; for it is the regulator and guide of all the
-others; it is that by which they attain their proper
-and ultimate object. Of whatever pleasure human
-nature is capable in sensation, in idea, in appetite,
-in passion, in emotion, in affection, in action;
-whatever is productive of real pleasure, in contradistinction
-to what only cheats with the false hope
-of pleasure; whatever is productive of pure pleasure,
-in contradistinction to what is productive
-partly of pleasure and partly of pain, and consequently
-productive not of pure, but of mixed pleasure;
-whatever is productive of a great degree of
-pleasure in contradistinction to what is productive
-of a small degree of pleasure; whatever is productive
-of lasting pleasure, in contradistinction to
-what is productive of temporary pleasure; whatever
-is productive of ultimate pleasure, in contradistinction
-to what is productive of immediate
-pleasure, but ultimate pain; this greatest and most
-perfect pleasure it is the part of the moral faculty
-to discover. In the degree in which the operation
-of this faculty is correct and complete, it enables
-the human being to derive from every faculty of
-his nature the greatest, the purest, the most enduring
-pleasure; that is, the maximum of felicity.
-This is the proper scope and aim of the moral
-faculty; to this its right exercise is uniformly conducive;
-and this, as it is better cultivated and
-directed, it will accomplish in a higher degree, in
-a continual progression, to which no limit can be
-
-<span class="pagenum"><a name="Page_98" id="Page_98">[Pg 98]</a></span>
-
-assigned. But if the operation of this faculty be
-to render every other in the highest degree conducive
-to happiness, conformity to the course of
-conduct required by it, must of course be that
-highest happiness. Conformity to the course of
-conduct pointed out by the moral faculty as conducive
-in the highest degree to happiness is moral
-excellence, or, in the definite and exact sense of
-the word, virtue. And in this sense it is that virtue
-is happiness. It is because it discriminates the
-true sources of happiness, that is, directs every
-other faculty into its proper course, and guides it
-in that course to the attainment of its ultimate object,
-that the moral faculty is ranked as the highest
-faculty of the mind. Supposing the operation of
-this faculty to be perfect, it is but an identical
-expression to say, that to follow its guidance implicitly
-is to follow the road that leads to the most
-perfect happiness. But, over and above the happiness
-thus directly and necessarily resulting from
-yielding uniform and implicit obedience to the
-moral faculty, there is, in the very consciousness of
-such conformity, a new happiness, as pure as it is
-exalted. Thus, in a twofold manner, is the moral
-the highest faculty of the mind, the source of its
-highest happiness; and thus manifest it is, from
-every view that can be taken of the constitution of
-human nature, that every faculty with which it is
-endowed, from the highest to the lowest, not only
-affords its own proper and peculiar pleasure, but
-
-<span class="pagenum"><a name="Page_99" id="Page_99">[Pg 99]</a></span>
-
-that each, as it successively rises in the scale, is
-proportionately the source of a nobler kind, and a
-larger amount of enjoyment.</p>
-
-<p>And the pleasure afforded by the various faculties
-with which the human being is endowed is the
-immediate and direct result of their exercise.
-With the exception of the organic organs, and the
-reason for the exception in regard to them has been
-assigned, the action of the organs is directly pleasurable.
-From the exercise of the organs of sense,
-from the operation of the intellectual faculties,
-from appetite, passion, and affection, pleasure
-flows as directly as the object for which the instrument
-is expressly framed.</p>
-
-<p>And pleasure is the ordinary result of the action
-of the organs; pain is sometimes the result, but it
-is the extraordinary not the ordinary result. Whatever
-may be the degree of pain occasionally produced,
-or however protracted its duration, yet it is
-never the natural, that is, the usual or permanent
-state, either of a single organ, or of an apparatus,
-or of the system. The usual, the permanent, the
-natural condition of each organ, and of the entire
-system, is pleasurable. Abstracting, therefore,
-from the aggregate amount of pleasure, the aggregate
-amount of pain, the balance in favour of pleasure
-is immense. This is true of the ordinary
-experience of ordinary men, even taking their physical
-and mental states such as they are at present;
-but the ordinary physical and mental states, considered
-
-<span class="pagenum"><a name="Page_100" id="Page_100">[Pg 100]</a></span>
-
-as sources of pleasure of every human being,
-might be prodigiously improved; and some attempt
-will be made, in a subsequent part of this work, to
-show in what manner and to what extent.</p>
-
-<p>It has been already stated that there are cases
-in which pleasure is manifestly given for its own
-sake; in which it is rested in as an ultimate object:
-but the converse is never found: in no case
-is the excitement of pain gratuitous. Among all
-the examples of secretion, there is no instance of a
-fluid, the object of which is to irritate and inflame:
-among all the actions of the economy, there is
-none, the object of which is the production of pain.</p>
-
-<p>Moreover, all such action of the organs, as is
-productive of pleasure, is conducive to their complete
-development, and consequently to the increase
-of their capacity for producing pleasure;
-while all such action of the organs as is productive
-of pain is preventive of their complete development,
-and consequently diminishes their capacity
-for producing pain. The natural tendency of
-pleasure is to its own augmentation and perpetuity.
-Pain, on the contrary, is self-destructive.</p>
-
-<p>Special provision is made in the economy, for
-preventing pain from passing beyond a certain
-limit, and from enduring beyond a certain time.
-Pain, when it reaches a certain intensity, deadens
-the sensibility of the sentient nerve; and when it
-lasts beyond a certain time, it excites new actions
-in the organ affected, by which the organ is either
-
-<span class="pagenum"><a name="Page_101" id="Page_101">[Pg 101]</a></span>
-
-restored to a sound state, or so changed in structure
-that its function is wholly abolished. But change
-of structure and abolition of function, if extensive
-and permanent, are incompatible with the continuance
-of life. If, then, the actions of the economy,
-excited by pain, fail to put an end to suffering by
-restoring the diseased organ to a healthy state, they
-succeed in putting an end to it by terminating life.
-Pain, therefore, cannot be so severe and lasting as
-materially to preponderate over pleasure, without
-soon proving destructive to life.</p>
-
-<p>But the very reverse is the case with pleasure.
-All such action of the organs as is productive of
-pleasure is conducive to the perpetuation of life.
-There is a close connexion between happiness and
-longevity. Enjoyment is not only the end of life,
-but it is the only condition of life which is compatible
-with a protracted term of existence. The
-happier a human being is, the longer he lives; the
-more he suffers, the sooner he dies; to add to enjoyment,
-is to lengthen life; to inflict pain, is to
-shorten the duration of existence. As there is a
-point of wretchedness beyond which life is not desirable,
-so there is a point beyond which it is not
-maintainable. The man who has reached an advanced
-age cannot have been, upon the whole, an
-unhappy being; for the infirmity and suffering
-which embitter life cut it short. Every document
-by which the rate of mortality among large numbers
-of human beings can be correctly ascertained
-
-<span class="pagenum"><a name="Page_102" id="Page_102">[Pg 102]</a></span>
-
-contains in it irresistible evidence of this truth. In
-every country, the average duration of life, whether
-for the whole people or for particular classes, is
-invariably in the direct ratio of their means of
-felicity; while, on the other hand, the number of
-years which large portions of the population survive
-beyond the adult age may be taken as a certain
-test of the happiness of the community. How
-clear must have been the perception of this in the
-mind of the Jewish legislator when he made the
-promise, <span class="smcap">that thy days may be long in the
-land which the Lord thy God hath given
-thee</span>&mdash;the sanction of every religious observance,
-and the motive to every moral duty!</p>
-
-<p>Deeply then are laid the fountains of happiness
-in the constitution of human nature. They spring
-from the depths of man's physical organization;
-and from the wider range of his mental constitution
-they flow in streams magnificent and glorious.
-It is conceivable that from the first to the last moment
-of his existence, every human being might
-drink of them to the full extent of his capacity.
-Why does he not? The answer will be found in
-that to the following question. What must happen
-before this be possible? The attainment of clear
-and just conceptions on subjects, in relation to
-which the knowledge hitherto acquired by the most
-enlightened men is imperfect. Physical nature,
-every department of it, at least, which is capable
-of influencing human existence and human sensation;
-
-<span class="pagenum"><a name="Page_103" id="Page_103">[Pg 103]</a></span>
-
-human nature, both the physical and the
-mental part of it; institutions so adapted to that
-nature as to be capable of securing to every individual,
-and to the whole community, the maximum
-of happiness with the minimum of suffering&mdash;this
-must be known. But knowledge of this kind is of
-slow growth. To expect the possession of it on
-the part of any man in such a stage of civilization
-as the present, is to suppose a phenomenon to
-which there is nothing analogous in the history of
-the human mind. The human mind is equally
-incapable of making a violent discovery in any
-department of knowledge, and of taking a violent
-bound in any path of improvement. What we call
-discoveries and improvements are clear, decided,
-but for the most part gentle, steps in advancement
-of the actual and immediately-preceding state of
-knowledge. The human mind unravels the great
-chain of knowledge, link by link; when it is no
-longer able to trace the connecting link, it is at a
-stand; the discoverer, in common with his contemporaries,
-seeing the last ascertained link, and
-from that led on by analogies which are not perceived
-by, or which do not impress, others, at
-length descries the next in succession; this brings
-into view new analogies, and so prepares the way
-for the discernment of another link; this again
-elicits other analogies which lead to the detection
-of other links, and so the chain is lengthened.
-And no link, once made out, is lost.</p>
-
-<p><span class="pagenum"><a name="Page_104" id="Page_104">[Pg 104]</a></span></p>
-
-<p>Chemists tell us that the adjustment of the component
-elements of water is such, that although
-they readily admit of separation and are subservient
-to their most important uses in the economy of nature
-by this very facility of decomposition, yet that
-their tendency to recombination is equal, so that
-the quantity of water actually existing at this present
-moment in the globe is just the same as on
-the first day of the creation, neither the operations
-of nature, nor the purposes to which it has been
-applied by man, having used up, in the sense of
-destroying, a single particle of it. Alike indestructible
-are the separate truths that make up the
-great mass of human knowledge. In their ready
-divisibility and their manifold applications, some of
-them may sometimes seem to be lost; but if they
-disappear, it is only to enter into new combinations,
-many of which themselves become new truths, and
-so ultimately extend the boundaries of knowledge.
-Whatever may have been the case in time past,
-when the loss of an important truth, satisfactorily
-and practically established, may be supposed possible,
-such an event is inconceivable now when
-the art of printing at once multiplies a thousand
-records of it, and, with astonishing rapidity, makes
-it part and parcel of hundreds of thousands of
-minds. A thought more full of encouragement to
-those who labour for the improvement of their
-fellow beings there cannot be. No onward step
-is lost; no onward step is final; every such step
-
-<span class="pagenum"><a name="Page_105" id="Page_105">[Pg 105]</a></span>
-
-facilitates and secures another. The savage state,
-that state in which gross selfishness seeks its object
-simply and directly by violence, is past. The
-semi-savage or barbarous state, in which the grossness
-of the selfishness is somewhat abated, and the
-violence by which it seeks its object in some degree
-mitigated, by the higher faculties and the gentler
-affections of our nature, but in which war still
-predominates, is also past. To this has succeeded
-the state in which we are at present, the so-called
-civilized state&mdash;a state in which the selfish principle
-still predominates, in which the justifiableness
-of seeking the accomplishment of selfish purposes
-by means of violence, that of war among
-the rest, is still recognized, but in which violence
-is not the ordinary instrument employed by selfishness,
-its ends being commonly accomplished
-by the more silent, steady, and permanent operation
-of institutions. This state, like the preceding,
-will pass away. How soon, in what precise mode,
-by what immediate agency, none can tell. But
-we are already in possession of the principle which
-will destroy the present and introduce a better
-social condition, namely, the principle at the basis
-of the social union, THE MAXIMUM OF THE AGGREGATE
-OF HAPPINESS; THE MAXIMUM OF THE
-AGGREGATE OF HAPPINESS SOUGHT BY THE PROMOTION
-OF THE MAXIMUM OF INDIVIDUAL HAPPINESS!</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_106" id="Page_106">[Pg 106]</a></span></p>
-<h2>CHAPTER IV.</h2>
-</div>
-
-<blockquote>
-<p>Relation between the physical condition and happiness, and
-between happiness and longevity&mdash;Longevity a good, and
-why&mdash;Epochs of life&mdash;The age of maturity the only one
-that admits of extension&mdash;Proof of this from physiology&mdash;Proof
-from statistics&mdash;Explanation of terms&mdash;Life a
-fluctuating quantity&mdash;Amount of it possessed in ancient
-Rome: in modern Europe: at present in England among
-the mass of the people and among the higher classes.</p>
-</blockquote>
-
-<p>Life depends on the action of the organic organs.
-The action of the organic organs depends on certain
-physical agents. As each organic organ is
-duly supplied with the physical agent by which it
-carries on its respective process, and as it duly
-appropriates what it receives, the perfection of the
-physical condition is attained; and, according to
-the perfection or imperfection of the physical condition,
-supposing no accident interrupt its regular
-course, is the length or the brevity of life.</p>
-
-<p>It is conceivable that the physical condition
-might be brought to a high degree of perfection,
-the mind remaining in a state but little fitted for
-enjoyment; because it is necessary to enjoyment
-that there be a certain development, occupation,
-and direction of the mental powers and affections:
-
-<span class="pagenum"><a name="Page_107" id="Page_107">[Pg 107]</a></span>
-
-and the mental state may be neglected, while attention
-is paid to the physical processes. But the
-converse is not possible. The mental energies
-cannot be fully called forth while the physical condition
-is neglected. Happiness presupposes a certain
-degree of excellence in the physical condition;
-and unless the physical condition be brought to a
-high degree of excellence, there can be no such
-development, occupation, and direction of the mental
-powers and affections as is requisite to a high
-degree of enjoyment.</p>
-
-<p>That state of the system in which the physical
-condition is sound is in itself conducive to enjoyment;
-while a permanent state of enjoyment is
-in its turn conducive to the soundness of the physical
-condition. It is impossible to maintain the
-physical processes in a natural and vigorous condition
-if the mind be in a state of suffering. The
-bills of mortality contain no column exhibiting the
-number of persons who perish annually from bodily
-disease, produced by mental suffering; but every
-one must occasionally have seen appalling examples
-of the fact. Every one must have observed
-the altered appearance of persons who have sustained
-calamity. A misfortune, that struck to the
-heart, happened to a person a year ago; observe
-him some time afterwards; he is wasted, worn,
-the miserable shadow of himself; inquire about
-him at the distance of a few months, he is no more.</p>
-
-<p>It is stated by M. Villermé, that the ordinary
-
-<span class="pagenum"><a name="Page_108" id="Page_108">[Pg 108]</a></span>
-
-rate of mortality in the prisons of France, taking
-all together, is one in twenty-three&mdash;a rate which
-corresponds to the age of sixty-five in the common
-course of life. But in the vast majority of cases
-the unfortunate victims of the law are no older than
-from twenty-five to forty-five years of age. Taking
-them at the mean age of thirty-five, it follows that
-the suffering from imprisonment, and from the
-causes that lead to it, is equivalent to thirty years
-wear and tear of life. But this is not all; for it is
-found that, during imprisonment, the ordinary
-chances of death are exactly quadrupled.</p>
-
-<p>In regard to the whole population of a country,
-indigence may be assumed to be a fair measure of
-unhappiness, and wealth of happiness. If the rate
-of mortality in the indigent class be compared with
-that of the wealthy, according to M. Villermé, it
-will be found in some cases to be just double.
-Thus it is affirmed that, in some cases in France,
-taking equal numbers, where there are one hundred
-deaths in a poor arrondissement, there are
-only fifty in a rich; and that taking together the
-whole of the French population, human life is
-protracted twelve years and a half among the
-wealthy beyond its duration among the poor:
-consequently, in the one class, a child, newly
-born, has a probability of living forty-two and a
-half years; in the other only thirty years.</p>
-
-<p>In the great life-insurance establishments in
-England, a vast proportion of the persons who
-
-<span class="pagenum"><a name="Page_109" id="Page_109">[Pg 109]</a></span>
-
-insure their lives are persons compelled to do so
-by their creditors; while three-fourths of those
-who voluntarily insure their lives are professional
-men, living in great towns, and experiencing the
-anxieties and fatigues, the hopes and disappointments
-of professional life. In one of these establishments
-in London, out of 330 deaths that
-happened in twenty-six years preceding the year
-1831, it was found that eleven died by suicide,
-being one in thirty, implying the existence of an
-appalling amount of mental suffering. The number
-of persons belonging to an insurance office who
-perish by suicide is sure to be accurately known,
-death by suicide rendering the policy void. It
-would be most erroneous to suppose that these
-persons put an end to their existence under the
-mere influence of the mental states of disappointment
-and despondency. The mind reacted upon
-the body: produced physical disease, probably inflammation
-of the brain, and under the excitement
-of this physical disease, the acts of suicide were
-committed. More than one case has come to my
-knowledge in which inflammation of the brain
-having been excited by mental suffering, suicide
-was committed by cutting the throat. During the
-flow of blood, which was gradual, the brain was
-relieved; the mind became perfectly rational; and
-the patient might have been saved had a surgeon
-been upon the spot, or had the persons about the
-patient known where and how to apply the pressure
-
-<span class="pagenum"><a name="Page_110" id="Page_110">[Pg 110]</a></span>
-
-of the finger to staunch the flow of blood, until
-surgical aid could be procured.</p>
-
-<p>By a certain amount and intensity of misery
-life may be suddenly destroyed; by a smaller
-amount and intensity, it may be slowly worn out
-and exhausted. The state of the mind affects the
-physical condition; but the continuance of life is
-wholly dependent on the physical condition: it
-follows that in the degree in which the state of the
-mind is capable of affecting the physical condition,
-it is capable of influencing the duration of life.</p>
-
-<p>Were the physical condition always perfect, and
-the mental state always that of enjoyment, the
-duration of life would always be extended to the
-utmost limit compatible with that of the organization
-of the body. But as this fortunate concurrence
-seldom or never happens, human life seldom
-or never numbers the full measure of its days.
-Uniform experience shows, however, that, provided
-no accident occur to interrupt the usual
-course, in proportion as body and mind approximate
-to this state, life is long; and as they recede
-from it, it is short. Improvement of the physical
-condition affords a foundation for the improvement
-of the mental state; improvement of the mental
-state improves up to a certain point the physical
-condition; and in the ratio in which this twofold
-improvement is effected, the duration of life increases.</p>
-
-<p>Longevity then is a good, in the first place, because
-
-<span class="pagenum"><a name="Page_111" id="Page_111">[Pg 111]</a></span>
-
-it is a sign and a consequence of the possession
-of a certain amount of enjoyment; and in
-the second place, because this being the case, of
-course in proportion as the term of life is extended,
-the sum of enjoyment must be augmented. And
-this view of longevity assigns the cause, and shows
-the reasonableness of that desire for long life which
-is so universal and constant as to be commonly
-considered instinctive. Longevity and happiness,
-if not invariably, are generally, co-incident.</p>
-
-<p>If there may be happiness without longevity,
-the converse is not possible: there cannot be longevity
-without happiness. Unless the state of the
-body be that of tolerable health, and the state of the
-mind that of tolerable enjoyment, long life is unattainable:
-these physical and mental conditions no
-longer existing, nor capable of existing, the desire
-of life and the power of retaining it cease together.</p>
-
-<p>An advanced term of life and decrepitude are
-commonly conceived to be synonymous: the extension
-of life is vulgarly supposed to be the protraction
-of the period of infirmity and suffering,
-that period which is characterized by a progressive
-diminution of the power of sensation, and a consequent
-and proportionate loss of the power of enjoyment,
-the "sans teeth, sans eyes, sans taste, sans
-every thing." But this is so far from being true,
-that it is not within the compass of human power
-to protract in any sensible degree the period of old
-age properly so called, that is, the stage of decrepitude.
-
-<span class="pagenum"><a name="Page_112" id="Page_112">[Pg 112]</a></span>
-
-In this stage of existence, the physical
-changes that successively take place clog, day by
-day, the vital machinery, until it can no longer
-play. In a space of time, fixed within narrow
-limits, the flame of life must then inevitably expire,
-for the processes that feed it fail. But though,
-when fully come, the term of old age cannot be
-extended, the coming of the term may be postponed.
-To the preceding stage, an indefinite number of
-years may be added. And this is a fact of the
-deepest interest to human nature.</p>
-
-<p>The division of human life into periods or epochs
-is not an arbitrary distinction, but is founded on
-constitutional differences in the system, dependent
-on different physiological conditions. The periods
-of infancy, childhood, boyhood, adolescence, manhood,
-and old age, are distinguished from each
-other by external characters, which are but the
-outward signs of internal states. In physiological
-condition, the infant differs from the child, the
-child from the boy, the boy from the man, and
-the adult from the old man, as much in physical
-strength as in mental power. There is an
-appointed order in which these several states succeed
-each other; there is a fixed time at which
-one passes into another. That order cannot be
-inverted: no considerable anticipation or postponement
-of that fixed time can be effected. In
-all places and under all circumstances, at a given
-time, though not precisely at the same time in all
-
-<span class="pagenum"><a name="Page_113" id="Page_113">[Pg 113]</a></span>
-
-climates and under all modes of life, infancy passes
-into childhood, childhood into boyhood, boyhood
-into adolescence, and adolescence into manhood.
-In the space of two years from its birth, every infant
-has ceased to be an infant, and has become a
-child; in the space of six years from this period,
-every male child will have become a boy; add eight
-years to this time, and every boy will have become
-a young man; in eight years more, every young
-man will have become an adult man; and in the
-subsequent ten years, every adult man will have
-acquired his highest state of physical perfection.
-But at what period will this state of physical perfection
-decline? What is the maximum time
-during which it can retain its full vigour? Is
-that maximum fixed? Is there a certain number
-of years in which, by an inevitable law, every adult
-man necessarily becomes an old man? Is precisely
-the same number of years appointed for this
-transition to every human being? Can no care
-add to that number? Can no imprudence take
-from it? Does the physiological condition or the
-constitutional age of any two individuals ever advance
-to precisely the same point in precisely the
-same number of years? Physically and mentally,
-are not some persons older at fifty than others are
-at seventy? And do not instances occasionally
-occur in which an old man, who reaches even his
-hundredth year, retains as great a degree of juvenility
-as the majority of those who attain to eighty?</p>
-
-<p><span class="pagenum"><a name="Page_114" id="Page_114">[Pg 114]</a></span></p>
-
-<p>If this be so, what follows? One of the most
-interesting consequences that can be presented to
-the human mind. The duration of the periods of
-infancy, childhood, boyhood, and adolescence, is
-fixed by a determinate number of years. Nothing
-can stay, nothing retard, the succession of each.
-Alike incapable of any material protraction is the
-period of old age. It follows that every year by
-which the term of human existence is extended is
-really added to the period of mature age; the
-period when the organs of the body have attained
-their full growth and put forth their full strength;
-when the physical organization has acquired its
-utmost perfection; when the senses, the feelings,
-the emotions, the passions, the affections, are in
-the highest degree acute, intense, and varied; when
-the intellectual faculties, completely unfolded and
-developed, carry on their operations with the
-greatest vigour, soundness, and continuity; in a
-word, when the individual is capable of receiving
-and of communicating the largest amount of the
-highest kind of enjoyment.</p>
-
-<p>A consideration more full of encouragement,
-more animating, there cannot be. The extension
-of human life, in whatever mode and degree it may
-be possible to extend it, is the protraction of that
-portion of it, and only of that portion of it, in
-which the human being is capable of <span class="smcap">RECEIVING
-AND OF COMMUNICATING THE LARGEST MEASURE
-OF THE NOBLEST KIND OF ENJOYMENT</span>.</p>
-
-<p><span class="pagenum"><a name="Page_115" id="Page_115">[Pg 115]</a></span></p>
-
-<p>Considerations, purely physiological, establish
-this indubitably; but it is curious that a class of
-facts, totally different from those of a physiological
-nature, equally prove it; namely, the results obtained
-from the observation of the actual numbers
-that die at different ages, and the knowledge consequently
-acquired of the progressive decrement
-of life. Mortality is subject to a law, the operation
-of which is as regular as that of gravitation. The
-labours of my valued friend Mr. Finlaison, the
-actuary of the National Debt, have not only determined
-what that law is in relation to different nations
-at different periods of their history, but this
-celebrated calculator has also invented a striking
-mode of expressing and representing the fact. He
-constructed a chart on which 100 perpendicular
-lines, answering to the respective ages of human
-life, are laid down and numbered in succession.
-These are crossed at right angles by 500 horizontal
-lines; so that, in the manner of musical notation,
-a point may be laid down either on the horizontal
-line, or on the space between any two of them:
-and thus, 1000 points may be laid down on each
-of the perpendicular lines. The horizontal lines
-are in like manner numbered from 1 to 1000,
-ascending from the base. Taking any observation
-which shows the number of living persons that
-commence, and in like manner the number that
-die in each particular year of human life, the calculator
-reduced by the rule of three every such
-
-<span class="pagenum"><a name="Page_116" id="Page_116">[Pg 116]</a></span>
-
-actual number of living persons for every separate
-year to 10,000: he next showed the corresponding
-proportion of deaths out of such 10,000. These
-proportions he represented on the chart by a point
-inserted on the horizontal line or space for the
-number of deaths, and on the perpendicular line
-for the particular age. He then connected all the
-points so laid down, and the result is a curve, representing
-the track of death through an equal
-number of human beings existing at each age of
-life. As the curve rises on the perpendicular line,
-at any given age, it indicates by so much an increase
-of the mortality at that age; and as the
-curve falls, the reverse is denoted.</p>
-
-<p>Now, it is a highly interesting fact, that the
-curves on this chart drawn upon it before the physiological
-phenomena were known to the operator,
-placed there because such he found to be the actual
-path along which death marshals his course,
-exactly correspond to the epochs which physiology
-teaches to be determinate stages of human existence.
-The infant, the child, the boy, the adolescent,
-the man, the old man, are not exposed to the
-same danger. The liability of each to death is not
-merely different; it is widely different; the liability
-of each class is uniformly the same, the circumstances
-influencing life remaining the same;
-and under no known change of circumstances does
-the relative liability of the class vary; under no
-change does the liability of the adolescent become
-
-<span class="pagenum"><a name="Page_117" id="Page_117">[Pg 117]</a></span>
-
-that of the infant, or the liability of the adult that
-of the aged. Take from any statistical document
-any number of persons; observe out of this number
-the proportion that dies at the different stages
-just enumerated; and the period of human life
-which admits of extension will be strikingly manifest.
-Take with this view the Prussian statistical
-tables, the general correctness of which is admitted.
-From these tables it appears, and the correctness
-of the result is confirmed by a multitude of other
-tables, that out of a million living male births,
-there will die in the first year of life 180,492 infants,
-and out of the like number of living female
-births, there will die 154,705 infants. Let us follow
-up the decrement of life through the different
-epochs of human existence, confining our observations
-to the male sex, in which the development is
-more emphatically marked.</p>
-
-<p>In Mr. Finlaison's report, printed by the House
-of Commons on the 30th of March, 1829, there are
-six original observations on the mortality of as
-many separate sets of annuitants of the male sex.</p>
-
-<p>From an examination and comparison of these
-observations, it appears&mdash;1st. That the rate of
-mortality falls to a minimum at the close of the
-period of childhood. 2d. That from this point
-the mortality rises until the termination of adolescence
-or the commencement of adult age. 3d.
-That from the commencement of adult age the
-mortality again declines, and continues to decline
-
-<span class="pagenum"><a name="Page_118" id="Page_118">[Pg 118]</a></span>
-
-to the period of perfect maturity. And 4th. That
-from the period of perfect maturity, the mortality
-rises, and uniformly, without a single exception,
-returns, at the age of forty-eight, to the point at
-which it stood at the termination of adolescence.
-These results clearly indicate that certain fixed
-periods are marked by nature as epochs of human
-life; and that at the date of the recorded facts
-which furnish the data for these observations, and
-as far as regards the class of persons to which they
-relate, the age of forty-eight was the exact point
-at which the meridian of life was just passed, and
-a new epoch began. The following table exhibits
-at one view the exact results of each of the observations.
-For example,</p>
-
-<div class="smaller">
-<table summary="mortality">
-<tr>
-<td class="tdmort">According to the observation No.</td>
-<td class="tdmort">The mortality is at a minimum at the age of</td>
-<td class="tdmort">From whence it rises until the age of</td>
-<td class="tdmort">From this point it declines to the age of</td>
-<td class="tdmort">And from this age it again rises but is not equal to mortality
-in the 2d column until the age of</td>
-</tr>
-
-<tr>
-<td class="tdc">15</td>
-<td class="tdc">13</td>
-<td class="tdc">23</td>
-<td class="tdc">34</td>
-<td class="tdc">48</td>
-</tr>
-<tr>
-<td class="tdc">16</td>
-<td class="tdc">13</td>
-<td class="tdc">23</td>
-<td class="tdc">35</td>
-<td class="tdc">48</td>
-</tr>
-<tr>
-<td class="tdc">17</td>
-<td class="tdc">14</td>
-<td class="tdc">22</td>
-<td class="tdc">33</td>
-<td class="tdc">48</td>
-</tr>
-<tr>
-<td class="tdc">18</td>
-<td class="tdc">13</td>
-<td class="tdc">23</td>
-<td class="tdc">33</td>
-<td class="tdc">48</td>
-</tr>
-<tr>
-<td class="tdc">19</td>
-<td class="tdc">13</td>
-<td class="tdc">24</td>
-<td class="tdc">34</td>
-<td class="tdc">48</td>
-</tr>
-<tr>
-<td class="tdc">20</td>
-<td class="tdc">13</td>
-<td class="tdc">24</td>
-<td class="tdc">34</td>
-<td class="tdc">48</td>
-</tr>
-</table>
-</div>
-
-<div class="topspace1"></div>
-
-<p>The observation, No. 15, is founded on the large
-mass of 9,347 lives and 4,870 deaths. From this
-observation, it appears that, at the age of thirteen,
-the mortality out of a million is 5,742, being
-174,750 less than in the first year of infancy
-
-<span class="pagenum"><a name="Page_119" id="Page_119">[Pg 119]</a></span>
-
-At the age of twenty-three, it is 15,074, being
-9,332 more than at the close of childhood. At the
-age of thirty-four, the period of complete manhood,
-it falls to 11,707, being 3,367 less than at the
-close of adolescence. At the age of forty-eight,
-the mortality returns to 14,870, all but identically
-the same as at twenty-three, the adult age. From
-the age of forty-eight, when, as has been stated,
-life just begins to decline from its meridian, the
-mortality advances slowly, but in a steady and
-regular progression. Thus, at the age of fifty-eight
-it is 29,185, being 14,315 more than at
-the preceding decade, or almost exactly double.
-At the age of sixty-eight, it is 61,741, being
-32,556 more than at the preceding decade, or
-more than double. At the age of seventy-eight,
-it is 114,255, being 52,514 more than at the preceding
-decade. At the age of eighty-eight, it is
-246,803, being 132,548 more than at the preceding
-decade.</p>
-
-<p>During the first year of infancy, as has been
-shown, the mortality out of a million is 180,492.
-At the extreme age of eighty-four, it is 178,130,
-very nearly the same as in the first year of infancy.
-Greatly as the mortality of all the other epochs of
-life is affected by country, by station, by a multitude
-of influences arising out of these and similar
-circumstances; yet the concurrent evidence of all
-observation shows that at this and the like advanced
-ages the mean term of existence is nearly
-
-<span class="pagenum"><a name="Page_120" id="Page_120">[Pg 120]</a></span>
-
-the same in all countries, at all periods, and among
-all classes of society. Thus, among the nobility
-and gentry of England, the expectation of life at
-eighty-four is four years; among the poor fishermen
-of Ostend, it is precisely the same. M. De Parcieux,
-who wrote just ninety years ago, establishes
-the expectation of life at that time in France, at
-the same age, to have been three and a half years;
-and Halley, who wrote 120 years ago, and whose
-observations are derived from documents which go
-back to the end of the seventeenth century, states
-the expectation of life at eighty-four to be two
-years and nine months.</p>
-
-<p>From these statements, then, it is obvious, that
-from the termination of infancy at three years of
-age, a decade of years brings childhood to a close,
-during which the mortality, steadily decreasing,
-comes to its minimum. Another decade terminates
-the period of adolescence, during which the mortality
-as steadily advances. A third decade changes
-the young adult into a perfect man, and during
-this period, the golden decade of human life, the
-mortality again diminishes; while, during another
-decade and a half, the mortality slowly rises, and
-returns at the close of the period to the precise
-point at which it stood at adult age. Thus the
-interval between the period of birth and that of
-adult age includes a term of twenty-three years.
-The interval between the period of adult age and
-that when life just begins to decline from its meridian,
-
-<span class="pagenum"><a name="Page_121" id="Page_121">[Pg 121]</a></span>
-
-includes a term of twenty-four years: consequently,
-a period more than equal to all the other
-epochs of life from birth to adult age is enjoyed,
-during which mortality makes no advance whatever.
-Now the term of years included in the several
-epochs that intervene between birth and adult
-age is rigidly fixed. Thus the period of infancy
-includes precisely three years, that of childhood
-ten years, and that of adolescence ten years.
-Within the space of time comprehended in these
-intervals, physiological changes take place, on
-which depend every thing that is peculiar to the
-epochs. These changes cannot be anticipated,
-cannot be retarded, except in a very slight degree.
-In all countries, among all classes, they take place
-in the same order and nearly in the same space of
-time. In like manner, in extreme old age, or the
-age of decrepitude, which may be safely assumed
-to commence at the period when the mortality
-equals that of the first year of infancy, namely, the
-age of eighty-four, physiological changes take place,
-which, within a given space of time, inevitably
-bring life to a close. That space of time, in all
-countries, in all ranks, in all ages, or rather as far
-back as any records enable us to trace the facts,
-appears to be the same. As within a given time
-the boy must ripen into manhood, so within a given
-time the man of extreme old age must be the victim
-of death. Consequently, it is the interval between
-the adult age and the age of decrepitude,
-
-<span class="pagenum"><a name="Page_122" id="Page_122">[Pg 122]</a></span>
-
-and only this, that is capable of extension. During
-the interval between adult age and the perfect meridian
-of life, comprehending at present, as we
-have seen, a period of twenty-four years, the constitution
-remains stationary, mortality making no
-sensible inroad upon it. But there is no known
-reason why this stationary or mature period of life
-should, like the determinate epochs, be limited to
-a fixed term of years. On the contrary, we do in
-fact know that it is not fixed; for we know that
-the physiological changes on which age depends
-are, in some cases, greatly anticipated, and in
-others, proportionately postponed; so that some
-persons are younger at sixty, and even at seventy,
-than others are at fifty; whereas, an analogous
-anticipation or postponement of the other epochs of
-life is never witnessed. So complete is the proof,
-that the extension of human life can consist in the
-protraction neither of the period of juvenility, nor
-in that of senility, but only in that of maturity.</p>
-
-<p>Were it necessary to adduce further evidence of
-this most interesting fact, it would be found equally
-in the statistics of disease as in those of mortality.
-Indeed, the evidence derived from both these
-sources must be analogous, because mortality is
-invariably proportionate to the causes of mortality,
-of which causes, sickness, in all its forms, may be
-taken as the general or collective expression.</p>
-
-<p>We do not possess the same means of illustrating
-the prevalence of disease through all the epochs
-
-<span class="pagenum"><a name="Page_123" id="Page_123">[Pg 123]</a></span>
-
-of life as we do of showing the intensity of mortality;
-yet the report of Mr. Finlaison, already
-referred to, enables us to show its comparative prevalence
-at several of those stages. Thus, from
-this document, it appears, that among the industrious
-poor of London, members of benefit societies,
-out of a million of males, the proportion constantly
-sick at the age of twenty-three, is 19,410; at the
-age of twenty-eight, it is 19,670; at the age of
-thirty-three, it is 19,400; at the age of thirty-eight,
-it is 23,870; at the age of forty-three, it is
-26,260; at the age of forty-eight, it is 26,140; at
-the age of fifty-three, it is 27,060; at the age of
-fifty-eight, it is 36,980; at the age of sixty-three,
-it is 57,000; at the age of sixty-eight, it is 108,040;
-at the age of seventy-three and upwards, it is
-317,230. The prevalence of sickness is not an
-exact and invariable measure of the intensity of
-mortality; but there is a close connexion between
-them, as is manifest from the progressively increasing
-amount of sickness, as age advances.
-Thus, in the first ten years from the age of twenty-three
-to that of thirty-three, there is no increase of
-sickness, its prevalence is all but identically the
-same; in the next ten years from the age of thirty-three
-to that of forty-three, the increase of sickness,
-as compared with that of the preceding
-decade, is 6,860; in the next ten years from the
-age of forty-three to that of fifty-three, the increase
-is only 800; in the next ten years from the age of
-
-<span class="pagenum"><a name="Page_124" id="Page_124">[Pg 124]</a></span>
-
-fifty-three to that of sixty-three, the increase is
-29,940, while from the age of sixty-three to seventy-three,
-it is 260,230.</p>
-
-<p>Such are the results derived from the experience
-of disease considered in the aggregate, all its varied
-forms taken together. I am enabled further to present
-an exact and most instructive proof, that one
-particular disease which, in this point of view, may
-be considered as more important than any other,
-because it is the grand agent of death, namely fever,
-carries on its ravages in a ratio which steadily and
-uniformly increases as the age of its victim advances.
-Having submitted the experience of the
-London Fever Hospital for the ten years preceding
-January 1834, an observation including nearly
-6,000 patients affected with this malady, to Mr.
-Finlaison, it was subjected by him to calculation.
-Among other curious and instructive results to be
-stated hereafter, it was found that the mortality of
-fever resolves itself into the following remarkable
-progression. Thus suppose 100,000 patients to
-be attacked with this disease between the ages of
-5 and 16, of these there would die - 8,266
-and of an equal number</p>
-
-
-<table summary="disease">
-
-<tr>
-<td class="tdl">between</td>
-<td class="tdl">15 and 26</td>
-<td class="tdl"> there would die</td>
-<td class="tdr">&nbsp;&nbsp;&nbsp;&nbsp;11,494</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">25 and 36</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 1.5em;">"</span></td>
-<td class="tdr">&nbsp;&nbsp;&nbsp;&nbsp;17,071</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">35 and 46</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 1.5em;">"</span></td>
-<td class="tdr">&nbsp;&nbsp;&nbsp;&nbsp;21,960</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">45 and 56</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 1.5em;">"</span></td>
-<td class="tdr">&nbsp;&nbsp;&nbsp;&nbsp;30,493</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">55 and 66</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 1.5em;">"</span></td>
-<td class="tdr">&nbsp;&nbsp;&nbsp;&nbsp;40,708</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">65 and upwards</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 1.5em;">"</span></td>
-<td class="tdr">&nbsp;&nbsp;&nbsp;&nbsp;44,643</td>
-</tr>
-</table>
-
-<p><span class="pagenum"><a name="Page_125" id="Page_125">[Pg 125]</a></span></p>
-
-<p>Thus the risk of life from this malady is twice as
-great at the age of thirty-one as it is at eleven. It
-is also nearly twice as great at forty-one as it is at
-twenty-one. It is five times as great at sixty-one
-as it is at eleven, and nearly four times as great
-above sixty-five as it is at twenty-one.</p>
-
-<p>From the whole of the foregoing statements, it
-is manifest that life is a fluctuating quantity. In
-order to compare this fluctuating quantity under
-different circumstances, writers on this branch of
-statistics use several terms, the exact meaning of
-which it is desirable to explain. It is, for example,
-very important to have a clear understanding of
-what is meant by such expressions as the following:
-the expectation, the probability, the value,
-the decrement of life, and the law of mortality.</p>
-
-<p>1. <span class="smcap">The Expectation of Life.</span> It is important
-to bear in mind that several expressions in common
-use have a signification perfectly synonymous with
-this: namely, <em>share of existence</em>; <em>mean duration of
-life</em>; <em>la vie moyenne</em>.</p>
-
-<p>By these terms is expressed the total number of
-years, including also the fractional parts of a year,
-ordinarily attained by human beings from and
-after any given age. Suppose, for example, that
-one thousand persons enter on the eighty-sixth
-year of their age: suppose the number of years
-and days which each one of them lives afterwards
-be observed and recorded; suppose the number
-ultimately attained by each be formed into a sum
-
-<span class="pagenum"><a name="Page_126" id="Page_126">[Pg 126]</a></span>
-
-total; suppose this total be divided equally among
-the thousand, the quotient of this division is said
-to be each one's share of existence, or his mean
-duration of life, or his expectation of life. Thus,
-of the thousand persons in the present case supposed
-to commence the age of eighty-five, suppose
-the number of years they collectively attain amount
-to 3,500 years: the one-thousandth part of 3,500
-is three and a half: three years and a half then is
-said to be the expectation of life at the age of
-eighty-five, because, of all the persons originally
-starting, this is the equal share of existence that
-falls to the lot of each.</p>
-
-<p>2. <span class="smcap">Probability of Life</span>; or <em>the probable duration
-of life</em>, <i lang="fr">la vie probable</i>. These are synonymous
-terms, in use chiefly among continental
-writers as an expression of the comparative duration
-of life. The tabular methods of setting forth
-the duration of life consist, for the most part, in
-assuming that 10,000 infants are born; and that
-at the age of one, two, three, and each successive
-year of life, there are so many still remaining in
-existence. Fix on any age; observe what number
-remain alive to commence that age; note at what
-age this number decreases to one-half; the age at
-which they so come to one-half is called the probable
-term of life; because, say the continental
-writers, it is an equal wager whether a person shall
-or shall not be alive at that period. Thus, suppose
-one thousand males commence together the age of
-
-<span class="pagenum"><a name="Page_127" id="Page_127">[Pg 127]</a></span>
-
-eighty-four; suppose the table indicate that there
-will be alive at the age of eighty-five, 817; at the
-age of eighty-six, 648; at the age of eighty-seven,
-493; at the age of eighty-eight, 357, and so on.
-In the present case, the probable duration of life
-at eighty-four is said to be very nearly three years,
-because, at the age of eighty-seven there are left
-alive 493, very nearly one-half of the thousand that
-originally started together.</p>
-
-<p>3. <span class="smcap">Value of Life.</span> This term, when used accurately,
-expresses the duration of life as measured
-by one or other of the methods already expounded.
-But it is sometimes popularly used in a loose and
-singularly inaccurate sense. Thus it is very commonly
-said&mdash;"Such a man's life is not worth ten
-years' purchase," which is the same thing as to
-say, that an annuity, suppose a hundred pounds a
-year, payable during the life of the person in question,
-is not worth ten times its magnitude, that is
-one thousand pounds. If a thousand pounds be
-put into a bank at some rate of interest to be agreed
-upon, and if a hundred pounds be drawn every
-year from the stock, the expression under consideration
-affirms that the person in question will be
-dead before the principal and interest are exhausted.
-For instance, at four per cent., the value of an annuity
-of one hundred pounds to a man of the age
-of twenty-five is 1694<i>l.</i>, which is 16-9/10 years' purchase;
-whereas, his expectation of life at that age
-is 35-9/10 years.</p>
-
-<p><span class="pagenum"><a name="Page_128" id="Page_128">[Pg 128]</a></span></p>
-
-<p>4. <span class="smcap">Law of Mortality.</span> By this term is expressed
-the proportion out of any determinate
-number of human beings who enter on a given
-year of age, that will die in that year. Every observation
-on the duration of life presents certain
-numbers, which, by recorded facts, are found to
-pass through each year of age, and also shows how
-many have died or failed to pass through every
-year of age. Those numbers, by the rule of three,
-are converted into the proportions who would die
-at each age out of one million of persons, if such
-a number had commenced it. Suppose, then, a
-million of persons to be in existence at the first
-year of age; suppose a million to be in existence
-at the second year of age; suppose a million to be
-in existence at the third year of age; and in this
-manner suppose an equal number to be in existence
-at the commencement of each and every year to
-the extreme term of human life. Now, the proportions
-that by actual observation are found to
-die at each and every year out of the million that
-were alive at the commencement of it, form separately
-the law of mortality for each year, and collectively
-for the whole of life.</p>
-
-<p>5. <span class="smcap">Decrement of Life.</span> Assuming, as before,
-that a million of male children are born alive (for
-the still-born must be excluded from the calculation)
-if it be found that 180,492 would die in the
-first year, it follows that the difference, namely,
-819,508, will enter upon the age of one year.
-
-<span class="pagenum"><a name="Page_129" id="Page_129">[Pg 129]</a></span>
-Suppose the law of mortality indicate that the proportion
-
-that will die, out of a million, between the
-age of one and two, is 30,000; it is plain that the
-number who would die out of 819,508 will by the
-rule of three be 27,863, and consequently that
-the residue, namely, 791,615, will remain alive,
-and so enter on the age of two years. This method
-being pursued through each and every age to
-the extreme term of life, when none of the original
-million survive, the result is a table of mortality
-in the form in which it is commonly presented in
-the works of writers on this branch of science. In
-the table thus constructed there is a column containing
-the number of living persons who, out of
-the original million, lived to enter upon each and
-every year. Of this rank of numbers the difference
-between each term and its next succeeding one, is
-the number who die in that particular interval:
-that number is the measure of what is technically
-called the decrement of life for that particular
-year, and the whole of the decrements for each
-and every year taken collectively is termed the decrement
-of life. The decrement of life, then, is
-not only not the same as the law of mortality, but
-is carefully to be distinguished from it. The law
-of mortality is derived from observing the number
-who die out of one and the same number which is
-always supposed to enter on each and every year.
-The decrement of life constitutes a rank of numbers
-arising out of the successive deaths; that is,
-
-<span class="pagenum"><a name="Page_130" id="Page_130">[Pg 130]</a></span>
-
-out of the original million in the first year; out of
-the survivors of that million in the second year;
-out of the survivors of those survivors in the third
-year, and so on. In the first case the number of
-the living is always the same; the number that
-die is the variable quantity: in the second case
-the number of the living is the variable quantity,
-while the number that die may remain pretty much
-the same for a succession of years; and on casting
-the eye on the tables constructed in the ordinary
-mode, it will be seen that the number often does
-remain the same for a considerable series of years.</p>
-
-<p>We have said that life is a fluctuating quantity.
-It fluctuates in different countries at the same period;
-in the same country at different periods; in
-the same country, at the same period, in different
-places; in the same country, at the same period,
-in the same place, among different classes; in the
-same country, at the same period, in the same
-place, among the same class, at the different determinate
-stages of life. Some few of these fluctuations,
-and more especially the last, depend on the
-primary constitution of the organization in which
-life itself has its seat, over which man has little
-or no control. The greater part of them depend
-on external and adventitious agencies over which
-man has complete control. Human ignorance,
-apathy, and indolence, may render the duration of
-life, in regard to large classes and entire countries,
-short; human knowledge, energy and perseverance,
-
-<span class="pagenum"><a name="Page_131" id="Page_131">[Pg 131]</a></span>
-
-may extend the duration of life far beyond what is
-commonly imagined. It will be interesting and
-instructive to select a few of the more striking examples
-of this from the records we possess, few and
-imperfect as they are, in relation to this subject.</p>
-
-<p>Of the duration of life in the earlier periods of
-the history of the human race we know nothing
-with exactness, though there are incidental statements
-which afford the means of deducing with
-some probability the rate of mortality in particular
-situations. There has come down to us one document
-through Domitius Ulpianus, a judge, who
-flourished in the reign of Alexander Severus, which
-enables us to form a probable conjecture at least
-of the opinion of the Roman people of the value of
-life among the citizens of Rome in that age. It
-happened at Rome as in other countries, that when
-an estate came into the possession of an individual
-it was burthened with a provision for another
-person during the life of the latter, a younger brother,
-for example. This provision was called by
-the Romans an aliment. No estate, burthened
-with such a provision, could be sold by the heir in
-possession, unless the purchaser retained in his
-hands so much of the price as was deemed adequate
-to secure the regular and continuous payment of
-the aliment. This imposed upon the Romans the
-necessity of considering what the term of life would
-probably be from and after any given age. What
-they did conceive that term to be is stated in a
-
-<span class="pagenum"><a name="Page_132" id="Page_132">[Pg 132]</a></span>
-
-document of Ulpianus, recorded by Justinian, and
-given in the note below.<a name="FNanchor_1_1" id="FNanchor_1_1"></a><a href="#Footnote_1_1" class="fnanchor">[1]</a> This document imports
-that from infancy up to the age of</p>
-
-<p><span class="pagenum"><a name="Page_133" id="Page_133">[Pg 133]</a></span></p>
-
-<table summary="justinian">
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">20,</td>
-<td class="tdr">there should be allowed</td>
-<td class="tdr">30</td>
-<td class="tdr">years</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; From</td>
-<td class="tdr">20 to 25</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span>
-<span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdr">28</td>
-<td class="tdr">&nbsp;&nbsp;"&nbsp;&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">25 to 30</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span>
-<span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdr">25</td>
-<td class="tdr">&nbsp;&nbsp;"&nbsp;&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">30 to 35</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span>
-<span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdr">22</td>
-<td class="tdr">&nbsp;&nbsp;"&nbsp;&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">35 to 40</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span>
-<span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdr">20</td>
-<td class="tdr">&nbsp;&nbsp;"&nbsp;&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">&mdash;&mdash;&mdash;&mdash;</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">&nbsp;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; From</td>
-<td class="tdr">50 to 55</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span>
-<span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdr"> 9</td>
-<td class="tdr">&nbsp;&nbsp;"&nbsp;&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">55 to 60</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span>
-<span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdr"> 7</td>
-<td class="tdr">&nbsp;&nbsp;"&nbsp;&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">And at all ages</td>
-<td class="tdr">above 60</td>
-<td class="tdl"><span style="margin-left: 1em;">"</span><span style="margin-left: 2em;">"</span>
-<span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdr"> 5</td>
-<td class="tdr">&nbsp;&nbsp;"&nbsp;&nbsp;</td>
-</tr>
-</table>
-
-<div class="topspace1"></div>
-
-<p>But between 40 and 50, as many years were to be
-allowed as the age of the party fell short of 60,
-deducting one year.</p>
-
-<p>No clue has hitherto been obtained to the discovery
-of the real meaning of this document. It is,
-however, highly probable that the Romans had
-fallen on one of the two methods of measuring the
-value of life already explained; namely, that termed
-the Probability of Life. Of the two modes of determining
-the value of life, the probability was
-more likely to occur to a Roman judge than the
-expectation. He had no tables, no registers to guide
-him. What course, then, would he be likely to
-take? Probably he would form a list of his own
-school-fellows and others within his own knowledge,
-of the age, say, of twenty. By prevailing on
-persons of his own age, on whose correctness he
-could rely, to draw out similar lists, he might accumulate
-some thousand names. In this list it is
-probable that the male sex alone would be included,
-on account of the greater ease of ascertaining both
-their exact age and the exact date of their death.
-For the same reason, it is probable that the list
-
-<span class="pagenum"><a name="Page_134" id="Page_134">[Pg 134]</a></span>
-
-would consist only of the nobility and the inhabitants
-of towns. Having thus completed his list,
-the next step would be to frame another list of all
-who died at the age of twenty-one; and next, another
-list of all who died at the age of twenty-two, and so
-on through each and every year of life. Now by subtracting
-the number in the list, No. 1, that is, those
-who died between twenty and twenty-one, from the
-number who originally started at twenty, which, in
-other words, would be to find the decrement of life,
-in the mode already explained, he would see how
-many lived to commence the age of twenty-one, and
-so on, through each year of life. But this would be
-to construct a table, showing the probable duration
-of life; that is, a table from which he could observe
-at what advanced age the number originally starting
-at twenty, and so on, came to diminish to one-half,
-when it would naturally occur to him that it is an
-equal wager whether such younger life would or
-would not be in existence at the advanced age so
-ascertained. If we suppose this to have been the
-method actually adopted by the Roman judge, and
-apply it to the table of Ulpianus, the result obtained
-is consistent in an extraordinary degree, and
-is highly interesting.</p>
-
-<p>There is reason to believe that the mortality at
-present throughout Europe, taking all countries
-together, including towns and villages, and combining
-all classes into one aggregate, is one in
-thirty-six. Süssmilch, a celebrated German writer,
-
-<span class="pagenum"><a name="Page_135" id="Page_135">[Pg 135]</a></span>
-
-who flourished about the middle of the last century,
-estimated it at this average at that period.
-The result of all Mr. Finlaison's investigations is
-a conviction that the average for the whole of
-Europe does not materially differ at the present
-time. He has ascertained by an actual observation,
-that in the year 1832 it was precisely this in
-the town of Ostend. Taking this town, then, as
-the subject of comparison, it is found that the probable
-duration of life among the male sex at
-Ostend exceeds the Roman allowance by the following
-number of years; namely,</p>
-
-<div class="romanindent">At the age of 17, the excess in round</div>
-
-<table summary="Roman">
-<tr>
-<td class="tdr">&nbsp;</td>
-<td class="tdr">numbers is</td>
-
-<td class="tdr">5</td>
-<td class="tdr">years.</td>
-</tr>
-<tr>
-<td class="tdr">22</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 5</span></td>
-</tr>
-<tr>
-<td class="tdr">27</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 5</span></td>
-</tr>
-<tr>
-<td class="tdr">32</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 5</span></td>
-</tr>
-
-<tr>
-<td class="tdr">37</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 3</span></td>
-</tr>
-<tr>
-<td class="tdr">42</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 3</span></td>
-</tr>
-<tr>
-<td class="tdr">47</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 5</span></td>
-</tr>
-<tr>
-<td class="tdr">52</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 5</span></td>
-</tr>
-<tr>
-<td class="tdr">57</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 4</span></td>
-</tr>
-<tr>
-<td class="tdr">62</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 4</span></td>
-</tr>
-<tr>
-<td class="tdr">67</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 2</span></td>
-</tr>
-<tr>
-<td class="tdr">72</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 1</span></td>
-</tr>
-<tr>
-<td class="tdr">77</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdl"><span style="margin-left: 1.5em;"> 0</span></td>
-</tr>
-</table>
-
-<div class="topspace1"></div>
-
-<p>But it is not improbable that the Romans made
-some deduction from what they knew to be the
-real value of life among the citizens of Rome, on
-account of the use of the money appropriated to
-
-<span class="pagenum"><a name="Page_136" id="Page_136">[Pg 136]</a></span>
-
-the aliment, which the purchaser of the estate
-retained in his own hands. It has been shown
-that the average mortality at present at Ostend is
-one in thirty-six; which is the same thing as to
-assert that a new-born child at Ostend has an expectation
-of thirty-five and a half years of life. The
-Roman allowance from birth, <i lang="fr">à primâ ætate</i>, was
-thirty years. If we suppose the Romans deducted
-from the real value of life five and a half years for
-the interest of money, it would bring the Roman
-allowance and the duration of life at Ostend to the
-same. The like deduction at the age of seventeen
-would likewise bring the probability of life in both
-cases to the same. It is not likely that the Romans,
-without any record of the individual facts, and
-acting only on a general principle of utility, the
-best they could find, would make any variation for
-the intermediate years of childhood and youth:
-consequently the presumption is, that the duration
-of life at Rome, 1300 years ago, was very much the
-same as it is throughout Europe at the present day.
-This estimate, however, for the reasons already
-assigned, includes only the resident citizens of
-Rome, the male sex, and the higher classes.
-What the mortality was at Rome among the lower
-class, including the slaves&mdash;what it was in the
-Roman provinces, and in the less civilized countries
-of that age&mdash;we have no means of forming even a
-conjecture. What it was in Europe during the
-succeeding ages of barbarism we do not know. In
-
-<span class="pagenum"><a name="Page_137" id="Page_137">[Pg 137]</a></span>
-
-civilized Rome, the value of life had probably
-reached a very high point; in barbarian Europe
-we may be sure it fell to an exceedingly low point.
-From that low point, in civilized Europe, it has
-been slowly but gradually rising, until, in modern
-times, the whole mass of the European population
-has, to say the very least, reached the highest
-point attained by the select class in ancient Rome.
-But in some favoured spots in Europe, the whole
-mass has advanced considerably beyond the select
-class in ancient Rome. In England, for example,
-the expectation of life, at the present day, for the
-mass of the people, as compared with that of the
-mass at Ostend, which, as has been shown, is the
-same as that of the whole of Europe, is as follows:&mdash;</p>
-
-<table summary="Roman">
-
-<tr>
-<td class="tdl">At</td>
-<td class="tdr"> birth</td>
-<td class="tdr">&nbsp; &nbsp; &nbsp; &nbsp; 41&#0189;</td>
-<td class="tdr">years.</td>
-</tr>
-<tr>
-<td class="tdl">At</td>
-<td class="tdr">12</td>
-<td class="tdr">46&#0190;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">17</td>
-<td class="tdr">41&#0189;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">22</td>
-<td class="tdr">38&#8540;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">27</td>
-<td class="tdr">35&#0188;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">32</td>
-<td class="tdr">32&nbsp;&nbsp;&nbsp;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">37</td>
-<td class="tdr">28&#0190;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">42</td>
-<td class="tdr">25&#0189;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">47</td>
-<td class="tdr">22&#0188;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">52</td>
-<td class="tdr">19&nbsp;&nbsp;&nbsp;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">57</td>
-<td class="tdr">16&nbsp;&nbsp;&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">62</td>
-<td class="tdr">13&nbsp;&nbsp;&nbsp;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">67</td>
-<td class="tdr">10&#0189;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">72</td>
-<td class="tdr">8&nbsp;&nbsp;&nbsp;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">77</td>
-<td class="tdr">6&nbsp;&nbsp;&nbsp;</td>
-<td class="tdr">&nbsp;</td>
-</tr>
-</table>
-
-<div class="topspace1"></div>
-
-<p><span class="pagenum"><a name="Page_138" id="Page_138">[Pg 138]</a></span></p>
-
-<p>It should be borne in mind that the females of
-the mass exceed in duration the lives of the males
-at every age by two or three years.</p>
-
-<p>The earliest statistical document bearing on the
-rate of mortality, in any European nation, emerging
-from the state of barbarism, appears to be a manuscript
-of the fourteenth century, relating to the
-mortality of Paris, from which M. Villermé has
-calculated that the mortality of Paris at that period
-was one in sixteen. How the individual facts
-contained in this manuscript were collected, from
-which M. Villermé's calculation is made, does not
-appear; and it makes the mortality so excessive
-as to be altogether incredible. Yet a statement
-scarcely less extraordinary is made with regard to
-Stockholm, in the middle of the last century.
-From a table given by Dr. Price, vol. ii., p. 411,
-it appears that, for all Sweden, between the years
-1756 and 1763, the expectation of life</p>
-
-<p>
-<span style="margin-left: 38%;">Of males at birth, was<span style="margin-left: 2em;"> Females,</span></span><br />
-<span style="margin-left: 42%;">33&#0188; years.<span style="margin-left: 4.3em;">35¾ years.</span></span>
-</p>
-
-<p>while at the same time it was at Stockholm,</p>
-
-<p>
-<span style="margin-left: 38%;">For males at birth,<span style="margin-left: 4em;">Females,</span></span><br />
-<span style="margin-left: 42%;">14&#0188; years.<span style="margin-left: 5em;">18 years.</span></span>
-</p>
-
-<p>Whereas, for the twenty years preceding 1800, it<br />
-was, for all Sweden, at birth,</p>
-
-<p>
-<span style="margin-left: 38%;">Males<span style="margin-left: 9.1em;">Females,</span></span><br />
-<span style="margin-left: 38%;">34&#0190;<span style="margin-left: 9.3em;">37&#0189; years.</span></span>
-</p>
-
-<div class="topspace1"></div>
-
-<p>Hitherto, in all places which man has made his
-abode, noxious agents have been present which act
-injuriously upon his body, tending to disturb the
-
-<span class="pagenum"><a name="Page_139" id="Page_139">[Pg 139]</a></span>
-
-actions of its economy, and ultimately to extinguish
-life. All these noxious agents, of whatever name
-or quality, may be included under the term Causes
-of Mortality. Inherent in the constitution of the
-body are conservative powers, the tendency of
-which is to resist the influence of these causes
-of mortality. The actual mortality at all times
-will of course be according to the relative strength
-of these destructive agents, and the relative weakness
-of these conservative powers. There are
-states of the system tending to enfeeble these conservative
-powers. Such states become tests, often
-exceedingly delicate, of the presence and power of
-the destructive agents to which the body is exposed;
-and such, more especially, are, the states
-of parturition, infancy, and sickness. During
-the prevalence of these states, in which the conservative
-powers of the body are weak, life is
-destroyed by causes which do not prove mortal in
-other conditions of the system. Accordingly, in
-every age and country, the rate of mortality among
-its lying-in women, its infants and its sick, may be
-taken as a measure of the degree in which the state
-of the whole population is favourable or unfavourable
-to life.</p>
-
-<p>The change that has taken place in the condition
-of lying-in women during the last century in all
-the nations of Europe cannot be contemplated
-without astonishment. The mortality of lying-in
-women in France, at the Hôtel Dieu of Paris, in
-
-<span class="pagenum"><a name="Page_140" id="Page_140">[Pg 140]</a></span>
-
-1780, is stated to have been one in 15. In
-1817, for the whole kingdom of Prussia, including
-all ranks, it was one in 112. In England, in the
-year 1750, at the British Lying-in Hospital of
-London, it was one in 42; in 1780, it diminished
-to one in 60; in the years between 1789
-and 1798, it further decreased to one in 288; in
-1822, at the Lying-in Hospital of Dublin, it was
-no more than one in 223; while during the last
-fifteen years at Lewes, a healthy provincial town,
-out of 2410 cases there have been only two deaths,
-that is, one in 1205. There is no reason to suppose
-that the mortality in the state of parturition
-is less at Lewes than in any other equally healthy
-country-town in England.</p>
-
-<p>Equally striking is the proof of the diminished
-violence of the prevalent causes of disease and death
-derived from the diminished mortality of children,
-the vital power of resistance being always comparatively
-weak in the human infant, and consequently,
-the agents that prove destructive to life
-exerting their main force on the new born, and on
-those of tender age. From mortuary tables, preserved
-with considerable accuracy at Geneva since
-the year 1566, it appears that at the time of the
-Reformation one-half of the children born died
-within the sixth year; in the seventeenth century,
-not till within the twelfth year; in the eighteenth
-century, not until the twenty-seventh year; consequently,
-in the space of about three centuries, the
-
-<span class="pagenum"><a name="Page_141" id="Page_141">[Pg 141]</a></span>
-
-probability that a child born in Geneva would
-arrive at maturity has increased fivefold. In the
-present day, at Ostend, only half of the new-born
-children attain the age of thirty; whereas, in England,
-they attain the age of forty-five.</p>
-
-<p>No less remarkable is the progressive diminution
-of mortality among the sick of all ages. Hippocrates
-has left a statement, which has come down
-to our times, of the history and fate of forty-two
-cases of acute disease. Out of this number, thirty-seven
-were cases of continued fever; of these thirty-seven
-febrile cases twenty-one died, above half of
-the whole. The remaining five were cases of local
-inflammation, and of these four were fatal; thus,
-of the whole number of the sick (forty-two),
-twenty-five were lost. Now, even in the Fever
-Hospital of London, to which, for the most part,
-only the worst cases that occur in the metropolis
-are sent, and even of these many not until so late
-a period of the disease that all hope of recovery is
-extinct, the mortality ranges in different years from
-one in six to one in twelve; and for a period of ten
-consecutive years, it is no more than one in seven;
-while, in the Dublin Fever Hospital, where most
-of the cases are sent very early, the average mortality
-from 1804 to 1812 was one in twelve. At
-the Imperial Hospital at Petersburg, the average
-mortality for fourteen years, ending in 1817, was
-one in four and a half. In the Charité of Berlin,
-on an average of twenty years, from 1796 to 1817,
-
-<span class="pagenum"><a name="Page_142" id="Page_142">[Pg 142]</a></span>
-
-it was one in six. At Dresden, it was one in seven;
-at Munich, it was one in nine, the lowest of any
-hospital of equal size in Germany. In the year
-1685, the average mortality at St. Bartholomew's
-and St. Thomas's Hospitals was from one in seven
-to one in ten. During the ten years from 1773 to
-1783, it decreased to one in fourteen. From 1803
-to 1813, it was one in sixteen. The average for
-fifty years from 1764 to 1813, was one in fifteen.
-In the smaller towns, the mortality is still less. It
-is less in Edinburgh and Dublin than in London;
-while in the hospital at Bath during 1827, even
-among the physician's patients, the mortality was
-only one in twenty. In the German provincial
-towns, the diminution is still more remarkable.
-In the hospital at Gottingen, for example, it is
-only one in twenty-one.</p>
-
-<p>If the accuracy of these statements could be
-relied on, they would not only afford striking illustrations
-of the well-known fact that extraordinary
-differences prevail in the rate of mortality in different
-places, at different periods, and under different
-circumstances; but they would further prove
-that, during the last century, a steady and progressive
-diminution of mortality has taken place in all
-the countries of Europe. But of the truth of this
-there is much more certain evidence than can be
-derived from calculations, the trustworthiness of
-the data of which is not established, and the correctness
-of the calculators not known. Both the
-
-<span class="pagenum"><a name="Page_143" id="Page_143">[Pg 143]</a></span>
-
-fluctuations of mortality and the increase in the
-value of life in the different countries of Europe,
-from the earliest period when statistical facts began
-to be collected and compared, are exhibited in a
-striking point of view in the following table, drawn
-up by Mr. Finlaison. The facts relating to selected
-lives and to the mass of the people are distinguished
-from each other, in order that they may be contrasted.
-The data are derived from the most authentic
-sources, and the calculations are made by
-men of the highest authority.</p>
-
-<div class="topspace2"></div>
-
-<p><span class="pagenum"><a name="Page_144" id="Page_144">[Pg 144]</a></span></p>
-
-<div class="mortality">
-<table summary="mortality2">
-<tr>
-<td class="tdl">Let it be conceived, that at each of the following ages, viz.</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">50&#9474;</td>
-<td class="tdr">55&#9474;</td>
-<td class="tdr">60&#9474;</td>
-<td class="tdr">65&#9474;</td>
-<td class="tdr">70&#9474;</td>
-<td class="tdr">75&#9474;</td>
-<td class="tdr">80&#9474;</td>
-<td class="tdr">85&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-<td class="tdr">Yrs.&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">The average duration of Human Life of both sexes collectively</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">may thenceforward be assumed at a maximum of<a name="FNanchor_2_2" id="FNanchor_2_2"></a><a href="#Footnote_2_2" class="fnanchor">[2]</a></td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">23&#9474;</td>
-<td class="tdr">19&#9474;</td>
-<td class="tdr">16&#9474;</td>
-<td class="tdr">13&#9474;</td>
-<td class="tdr">11&#9474;</td>
-<td class="tdr">8&#9474;</td>
-<td class="tdr">6&#9474;</td>
-<td class="tdr">3&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&ndash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-<td class="tdr">&mdash;&mdash;&mdash;</td>
-</tr>
-<tr>
-<td class="tdchap"></td>
-</tr>
-
-<tr>
-<td class="tdl">By how many weeks does the average duration which results</td>
-</tr>
-<tr>
-<td class="tdl">from the most authentic Tables at present known fall short of the</td>
-</tr>
-<tr>
-<td class="tdl">maximum Term thus assumed?</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-</tr>
-<tr>
-<td class="tdc">Answer.</td>
-<td class="tdc">&nbsp;&nbsp;&nbsp;&nbsp;Name of the&nbsp;&nbsp;&nbsp;&nbsp;</td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-<td class="tdchap"></td>
-</tr>
-<tr>
-<td class="tdc">&nbsp;</td>
-<td class="tdc">Observer.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-<td class="tdr">Wks.&#9474;</td>
-</tr>
-<tr>
-<td class="tdc"><span class="large"><b>Among the higher classes of people exclusively.</b></span></td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">In England&mdash;Among the Government Annuitants,</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-<tr>
-<td class="tdl"><span style="margin-left: 5.5em;">between 1775 and 1822</span></td>
-<td class="tdc">John Finlaison. </td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">35&#9474;</td>
-<td class="tdr">1&#9474;</td>
-<td class="tdr">7&#9474;</td>
-<td class="tdr">10&#9474;</td>
-<td class="tdr">47&#9474;</td>
-<td class="tdr">11&#9474;</td>
-<td class="tdr">14&#9474;</td>
-<td class="tdr">53&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl"><span style="margin-left: 5.5em;">Among the Lives assured at the Equitable</span></td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-<tr>
-<td class="tdl"><span style="margin-left: 5.5em;">Office, between 1760 and 1834</span></td>
-<td class="tdc">Arthur Morgan.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">119&#9474;</td>
-<td class="tdr">83&#9474;</td>
-<td class="tdr">87&#9474;</td>
-<td class="tdr">81&#9474;</td>
-<td class="tdr">96&#9474;</td>
-<td class="tdr">33&#9474;</td>
-<td class="tdr">10&#9474;</td>
-<td class="tdr">27&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-<tr>
-<td class="tdl"><span style="margin-left: 5.5em;">Among the Nominees of the Tontine of 1693</span></td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-<tr>
-<td class="tdl"><span style="margin-left: 5.5em;">&mdash;between that year and 1775</span></td>
-<td class="tdc">John Finlaison.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">269&#9474;</td>
-<td class="tdr">195&#9474;</td>
-<td class="tdr">170&#9474;</td>
-<td class="tdr">141&#9474;</td>
-<td class="tdr">157&#9474;</td>
-<td class="tdr">110&#9474;</td>
-<td class="tdr">90&#9474;</td>
-<td class="tdr">89&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">In France &mdash; Among the Nominees of the Tontine of 1693</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-<tr>
-<td class="tdl"><span style="margin-left: 5.5em;">&mdash;between that year and 1745</span></td>
-<td class="tdc">M. de Parcieux.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">133&#9474;</td>
-<td class="tdr">88&#9474;</td>
-<td class="tdr">87&#9474;</td>
-<td class="tdr">86&#9474;</td>
-<td class="tdr">118&#9474;</td>
-<td class="tdr">70&#9474;</td>
-<td class="tdr">55&#9474;</td>
-<td class="tdr">65&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">In Holland &mdash; Among the Public Annuitants, between 1615 and 1740</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-<tr>
-<td class="tdl"><span style="margin-left: 5.5em;"> and 1740</span></td>
-<td class="tdc">M. Kersseboom.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">186&#9474;</td>
-<td class="tdr">118&#9474;</td>
-<td class="tdr">104&#9474;</td>
-<td class="tdr">75&#9474;</td>
-<td class="tdr">96&#9474;</td>
-<td class="tdr">61&#9474;</td>
-<td class="tdr">48&#9474;</td>
-<td class="tdr">84&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdc"><span class="large"><b>In regard to the mass of the people.</b></span></td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">&nbsp;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-<td class="tdr">&nbsp;&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">In Breslau in Silesia, between 1700 and 1725,</td>
-<td class="tdc">Dr. Halley.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">275&#9474;</td>
-<td class="tdr">211&#9474;</td>
-<td class="tdr">181&#9474;</td>
-<td class="tdr">150&#9474;</td>
-<td class="tdr">166&#9474;</td>
-<td class="tdr">100&#9474;</td>
-<td class="tdr">36&#9474;</td>
-<td class="tdr">137&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">In Sweden, between 1775 and 1795,</td>
-<td class="tdc">M. Nicander,</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">and Mr. Milne.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">207&#9474;</td>
-<td class="tdr">161&#9474;</td>
-<td class="tdr">164&#9474;</td>
-<td class="tdr">146&#9474;</td>
-<td class="tdr">156&#9474;</td>
-<td class="tdr">94&#9474;</td>
-<td class="tdr">60&#9474;</td>
-<td class="tdr">60&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">In Northampton, in England, between&nbsp; 1735 and 1780,</td>
-<td class="tdc">Dr. Price.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">209&#9474;</td>
-<td class="tdr">178&#9474;</td>
-<td class="tdr">145&#9474;</td>
-<td class="tdr">110&#9474;</td>
-<td class="tdr">125&#9474;</td>
-<td class="tdr">76&#9474;</td>
-<td class="tdr">65&#9474;</td>
-<td class="tdr">85&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">In Carlisle, in England, between&nbsp; 1779 and 1787,</td>
-<td class="tdc">Dr. Heysham,</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">&#9474;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">and Mr. Milne.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">98&#9474;</td>
-<td class="tdr">74&#9474;</td>
-<td class="tdr">86&#9474;</td>
-<td class="tdr">63&#9474;</td>
-<td class="tdr">94&#9474;</td>
-<td class="tdr">52&#9474;</td>
-<td class="tdr">26&#9474;</td>
-<td class="tdr">46&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">In all England and Wales, between&nbsp;  1811 and 1831,</td>
-<td class="tdc">John Finlaison.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">100&#9474;</td>
-<td class="tdr">59&#9474;</td>
-<td class="tdr">65&#9474;</td>
-<td class="tdr">58&#9474;</td>
-<td class="tdr">87&#9474;</td>
-<td class="tdr">48&#9474;</td>
-<td class="tdr">37&#9474;</td>
-<td class="tdr">49&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">In the town of Ostend, in Flanders, between 1805 and 1832,</td>
-<td class="tdc">John Finlaison.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">276&#9474;</td>
-<td class="tdr">210&#9474;</td>
-<td class="tdr">184&#9474;</td>
-<td class="tdr">146&#9474;</td>
-<td class="tdr">143&#9474;</td>
-<td class="tdr">76&#9474;</td>
-<td class="tdr">50&#9474;</td>
-<td class="tdr">75&#9474;</td>
-</tr>
-
-<tr>
-<td class="tdl">In all Belgium, between 1725 and 1832,</td>
-<td class="tdc"> M. Quetelet.</td>
-<td class="tdr">&#9474;</td>
-<td class="tdr">183&#9474;</td>
-<td class="tdr">133&#9474;</td>
-<td class="tdr">133&#9474;</td>
-<td class="tdr">117&#9474;</td>
-<td class="tdr">112&#9474;</td>
-<td class="tdr">84&#9474;</td>
-<td class="tdr">50&#9474;</td>
-<td class="tdr">61&#9474;</td>
-</tr>
-</table>
-</div>
-
-<div class="topspace2"></div>
-<p><span class="pagenum"><a name="Page_145" id="Page_145">[Pg 145]</a></span></p>
-
-<p>Let us trace from this table the differences that
-have taken place, in different countries at different
-periods, in the duration of life at a given age. Let
-us take the age given in the first column, namely,
-fifty. Assuming, then, the highest degree of longevity
-hitherto attained at the age of fifty to be
-twenty-three years, it appears that, between the
-years 1700 and 1725, the mass of the people in
-Breslau, in Silesia, fell short of reaching this period
-by 275 weeks; the inhabitants of the town of
-Ostend in Flanders, between 1805 and 1832, by
-276 weeks; the nominees of the tontine of England,
-between the years 1693 and 1775, by 269
-weeks; the inhabitants of the town of Northampton
-in England, between 1735 and 1780, by 209
-weeks; the mass of the people in Sweden, between
-1775 and 1795, by 207 weeks; the public annuitants
-of Holland, between 1615 and 1740, by 186
-weeks; the inhabitants of all Belgium, between
-1725 and 1832, by 183 weeks; the persons assured
-at the Equitable Office, between 1760 and 1834,
-by 119 weeks; the inhabitants of all England and
-Wales, between 1811 and 1831, by 100 weeks;
-the English government annuitants, between 1775
-and 1832, only by 35 weeks.</p>
-
-<p>From these statements, it appears that, towards
-the close of the seventeenth century, the duration
-of life in England was considerably less than in
-France: less even than in Holland nearly a century
-earlier. Thus, the nominees of the tontine of
-
-<span class="pagenum"><a name="Page_146" id="Page_146">[Pg 146]</a></span>
-
-France, between the years 1693 and 1745, at the
-age of fifty, according to M. De Parcieux, fell short
-of the maximum longevity by 133 weeks; the public
-annuitants of Holland, seventy-eight years before,
-namely, between the years 1615 and 1740,
-according to M. Kersseboom, fell short of the
-maximum longevity by 186 weeks; whereas, the
-nominees of the tontine of England, between the
-years 1693 and 1775, according to Mr. Finlaison,
-fell short of it by 269 weeks; a difference nearly
-double that of Holland, and quite double that of
-France in persons of the corresponding rank in
-society.</p>
-
-<p>Since that period, surprising changes have taken
-place in all the nations of Europe; but in none has
-the change been so great as in England. From
-that period, when its mortality exceeded that of
-any great and prosperous European country, its
-mortality has been steadily diminishing, and at
-the present time the value of life is greater in
-England than in any other country in the world.
-Not only has the value of life been regularly increasing
-until it has advanced beyond that of any
-country of which there is any record; but the remarkable
-fact is established, that the whole mass
-of its people now live considerably longer than its
-higher classes did in the seventeenth and eighteenth
-centuries. Thus, by inspecting the preceding table,
-it will be seen that between the years 1693 and
-1715, the nominees of the tontine of England, at
-
-<span class="pagenum"><a name="Page_147" id="Page_147">[Pg 147]</a></span>
-
-the age of fifty, fell short of the maximum longevity
-by 269 weeks; whereas, the mass of the people
-in all England and Wales, between the years
-1811 and 1831, fell short of it only by 100 weeks;
-the entire mass having not only reached the select
-class, but absolutely advanced beyond it by 169
-weeks.</p>
-
-<p>There cannot be a more interesting and instructive
-thing than to connect these facts with their
-causes. This will be attempted in a subsequent
-part of this work; but the reader will be incomparably
-better prepared for the investigation when
-the processes of life have been explained, and the
-influence of physical and moral agents upon them
-traced. And with this exposition we now proceed.</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_148" id="Page_148">[Pg 148]</a></span></p>
-<h2>CHAPTER V.</h2>
-</div>
-
-<blockquote>
-<p>Ultimate elements of which the body is composed&mdash;Proximate
-principles&mdash;Fluids and solids&mdash;Primary tissues&mdash;Combinations&mdash;Results&mdash;Organs,
-systems, apparatus&mdash;Form of the body&mdash;Division into head, trunk, and extremities&mdash;Structure
-and function of each&mdash;Regions&mdash;Seats
-of the more important internal organs.</p>
-</blockquote>
-
-<p>1. The ultimate elements of which the human
-body is composed are azote, oxygen, and hydrogen
-(gaseous fluids); and carbon, phosphorus, calcium,
-sulphur, sodium, potassium, magnesium,
-and iron (solid substances). These bodies are
-called elementary and ultimate, because they are
-capable of being resolved by no known process
-into more simple substances.</p>
-
-<p>2. These elementary bodies unite with each
-other in different proportions, and thus form compound
-substances. A certain proportion of azote
-uniting with a certain proportion of oxygen, hydrogen,
-and carbon, forms a compound substance possessing
-certain properties. Another proportion of
-azote uniting with a different proportion of oxygen,
-hydrogen, and carbon, forms another compound
-substance possessing properties different from the
-former. Oxygen, hydrogen, and carbon, uniting
-in still different proportions without any admixture
-
-<span class="pagenum"><a name="Page_149" id="Page_149">[Pg 149]</a></span>
-
-of azote, form a third compound possessing properties
-different from either of the preceding. The
-compounds thus formed by the primary combinations
-of the elementary substances with each other
-are called <span class="smcap">PROXIMATE PRINCIPLES</span>.</p>
-
-<p>3. Each proximate principle constitutes a distinct
-form of animal matter, of which the most
-important are named gelatin, albumen, fibrin, oily
-or fatty matter, mucus, urea, pichromel, osmazome,
-resin, and sugar.</p>
-
-<p>4. By chemical analysis it is ascertained that
-all the proximate principles of the body, however
-they may differ from each other in appearance and
-in properties, are composed of the same ultimate
-elements. Gelatin, for example, consists (in 100
-parts) of azote 16-988/1000, oxygen 27-207/1000, hydrogen
-7-914/1000, carbon 47-881/1000 parts. The elementary
-bodies uniting in the above proportions form an
-animal substance, soft, tremulous, solid, soluble in
-water, especially when heated, and on cooling,
-which may be considered as its distinctive property,
-separating from its solution in water into
-the same solid substance, without undergoing any
-change in its chemical constitution.</p>
-
-<p>5. Again, albumen consists of azote 15-705/1000,
-oxygen 23-872/1000, hydrogen 7-540/1000, carbon 52-888/1000,
-parts. The elementary bodies uniting in these
-different proportions, there results a second proximate
-principle, an adhesive fluid, transparent,
-destitute of smell and taste, miscible in water, but
-
-<span class="pagenum"><a name="Page_150" id="Page_150">[Pg 150]</a></span>
-
-when subjected to a temperature of about 165°,
-converted into a solid substance no longer capable
-of being dissolved in water. This conversion of
-albumen from a fluid, which is its natural state,
-into a solid, by the application of heat, is called
-coagulation. It is a process familiar to every one.
-The white of egg is nearly pure albumen, naturally
-a glary and adhesive fluid: by boiling, it is
-coagulated into a white and firm solid.</p>
-
-<p>6.  In like manner, fibrin consists of azote
-19-934/1000, oxygen 19-685/1000, hydrogen 7-021/1000, carbon
-53-360/1000 parts, forming a solid substance of a pale
-whitish colour and firm consistence, the peculiar
-character of which is its disposition to arrange
-itself into minute threads or fibres.</p>
-
-<p>7. On the other hand, fat or oil, which is a fluid
-substance of a whitish yellow colour, inodorous,
-nearly insipid, unctuous, insoluble in water and
-burning with rapidity, consists of a larger proportion
-of hydrogen, a small proportion of oxygen,
-and a still smaller proportion of carbon, without
-any admixture of azote.</p>
-
-<p>8. From this account of the composition of the
-proximate principles, which it is not necessary to
-extend further, it is manifest that all of them consist
-of the same ultimate elements, and that they
-derive their different properties from the different
-proportions in which their elements are combined.</p>
-
-<p>9. The ultimate elements that compose the
-body are never found in a separate or gaseous
-
-<span class="pagenum"><a name="Page_151" id="Page_151">[Pg 151]</a></span>
-
-state, but always in combination in the form of
-one or other of the proximate principles.</p>
-
-<p>10. In like manner, the proximate principles
-never exist in a distinct and pure state, but each
-is combined with one or more of the others. No
-part consists wholly of pure albumen, gelatin, or
-mucus, but albumen is mixed with gelatin, or both
-with mucus.</p>
-
-<p>11. Simple or combined, every proximate principle
-assumes the form either of a fluid or of a
-solid, and hence the most general and obvious
-division of the body is into fluids and solids. But
-the terms fluid and solid are relative, not positive;
-they merely express the fact that some of the substances
-in the body are soft and liquid compared
-with others which are fixed and hard; for there is
-no fluid, however thin, which does not hold in
-solution some solid matter, and no solid, however
-dense, which does not contain some fluid.</p>
-
-<p>12. Fluids and solids are essentially the same
-in nature; they differ merely in their mode of
-aggregation; hence the easy and rapid transition
-from the one to the other which incessantly takes
-place in the living body, in which no fluid long
-remains a fluid, and no solid a solid, but the fluid
-is constantly passing into the solid and the solid
-into the fluid.</p>
-
-<p>13. The relative proportion of the fluids in the
-human body is always much greater than that of
-the solids; hence its soft consistence and rounded
-
-<span class="pagenum"><a name="Page_152" id="Page_152">[Pg 152]</a></span>
-
-form. The excess, according to the lowest estimate,
-is as 6 to 1, and according to the highest,
-as 10 to 1. But the proportion is never constant;
-it varies according to age and to the state of the
-health. The younger the age, the greater the preponderance
-of the fluids. The human embryo,
-when first perceptible, is almost wholly fluid:
-solid substances are gradually but slowly superadded,
-and even after birth the preponderance is
-strictly according to age; for in the infant, the
-fluids abound more than in the child; in the child,
-more than in the youth; in the youth, more than
-in the adolescent; in the adolescent, more than in
-the adult; and in the adult, more than in the aged.
-Thus, among the changes that take place in the
-physical constitution of the body in the progress of
-life, one of the most remarkable is the successive
-increase in the proportion of its solid matter:
-hence the softness and roundness of the body in
-youth; its hard, unequal, and angular surface in
-advanced life; its progressively increasing fixedness
-and immobility in old age, and ultimate inevitable
-death.</p>
-
-<p>14. The fluids are not only more abundant than
-the solids, but they are also more important, as
-they afford the immediate material of the organization
-of the body; the media by which both its
-composition and its decomposition are effected.
-They bear nourishment to every part, and by them
-are carried out of the system its noxious and useless
-
-<span class="pagenum"><a name="Page_153" id="Page_153">[Pg 153]</a></span>
-
-matter. In the brain they lay down the soft
-and delicate cerebral substance; in the bone, the
-hard and compact osseous matter; and the worn-out
-particles of both are removed by their instrumentality.
-Every part of the body is a laboratory
-in which complicated and transforming changes
-go on every instant; the fluids are the materials
-on which these changes are wrought; chemistry is
-the agent by which they are effected, and life is
-the governing power under whose control they
-take place.</p>
-
-<p>15. The fluids, composed principally of water
-holding solid matter in solution, or in a state of
-mechanical division, either contribute to the formation
-of the blood, or constitute the blood, or
-are derived from the blood; and after having
-served some special office in a particular part of
-the system, are returned to the blood; and according
-to the nature and proportion of the substances
-they contain, are either aqueous, albuminous, mucous,
-gelatinous, fibrinous, oleaginous, resinous, or
-saline.</p>
-
-<p>16. When the analysis of the different kinds
-of animal matter that enter into the composition
-of the body has been carried to its ultimate point,
-it appears to be resolvable into two primitive forms:
-first, a substance capable of coagulation, but possessing
-no determinate figure; and secondly, a
-substance having a determinate figure and consisting
-of rounded particles. The coagulable substance
-
-<span class="pagenum"><a name="Page_154" id="Page_154">[Pg 154]</a></span>
-
-is capable of existing by itself; the rounded particles
-are never found alone, but are invariably
-combined with coagulated or coagulable matter.
-Alone or combined with the rounded particles, the
-coagulable matter forms, when liquid, the fluids,
-when coagulated, the solids.</p>
-
-<p>17. When solid, the coagulable substance is
-disposed in one of two forms, either in that of
-minute threads or fibres, or in that of minute
-plates or laminæ; hence every solid of the body
-is said to be either fibrous or laminated. The
-fibres or laminæ are variously interwoven and interlaced,
-so as to form a net-work or mesh; and
-the interspaces between the fibres or laminæ are
-commonly denominated areolæ or cells (fig. XVII).</p>
-
-<p>18. This concrete substance, fibrous or laminated,
-is variously modified either alone or in combination
-with the rounded particles. These different
-modifications and combinations constitute
-different kinds of organic substance. When so
-distinct as obviously to possess a peculiar structure
-and peculiar properties, each of these modifications
-is considered as a separate form of organized
-matter, and is called a <span class="smcap">PRIMARY TISSUE</span>.
-Anatomists and physiologists have been at great
-pains to discriminate and classify these primary
-tissues; for it is found that when employed in the
-composition of the body, each preserves its peculiar
-structure and properties wherever placed, however
-combined, and to whatever purpose applied, undergoing
-
-<span class="pagenum"><a name="Page_155" id="Page_155">[Pg 155]</a></span>
-
-only such modification as its local connexions
-and specific uses render indispensable.
-Considering every substance employed in the construction
-of the body, not very obviously alike, as
-a distinct form of organized matter, these primary
-tissues may be said to consist of five, namely, the
-membranous, the cartilaginous, the osseous, the
-muscular, and the nervous.</p>
-
-<p>19. The first primary tissue is the peculiar
-substance termed <span class="smcap">MEMBRANE</span>. It has been already
-stated (16) that one of the ultimate forms of animal
-matter is a coagulable substance, becoming concrete
-or solid under the process of coagulation.
-The commencement of organization seems to be
-the arrangement of this concrete matter into
-straight thready lines, at first so small as to be imperceptible
-to the naked eye. Vast numbers of
-these threads successively uniting, at length form a
-single thread of sufficient magnitude to be visible,
-but still smaller than the finest thread of
-the silkworm. If the length of these threads
-be greater than their breadth, they are called
-fibres; if, on the contrary, their breadth exceed
-their length, they are termed plates or laminæ.
-By the approximation of these fibres or plates in
-every possible direction, and by their accumulation,
-combination, and condensation, is constituted
-the simplest form of organized substance, the primary
-tissue called membrane.</p>
-
-<p>20. Membrane once formed is extensively employed
-
-<span class="pagenum"><a name="Page_156" id="Page_156">[Pg 156]</a></span>
-
-in the composition of the body: it is indeed
-the material principally used in producing, covering,
-containing, protecting, and fixing every other
-component part of it. It forms the main bulk of
-the cartilaginous tissue; it receives into its cells
-the earthy matter on which depend the strength
-and hardness of the osseous tissue; it composes
-the canals or sheaths in which are deposited the
-delicate substance of the muscular, and the still
-more tender pulp of the nervous tissue; it gives
-an external covering to the entire body; it lines
-all its internal surfaces; it envelopes all internal
-organs; it enters largely as a component element
-into the substance of every organ of every kind; it
-almost wholly constitutes all the internal pouches
-and sacs, such as the stomach, the intestines, the
-bladder; and all tubes and vessels, such as arteries,
-veins, and lymphatics; it furnishes the common
-substance in which all the parts of the body
-are, as it were, packed; it fills up the interstices
-between them; it fixes them in their several situations;
-it connects them all together; in a word,
-it forms the basis upon which the other parts are
-superinduced; or rather the mould into which
-their particles are deposited; so that were it possible
-to remove every other kind of matter, and to
-leave this primary tissue unaltered in figure and
-undiminished in bulk, the general form and outline
-of the body, as well as the form and outline of all
-its individual parts, would remain unchanged.</p>
-
-<p><span class="pagenum"><a name="Page_157" id="Page_157">[Pg 157]</a></span></p>
-
-<p>21. The properties which belong to membrane
-are cohesion, flexibility, extensibility, and elasticity.
-By its property of cohesion, the several parts of
-the body are held together; by its combined properties
-of cohesion, flexibility, and extensibility,
-the body in general is rendered strong, light, and
-yielding, while particular parts of it are made
-capable of free motion. But elasticity, that property
-by which parts removed from their situation
-in the necessary actions of life are restored to their
-natural position, may be regarded as its specific
-property. The varied purposes accomplished in
-the economy by the property of elasticity will be
-apparent as we advance in our subject. Meantime,
-it will suffice to observe that it is indispensable
-to the action of the artery in the function of
-the circulation; to the action of the thorax in the
-function of respiration; to the action of the joints
-in the function of locomotion: in a word, to the
-working of the entire mechanism by which motion
-of every kind and degree is effected. All these
-properties are physical, not vital; vital properties
-do belong even to this primary form of animal
-matter; but they are comparatively obscure. In
-the tissue with which organization commences,
-and which is the least removed from an inorganic
-substance, the properties that are prominent and
-essential are merely physical.</p>
-
-<p>22. By chemical analysis, membrane is found
-to contain but a small proportion of azote, the
-
-<span class="pagenum"><a name="Page_158" id="Page_158">[Pg 158]</a></span>
-
-peculiar element of animal matter. Its proximate
-principles are gelatin, albumen, and mucus. In
-infancy and youth, gelatin is the most abundant
-ingredient; at a more advanced period, albumen
-predominates<a name="FNanchor_3_3" id="FNanchor_3_3"></a><a href="#Footnote_3_3" class="fnanchor">[3]</a>. Gelatin differs from albumen in
-containing a less proportion of azote and a greater
-proportion of oxygen; on both accounts it must be
-regarded as less animalized. Thus animalization
-bears a certain relation to organization. The
-simplest animal tissue is the least animalized, and
-the least of all at the earliest period of life. Not
-only are the physical and mental powers less developed
-in the young than in the adult, but the
-very chemical composition of the primary tissue of
-which the body is constructed is less characteristic
-of the perfect animal.</p>
-
-<p>23. Membrane exists under several distinct
-forms; a knowledge of the peculiarities of which
-will materially assist us in understanding the composition
-of the body. The simplest form of membrane,
-and that which is conceived to constitute
-the original structure from which all the others
-art produced, is termed the <i>cellular</i>. When in
-thin slices, <i>cellular membrane</i> appears as a semi-transparent
-and colourless substance; when examined in thicker masses,
-
-<span class="pagenum"><a name="Page_159" id="Page_159">[Pg 159]</a></span>
-
-it is of a whitish or
-greyish colour. It consists of minute threads,
-which cross each other in every possible direction,
-leaving spaces between them, and thus forming a
-mesh or net-work (fig. XVII.), not unlike the
-spider's web. The term cells, given to these interspaces,
-is employed rather in a figurative sense
-than as the expression of the fact; for there are
-no such distinct partitions as the term cell implies.
-The best conception that can be formed of the
-arrangement of the component parts of this structure
-is, to suppose a substance consisting of an
-infinite number of slender thready lines crossing
-each other in every possible direction (fig. XVII.).
-The interspaces between these lines during life,
-and in the state of health, are filled with a thin
-
-<span class="pagenum"><a name="Page_160" id="Page_160">[Pg 160]</a></span>
-
-exhalation of an aqueous nature, a vapour rather
-than a fluid, rendering and keeping the tissue
-always moist. This vapour consists of the thinner
-part of the blood, poured into these interstitial
-spaces by a process hereafter to be described,
-termed secretion. When occupying those spaces, it
-makes no long abode within them, but is speedily
-removed by the process of absorption. In health,
-these two operations exactly equal each other; but
-if any cause arise to disturb the equilibrium, the
-vapour accumulates, condenses and forms an
-aqueous fluid, which distends the cells and gravitates
-to the most depending parts. Slightly organized
-as this tissue is, and indistinct as its vita
-functions may be, it is obvious that it must be
-the seat of at least two vital functions, secretion
-and absorption.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_159.png" alt="Fig. XVII." />
-<div class="caption">A single film of the cellular tissue lifted up and<br />
-slightly distended.</div>
-</div>
-
-<p>24. It is certain that the interspaces or cells of
-this membrane have no determinate form or size,
-that they communicate freely with each other, and
-that this communication extends over the whole
-body; for if a limb which has been infiltrated be
-frozen, a thousand small icicles will be formed,
-assuming the shape of the containing cells, some
-of which are found to be circular and others cylindrical,
-and so on. If air or water escape into any
-particular part of the body, it is often effused over
-the whole extent of it, and butchers are observed
-to inflate animals by making a puncture in some
-part where the cellular tissue is loose, and from
-
-<span class="pagenum"><a name="Page_161" id="Page_161">[Pg 161]</a></span>
-
-this one aperture the air is forced to the most
-distant parts of the body.</p>
-
-<p>25. Cellular membrane, variously modified and
-disposed, forms the main bulk of all the other
-solid parts of the body, constituting their common
-envelope and bond of union, and filling up all their
-interstices. It is dense or loose, coarse or fine,
-according to its situation and office. Wherever it
-is subject to pressure, it is dense and firm, as in
-the palm of the hand and the sole of the foot;
-around the internal organs it is more loose and
-delicate, and it becomes finer and finer as it divides
-and subdivides, in order to envelope the soft and
-tender structures of the body.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_161.png" alt="Fig. XVIII." />
-<div class="caption">A portion of cellular tissue, very highly magnified, showing<br />
-the strings of globules of which its ultimate fibres are by<br />
-some supposed to consist.</div>
-</div>
-
-<p>26. According to some who have carefully examined
-with the microscope its component threads,
-they consist of minute particles of a globular figure
-(fig. XVIII.); other microscopical observers regard
-
-<span class="pagenum"><a name="Page_162" id="Page_162">[Pg 162]</a></span>
-
-the cellular threads as coagulated or condensed
-animal substance, perfectly amorphous
-(without form).</p>
-
-<p>27. Every part of this tissue is penetrated by
-arteries, veins, absorbents, and nerves, endowing
-it with properties truly vital, though in a less degree
-than any of the other primary tissues; and
-varied and important as the uses are which it
-serves in the economy, the most manifest, though
-certainly not the only ones, are those which depend
-upon its physical properties of cohesion,
-flexibility, extensibility, and elasticity.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_162.png" alt=" Fig. XIX." />
-<div class="caption">1, A portion of adipose tissue; 2, minute bags containing<br />
-the fat; 3, a cluster of the bags, separated and suspended.</div>
-</div>
-
-
-<p>28. The tissue which contains the fat, termed
-the <i>adipose</i>, is the second form of membrane; it is
-obviously a modification of the cellular, from
-
-<span class="pagenum"><a name="Page_163" id="Page_163">[Pg 163]</a></span>
-
-which it differs both in the magnitude of its fibres,
-whence it constitutes a tougher and coarser web,
-and in their arrangement; for it is so disposed as
-to form distinct bags in which the fat is contained.
-Adipose tissue consists of rounded packets, separated
-from each other by furrows (fig. XIX. 2,
-2); each packet is composed of small spheroidal
-particles (fig. XIX. 2, 2); each particle is again
-divisible into still smaller grains, which, on minute
-inspection, present the appearance of vesicles filled
-with the adipose matter (fig. XIX. 3).</p>
-
-<p>29.  The cells of the cellular tissue, as has been
-shown (24), are continuous over the whole body;
-but each adipose vesicle is a distinct bag, having no
-communication whatever with any other (fig. XIX.
-2, 2). The cellular tissue is universally diffused;
-but the adipose is placed only in particular parts of
-the body; principally beneath the skin, and more
-especially between the skin and the abdominal
-muscles, and around some of the organs contained
-in the chest and abdomen, as the heart, the kidneys,
-the mesentery, and the omenta. In most of
-these situations some portion of it is generally
-found, whatever be the degree of leanness to which
-the body may be reduced; while in the cranium,
-the brain, the eye, the ear, the nose, and several
-other organs, there is none, whatever be the degree
-of corpulency. The uses of the fat, which
-are various, will be stated hereafter.</p>
-
-<p>30. The third form of membrane is termed the</p>
-
-<p><span class="pagenum"><a name="Page_164" id="Page_164">[Pg 164]</a></span></p>
-
-<p><i>serous</i>. Like the adipose, <i>serous membrane</i> is a
-modification of the cellular, and, like it also, it is
-limited in its situation to particular parts of the
-body, that is, to its three great cavities, namely,
-the head, the chest, and the abdomen. To the
-two latter it affords an internal lining, and to all
-the organs contained in all the three cavities, it
-affords a covering. By its external surface it is
-united to the wall of the cavity or the substance
-of the organ it invests; by its internal surface it
-is free and unattached; whence this surface is in
-contact only with itself, forming a close cavity or
-shut sac, having no communication with the external
-air. Smooth and polished (fig. XX.), it is
-rendered moist by a fluid which is supposed to be
-exhaled in a gaseous state from the serum of the
-blood; and from this serous fluid the membrane
-derives its name.</p>
-
-<p><span class="pagenum"><a name="Page_165" id="Page_165">[Pg 165]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_164.png" alt=" Fig. XX." />
-<div class="caption">A portion of intestine, showing its external surface or <br />
-serous coat.</div>
-</div>
-
-
-<p>31. Though thin, serous membrane is dense,
-compact, and of great strength in proportion to
-its bulk: it is extensible and elastic; extensible,
-for it expands with the dilatation of the chest
-in inspiration; elastic, for it contracts with the
-diminished size of the chest in expiration. In
-like manner, it stretches with the enlargement of
-the stomach during a hearty meal, and contracts
-as the stomach gradually diminishes on emptying
-itself of its contents. It is furnished with no
-blood-vessels large enough to admit the colouring
-matter of the blood; but it is supplied with
-a great number of the colourless vessels termed
-exhalents, with the vessels termed absorbents,
-and with a few nerves. It indicates no vital properties,
-but those which are common to the simple
-form of the primary tissue. Its specific uses are
-to afford a lining to the internal cavities; to furnish
-a covering to the internal organs; by its
-polished and smooth surface, to allow a free motion
-of those organs on each other, and by the moisture
-with which it is lubricated, to prevent them from
-adhering together, however closely, or for however
-long a period they may be in contact.</p>
-
-<p>32. The fourth form of membrane, the <i>fibrous</i>,
-named from the obvious arrangement of its component
-parts, consists of longitudinal fibres, large
-enough to be visible to the naked eye, placed
-parallel to each other, and closely united. Sometimes
-these fibres are combined in such a manner
-
-<span class="pagenum"><a name="Page_166" id="Page_166">[Pg 166]</a></span>
-
-as to form a continuous and extended surface,
-constituting a thin, smooth, dense, and strong
-membrane, such as that which lines the external
-surface of bones termed <span class="smcap">PERIOSTEUM</span>, or the internal
-surface of the skull (dura mater). At other
-times, they form a firm and tough expansion
-(aponeurosis) which descends between certain
-muscles, separating them from each other, and
-affording a fixed point for the origin or insertion
-of neighbouring muscles; or which is stretched
-over muscles, and sometimes over even an entire
-limb, in order to confine the muscles firmly in
-their situation, and to aid and direct their action
-(fig. XXVII.). Fibrous membrane also constitutes
-the compact, strong, tough, and flexible
-bands used for tying parts firmly together, termed
-<span class="smcap">LIGAMENTS</span>, principally employed in connecting
-the bones with each other, and particularly about
-the joints; and lastly, fibrous membrane forms the
-rounded white cords in which muscles often terminate,
-called <span class="smcap">TENDONS</span> (fig. XXV., XXVI.), the
-principal use of which is to connect the muscles
-with the bones, and to serve as cords or ropes to
-transmit the action of the muscle to a distant
-point, in the accomplishment of which purposes
-their operation appears to be entirely mechanical.</p>
-
-<p>33. The fifth form of membrane, the <i>mucous</i>
-(fig. XXI.), derives its name from the peculiar fluid
-with which its surface is covered, called mucus,
-and which is secreted by numerous minute glands,
-
-<span class="pagenum"><a name="Page_167" id="Page_167">[Pg 167]</a></span>
-
-imbedded in the substance of the membrane. As
-serous membrane forms a shut sac, completely excluding
-the air, mucous membrane, on the contrary,
-lines the various cavities which are exposed to the
-air, such as the mouth, the nostrils, the wind-pipe,
-the gullet, the stomach, the intestines, the urinary
-organs, and the uterine system. Its internal surface,
-or that by which it is attached to the passages
-it lines, is smooth and dense; its external surface,
-or that which is exposed to the contact of the air,
-is soft and pulpy, like the pile of velvet (fig. XXI.).
-It bears a considerable resemblance to the external
-surface of the rind of the ripe peach.</p>
-
-<div class="topspace1"></div>
-<div class="figcenter">
-<img src="images/i_167.png" alt="Fig. XXI" />
-<div class="caption">A portion of the stomach, showing its internal surface<br />
-or mucous coat.</div>
-</div>
-
-
-<p>Unlike all the other tissues of this class, the mucous
-membranes are the immediate seat of some of the
-
-<span class="pagenum"><a name="Page_168" id="Page_168">[Pg 168]</a></span>
-
-most important functions of the economy; in the
-lung, of respiration; in the stomach, of digestion;
-in one part of the intestine, of chylification; in
-another, of excretion; while in the mouth and
-nose, they are the seat of the animal functions of
-taste and smell; and they are highly organized in
-accordance with the importance of the functions
-they perform.</p>
-
-<p>34. The last form of membrane which it is necessary
-to our present purpose to particularize, is
-that which constitutes the external covering of the
-body, and which is called the <i>skin</i>. The skin is
-everywhere directly continuous with the mucous
-membranes that line the internal passages, and its
-structure is perfectly analogous. Both the external
-and the internal surface of the body may be said
-therefore to be covered by a continuous membrane,
-possessing essentially the same organization, and
-almost identically the same chemical composition.
-The skin is an organ which performs exceedingly
-varied and important functions in the economy, to
-the understanding of which it is necessary to have
-a clear conception of its structure; some further
-account of it will therefore be required; but this
-will be more advantageously given when the offices
-it serves are explained.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_169.png" alt="Fig. XXII." />
-<div class="caption">Portions of cartilage, seen in section.</div>
-</div>
-
-
-<p>35. Such is the structure, and such are the properties,
-of the first distinct form of organized matter.
-The second primary tissue, termed the <span class="smcap">CARTILAGINOUS</span>
-(fig. XXII.), is a substance intermediate
-
-<span class="pagenum"><a name="Page_169" id="Page_169">[Pg 169]</a></span>
-
-between membrane and bone. The nature of its
-organization is not clearly ascertained. By some
-anatomists, it is regarded as a uniform and homogeneous
-substance, like firm jelly, without fibres,
-plates, or cells; others state that they have been
-able to detect in it longitudinal fibres, interlaced
-by other fibres in an oblique and transverse direction,
-but without determinate order. All are agreed
-that it is without visible vessels or nerves: not that
-it is supposed to be destitute of them, but that they
-are so minute as to elude observation. Its manifest
-
-<span class="pagenum"><a name="Page_170" id="Page_170">[Pg 170]</a></span>
-
-properties are wholly mechanical. It is dense,
-strong, inextensible, flexible, and highly elastic.
-It is chiefly by its property of elasticity that it
-accomplishes the various purposes it serves in the
-economy. It is placed at the extremities of bones,
-especially about the joints, where, by its smooth
-surface, it facilitates motion, and, by its yielding
-nature, prevents the shock or jar which would be
-produced were the same kind and degree of motion
-effected by a rigid and inflexible substance.
-Where a certain degree of strength with a considerable
-degree of flexibility are required, it supplies
-the place of bone, as in the spinal column,
-the ribs and the larynx.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_171.png" alt="Fig. XXIII." />
-<div class="caption">Membranous portion of bone; the osseous portion being<br />
-so completely removed, that the bone is capable of being
-tied in a knot.</div>
-</div>
-
-
-<p>36. The third distinct form of organized matter
-is termed the <span class="smcap">OSSEOUS</span> tissue. Bone is composed
-of two distinct substances, an animal and an
-earthy matter: the former organic, the latter inorganic.
-The animal or organic matter is analogous
-both in its nature and in its arrangement to cellular
-tissue; the earthy or inorganic matter consists
-of phosphoric acid combined with lime, forming
-phosphate of lime. The cellular tissue is aggregated
-into plates or laminæ, which are placed one
-upon another, leaving between them interspaces
-or cells, in which is deposited the earthy matter
-(phosphate of lime). If a bone, for example, the
-bone called the radius, one of the bones of the
-fore-arm, be immersed in diluted sulphuric, nitric,
-muriatic, or acetic acid, it retains its original bulk
-
-<span class="pagenum"><a name="Page_171" id="Page_171">[Pg 171]</a></span>
-
-and shape; it loses, however, a considerable portion
-of its weight, while it becomes so soft and
-pliable, that it may be tied in a knot (fig. XXIII.).
-In this case, its earthy matter is removed by the
-agency of the acid, and is held in solution in the
-fluid; what remains is membranous matter (cellular
-tissue). If the same bone be placed in a charcoal
-fire, and the heat be gradually raised to
-whiteness, it appears on cooling as white as chalk;
-it is extremely brittle; it has lost much of its
-weight, yet its bulk and shape continue but little
-changed. In this case, the membraneous matter is
-
-<span class="pagenum"><a name="Page_172" id="Page_172">[Pg 172]</a></span>
-
-wholly consumed by the fire, while the earth is left
-unchanged (fig. XXIV.). Every constituent atom
-of bone consists, then, essentially of animal and
-earthy matter intimately combined. A little more
-than one-third part consists of animal matter
-(albumen), the remaining two-thirds consist of
-earthy matter (phosphate of lime); other saline
-substances, as the fluate of lime and the phosphate
-of magnesia, are also found in minute quantity, but
-they are not peculiar to bone.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_172.png" alt="Fig. XXIV." />
-<div class="caption">Earthy portion of bone.</div>
-</div>
-
-
-<p>37. In general, the osseous tissue is placed in
-the interior of the body. Even when bone approaches
-the surface, it is always covered by soft
-parts. It is supplied with but few blood-vessels,
-with still fewer nerves, with no absorbents large
-enough to be visible, so that though it be truly
-alive, yet its vital properties are not greatly developed.
-The arrangement of its component particles
-is highly curious; the structure, the disposition,
-and the connexion of individual bones afford
-striking examples of mechanism, and accomplish
-most important uses in the economy; but those
-
-<span class="pagenum"><a name="Page_173" id="Page_173">[Pg 173]</a></span>
-
-uses are dependent rather upon mechanical than
-vital properties. The chief uses of bone are&mdash;
-1. By its hardness and firmness to afford a support
-to the soft parts, forming pillars to which the more
-delicate and flexible organs are attached and kept in
-their relative positions. 2. To defend the soft and
-tender organs by forming a case in which they are
-lodged and protected, as that formed by the bones
-of the cranium for the lodgment and protection of
-the brain (fig. XLVII.); by the bones of the spinal
-column for the lodgment and protection of the spinal
-cord (fig. XLVIII.); by the bones of the thorax
-(fig. LIX.), for the lodgment and protection of the
-lungs, the heart, and the great vessels connected
-with it (fig. LIX.). 3. By affording fixed points
-for the action of the muscles, and by assisting in
-the formation of joints to aid the muscles in accomplishing
-the function of locomotion.</p>
-
-<p>38. All the primary tissues which have now
-been considered consist of precisely the same
-proximate principles. Albumen is the basis of
-them all; with the albumen is always mixed more
-or less gelatin, together with a minute quantity of
-saline substance: to the osseous tissue is superadded
-a large proportion of earthy matter. With
-the exception of the mucous, the organization of
-all these tissues is simple; their vital properties
-are low in kind and in degree; their decided properties
-are physical, and the uses they serve in the
-economy are almost wholly mechanical.</p>
-
-<p><span class="pagenum"><a name="Page_174" id="Page_174">[Pg 174]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_174.png" alt="Fig. XXV." />
-<div class="caption">Portion of a muscle; showing (<i>a</i>) the muscular fibres<br />
-and their parallel direction; and (<i>b</i>) the termination of<br />
-the fibres in tendon.</div>
-</div>
-
-
-<p>39. But we next come to a tissue widely different
-in every one of those circumstances, a tissue
-consisting of a new kind of animal matter, and
-endowed with a property not only peculiar to itself,
-but proper to living substance, and characteristic
-of a high degree of vital power. <span class="smcap">Muscular tissue</span>,
-the fourth distinct form of animal matter, commonly
-known under the name of flesh, is a substance
-resembling no other in nature. It consists
-of a soft and pulpy substance, having little cohesive
-power, arranged into fibres which are distinctly
-visible to the naked eye, and which are
-disposed in a regular and uniform manner, being
-placed close and parallel to each other (fig. XXV.).
-These fibres are every where pretty uniformly the
-same in shape, size, and general appearance, being
-delicate, soft, flattened, and though consisting only
-of a tender pulp, still solid (fig. XXV.). When
-examined under the microscope, fibres, which to
-the naked eye appear to be single threads, are seen
-to divide successively into smaller threads, the
-
-<span class="pagenum"><a name="Page_175" id="Page_175">[Pg 175]</a></span>
-
-minutest or the ultimate division not exceeding,
-as is supposed, the 40,000th part of an inch in
-diameter. On the other hand, the fibres which
-are large enough to be visible to the naked eye,
-are obviously aggregated into bundles of different
-magnitude in different muscles, but always of
-the same uniform size in the same muscle (fig.
-XXV.).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_175.png" alt="Fig. XXVI." />
-<div class="caption">Two portions of muscle; one of which, <i>a</i>, is covered with<br />
-membrane; the other, <i>b</i>, is uncovered; <i>c</i>, the muscular<br />
-fibres terminating in tendon.</div>
-</div>
-
-
-<p>40. The ultimate thread, or the minutest division
-of which the muscular fibre is susceptible,
-is called a filament; the smallest thread which
-can be distinguished by the naked eye is termed a<span class="pagenum"><a name="Page_176" id="Page_176">[Pg 176]</a></span>
-fibre (fig. XXVI.); and the bundle which is
-formed by the union of fibres is denominated a
-fasciculus. The proper muscular substance is
-thus arranged into three distinct forms progressively
-increasing in size,&mdash;the filament, the fibre,
-and the fasciculus. The filament, the fibre, the
-fasciculus, as well as the muscle itself, formed by
-the aggregation of fasciculi, is each inclosed in its
-own distinct sheath of cellular membrane (fig.
-XXVI. <i>a</i>).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_176.png" alt="Fig. XXVII." />
-<div class="caption">Portion of a muscle enclosed in a sheath of fascia<br />
-or aponeurosis.</div>
-</div>
-
-<p>41. The composition of the ultimate filament has
-been very carefully examined by many distinguished
-physiologists with microscopes of high magnifying
-power. Under some of these microscopes the filament
-appears to consist of a series of rounded particles
-or globules of the same size as the particles of
-the blood when deprived of their colouring matter, so
-that it looks like a string of pearls (fig. XXVIII.),
-each globule being commonly stated to be about
-the 2000th part of an inch in diameter. But it is
-
-<span class="pagenum"><a name="Page_177" id="Page_177">[Pg 177]</a></span>
-
-now pretty generally agreed that this globular appearance
-of the ultimate muscular fibre vanishes
-under the more improved microscopes of the present
-day, and, as viewed by the latter, appears as
-a peculiar pulpy substance arranged into threads
-of extreme minuteness, placed close and parallel
-to each other, intersected by a great number of
-delicate lines passing transversely across the muscular
-threads (fig. XXIX.),</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_177.png" alt="Fig. XXVIII." />
-<div class="caption">Ultimate fibres of muscle, very greatly magnified; showing<br />
-the strings of globules of which they are supposed by<br />
-some to consist.</div>
-</div>
-
-
-<p>42.  With the exception of the organs of sense,
-the muscular tissue is more abundantly supplied
-with arteries, veins, and nerves, than any other
-substance of the body. Every ultimate thread or
-filament appears to be provided with the ultimate
-
-<span class="pagenum"><a name="Page_178" id="Page_178">[Pg 178]</a></span>
-
-branch of an artery, vein, and nerve. These
-vessels are seen ramifying on the surface of the
-delicate web of membrane that incloses the pulp,
-but cannot be traced into it.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_178.png" alt="Fig. XXIX." />
-<div class="caption">The appearance of the ultimate muscular fibres and of<br />
-their transverse lines, as seen under the microscope of Mr. Lister,<br />
-when the object is magnified 500 diameters.</div>
-</div>
-
-
-<p>43. The proximate principle of which the muscular
-pulp is composed is fibrin. From the pulp,
-when inclosed in its sheath of membrane, albumen,
-jelly, various salts, and a peculiar animal extract
-called osmazome, are also obtained; but these
-substances are probably derived from the membranous,
-not the muscular, matter. Fibrin contains
-a larger proportion of azote, the element peculiar
-to the animal body, and by the possession of which
-its chemical composition is distinguished from that
-of the vegetable, than any other animal substance.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_179.png" alt="Fig. XXX." />
-<div class="caption">Portion of the trunk of<br />
-a nerve; dividing into branches.</div>
-</div>
-
-
-<p>44. Muscular tissue possesses a slight degree of
-
-<span class="pagenum"><a name="Page_179" id="Page_179">[Pg 179]</a></span>
-
-cohesion, a high degree of flexibility and extensibility,
-but no degree of elasticity; for although
-muscle, considered as a compound of muscular
-substance and membrane, be highly elastic, yet
-this property is probably altogether
-owing to the membranous
-matter in which it
-is enveloped. Its peculiar
-and distinctive property is
-vital, not physical, and consists
-in the power of diminishing
-its length, or of
-contracting or shortening
-itself on the application of
-a stimulus. This property,
-which is termed contractility,
-is the great, if not
-the sole source of motion in
-the body. Without doubt,
-elasticity and gravity, under
-the generating and controlling
-powder of contractility,
-aid in accomplishing
-various kinds of motion.
-Thus membranes, tendons,
-ligaments, cartilages, and
-bones, by their physical
-and mechanical properties,
-modify, economize, facilitate,
-concentrate and direct
-
-<span class="pagenum"><a name="Page_180" id="Page_180">[Pg 180]</a></span>
-
-the motive power generated by the pure muscular
-substance; but still the only real source of motion
-in the body is muscular tissue, and the only mode
-in which motion is generated is by contractility.
-This will be more fully understood hereafter.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_180.png" alt="Fig. XXXI." />
-<div class="caption">Ultimate fibres of nerve, very highly magnified; showing<br />
-the strings of globules of which they consist.</div>
-</div>
-
-
-<p>45. The last primary tissue, termed the <span class="smcap">NERVOUS</span>,
-is equally distinct in nature and peculiar in property.
-It consists of a soft and pulpy matter, of a brownish
-white colour (fig. XXX.). According to some, the
-nervous, like the muscular pulp, is composed of
-minute globules, arranged in the same manner like a
-string of pearls (fig. XXXI.); according to others,
-
-<span class="pagenum"><a name="Page_181" id="Page_181">[Pg 181]</a></span>
-
-it consists of solid elongated threads, of a cylindrical
-form, differing in thickness from that of a hair
-to the finest fibre of silk. The pulp, whatever its
-form of aggregation, is inclosed in a sheath of
-delicate cellular tissue. This external or containing
-membrane is called the neurilema, or the
-nerve-coat; the internal or contained substance,
-the proper nervous matter, is termed the nerve-string.
-The nerve-string, enveloped in its nerve-coat,
-constitutes the nervous filament. As in the
-muscle, so in the nerve, many filaments unite to
-form a fibre, many fibres to form a fasciculus, and
-many fasciculi to form the large cord termed
-a nerve. Moreover, as in the muscle, so in the
-nerve, the filament, the fibre, the fasciculus, the
-nervous cord itself, are each enveloped in its own
-distinct sheath of cellular membrane; but the
-arrangement of the nervous fibres differs from that
-of the muscular in this, that though the nervous
-fibres are placed in juxtaposition, yet they do not,
-like the muscular, maintain through their entire
-course a parallel disposition, but cross and penetrate
-each other, so as to form an intimate interlacement
-(fig. XXXII.).</p>
-
-<p><span class="pagenum"><a name="Page_182" id="Page_182">[Pg 182]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_182.png" alt="Fig. XXXII." />
-<div class="caption">Nervous fibres, deprived of their neurilema and unravelled,<br />
-showing the smaller threads, or filaments, of which<br />
-the fibres consist.</div>
-</div>
-
-
-<p>46. The nervous pulp is at least as liberally
-supplied with blood-vessels as the muscular; the
-vessels are spread out upon the nerve-coat, in
-which they divide into innumerable branches of
-extreme minuteness, the distribution of which is
-so perfect, that there is not a particle of nervous
-
-<span class="pagenum"><a name="Page_183" id="Page_183">[Pg 183]</a></span>
-
-matter which is not supplied both with an arterial
-and a venous vessel. Hence the neurilema is not
-merely a sheath containing and protecting the
-nervous pulp, but it affords an extended mechanical
-surface for sustaining the arterial vessels, from
-which the pulp is probably secreted, and certainly
-nourished.</p>
-
-<p>47. Albumen, in conjunction with a peculiar
-fatty matter, constitutes the chief proximate principles
-of which the nervous tissue is composed.
-To these are added a small proportion of the animal
-substance termed osmazome, a minute quantity
-of phosphorus, some salts, and a very large
-proportion of water; for out of one hundred parts
-of nervous substance, water constitutes as much as
-eighty. Its peculiar vital property is sensibility;
-and as all motion depends on the contractility of
-the muscular fibre, so all sensation depends on the
-sensibility of the nervous substance.</p>
-
-<p>48. Such are the primary tissues, or the several
-kinds of organized matter of which the body is
-composed; and from this account it is obvious that
-they consist of three only&mdash;namely, the concrete
-matter forming the basis of membrane, the pulpy
-matter forming the proper muscular substance, and
-the pulpy matter forming the proper nervous substance.
-Of these three kinds of animal matter the
-component parts of the body consist. In combining
-to form the different structures, these primary
-substances are intermixed and arranged in a great
-
-<span class="pagenum"><a name="Page_184" id="Page_184">[Pg 184]</a></span>
-
-variety of modes; and from these combinations
-and arrangements result either an organ, a system,
-or an apparatus.</p>
-
-<p>49. As filaments unite to form fibres, and fibres
-to form tissues, so tissues unite to form organs:
-that is, bodies having a determinate size and figure,
-and capable of performing specific actions. The
-cellular, the muscular, and the nervous tissues
-are not organs; membranes, muscles, and nerves
-are organs. The tissue, the simple animal substance,
-is merely one of the elements of which the
-organ is composed; the organ is compounded of
-several of those simple substances, arranged in a
-determinate manner, and moulded into a given
-shape, and so constituting a specific instrument.
-The basis of the muscle is muscular tissue; but
-to this are added, invariably, membrane, often tendon,
-and always vessels and nerves. It is this
-combination that forms the specific instrument
-called a muscle, and that renders it capable of
-performing its specific action. And every such
-combination, with its appropriate endowment,
-constitutes an organ.</p>
-
-<p>50. Organs are arranged into groups or classes,
-according as they possess an analogous structure,
-and perform an analogous function; and this assemblage
-constitutes a <span class="smcap">SYSTEM</span>. All the muscles
-of the body, for example, whatever their size, form,
-situation, or use, have an analogous structure, and
-perform an analogous function, and hence are
-
-<span class="pagenum"><a name="Page_185" id="Page_185">[Pg 185]</a></span>
-
-classed together under the name of the muscular
-system. All the bones, whatever their figure,
-magnitude, density, position, or office, are analogous
-in structure and function; and hence are classed
-together under the name of the osseous system.
-For the same reason, all the cartilages, ligaments,
-vessels and nerves, form respectively the cartilaginous,
-ligamentous, vascular and nervous systems.</p>
-
-<p>51. An <span class="smcap">APPARATUS</span>, on the contrary, is an assemblage
-of organs, it may be differing widely from
-each other in structure, and exercising various and
-even opposite functions; but all nevertheless concurring
-in the production of some common object.
-The apparatus of nutrition consists of the organs
-of mastication, deglutition, digestion, absorption,
-and assimilation. Among the individual organs
-which concur in carrying on these functions may
-be reckoned the lips, the teeth, the tongue, the
-muscles connected with the jaws, the gullet, the
-stomach, the duodenum, the small intestines, the
-pancreas, the liver, the lacteal vessels, the mesenteric
-glands, and the lungs. Many of these organs
-have no similarity in structure, and few have any
-thing analogous in function; yet all concur, each
-in its appropriate mode and measure, to the conversion
-of the aliment into blood. In the apparatus
-of respiration, in that of circulation, of secretion,
-of excretion; in the apparatus of locomotion, in
-the apparatus of sensation, and more especially in
-the apparatus of the specific sensations,&mdash;vision,
-
-<span class="pagenum"><a name="Page_186" id="Page_186">[Pg 186]</a></span>
-
-hearing, smell, taste, touch, organs are combined
-which have nothing in common but their concurrence
-in the production of a common end: but
-this concurrence is the principle of their combination;
-and the individual organs having this conjoint
-operation, taken together, constitute an apparatus.</p>
-
-<p>52. A clear idea may now be affixed to the
-terms structure and organization. Structure may
-be considered as synonymous with arrangement;
-the disposition of parts in a determinate order;
-that which is constructed or built up in a definite
-mode, according to a determinate plan. The
-arrangement of the threads of the cellular web into
-areolæ or cells; the combination of the primary
-threads into fibres or laminæ; the disposition of
-the muscular pulp into filaments, placed parallel
-to each other; the investment of the filaments in
-membraneous sheaths; the combination of the filaments,
-included in their sheaths, into fibres; the
-aggregation of fibres into fasciculi; and the analogous
-arrangement and combination of the nervous
-pulp, are examples of structure. But when those
-structures are applied to particular uses; when
-they are so combined and disposed as to form a
-peculiar instrument, endowed with a specific function;
-when the cellular fibres, for example, are so
-arranged as to make a thin, dense, and expanded
-tissue; when to this tissue are added blood-vessels,
-absorbents, and nerves; when, in a word, a membrane
-is constructed, an organ is formed; when,
-
-<span class="pagenum"><a name="Page_187" id="Page_187">[Pg 187]</a></span>
-
-in like manner, to the muscular and the nervous
-fibres, arranged and moulded in the requisite mode,
-are added blood-vessels, absorbents, and nerves,
-other organs are constructed capable of performing
-specific functions: and this is organization&mdash;the
-building up of organs&mdash;the combination of definite
-structures into special instruments. Structure is
-the preparatory process of organization; the one
-is the mere arrangement of the material; the other
-is the appropriation of the prepared material to a
-specific use.</p>
-
-<p>53. The term organization is employed in reference
-both to the component parts of the body,
-and to the body considered as a whole. We speak
-of an organized substance and of an organized
-body. An organized substance is one in which
-there is not only a definite arrangement of its
-component parts (structure), but in which the
-particular arrangement is such as to fit it for accomplishing
-some special use. Every organized
-substance is therefore essentially a special organ;
-limited in its object it may be, and perhaps only
-conducive to some further object; but still its distinctive
-character is, that it has a peculiar structure,
-fitting it for the accomplishment of some
-appropriate purpose. On the other hand, an organized
-body is a congeries of organs&mdash;the aggregate
-of the individual organs. Attention was directed
-in the early part of this work to one peculiar
-and essential character, by which such an organized
-
-<span class="pagenum"><a name="Page_188" id="Page_188">[Pg 188]</a></span>
-
-is distinguished from an unorganized body.
-Between the individual parts of the organized body
-there is so close a relation, that no one of them
-can be removed or injured, or in any manner
-affected without a corresponding affection of the
-whole. The action of the heart cannot cease without
-the cessation of the action of the lung; nor that
-of the lung without that of the brain; nor that of
-the brain without that of the stomach; in a word,
-there is no organ in whatever distant nook of the
-system it be placed, or however apparently insignificant
-its function, that is not necessary to the
-perfection of the whole. But into whatever number
-of portions an unorganized body may be divided,
-each portion retains the properties of the
-mass, and constitutes in itself a perfect existence;
-there being no relation between its individual
-parts, excepting that of physical attraction: on
-the contrary, each component part of an organized
-body, being endowed with some appropriate and
-specific power, on the exercise of which the powers
-of all the other parts are more or less dependent,
-the whole must necessarily suffer if but one part
-fail.</p>
-
-<p>54. From the whole, then, we see that the human
-body is a congeries of organs; that those organs are
-constructed of a few simple tissues; and that all
-its parts, numerous, diversified, and complex as
-they are, are composed of but three primary forms
-of animal matter variously modified and combined.</p>
-
-<p><span class="pagenum"><a name="Page_189" id="Page_189">[Pg 189]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_189.png" alt=" Fig. XXXIII." />
-<div class="caption">Muscles of the back and shoulders; showing their symmetrical<br />
-disposition.</div>
-</div>
-
-<p>55. But though by the analysis of its component
-parts, this machine, so complex in its construction,
-and so wonderfully endowed, may be reduced to this
-state of simplicity; and although this analytical
-view of it be highly useful in enabling us to form
-a clear conception of the nature of its composition;
-yet it is only by considering its individual parts
-such as they actually are, and by studying their
-situation, connexion, structure, and action, that
-
-<span class="pagenum"><a name="Page_190" id="Page_190">[Pg 190]</a></span>
-
-we can understand it as a whole, and apply our
-knowledge of it to any practical use.</p>
-
-<p>56. Viewing then the human body as a complicated
-whole, as a congeries of organs made up of
-various combinations of simple tissues, it may be
-observed, in reference to its external configuration,
-that it is rounded. This rounded form is principally
-owing to the large proportion of fluids which
-enter into its composition. The roundness of the
-face, limbs, and entire surface of the child, are in
-striking contrast to the unequal and irregular surface
-of the old man, whose humours are comparatively
-very much smaller in quantity.</p>
-
-<p>57. The length of the human body exceeds its
-breadth and thickness; the degree of the excess
-varying at different periods of life, and according
-to the peculiar constitution of the individual. In
-the extremities, the bones, muscles, vessels, and
-nerves, are especially distinguished by their length.</p>
-
-<p><span class="pagenum"><a name="Page_191" id="Page_191">[Pg 191]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_191.png" alt="Fig. XXXIV." />
-<div class="caption">Front view of the skeleton. 1. the head; 2. the trunk;<br />
-3. the superior extremities; 4. the inferior extremities.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_192" id="Page_192">[Pg 192]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_192.png" alt="Fig. XXXV." />
-<div class="caption">Back view of the skeleton. 1. the head; 2. the trunk;
-3. the superior extremities; 4. the inferior extremities.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_193" id="Page_193">[Pg 193]</a></span></p>
-
-<p>58.  The form of the human body is symmetrical,
-that is, it is capable of being divided into two lateral
-and corresponding halves. Suppose a median
-line to pass from the vertex of the head through the
-centre of the spinal column (fig. XXXIV. 1, 2);
-if the body be well formed, it will be divided by this
-line into two exactly equal and corresponding portions
-(fig. XXXV. 1). This symmetrical disposition
-of the body is not confined to its external
-configuration. It is true of many of the internal
-organs; but principally, as has been already stated,
-of those that belong to the animal life. The brain
-and the spinal cord are divisible into two exactly
-equal halves (figs. XLVIII. <i>d</i>, and XLIX. 1, 2, 3);
-the organs of sense are double and symmetrical:
-the muscles of one side of the body exactly correspond
-to those of the other (fig. XXXIII.); the
-two hands and arms and the two lower extremities
-are alike (figs. XXXIV., XXXV.); but for the
-most part, the organs of the organic life, the
-stomach, the intestines, the liver, the spleen,
-for example, are single, and not symmetrical.</p>
-
-<p>59. The human body is divided into three great
-portions, the head, the trunk, and the extremities
-(figs. XXXIV. and XXXV. 1, 2, 3, 4).</p>
-
-<p>60. By the <span class="smcap">head</span> is meant all that part of the
-body which is placed above the first bone of the
-neck (fig. XXXIV. 1). It is of a spheroidal
-figure, broader and deeper behind than before,
-somewhat like an egg in shape, with the broad end
-behind; it is flattened at its sides (figs. XXXV. 1,
-and XXXVI. 2, 4). Its peculiar figure renders it
-at once stronger and more capacious than it could
-have been had it possessed any other form. It is
-supported by its base on the spinal column, to
-which it is attached by the peculiar structure
-termed a joint (fig. XXXIV.), and fastened by
-ligaments of exceeding strength.</p>
-
-<p>61. The head contains the central organ of the
-nervous system; the organs of the senses, with
-the exception of that of touch; and the organs of
-
-<span class="pagenum"><a name="Page_194" id="Page_194">[Pg 194]</a></span>
-
-mastication. It comprehends the cranium and the
-face. Both are composed partly of soft parts, as
-the teguments, namely, skin, fat, &amp;c., and muscles;
-and partly of bones.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_194.png" alt="Fig. XXXVI." />
-<div class="caption">1. Frontal bone; 2. parietal bone; 3. occipital bone;<br />
-4. temporal bone; 5. nasal bone; 6. malar bone; 7. superior<br />
-maxillary bone; 8. inferior maxillary bone.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_195" id="Page_195">[Pg 195]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_195.png" alt="Fig. XXXVII." />
-<div class="caption">Bones of the skull, separated; front view. 1. Frontal<br />
-bone; 2. portions of the parietal bones; 3. malar or cheek<br />
-bones; 4. nasal bones; 5. superior maxillary or bones of<br />
-the upper jaw; 6. the vomer; 7. the inferior maxillary or<br />
-bone of the lower jaw.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_196" id="Page_196">[Pg 196]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_196.png" alt="Fig. XXXVIII." />
-<div class="caption">Bones of the skull separated; side view. 1. Frontal<br />
-bone; 2. parietal bone; 3. occipital bone; 4. temporal<br />
-bone; 5. nasal bone; 6. malar bone; 7. superior maxillary<br />
-bone; 8. the unguis; 9. the inferior maxillary bone.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_197" id="Page_197">[Pg 197]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_197.png" alt="Fig. XXXIX." />
-<div class="caption">Bones forming the base of the skull; viewed from the<br />
-inside. 1. Occipital bone; 2. temporal bones; 3. sphenoid<br />
-bone; 4. ethmoid bone; 5. superior maxillary bones, or<br />
-bones of the upper jaw; 6. malar or cheek bones; 7. foramen<br />
-magnum.</div>
-</div>
-
-
-<p>62. The bones of the cranium are eight in number,
-six of which are proper to the cranium, and
-two are common to it and to the face. The six
-bones proper to the cranium are the frontal (fig.
-XXXVII. 1), the two parietal (fig. XXXVI. 2),
-the two temporal (fig. XXXVIII. 4), and the
-occipital (fig. XXXVIII. 3); the two common to
-the cranium and face are the ethmoidal (fig.
-XXXIX. 4), and the sphenoidal (fig. XXXIX.3).
-The frontal bone forms the entire forepart of
-the vault (fig. XXXVII. 1); the two parietal form
-the upper and middle part of it (fig. XXXVIII. 2);
-the two temporal form the lower part of the sides
-(fig. XXXVIII. 4); the occipital forms the whole
-hinder part, together with a portion of the base
-(figs. XXXVIII. 3, XXXVI. 3, XXXIX. 1);
-while the ethmoidal forms the forepart, and the
-sphenoidal the middle part of the base (fig.
-XXXIX. 3, 4).</p>
-
-<p><span class="pagenum"><a name="Page_198" id="Page_198">[Pg 198]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_198.png" alt="Fig. XL." />
-<div class="caption">Portions of the bones of the cranium; showing the corresponding<br />
-inequalities in their margins: which margins,<br />
-when in apposition, constitute the mode of union termed<br />
-suture. 1. External surface of the bone; 2. internal surface.</div>
-</div>
-<div class="topspace4"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_199.png" alt="Fig. XLI and Fig. XLII." />
-<div class="caption">1. Side view of the adult skull, showing the several bones<br />
-united by suture; 2. side view of the f&oelig;tal skull, showing<br />
-the bones imperfectly ossified, separated to some extent<br />
-from each other, the interspace being occupied by membrane.<br />
-The small size of the face compared with that of<br />
-the cranium is strikingly apparent.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_199" id="Page_199">[Pg 199]</a></span></p>
-
-<p>63. These bones are firmly united together.
-The union of bones is technically called an <i>articulation</i>
-or <i>joint</i>. All joints are either immoveable or
-moveable. The union of the bones of the cranium
-affords an example of an immoveable articulation.
-Prominences and indentations, like the teeth of a
-saw, are formed in the margins of the contiguous
-bones (figs. XXXVIII. and XL.). At these
-inequalities of surface, which are exactly adapted
-to each other (figs. XXXVIII. and XL.), the
-two bones are in immediate apposition in such
-a manner as to preclude the possibility of motion,
-and even to render the separation extremely difficult.
-This mode of articulation is termed a <i>suture</i>.
-There are certain advantages in constructing the
-cranium of several distinct bones, and in uniting
-
-<span class="pagenum"><a name="Page_200" id="Page_200">[Pg 200]</a></span>
-
-them in this peculiar mode. 1. The walls of the
-vault are stronger than they could have been had
-they been formed of a single piece. 2. In the
-f&oelig;tus, the bones are at some distance from each
-other (fig. XLII.); at birth, they yield and overlap
-one another; and in this manner they conduce to the
-security and ease of that event. 3. Minute vessels
-pass abundantly and securely through the interstices
-of the sutures to and from the interior of the
-cranium; in this manner, a free communication is
-established between the vessels within and without
-this cavity. 4. It is probable that the shock produced
-by external violence is diminished in consequence
-of the interruption of the vibration occasioned
-by the suture; it is certain that fracture is
-prevented by it from extending as far as it would
-do in one continued bony substance.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_201.png" alt="Fig. XLIII." />
-<div class="caption">Section of the skull. 1. Cavity of the cranium occupied by<br />
-the brain; 2. cut edge of the bones of the cranium, showing<br />
-the two tables of compact bone and the intervening spongy<br />
-texture called diploë.</div>
-</div>
-
-<p>64. The vault of the cranium forms a cavity
-which contains the brain (fig. XLIII.and XLVIII.)
-The size of this cavity is invariably proportioned to
-that of the organ it lodges and protects. The form
-and magnitude of the cavity, and consequently the
-shape and size of the cranium, depend upon the
-brain, and not of the brain upon the cranium.
-The soft parts model and adapt to themselves the
-hard, and not the hard the soft. The formation
-of the brain in the f&oelig;tus is anterior to that of the
-case which ultimately contains it; and the hard
-bone is moulded upon the soft pulp, not the pulp
-upon the bone. At every period of life, on the
-
-<span class="pagenum"><a name="Page_201" id="Page_201">[Pg 201]</a></span>
-
-inner surface of the cranium there are visible impressions
-made by the convolutions of the brain, and
-the ramifications of the arteries (figs. XXXIX. 1,
-2, and XL. 2), and on its external surface are
-depressions occasioned by the action of the external
-muscles. Nor does the modifying power of the brain
-over the bones of the cranium terminate at birth.
-The formation of bone, always a slow process, is
-never completed until the child has attained its
-third or fourth year, and often not until a much
-later period. At this tender age, the bones, which in
-advanced life are hard and rigid, are comparatively
-soft and yielding, and consequently more readily
-
-<span class="pagenum"><a name="Page_202" id="Page_202">[Pg 202]</a></span>
-
-receive and retain the impression of the convolutions
-and of the other projecting parts of the brain,
-by which they are sometimes so deeply marked,
-that an attentive examination of the inner surface
-of the cranium is of itself sufficient to determine
-not only that some part, but to indicate the very
-part of the brain which has been preternaturally
-active. At this tender age, pressure, internal or
-external, general or partial, may readily change
-the form of the cranium. If, by a particular posture,
-the head of a child be unequally balanced on
-the spine, the brain will press more on that side of
-the cranium than on the other; the organ will expand
-in the direction to which it inclines; that
-portion of it will become preternaturally developed,
-and consequently the balance of its functions will
-be disturbed. An awkward way of standing or
-sitting, perhaps contracted inadvertently and kept
-up by habit; a wry neck; any cause that keeps
-the head constantly inclined to one side, may produce
-this result, examples of which and of its consequences
-will be given hereafter.</p>
-
-<p>65. Tracing them from without inwards we see,
-then, that the various coverings afforded to the
-brain, the central organ of the animal life, seated
-in its vaulted cavity, are: 1. The tegument, consisting
-of the skin and of cellular and adipose
-membrane. 2. Beneath the tegument, muscles,
-in the forepart and at the vertex, comparatively
-slender and delicate; at the sides and posteriorly,
-
-<span class="pagenum"><a name="Page_203" id="Page_203">[Pg 203]</a></span>
-
-thick, strong, and powerful (fig. XLIV.). 3. Beneath
-the muscles, a thin but dense membrane,
-termed the pericranium, lining the external surface
-of the cranial bones. 4. Beneath the pericranium,
-the bony substance of the cranium, consisting of
-two firm and hard bony plates, with a spongy, bony
-structure, called diploë, interposed between them
-(fig. XLIII. 2). 5. Immediately in contact with
-the inner surface of the bony substance of the
-cranium, and forming its internal lining, the dense
-and strong membrane, called the <i lang="la">dura mater</i>, not
-only affording a general covering to the brain, but
-sending firm partitions between individual portions
-of it (fig. XLVIII. <i>c.</i>). 6. A serous membrane
-lining the internal surface of the dura mater, and
-reflected over the entire surface of the brain, termed
-the arachnoid tunic. 7. A thin and delicate membrane
-in immediate contact with the substance of
-the brain, descending between all its convolutions,
-lining all its cavities and enveloping all its fibres,
-called the pia mater. 8. An aqueous fluid, contained
-between the arachnoid membrane and the
-pia mater. Skin, muscle, pericranium, bone, dura
-mater, arachnoid membrane, pia mater, and aqueous
-fluid, superimposed one upon another, form,
-then, the covering and defence of the brain; so
-great is the care taken to protect this soft and
-tender substance.</p>
-
-<p>66.  The bones of the <i>face</i> consist of fourteen,
-namely, the two superior maxillary or jaw-bones
-
-<span class="pagenum"><a name="Page_204" id="Page_204">[Pg 204]</a></span>
-
-(fig. XXXVII. 5), the two malar or cheek bones
-(fig. XXXVII. 3), the two nasal bones (fig.
-XXXVII. 4), the two palate bones, the two ossa
-unguis (fig. XXXVIII. 8), the two inferior turbinated
-bones, the vomer (fig. XXXVII. 6), and
-the inferior maxilla or the lower jaw (fig. XXXVII.
-7.) This irregular pile of bones is divided into the
-superior and inferior maxilla or jaws; the superior
-maxilla being the upper and immoveable portion of
-the face; the inferior maxilla being the lower and
-moveable portion of it. Besides these bones, the
-face contains thirty-two teeth, sixteen in each jaw.
-The bones of the upper jaw are united together by
-sutures, and the union is so firm, that they have no
-motion but what they possess in common with the
-cranium. The lower jaw is united by a distinct
-articulation with the cranium (figs. XXXIV. and
-XXXV.).</p>
-
-<p>67. Besides the bones and the teguments, the face
-contains a number of muscles, which for the most
-part are small and delicate (fig. XLIV.), together
-with a considerable portion of adipose matter; while,
-as has been stated, the face and head together contain
-all the senses, with the exception of that of
-touch, which is diffused, more or less, over the entire
-surface of the body.</p>
-
-<p><span class="pagenum"><a name="Page_205" id="Page_205">[Pg 205]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_205.png" alt="Fig. XLIV." />
-<div class="caption">Muscles of the face.</div>
-</div>
-
-<p>68. The second great division of the body,
-termed the <span class="smcap">TRUNK</span>, extends from the first bone of
-the neck to that called the pubis in front, and to
-the lower end of the coccyx behind (fig. XXXIV. 2).
-
-It is subdivided into the thorax, the abdomen,
-and the pelvis (fig. XLV.).</p>
-
-<p>69. The <i>thorax</i> or <i>chest</i> extends above from the
-first bone of the neck, by which it is connected
-with the head, to the diaphragm below, by which
-it is divided from the abdomen (figs. XLV. and
-
-<span class="pagenum"><a name="Page_206" id="Page_206">[Pg 206]</a></span>
-
-LXI.). It consists partly of muscles and partly
-of bones; the muscular and the osseous portions
-being in nearly equal proportions. Both together
-form the walls of a cavity in which are placed the
-central organs of circulation and respiration (fig.
-LX. 2, 5). The chief boundaries of the cavity
-of the thorax before, behind, and at the sides, are
-osseous (fig. XLV.); being formed before, by the
-sternum or breast-bone (fig. XLV. 6); behind,
-by the spinal column or back bone (fig. XLV.
-2, 4); and at the sides, by the ribs (fig. XLV.
-7). Below, the boundary is muscular, being
-formed by the diaphragm (fig. LXI. 2), while
-above the thorax is so much contracted (fig.
-XLV.), that there is merely a space left for the
-passage of certain parts which will be noticed immediately.</p>
-
-<p>70. The figure of the thorax is that of a cone,
-the apex being above (fig. XLV.), through the
-aperture of which pass the tubes that lead to the
-lungs and stomach, and the great blood-vessels
-that go to and from the heart (fig. LX.). The
-base of the cone is slanting, and is considerably
-shorter before than behind, like an oblique section
-of the cone (fig. XLV.).</p>
-
-<p>71. The osseous portion of the walls of the
-thorax is formed behind by the spinal column, a
-range of bones common indeed to all the divisions
-of the trunk; for it constitutes alike the posterior
-boundary of the thorax, abdomen, and pelvis (fig.
-
-<span class="pagenum"><a name="Page_207" id="Page_207">[Pg 207]</a></span>
-
-XLV. 2, 4, 6). It is composed of thirty distinct
-bones, twenty-four of which are separate and moveable
-on one another, and on this account are called
-true vertebræ (fig. XLV. 2, 4); the other five,
-though separate at an early period of life, are subsequently
-united into a single solid piece, called
-the sacrum (fig. XLV. 5). The bones composing
-this solid piece, as they admit of no motion
-on each other, are called false vertebræ (fig.
-XLV. 5). To the extremity of the sacrum is
-attached the last bone of the series, termed the
-coccyx (fig. XXXV.).</p>
-
-<p>72. From above downwards, that is, from the
-first bone of the neck to the first bone of the sacrum,
-the separate bones forming the column progressively
-increase in size; for this column is the
-chief support of the weight of the head and trunk,
-and this weight is progressively augmenting to this
-point (fig. XLV. 2, 4). From the sacrum to the
-coccyx, the bones successively diminish in size,
-until, at the extremity of the coccyx, they come to
-a point (fig. XXXV.). The spinal column may
-therefore be said to consist of two pyramids united
-at their base (fig. XLV. 4, 5). The superior
-pyramid is equal in length to about one third of
-the height of the body, and it is this portion of
-the column only that is moveable.</p>
-
-<p>73. The two surfaces of the spinal column, the
-anterior and the posterior, present a striking contrast
-(figs. XXXIV. and XXXV.). The anterior
-
-<span class="pagenum"><a name="Page_208" id="Page_208">[Pg 208]</a></span>
-
-surface, which in its whole extent is rounded
-and smooth, is broad in the region of the neck,
-narrow in the region of the back, and again broad
-in the region of the loins (fig. XLV. 2, 4.). It
-presents three curvatures (fig. XLV. 2, 4); the
-convexity of that of the neck being forwards, that
-of the back backwards, and that of the loins again
-forwards (fig. XLV. 2, 4).</p>
-
-<p>74. From the posterior surface of the column,
-which is every where irregular and rough, spring,
-along the median line, in regular series, strong,
-sharp, and pointed projections of bone (fig.
-XXXV.), which from being sharp and pointed,
-like elongated spines, are called spinous processes,
-and have given name to the whole chain of bones.
-These processes afford fixed points for the action
-of powerful muscles. Extending the whole length
-of the column, from the base of the skull to the
-sacrum, on each side of the spinous processes, are
-deep excavations, which are filled up with the
-powerful muscles that maintain the trunk of the
-body erect.</p>
-
-<p>75. From the lateral surfaces of the column
-likewise spring short but strong projections of
-bone, termed transverse processes, which also give
-attachment to powerful muscles (fig. XLVI.).</p>
-
-<p><span class="pagenum"><a name="Page_209" id="Page_209">[Pg 209]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_209.png" alt="Fig. XLV." />
-<div class="caption">Bones of the trunk. 1. Spinal column; 2. the seven cervical<br />
-vertebræ; 3. the twelve dorsal vertebræ; 4. the five<br />
-lumbar vertebræ; 5. the sacrum; 6. the sternum; 7. the<br />
-true ribs; 8. the false ribs; 9. the clavicle; 10. the scapula;<br />
-11. the ilium; 12. the ischium; 13. the pubes;<br />
-14. the acetabulum; 15. the brim of the pelvis.</div>
-</div>
-
-<p>76. The separate bones of the series have a kind
-of turning motion on each other; hence each is
-called a vertebra, and the name of vertebral column
-is often given to the entire series, as well as
-
-<span class="pagenum"><a name="Page_210" id="Page_210">[Pg 210]</a></span>
-
-that of spinal column. That portion of the column
-which forms the neck consists of seven distinct
-bones, called cervical vertebræ (fig. XLV. 2);
-that portion which forms the back consists of
-twelve, called dorsal vertebræ (fig. XLV. 3);
-that portion which forms the loins consists of five,
-called lumbar vertebræ (fig. XLV. 4). Between
-each of these classes of vertebræ there are
-specific differences, but they need not be described
-here: all that is necessary to the present purpose
-is an account of the structure which is common
-to every vertebra.</p>
-
-<p>77. By inspecting fig. XLVI. 1, it will be seen
-that the upper and under edges of each vertebra
-consist of a ring of bone, of a firm and compact
-texture, rendering what may be called the body of
-the vertebra exceedingly strong (fig. XLVI. 3).
-This ring of bone forms a superficial depression
-(fig. XLVI. 2), for the reception of a peculiar
-substance, immediately to be described, which is
-interposed between each vertebra (fig. XLVII. 2).</p>
-
-<p>78. The anterior surface of the body of the vertebra
-is convex (fig. XLVI. 3); its posterior surface
-is concave (fig. XLVI. 4); from the posterior surface
-springs a bony arch (figs. XLVI. 5 and LIII. 1),
-which, together with the posterior concavity, forms
-an aperture of considerable magnitude (fig. XLVI.
-6), a portion of the canal for the passage of the
-spinal cord (figs. XLVII. 3, and XLIX. 3).</p>
-
-<p><span class="pagenum"><a name="Page_211" id="Page_211">[Pg 211]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_211.png" alt="Fig. XLVI." />
-<div class="caption">View of some of the vertebræ, which by their union form<br />
-the spinal column.
-
-<div class="topspace1"></div>
-
-<i>a.</i> A vertebra of the neck; <i>b.</i> a vertebra of the back;<br />
-a vertebra of the loins.
-
-<div class="topspace1"></div>
-
-1. Ring of compact bone forming, 3, the body of the<br />
-vertebra; 2. superficial depression for the reception of the<br />
-intervertebral cartilage; 3. anterior surface of the body of<br />
-the vertebra; 4. posterior surface; 5. bony arch; 6. opening<br />
-for the passage of the spinal cord; 7. opening for the passage<br />
-of the spinal nerves; 8. articulating processes by<br />
-which the vertebræ are joined to each other; 9. two dorsal<br />
-vertebræ united, showing the arrangement of, 10, the spinous<br />
-processes; 11. a portion of a rib articulated with the side<br />
-of the vertebra.</div>
-</div>
-
-<p>79. Both the upper and under edges of the arch
-form a notch (fig. XLVI. 7.), which, together with
-a corresponding notch in the contiguous vertebra,
-completes another aperture rounder and smaller
-than the former, but still of considerable size (fig.
-XLVI. 7.), the passage of the spinal nerves (fig.
-XLVII. 3).</p>
-
-<p>80. From both the upper and under sides of the
-arch proceed two short but strong projections of
-bone (fig. XLVI. 8.), termed the articulating processes,
-because it is chiefly by these processes that
-the vertebræ are connected together. From the
-beginning to the end of the series, the two upper
-processes of the one vertebra are united with the
-two lower processes of the vertebra immediately
-above it (fig. XLVI. 9), and around the edges of
-all the articulating processes are visible rough
-lines, which mark the places to which the articulating
-ligaments are attached.</p>
-
-<p>81. No vertebra, except the first, rests immediately
-upon its contiguous vertebra (fig. XLV.
-2, 4). Each is separated from its fellow by a
-substance of a peculiar nature interposed between
-them, termed the intervertebral substance (figs.
-
-<span class="pagenum"><a name="Page_213" id="Page_213">[Pg 213]</a></span>
-
-XLVII. 2, and L. 2). This substance partakes
-partly of the nature of cartilage, and partly of
-that of ligament. It is composed of concentric
-plates, formed of oblique fibres which intersect
-each other in every direction. This substance,
-for about a quarter of an inch from its circumference
-towards its centre, is tough, strong,
-and unyielding; then it becomes softer, and is
-manifestly elastic; and so it continues until it
-approaches the centre, when it becomes pulpy, and
-is again inelastic. The exterior tough and unyielding
-matter is for the firmness of the connexion
-of the several vertebræ with each other; the interior
-softer and elastic matter is for the easy play of
-the vertebræ upon each other; the one for security,
-
-<span class="pagenum"><a name="Page_214" id="Page_214">[Pg 214]</a></span>
-
-the other for pliancy. And the adjustment of the
-one to the other is such as to combine these properties
-in a perfect, manner. The quantity of the
-unyielding substance is not so great as to produce
-rigidity; the quantity of the elastic substance is
-not so great as to occasion insecurity. The firm
-union of its solid matter renders the entire column
-strong; the aggregate elasticity of its softer substance
-renders it springy.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_213.png" alt="Fig. XLVII." />
-<div class="caption">1. One of the Lumbar vertebræ. 2. Intervertebral substance.
-3. A portion of the spinal cord in its canal.</div>
-</div>
-
-<p>82. The column is not constructed in such a
-manner as to admit of an equal degree of motion
-in every part of it. Every thing is contrived to
-give to that portion which belongs to the neck
-freedom of motion, and, on the contrary, to render
-that portion which belongs to the back comparatively
-fixed. In the neck the mechanism of the
-articulating processes is such as to admit of an
-equal degree of sliding motion forwards, backwards,
-and from side to side, together with a turning motion
-of one bone upon another; at the same time,
-the intervertebral substance between the several
-vertebræ is thick. In consequence of this mechanism,
-we can touch the breast with the chin,
-the back with the hind head, and the shoulders
-with the ear, while we can make the head describe
-more than a semicircle. But, in the back, the
-articulating processes are so connected as to prevent
-the possibility of any motion, either forwards
-or backwards, or any turning of one vertebra upon
-another, while the intervertebral substance is comparatively
-
-<span class="pagenum"><a name="Page_215" id="Page_215">[Pg 215]</a></span>
-
-thin (fig. XLV. 2, 4). That portion of
-the column which belongs to the back is intended
-to afford a fixed support for the ribs, a support
-which is indispensable to their action in the function
-of respiration. In the loins, the articulating
-processes are so connected as to admit of a considerable
-degree of motion in the horizontal direction,
-and from side to side, and the intervertebral substance
-here progressively increases in thickness to
-the point at which the upper portion of the column
-is united to the sacrum (fig. XLV. 2, 4), where
-the degree of motion is extensive.</p>
-
-<p>83. The canal for the spinal cord, formed partly
-by the concavity in the posterior surface of the vertebra,
-and partly by the arch that springs from it
-(fig. XLVI. 6.), is lined by a continuation of the
-dense and strong membrane that constitutes the
-internal periosteum of the cranium, the dura mater
-(fig. XLVIII. <i>c</i>), which, passing out of the opening
-in the occipital bone, called the foramen magnum
-(figs. XXXIX. 7, and XLIX. 3), affords a
-smooth covering to the canal throughout its whole
-extent.</p>
-
-<p><span class="pagenum"><a name="Page_216" id="Page_216">[Pg 216]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_216.png" alt="Fig. XLVIII" />
-<div class="caption"><i>a.</i>  The scalp, turned down.<br />
-<i>b.</i>  The cut edge of the bones of the skull.<br />
-<i>c.</i>  The external strong membrane of the brain (Dura Mater)<br />
-suspended by a hook.<br />
-<i>d.</i>  The left hemisphere of the brain, showing its convolutions.<br />
-<i>e.</i> The superior edge of the right hemisphere.<br />
-<i>f.</i> The fissure between the two hemispheres.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_217" id="Page_217">[Pg 217]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_217.png" alt="Fig. XLIX" />
-<div class="caption">1. Hemispheres of the brain proper, or cerebrum;<br />
-2. hemispheres of the smaller brain, or cerebellum; 3. spinal<br />
-cord continuous with the brain, and the spinal nerves proceeding<br />
-from it on each side.</div>
-</div>
-
-<p>84. The spinal cord itself, continuous with the
-substance of the brain, passes also out of the cranium
-through the foramen magnum into the spinal
-canal (fig. XLIX. 3), enveloped in the delicate
-membranes that cover it, and surrounded by the
-aqueous fluid contained between those membranes.
-The size of the spinal canal, accurately adapted to
-that of the spinal cord, which it lodges and protects,
-is of considerable size, and of a triangular
-shape in its cervical portion (fig. XLIX. 3),
-smaller and rounded in its dorsal portion (fig.
-XLIX. 3), and again large and triangular in its
-lumbar portion (fig. XLIX. 3).</p>
-
-<p><span class="pagenum"><a name="Page_218" id="Page_218">[Pg 218]</a></span></p>
-
-<p>85. The spinal column performs several different,
-and apparently incompatible, offices.</p>
-
-<p>First, it affords a support and buttress to other
-bones. It sustains the head (fig. XXXIV. 1); it
-is a buttress to the ribs (fig. XLVI. 7); through
-the sternum and ribs it is also a buttress to the
-superior, and through the pelvis, to the lower,
-extremities (fig. XXXIV. 2, 3, 4).</p>
-
-<p>Secondly, it affords a support to powerful muscles,
-partly to those that maintain the trunk of the
-body in the erect posture against the force of gravitation,
-and partly to those that act upon the superior
-and inferior extremities in the varied, energetic,
-and sometimes long-continued movements
-they execute.</p>
-
-<p>Thirdly, it forms one of the boundaries of the
-great cavities that contain the chief organs of the
-organic life. To the support and protection of those
-organs it is specially adapted; hence the surface
-in immediate contact with them is even and
-smooth; hence its different curvatures, convexities,
-and concavities, have all reference to their accommodation;
-hence in the neck it is convex (fig.
-XLV. 2), in order to afford a firm support to the
-esophagus, the wind-pipe, the aorta, and the great
-trunks of the venous system (fig. LX. 3, 4); in
-the back it is concave, in order to enlarge the space
-
-<span class="pagenum"><a name="Page_219" id="Page_219">[Pg 219]</a></span>
-
-for the dilatation of the lung in the act of inspiration
-(figs. XLV. 3, and LX. 5); in the loins
-it is convex, in order to sustain and fix the loose
-and floating viscera of the abdomen (figs. XLV.
-4, and LX. 6, 7, 8, 9); in the pelvis it is concave,
-in order to enlarge the space for lodging the
-numerous delicate and highly-important organs
-contained in that cavity (fig. XLV. 5).</p>
-
-<p>Fourthly, it forms the osseous walls of a canal
-(figs. XLVI. 6, and XLVII. 3) for the lodgment
-and protection of the soft and tender substance of
-the spinal cord, one of the great central masses of
-the nervous system, the seat of the animal life (fig.
-XLIX. 3).</p>
-
-<p>Fifthly, it affords in its osseous walls secure
-apertures for the passage of the spinal nerves (figs.
-XLVI. 7, and XLIX. 3), by which impressions are
-transmitted from the organs to the spinal cord and
-brain, in the function of sensation; and from the
-spinal cord and brain to the organs in the function
-of volition.</p>
-
-<p>86. For the due performance of these offices, it
-is indispensable that it should be firm, rigid, strong,
-and yet to a certain extent readily flexible in every
-direction. By what mechanism is it endowed with
-these apparently incompatible properties?</p>
-
-<p>87. By means of the ring of compact bone,
-which forms so large a part of its body (fig. XLVI.
-1) it is rendered firm, rigid, and strong. By means
-of its numerous separate pieces, exactly adjusted to
-
-<span class="pagenum"><a name="Page_220" id="Page_220">[Pg 220]</a></span>
-
-each other, and dove-tailed into one another, an
-increase of strength is gained, such as it would not
-have been possible to communicate to a single solid
-piece. By the same mechanism, some degree of flexibility
-is also obtained; each separate bone yielding
-to some extent, which, though slight in a single
-bone, becomes considerable in the twenty-four.</p>
-
-<p>88. But the flexibility required is much greater
-than could be obtained by this expedient alone.
-A rigid and immoveable pile of bones, in the position
-of the spinal column, on which all the other
-parts of the body rest, and to which they are
-directly or indirectly attached, would necessarily
-have rendered all its movements stiff and mechanical;
-and every movement of every kind impossible,
-but in a given direction. That the movements of
-the body may be easy, free, and varied; that it
-may be possible to bring into play new and complex
-combinations of motion at any instant, with
-the rapidity of the changes of thought, at the command
-of the impulses of feeling, it is indispensable
-that the spinal column be flexible in every direction,
-forwards, backwards, and at the sides: it is
-equally indispensable that it be thus capable of
-yielding, without injuring the spinal cord; without
-injuring the spinal nerves; without injuring the
-thoracic and abdominal viscera; and without injuring
-the muscles of the trunk and extremities.
-The degree in which it possesses this power of
-flexibility, and the extent to which, by the cultivation
-
-<span class="pagenum"><a name="Page_221" id="Page_221">[Pg 221]</a></span>
-
-of it, it is sometimes actually brought, is exemplified
-in the positions and contortions of the
-posture-master and the tumbler. It is acquired by
-means of the intervertebral substance, the compressible
-and elastic matter interposed between the
-several vertebræ. So compressible is this substance,
-that the human body is half an inch shorter
-in the evening than in the morning, having lost
-by the exertions of the day so much of its stature;
-yet, so elastic is this matter, that the stature lost
-during the day is regained by the repose of the
-night. The weight of the body pressing in all
-directions upon the spinal column; muscles, bones,
-cartilages, ligaments, membranes, with all their
-vessels and all the fluids contained in them; the
-weight of all these component parts of the head,
-trunk, and extremities, pressing, without the cessation
-of an instant, during all the hours of vigilance,
-upon the intervertebral substance, compresses
-it; but this weight, being taken off during
-the night, by the recumbent posture of the body,
-the intervertebral substance, in consequence of its
-elasticity, regains its original bulk, and of course
-the spinal column its original length.</p>
-
-<p>89.  But the flexibility acquired through the combined
-properties of compressibility and elasticity
-is exceedingly increased by the action of the pulpy
-and inelastic matter in the centre of the intervertebral
-substance; this matter serving as a pivot
-to the vertebræ, facilitating their motion on each
-
-<span class="pagenum"><a name="Page_222" id="Page_222">[Pg 222]</a></span>
-
-other. Its effect has been compared to that of a
-bladder partly filled with water, placed between
-two trenchers; in this case, the approximation of
-the circumference of the two trenchers on one side,
-would instantly displace a portion of the water on
-that side, which would occupy the increasing space
-on the other, with the effect of facilitating the
-change, in every possible direction, of the position
-of the two trenchers in relation to each other. To
-this effect, however, it is indispensable that the
-matter immediately around this central pivot should
-be, not like itself, rigid and unyielding, but compressible
-and elastic. It is an interesting fact, that
-since this illustration was suggested, it has been
-discovered that this very arrangement is actually
-adopted in the animal body. In certain animals,
-in the very centre of their intervertebral substance,
-there has been actually found a bag of water, with
-a substance immediately surrounding the bag, so
-exceedingly elastic, that when the bag is cut, the
-fluid contained in it is projected to the height of
-several feet in a perpendicular stream.</p>
-
-<p>90.  But besides securing freedom and extent of
-motion, the intervertebral substance serves still
-another purpose, which well deserves attention.</p>
-
-<p>Firmness and strength are indispensable to the
-fundamental offices performed by the column; and
-to endow it with these properties, we have seen
-that the external concentric layers of the intervertebral
-substance are exceedingly tough and that
-
-<span class="pagenum"><a name="Page_223" id="Page_223">[Pg 223]</a></span>
-
-they are attached to the bodies of the vertebræ,
-which are composed of dense and compact bone.
-But than dense and compact bone, nothing can be
-conceived better calculated to receive and transmit
-a shock or jar on the application of any degree of
-force to the column. Yet such force must necessarily
-be applied to it in every direction, from
-many points of the body, during almost every moment
-of the day; and did it actually produce a
-corresponding shock, the consequence would be
-fatal: the spinal cord and brain would be inevitably
-killed; for the death of these tender and
-delicate substances may be produced by a violent
-jar, although not a particle of the substances themselves
-be touched. A blow on the head may destroy
-life instantaneously, by what is termed concussion;
-that is, by the communication of a shock to the
-brain through the bones of the cranium. The
-brain is killed; but on careful examination of
-the cerebral substance after death, not the slightest
-morbid appearance can be detected: death is
-occasioned merely by the jar. A special provision
-is made against this evil, in the structure of
-the bones of the cranium, by the interposition between
-its two compact plates of the spongy substance
-called diploë (fig. XLIII. 2); and this is
-sufficient to prevent mischief in ordinary cases.
-A great degree of violence applied directly to the
-head is not common: when it occurs it is accidental:
-thousands of people pass through life
-
-<span class="pagenum"><a name="Page_224" id="Page_224">[Pg 224]</a></span>
-
-without ever having suffered from it on a single
-occasion: but every hour, in the ordinary movements
-of the body, and much more in the violent
-movements which it occasionally makes, a degree
-of force is applied to the spinal column, and through
-it transmitted to the head, such as, did it produce
-a proportionate shock, would inevitably and instantly
-destroy both spinal cord and brain. The
-evil is obviated partly by the elastic, and partly by
-the non elastic properties of the matter interposed
-between the several layers of compact bone. By
-means of the elastic property of this matter, the
-head rides upon the summit of the column as upon
-a pliant spring, while the canal of the spinal cord
-remains secure and uninvaded. By means of the
-soft and pulpy portion of this matter, the vibrations
-excited in the compact bone are absorbed point by
-point as they are produced: as many layers of this
-soft and pulpy substance, so many points of absorption
-of the tremors excited in the compact
-bone; so many barriers against the possibility of
-the transmission of a shock to the delicate nervous
-substance.</p>
-
-<p>91.  Alike admirable is the mechanism by which
-the separate pieces of the column are joined together.
-If but one of the bones were to slip off
-its corresponding bone, or to be displaced in any
-degree, incurable paralysis, followed ultimately
-by death, or instantaneous death, would happen;
-for pressure on the spinal cord in a certain part of
-
-<span class="pagenum"><a name="Page_225" id="Page_225">[Pg 225]</a></span>
-
-its course is incompatible with the power of voluntary
-motion, and with the continuance of life for
-any protracted term; and in another part of its
-course, with the maintenance of life beyond a few
-moments. To prevent such consequences, so great
-is the strength, so perfect the attachment, so unconquerable
-the resistance of that portion of the
-intervertebral substance which surrounds the edge
-of the bodies of the vertebræ, that it will allow the
-bone itself to give way rather than yield. Yet such
-is the importance of security to this portion of the
-frame, that it is not trusted to one expedient alone,
-adequate as that might seem. Besides the intervertebral
-substance, there is another distinct provision
-for the articulation of the bodies of the vertebræ.
-Commencing at the second cervical vertebra, in its
-
-<span class="pagenum"><a name="Page_226" id="Page_226">[Pg 226]</a></span>
-
-fore part, and extending the whole length of the
-column to the sacrum, is a powerful ligament,
-composed of numerous distinct longitudinal fibres
-(fig. L.), which are particularly expanded over
-the intervals between the bones occupied by the
-intervertebral substance (figs. L. 1, and LI.
-2,  2). This ligament is termed the <i>common
-anterior vertebral</i>, beneath which, if it be raised
-from the intervertebral substance, may be seen
-small <i>decussating</i> fibres, passing from the lower
-edge of the vertebra above, to the upper edge of
-the vertebra below (fig. L. 3), from which circumstance
-these fibres are termed <i>crucial</i>.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_225.png" alt="Fig. L." />
-<div class="caption">1. Common anterior ligament; 2. intervertebral substance.
-The anterior ligament is removed to exhibit (3.)
-the crucial fibres passing over it.</div>
-</div>
-<div class="topspace4"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_226.png" alt="Fig. LI." />
-<div class="caption">1. Portion of the occipital bone; 2. common anterior
-ligament.</div>
-</div>
-
-<p>92.  Corresponding with the ligament on the
-
-<span class="pagenum"><a name="Page_227" id="Page_227">[Pg 227]</a></span>
-
-anterior, is another on the posterior part of the
-spine (fig. LII. 1), which takes its origin from the
-foramen magnum (fig. LII. 1); descends from
-thence, within the vertebral canal, on the posterior
-surface of the bodies of the vertebra (fig. LII. 1),
-and extends to the sacrum. This ligament is
-termed the <i>common posterior vertebral</i>, which,
-besides adding to the strength of the union of the
-bodies of the vertebræ, prevents the column itself
-from being bent too much forward.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_227.png" alt="Fig. LII." />
-<div class="caption">1. Posterior vertebral ligament.</div>
-</div>
-
-<p>93.  Moreover, the bony arches of the vertebræ
-(fig. LIII. 1) are connected by means of a substance
-
-<span class="pagenum"><a name="Page_228" id="Page_228">[Pg 228]</a></span>
-
-partly ligamentous, and partly cartilaginous
-(fig. LIII. 2), which, while it is extremely elastic,
-is capable of resisting an extraordinary degree of
-force.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_228.png" alt="Fig. LIII." />
-<div class="caption">1. Arches of the vertebræ seen from within;<br />
-2. ligaments connecting them.</div>
-</div>
-
-<p>94.  And in the last place, the articular processes
-form so many distinct joints, each being
-furnished with all the apparatus of a moveable
-joint, and thus possessing the ordinary provision
-for the articulation of bones, in addition to the
-whole of the foregoing securities.</p>
-
-<p>95. "In the most extensive motion of which the
-spinal column is capable, that of flexion, the common
-anterior ligament is relaxed; the fore part of
-the intervertebral substance is compressed, and its
-back part stretched; while the common posterior
-ligament is in a state of extension. In the <i>extension</i>
-
-<span class="pagenum"><a name="Page_229" id="Page_229">[Pg 229]</a></span>
-
-of the column the state of the ligaments is
-reversed; those which were extended being in their
-turn relaxed, while the common anterior vertebral
-is now put upon the stretch. In the <i>lateral inclination</i>
-of the column, the intervertebral substance
-is compressed on that side to which the body is
-bent. In the <i>rotatory</i> motion of the column, which
-is very limited in all the vertebræ, but more particularly
-in the dorsal, in consequence of their
-attachment to the ribs, the intervertebral substance
-is contorted, as are likewise all the ligaments. All
-the motions of the column are capable of being
-aided to a great extent by the motion of the pelvis
-upon the thighs."</p>
-
-<p>96. "The number and breadth of the attachments
-of these bones," says an accomplished anatomist
-and surgeon,<a name="FNanchor_4_4" id="FNanchor_4_4"></a><a href="#Footnote_4_4" class="fnanchor">[4]</a>
-"their firm union by ligament,
-the strength of their muscles, the very inconsiderable
-degree of motion which exists between
-any two of them, and lastly, the obliquity of their
-articular processes, especially in the dorsal and
-lumbar vertebræ, render dislocation of them, at
-least in those regions, impossible without fracture;
-and I much doubt whether dislocation even of the
-cervical vertebræ ever occurs without fracture,
-either through their bodies or their articular processes.
-The effects of each of these accidents
-would produce precisely the same injury to the
-
-<span class="pagenum"><a name="Page_230" id="Page_230">[Pg 230]</a></span>
-
-spinal marrow, and symptoms of greater or less
-importance, according to the part of the spinal
-column that is injured. Death is the immediate
-consequence if the injury be above the third cervical
-vertebra, the necessary paralysis of the parts
-to which the phrenic and intercostal nerves are
-distributed causing respiration instantly to cease.
-If the injury be sustained below the fourth cervical
-vertebra, the diaphragm is still capable of action,
-and dissolution is protracted. The symptoms, in
-fact, are less violent in proportion as the injury to
-the spinal marrow is further removed from the
-brain; but death is the inevitable consequence,
-and that in every case at no very distant period."</p>
-
-<p>97. So the object of the construction of the
-spinal column being to combine extent and freedom
-of motion with strength, and it being necessary to
-the accomplishment of this object to build up the
-column of separate pieces of bone, the connecting
-substances by which the different bones are united
-are constituted and disposed in such a manner as
-to prove absolutely stronger than the bones themselves.
-Such is the structure of this important
-portion of the human body considered as a piece
-of mere mechanism; but our conception of its
-beauty and perfection would be most inadequate
-if we did not bear in mind, that while the spinal
-column performs offices so varied and apparently
-so incompatible, it forms an integrant portion of a
-living machine: it is itself alive: every instant,
-
-<span class="pagenum"><a name="Page_231" id="Page_231">[Pg 231]</a></span>
-
-blood-vessels, absorbents and nerves, are nourishing,
-removing, renewing, and animating every part
-and particle of it.</p>
-
-<p>98. The anterior boundary of the thorax is
-formed by the bone called the sternum, or the
-breast-bone, which is broad and thick at its upper,
-and thin and elongated at its lower extremity (figs.
-XLV. 6, and LIV.), where it gives attachment
-to a cartilaginous appendix, which being pointed
-and somewhat like a broadsword, is called the
-ensiform cartilage.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_231.png" alt="Fig. LIV." />
-<div class="caption">Anterior view of the sternum.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_232" id="Page_232">[Pg 232]</a></span></p>
-
-<p>99. Its position is oblique, being near the vertebral
-column at the top, and distant from it at
-the bottom (fig. XLV. 6). Its margins are thick,
-and marked by seven depressions, for the reception
-of the cartilages of the seven true ribs (fig. LIV).
-Its anterior surface is immediately subjacent to the
-skin, and gives attachment to powerful muscles,
-which act on the superior extremities: its posterior
-surface is slightly hollowed in order to enlarge the
-cavity of the thorax (fig. LV.).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_232.png" alt="Fig. LV." />
-<div class="caption">Posterior view of the sternum.</div>
-</div>
-
-<p>100. The thorax is bounded at the sides by the
-ribs, which extend like so many arches between
-
-<span class="pagenum"><a name="Page_233" id="Page_233">[Pg 233]</a></span>
-
-the spinal column and the sternum (fig. XLV. 7,
-8). They are in number twenty-four, twelve on
-each side, of which the seven upper are united to
-the sternum by cartilage, and are called true ribs
-(fig. XLV. 7); the cartilages of the remaining
-five are united with each other and are not attached
-to the sternum; these are called false ribs (fig.
-XLV. 8): all of them are connected behind to
-the spinal column (fig. XXXV.).</p>
-
-<p>101. The ribs successively and considerably increase
-in length as far as the seventh, by which
-the cavity they encompass is enlarged; from the
-seventh they successively diminish in length, and
-the capacity of the corresponding part of the cavity
-is lessened. The direction of the ribs from above
-downwards is oblique (fig. XLV. 7, 8). Their
-external or anterior surface is convex (fig. XLV.
-7, 8); their internal or posterior surface is concave:
-by the first their strength is increased; by
-the second the general cavity of the thorax is enlarged
-(fig. XLV. 7, 8). Their upper margin is
-smooth and rounded, and gives attachment to a
-double layer of muscles, called the intercostal,
-placed in the intervals that separate the ribs from
-each other (fig. LIX.). Along the lower margin
-is excavated a deep groove, for the lodgment and
-protection of the intercostal vessels.</p>
-
-<p>102. The ribs are connected with the spinal
-column chiefly by what is termed the <i>anterior
-ligament</i> (fig. LVI. 1), which is attached to the
-
-<span class="pagenum"><a name="Page_234" id="Page_234">[Pg 234]</a></span>
-
-head of the rib (fig. LVI.), and which, dividing
-into three portions (fig. LVI. 1), firmly unites
-every rib to two of the vertebræ, and to the intervertebral
-substance (fig. LVI. 1). This articulation
-is fortified by a second ligament (fig. LVI.
-2), also attached to a head of the rib, termed the
-<i>interarticular</i> (fig. LVI. 2), and by three others,
-one of which is attached on the fore part, and the
-two others in the back part, to the neck of the
-rib (fig. LVII. 1).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_234.png" alt="Fig. LVI." />
-<div class="caption">Ligaments connecting the ribs to the spinal column.<br />
-1. anterior ligaments; 2. interarticular ligament; 3. ligaments<br />
-of the necks of the ribs.</div>
-</div>
-
-<p>The cartilages of the seven superior ribs are
-attached to the sternum by a double layer of ligamentous
-
-<span class="pagenum"><a name="Page_235" id="Page_235">[Pg 235]</a></span>
-
-fibres, termed the <i>anterior and the posterior
-ligaments of the sternum</i> (fig. LVIII.). So
-strong are the bands which thus attach the ribs
-to the spinal column and the sternum, that the
-ribs cannot be dislocated without fracture. "Such
-at least is the case in experiments upon the dead
-body, where, though the rib be subjected to the
-application of force by means of an instrument
-best calculated to detach its head from the articulation,
-yet it is always broken."</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_235.png" alt="Fig. LVII." />
-<div class="caption">1, &amp;c. Ligaments connecting the ribs to the vertebræ
-behind.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_236" id="Page_236">[Pg 236]</a></span></p>
-
-<p>While thus firmly attached to their points of
-support, the ligaments, which fix them, are so
-disposed as to render the ribs capable of being
-readily moved upwards and downwards: upwards
-in inspiration; downwards in expiration; and it
-is by this alternate action that they enlarge and
-diminish the cavity of the thorax in the function
-of respiration.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_236.png" alt="Fig. LVIII." />
-<div class="caption">Ligaments joining the cartilages of the ribs to the sternum.</div>
-</div>
-
-<p>103.  Such are the boundaries of the cavity of
-the thorax as far as its walls are solid. The interspaces
-between these solid portions at the sides are
-
-<span class="pagenum"><a name="Page_237" id="Page_237">[Pg 237]</a></span>
-
-filled up by muscles, principally by those termed
-the intercostal (fig. LIX.); below, the boundary
-is formed by the diaphragm (fig. LXI. 2); while
-above, as has been already stated (69), the cavity
-is so contracted as only to leave an opening for the
-passage of certain parts to and from the chest.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_237.png" alt="Fig. LIX." />
-<div class="caption">A view of the muscles called <i>Intercostals</i>, filling up the<br />
-spaces between the ribs.</div>
-</div>
-
-<p>104.  The inner surface of the walls of the thorax,
-in its whole extent, is lined by a serous membrane,
-exceedingly thin and delicate, but still firm, called
-the pleura. The same membrane is reflected over
-
-<span class="pagenum"><a name="Page_238" id="Page_238">[Pg 238]</a></span>
-
-the organs of respiration contained in the cavity,
-so as to give them an external coat. The membrane
-itself is every where continuous, and every
-where the same, whether it line the containing or
-the contained parts; but it receives a different
-name as it covers the one or the other: that portion
-of it which lines the walls of the cavity being
-called the costal pleura (fig. LXI. <i>a</i>), while that
-which covers the organs contained in the cavity
-is termed the pulmonary pleura (fig. LX. 5, 1).</p>
-
-<p>105. A fold of each pleura passes directly across
-the central part of the cavity of the thorax; extending
-from the spinal column to the sternum, and
-dividing the general cavity into two. This portion
-of the pleura is called the mediastinum, from its
-situation in the centre of the thorax, and it so
-completely divides the thoracic cavity into two,
-that the organs on one side of the chest have no
-communication with those of the other; so that
-there may be extensive disease in one cavity (for
-example, a large accumulation of water,) while the
-other may be perfectly sound.</p>
-
-<p>106. The main organs contained in the cavity of
-the thorax are the lungs with their air tube; the
-heart with its great vessels; and the tube passing
-from the mouth to the stomach (fig. LX.).</p>
-
-<p>107. The two lungs occupy the sides of the chest
-(fig. LX. 5). They are completely separated
-from each other by the membranous partition just
-described, the mediastinum. Between the two
-
-<span class="pagenum"><a name="Page_239" id="Page_239">[Pg 239]</a></span>
-
-folds of the mediastinum, namely, in the middle
-of the chest, but inclining somewhat to the left
-side, is placed the heart, enveloped in another
-serous membrane, the pericardium (fig. LX.
-2, 1).</p>
-
-<p>108. The lungs are moulded to the cavities they
-fill; whence their figure is conical, the base of the
-cone being downwards, resting on the diaphragm
-(fig. LX. 5, <i>b</i>); and the apex upwards, towards
-the neck (fig. LX. 5).</p>
-
-<p>109. That surface of each lung which corresponds
-to the walls of the chest is convex in its
-whole extent (fig. LX. 5); on the contrary, that
-surface which corresponds to the mediastinum is
-flattened (fig. LX. 5). The basis of the lung is
-concave, adapted to the convexity of the diaphragm
-on which it rests (fig. LX. 5).</p>
-
-<p>110. The air-vessel of the lungs, termed the
-bronchus, together with the blood-vessels and nerves,
-enter the organ at its flattened side, not exactly in
-the middle, but rather towards the upper and back
-part. This portion is termed the root of the lung.</p>
-
-<p>111. The lungs are attached to the neck by the
-trachea (fig. LX. 4), the continuation of which
-forms the bronchus; to the spinal column by the
-pleura, and to the heart by the pulmonary vessels
-(fig. LX. 3, <i>d</i>): their remaining portion is free
-and unattached.</p>
-
-<p>112. In the living body, the lungs on each side
-completely fill the cavity of the chest, following
-passively the movements of its walls, and accurately
-adapting themselves to its size, whether its
-capacity enlarge in inspiration, or diminish in expiration,
-so that the external surface of the lung
-(the pulmonary pleura) is always in immediate
-contact with the lining membrane of the walls of
-the cavity (the costal pleura); consequently,
-during life, there is no cavity, the chest being
-always completely full.</p>
-
-<p><span class="pagenum"><a name="Page_240" id="Page_240">[Pg 240]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_240.png" alt="Fig. LX." />
-<div class="caption"><i>a.</i> The cut edges of the ribs, forming the lateral boundaries of the<br />
-cavity of the thorax.<br />
-
-<i>b.</i>  The diaphragm, forming the inferior boundary of the thorax, and<br />
-the division between the thorax and the abdomen.<br />
-
-<i>c.</i>  The cut edges of the abdominal muscles, turned aside, exposing<br />
-the general cavity of the abdomen.<br />
-
-1. The cut edge of the pericardium<br />
-turned aside.<br />
-
-2. The heart.<br />
-
-3. The great vessels in immediate<br />
-connexion with the<br />
-heart.<br />
-
-4. The trachea, or wind-pipe.<br />
-
-5. The lungs.<br />
-
-6. The liver.<br />
-
-7. The stomach.<br />
-
-8. The large intestine.<br />
-
-9. The small intestines.<br />
-
-10. The urinary bladder.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_241" id="Page_241">[Pg 241]</a></span></p>
-
-<p>113.  The anterior surface of the pericardium,
-the bag which envelopes the heart, lies immediately
-behind the sternum, and the cartilages of the
-second, third, fourth, and fifth ribs, covered at its
-sides by the pleura, and firmly attached below to
-the diaphragm (fig. LX. 1).</p>
-
-<p>114.  Surrounded by its pericardium, within the
-mediastinum, the heart is placed nearly in the
-centre of the chest, but its direction is somewhat
-oblique, its apex being directly opposite to the interval
-between the fifth and sixth ribs on the left
-side (fig. LX. 2); while its basis is directed upwards,
-backwards, and towards the right (fig.
-LX. 2). That portion of its surface which is
-presented to view on opening the pericardium is
-convex (fig. LX. 2); but its opposite surface,
-namely, that which rests upon the part of the pericardium
-which is attached to the diaphragm, is
-flattened (fig. LX. 1). It is fixed in its situation
-partly by the pericardium and partly by the great
-vessels that go to and from it. But under the
-different states of expiration and inspiration, it
-
-<span class="pagenum"><a name="Page_242" id="Page_242">[Pg 242]</a></span>
-
-accompanies, in some degree, the movements of
-the diaphragm; and in the varied postures of the
-body, the heart deviates to a certain extent from
-the exact position here described.</p>
-
-<p>115. The second division of the trunk, the <i>abdomen</i>,
-is bounded above by the diaphragm (fig.
-LXI. 2), below by the pelvis (fig. LXI. 3), behind
-and at the sides by the vertebræ and muscles of
-the loins (fig. LXIII.), and before by the abdominal
-muscles (fig. LXIII. 9).</p>
-
-<p>116. The organ which forms the superior boundary
-of the abdomen, the diaphragm (midriff), is
-a circular muscle, placed transversely across the
-trunk, nearly at its centre (fig. LXI. 2). It forms
-a vaulted partition between the thorax and the
-abdomen (fig. LXI. 2). All around its border it
-is fleshy (fig. LXI. 2); towards its centre it is
-tendinous (fig. LXI. 2); the surface towards the
-abdomen is concave (fig. LXI. 2); that towards
-the thorax convex (fig. LXI. 2); while its middle
-tendinous portion ascends into the thorax as high
-as the fourth rib (fig. LXI. 2).</p>
-
-<p><span class="pagenum"><a name="Page_243" id="Page_243">[Pg 243]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_243.png" alt="Fig. LXI." />
-<div class="caption">View of the diaphragm. 1. Cavity of the thorax;<br />
-2. diaphragm separating the cavity of the thorax from that of<br />
-the abdomen; 3. cavity of the pelvis.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_244" id="Page_244">[Pg 244]</a></span></p>
-
-<p>117. The diaphragm is perforated by several
-apertures, for the transmission of tubes and vessels,
-which pass reciprocally between the thorax and
-abdomen (fig. LXII.).</p>
-
-<p>1. A separate aperture is formed to afford an
-exit from the thorax of the aorta, the common
-source of the arteries (fig. LXII. 2), and an entrance
-into the thorax of the thoracic duct, the tube that
-bears the digested aliment to the heart. 2. A little
-to the left of the former, there is another aperture,
-through which passes the esophagus or gullet (fig.
-LXII. 3), the tube that conveys the food from the
-mouth to the stomach. 3. On the right side, in
-the tendinous portion of the diaphragm, very carefully
-constructed, is a third aperture for the passage
-of the vena cava (fig. LXII. 4), the great vessel that
-returns the blood to the heart from the lower parts
-of the body.</p>
-
-<p><span class="pagenum"><a name="Page_245" id="Page_245">[Pg 245]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_244.png" alt="Fig. LXII." />
-<div class="caption">View of the diaphragm with the tubes that pass through<br />
-it. 1. Arch of the diaphragm; 2. the trunk of the aorta<br />
-passing from the chest into the abdomen; 3. the esophagus<br />
-passing from the chest through the diaphragm to the stomach;<br />
-4. the vena cava, the great vein that returns the<br />
-blood to the heart from the lower parts of the body, passing<br />
-from the abdomen, into the chest, in its way to the right<br />
-side of the heart; 5. 6. muscles that arise in the interior of<br />
-the trunk and that act upon the thigh; 5. the muscle called<br />
-psoas; 6. the muscle called iliacus.</div>
-</div>
-
-<p>118. The partition formed by the diaphragm between
-the thorax and abdomen, though complete,
-is moveable; for as the diaphragm descends in inspiration
-and ascends in expiration, it proportionally
-enlarges or diminishes the cavities between
-which it is placed; consequently, the actual magnitude
-of these cavities varies every moment, and
-the size of the one is always in the inverse ratio of
-that of the other.</p>
-
-<p>119. Between the abdomen and the pelvis there
-is no separation; one cavity is directly continuous
-with the other (fig. LXI. 3); but along the inner
-surface of the expanded bones, which form a part
-of the lateral boundary of the abdomen, there is a
-prominent line, termed the brim of the pelvis (fig.
-XLV. 15), marking the point at which the abdomen
-is supposed to terminate and the pelvis to
-commence.</p>
-
-<p>120. Behind and at the sides the walls of the
-abdomen are completed partly by the lumbar portion
-of the spinal column and partly by the lumbar
-muscles (fig. XLV. 4), and before by the abdominal
-muscles (fig. LXIII. 9).</p>
-
-<p>121. The inner surface of the walls of the abdomen
-is lined throughout by a serous membrane,
-termed the peritoneum (fig. LXIII.). From the
-
-<span class="pagenum"><a name="Page_246" id="Page_246">[Pg 246]</a></span>
-
-walls of the abdomen, the peritoneum is reflected
-upon the organs contained in the cavity, and is
-continued over them so as to form their external
-coat. The peritoneum also descends between the
-several organs, connecting them together, and
-holding them firmly in their situation; and it likewise
-forms numerous folds, in which are embedded
-the vessels and nerves that supply the organs. It
-secretes a serous fluid, by which its own surface
-and that of the organs it covers is rendered moist,
-polished, and glistening, and by means of which
-the organs glide smoothly over it, and over one
-another in the various movements of the body,
-and are in constant contact without growing together.
-In structure, distribution, and function,
-the peritoneum is thus perfectly analogous to the
-pleura.</p>
-
-<p>122. Like the thorax, the abdomen is always
-completely full. When the diaphragm is in
-action, it contracts. When the diaphragm is in
-the state of contraction, the abdominal and lumbar
-muscles are in the state of relaxation. By the
-contraction of the diaphragm, the organs contained
-in the abdomen are pushed downwards, and the
-anterior and lateral walls of the cavity being at
-this moment in a state of relaxation, they readily
-yield, and, consequently, the viscera are protruded
-forwards and at the sides. But the abdominal and
-lumbar muscles in their turn contract, the diaphragm
-relaxing; and, consequently, the viscera,
-
-<span class="pagenum"><a name="Page_247" id="Page_247">[Pg 247]</a></span>
-
-forced from the front and sides of the abdomen,
-are pushed upwards, together with the diaphragm,
-into the cavity of the thorax. A firm and uniform
-pressure is thus at all times maintained upon the
-whole contents of the abdomen: there is an exact
-adaptation of the containing to the contained parts,
-and of one organ to another. No space intervenes
-either between the walls of the abdomen and the
-organs they enclose, or between one organ and
-another: so that the term cavity does not denote
-a void or empty space, but merely the extent of the
-boundary within which the viscera are contained.</p>
-
-<p>123. The contents of the abdomen consist of the
-organs which belong to the apparatus of digestion,
-and of those which belong to the apparatus of
-excretion.</p>
-
-<p>124. The organs which belong to the apparatus
-of digestion are&mdash;1. The stomach (fig. LXIII. 2)
-2.  The duodenum (fig. LXIII. 4). 3. The jejunum
-(fig. LXIII. 5). 4. The ilium (fig. LXIII. 5). The
-three last organs are called the small intestines,
-and their office is partly to carry on the digestion
-of the aliment commenced in the stomach, and
-partly to afford an extended surface for the absorption
-of the nutriment as it is prepared from the
-aliment. 5. The pancreas (fig. LXIV. 5). 6.
-The liver (fig. LXIV. 2). 7. The spleen (fig.
-LXIV. 4). The three last organs truly belong
-to the apparatus of digestion, and their office is to
-co-operate with the stomach and the small intestines
-in the conversion of the aliment into nutriment.</p>
-
-<p><span class="pagenum"><a name="Page_248" id="Page_248">[Pg 248]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_248.png" alt="Fig. LXIII." />
-<div class="caption">1. Esophagus; 2. stomach; 3. liver raised, showing its<br />
-under surface; 4. duodenum; 5. small intestines; 6. cæcum;
-7. colon; 8. urinary bladder; 9. gall bladder;<br />
-10. abdominal muscles divided and reflected.</div>
-</div>
-
-<p>125. The organs which belong to the apparatus
-of excretion are&mdash;1. The large intestines consisting
-
-<span class="pagenum"><a name="Page_249" id="Page_249">[Pg 249]</a></span>
-
-of the cæcum (fig. LXIII. 6). 2. The
-colon (fig. LXIII. 7). 3. The rectum (fig.
-LXIV. 10). It is the office of these organs, which
-are called the large intestines, to carry out of the
-system that portion of the alimentary mass which
-is not converted into nourishment. 4. The kidneys
-(fig. LXIV. 6), the organs which separate in
-the form of the urine an excrementitious matter
-from the blood, in order that it may be conveyed
-out of the system.</p>
-
-<p><span class="pagenum"><a name="Page_250" id="Page_250">[Pg 250]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_250.png" alt="Fig. LXIV." />
-<div class="caption">General view of the viscera of the abdomen. 1. Stomach<br />
-raised; 2. under surface of liver; 3. gall bladder; 4. spleen;<br />
-5.  pancreas; 6. kidneys; 7. ureters; 8. urinary bladder;<br />
-9.  portion of the intestine called duodenum; 10. portion of<br />
-the intestine called rectum; 11. the aorta.</div>
-</div>
-
-<p>126. The last division of the trunk, called the
-pelvis (fig. LXI. 3), consists of a circle of large
-and firm bones, interposed between the lower
-portion of the trunk and the inferior extremities
-(fig. XLV.). The bones that compose the
-circle, distinct in the child, are firmly united in
-the adult into a single piece; but as the original
-separation between each remains manifest, they
-are always described as separate bones. They are
-the sacrum (fig. XLV. 5), the coccyx (fig.
-XXXV.), the ilium (fig. XLV. 11), the ischium
-(fig. XLV. 12), and the pubis (fig. XLV. 13).</p>
-
-<p>127. The sacrum, placed like a wedge between
-the moveable portion of the spinal column and the
-lower extremities, forms the posterior boundary of
-the pelvis. The figure of this bone is triangular
-(fig. XLV. 5); its anterior surface is concave
-and smooth, for enlarging the cavity of the pelvis
-and sustaining the organs contained in it (fig.
-XLV. 5); its posterior surface is convex,
-
-<span class="pagenum"><a name="Page_251" id="Page_251">[Pg 251]</a></span>
-
-irregular, and rough (fig. XXXV.), giving origin to
-the great muscles that form the contour of the
-hip, and to the strong muscles of the back and
-loins that raise the spine and maintain the trunk
-of the body erect.</p>
-
-<p>128. The base or upper part of the sacrum receives
-the last vertebra of the loins on a large and
-broad surface (fig. XLV. 4), forming a moveable
-joint; and the degree of motion at this point is
-greater than it is at the higher points of the spinal
-column. Firmly united at its sides with the
-haunch bones, it admits there of no degree of
-motion.</p>
-
-<p>129. The coccyx, so named from its resemblance
-to the beak of the cuckoo, when elongated
-by a succession of additional bones, forms the tail
-in quadrupeds; but in man it is turned inwards to
-support the parts contained in the pelvis, and to
-contract the lower opening of the cavity. By
-means of a layer of cartilage, the medium by
-which this bone is connected with the sacrum, it
-forms a moveable articulation, continuing moveable
-in men until the age of twenty-five, and in
-women until the age of forty-five; continuing
-moveable in women thus long, in order that by
-yielding to the force which tends to push it backwards
-during the period of labour, it may enlarge
-the lower aperture of the pelvis, and so facilitate
-the process of parturition and diminish its suffering.</p>
-
-<p>130. The lateral boundaries of the pelvis are
-
-<span class="pagenum"><a name="Page_252" id="Page_252">[Pg 252]</a></span>
-
-formed by the ilium, the haunch bone (fig. XLV.
-11), and by the ischium, the hip bone (fig. XLV.
-12). The ilium forms the lower part of the
-abdomen and the upper part of the pelvis (fig.
-XLV. 11); its broad expanded wing supports
-the contents of the abdomen, and gives attachment
-to the muscles that form the anterior portion of its
-walls (figs. XLV. 11, and LXIII. 9); its external
-convex surface sustains the powerful muscles that
-extend the thigh; and along its internal surface
-is the prominent line which marks the brim of the
-pelvis (fig. XLV. 15), and which divides this
-cavity from that of the abdomen.</p>
-
-<p>131. The ischium or hip bone is the lower part
-of the pelvis (fig. XLV. 12); at its undermost
-portion is a rounded prominence called the tuberosity
-(fig. XLV. 12), in its natural condition
-covered with cartilage, upon which is superimposed
-a cushion of fat. It is this part on which the body
-is supported in a sitting posture.</p>
-
-<p>132. The pubis or share bone forms the upper
-and fore part of the pelvis (fig. XLV. 13), and
-together with the two former bones, completes the
-large and deep socket, termed the acetabulum (fig.
-XLV. 14), into which is received the head of the
-thigh-bone (fig. XXXIV. 4). The margin of the
-acetabulum and the greater part of its internal
-surface is lined with cartilage, so that in its natural
-condition it is much deeper than it appears to be
-when the bones alone remain.</p>
-
-<p><span class="pagenum"><a name="Page_253" id="Page_253">[Pg 253]</a></span></p>
-
-<p>133. The lower aperture of the pelvis, which
-appears large when all the soft parts are removed,
-is not really large, for in its natural state it is filled
-up partly by muscles and partly by ligaments,
-which sustain and protect the pelvic organs, leaving
-only just space enough for the passage to and from
-those which have their opening on the external
-surface.</p>
-
-<p>134. The cavity of the pelvis, together with all
-the organs contained in it, are lined by a continuation
-of the membrane that invests the abdomen
-and its contents.</p>
-
-<p>135. The organs contained in the pelvis are the
-rectum (fig. LXIV. 9), which is merely the termination
-of the large intestines, the urinary bladder
-(fig. LXIV. 8), and the internal part of the apparatus
-of reproduction.</p>
-
-<p>136. The large and strong bones of the pelvis
-not only afford lodgment and protection to the
-tender organs contained in its cavity, but sustain
-the entire weight of the body, the trunk resting on
-the sacrum as on a solid basis (fig. XLV. 5),
-and the lower extremities being supported in the
-sockets in which the heads of the thigh-bones play,
-in the varied movements of locomotion (fig.
-XXXIV. 4).</p>
-
-<p>137. The last division of the body comprehends
-the superior and the inferior extremities.</p>
-
-<p>138. The superior extremities consist of the
-shoulder, arm, fore-arm, and hand.</p>
-
-<p><span class="pagenum"><a name="Page_254" id="Page_254">[Pg 254]</a></span></p>
-
-<p>139. The soft parts of the <span class="smcap">SHOULDER</span> are composed
-chiefly of muscles; its bones are two, the
-scapula or the <i>blade bone</i>, and the clavicle or
-the <i>collar bone</i> (fig. LXV. 2, 4).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_254.png" alt="Fig. LXV." />
-<div class="caption">1. Sternum; 2. clavicle; 3. ribs; 4. anterior surface of<br />
-scapula; 5. coracoid process of scapula; 6. acromion process<br />
-of scapula; 7. margin of glenoid cavity of scapula;<br />
-8. body of the humerus or bone of the arm; 9. head of the<br />
-humerus.</div>
-</div>
-
-<p>140. The <span class="smcap">SCAPULA</span> is placed upon the upper and
-back part of the thorax, and occupies the space
-from the second to the seventh ribs (fig. LXV. 4)</p>
-
-<p><span class="pagenum"><a name="Page_255" id="Page_255">[Pg 255]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_255.png" alt="Fig. LXVI." />
-<div class="caption">1. Posterior surface of scapula; 2. margin of scapula;<br />
-3. acromion process; 4. margin of glenoid cavity; 5. clavicle;<br />
-6. body of humerus; 7. head of humerus.</div>
-</div>
-
-<p>Unlike that of any other bone of the body, it
-is embedded in muscles, without being attached
-to any bone of the trunk, excepting at a single
-point. From the bones of the thorax it is separated
-by a double layer of muscles, on which
-it is placed as upon a cushion, and over the smooth
-surface of which it glides. Originally, like the
-bones of the skull, it consisted of two tables of
-compact bone, with an intermediate layer of spongy
-bony substance (diploë); but, by the pressure of
-the muscles that act upon it, it gradually grows
-thinner and thinner, until, as age advances, it becomes
-
-<span class="pagenum"><a name="Page_256" id="Page_256">[Pg 256]</a></span>
-
-in some parts quite transparent and as thin
-as a sheet of paper.</p>
-
-<p>141. The figure of the scapula is that of an
-irregular triangle (fig. LXVI.). Its anterior surface
-is concave (fig. LXV. 4), corresponding to the
-convexity of the ribs (fig. XLV. 7); its posterior
-surface is very irregular (fig. LXVI. 1), being in
-some parts concave and in others convex, giving
-origin especially to two large processes (figs. LXV.
-5, and LXVI. 3); one of which is termed the
-<i>acromion</i> (fig. LXVI. 3), and the other the <i>coracoid</i>
-process of the scapula (fig. LXV. 5). The
-margins of the bone, whatever the thinness of
-some portions of it, are always comparatively thick
-and strong (fig. LXVI. 2), affording points of
-origin or of insertion to powerful muscles. At
-what is called the anterior angle of the bone there
-is a shallow oval depression covered with cartilage
-and deepened by a cartilaginous margin, called
-the <i>glenoid</i> cavity of the scapula (figs. LXV. 7,
-and LXVI. 4), which receives the head of the
-humerus or bone of the arm (figs. LXV. 9, and
-LXVI. 7, 6).</p>
-
-<p>142. The clavicle, the second bone of the shoulder,
-is a long and slender bone, of the form of an italic
-<span class="figcenter">
-<img src="images/i_262.png" alt="" width="28" height="15" /></span>,
-projecting a little forwards towards its
-middle, so as to give a slight convexity of outline
-to the top of the chest and the bottom of the neck
-(fig. LXV. 2). It is attached by one extremity
-to the sternum (fig. LXV. 2) and by the other to
-
-<span class="pagenum"><a name="Page_257" id="Page_257">[Pg 257]</a></span>
-
-the scapula (fig. LXV. 2), by moveable joints.
-The nature of an immoveable joint has been explained
-(63). In the connexion of the bones
-of the trunk, while the main object is to secure
-firmness of attachment, some degree of motion is
-at the same time obtained (81 et seq.): but the
-mode in which the several bones of the extremities
-are connected with each other and with the trunk,
-admits of so great a degree of motion, that these
-articulations are pre-eminently entitled to the name
-of moveable joints. The component parts of all
-moveable joints are bone, cartilage, synovial membrane,
-and ligament. The great character of a
-moveable joint is the approximation of two or more
-bones; yet these bony surfaces are never in actual
-contact, but are invariably separated from each
-other by cartilage. The cartilage either covers the
-entire extent of the articulating surface of the
-bones, as in the shoulder-joint, where both the head
-of the humerus and the cavity of the scapula that
-receives it are enveloped in this substance (fig.
-LXV. 7. 9), or a portion of it is placed between
-the articulating surfaces of the bones, as in the
-joint between the clavicle and sternum (fig. LXVII.
-<i>a</i>); which, when so placed, is termed an interarticular
-cartilage (fig. LXVII. <i>a</i>). By its
-smooth surface cartilage lessens friction; while by
-its elasticity it facilitates motion and prevents concussion.
-Slightly organized cartilage is provided
-with comparatively few blood-vessels and nerves.
-
-<span class="pagenum"><a name="Page_258" id="Page_258">[Pg 258]</a></span>
-
-Had it been vascular and sensible like the skin
-and the muscle, the force applied in the movements
-of the joint would have stimulated the blood-vessels
-to inordinate action, and the sensibility of the
-nerves would have been the source of constant
-pain: every motion of every joint would have been
-productive of suffering, and have laid the foundation
-of disease. The facility and ease of motion
-obtained by the smoothness, elasticity, and comparative
-insensibility of cartilage are still further
-promoted by the fluid which lubricates it, termed
-synovia, secreted by a membrane called synovial,
-which lines the internal surface of the joint, and
-which bears a close resemblance to the serous
-(30). Synovia is a viscid fluid of the consistence
-of albumen (5). It is to the joint what
-oil is to the wheel, preventing abrasion and facilitating
-motion; but it is formed by the joint
-itself, at the moment when needed, and in the
-quantity required. The motion of the joint stimulates
-the synovial membrane to secretion, and
-hence the greater the degree of motion, the larger
-the quantity of lubricating fluid that is supplied.
-The several parts of the apparatus of moveable
-joints are retained in their proper position by ligamentous
-substance, which, as has been shown (96
-and 97), is oftentimes so strong that it is easier
-to fracture the bone than to tear the ligament, and
-in every case the kind and extent of motion possessed
-by the joint are dependent mainly on the
-
-<span class="pagenum"><a name="Page_259" id="Page_259">[Pg 259]</a></span>
-
-form of the articulatory surfaces of the bones and
-on the disposition of the ligaments.</p>
-
-<p>143. In the joint formed by the clavicle and
-the sternum (fig. LXVII. <i>a</i>) an interarticular cartilage
-is placed between the two bones which are
-united, first by a strong fibrous ligament, which
-envelops them as in a capsule (fig. LXVII. 1);
-by a second ligament, which extends from the
-cartilage of the first rib to the clavicle (fig.
-LXVII. 4), by which the attachment of the clavicle
-to the sternum is materially strengthened;
-and by a third ligament which passes transversely
-from the head of one clavicle to that of the other
-(fig. LXVII. 3). The joint thus formed, though
-so strong and firm that the dislocation of it is exceedingly
-
-<span class="pagenum"><a name="Page_260" id="Page_260">[Pg 260]</a></span>
-
-rare, yet admits of some degree of motion
-in every direction, upwards, downwards, forwards,
-and backwards; and this articulation is the
-sole point by which the scapula is connected with
-the trunk, and consequently by which the upper
-extremity can act, or be acted upon, by the rest of
-the body.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_259.png" alt="Fig. LXVII." />
-<div class="caption">1. The fibrous capsule of the sternum and clavicle; 2. the<br />
-same laid open, showing <i>a</i>, the interarticular cartilage;<br />
-3. the ligament connecting the two clavicles; 4. the ligament<br />
-joining the clavicle to the first rib; 5. ligaments<br />
-passing down in front of the sternum.</div>
-</div>
-
-<p>144. The scapular extremity of the clavicle
-(fig. LXVIII. 6) is attached to the processes of the
-scapula (fig. LXVIII. 4. 3) by several ligaments
-of great strength (fig. LXVIII. 7, 8, 9). First
-by very strong fasciculi which pass from the upper
-surface of the clavicle to the acromion of the scapula
-(fig. LXVIII. 6); and secondly by two ligaments
-
-<span class="pagenum"><a name="Page_261" id="Page_261">[Pg 261]</a></span>
-
-which unite the clavicle with the coracoid
-process of the scapula (fig. LXVIII. 8, 9). These
-ligaments are so powerful that they resist a
-force capable of fracturing the clavicle; and they
-need to be thus strong, for the clavicle is a shaft
-which sustains the scapula, and through the
-scapula the whole of the upper extremity; and the
-main object of the joint by which these bones are
-united, is to afford a firm attachment of the scapula
-to its point of support.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_260.png" alt="Fig. LXVIII." />
-<div class="caption">1. The clavicle; 2. the anterior part of the scapula;<br />
-3. the coracoid process; 4. the acromion process; 5. the humerus;<br />
-6. ligaments binding the scapular end of the clavicle<br />
-to the acromion; 7. 8. 9. ligaments passing from one<br />
-process of the scapula to the other; 10. the fibrous capsule<br />
-of the shoulder-joint.</div>
-</div>
-
-<p>145.  The clavicle serves the following uses:
-it sustains the upper extremity; it connects
-the upper extremity with the thorax; it prevents
-the upper extremity from falling forwards upon
-the thorax; and it affords a fixed point for steadying
-the extremity in the performance of its various
-actions.</p>
-
-<p>146.  The glenoid cavity of the scapula (fig.
-LXV. 7) receives the head of the humerus, the bone
-of the arm (fig. LXV. 9), and the two bones being
-united by ligament form the shoulder-joint (fig.
-LXVIII.). This joint is what is termed a ball
-and socket joint, the peculiarities of which are two:
-first, beyond all others this mode of articulation
-admits of free and extensive motion; in the present
-case, there is the utmost freedom of motion in
-every direction, upwards, downwards, backwards,
-and forwards. In the second place, this mode of
-articulation admits of the motion of the limb without
-that of the body, or of the motion of the body
-
-<span class="pagenum"><a name="Page_262" id="Page_262">[Pg 262]</a></span>
-
-without that of the limb. When at rest, the arm
-may be moved in almost any direction without
-disturbing the position of any other part of the
-frame; the manifold advantages of which are obvious.
-On the other hand, by careful management,
-very considerable variations in the posture
-of the body may be effected without the communication
-of any degree of motion to the limb; an
-unspeakable advantage when the limb has sustained
-injury, or is suffering from disease.</p>
-
-<p>147.  It does not seem possible to construct a
-joint of great strength, capable, at the same time,
-of the degree of motion possessed by the joint of
-the shoulder. So shallow is the socket of the scapula,
-and so large the head of the humerus, that
-it seems as if the slightest movement must dislodge
-it from its cavity (fig. LXVI. 4. 7). For sustaining
-heavy weights or resisting a great amount
-of pressure, applied to it suddenly and in various
-directions, the arm is obviously unfitted. But this
-is not its office. The superior extremities are the
-organs of apprehension&mdash;the instruments by which
-the mind executes the commands of the will. They
-do not need the strength required by the organs
-that sustain the weight of the body and that perform
-the function of locomotion; but they do need
-freedom and extent of motion: to this strength
-may be sacrificed, and so it is; yet what can be
-done to combine strength with mobility is effected.
-Large and strong processes of bone, proceeding
-
-<span class="pagenum"><a name="Page_263" id="Page_263">[Pg 263]</a></span>
-
-as has been shown (141), from the convex surface
-of the scapula (figs. LXV. and LXVI.),
-overhang, and to a considerable extent surround,
-the head of the arm-bone, especially resisting the
-force that would dislodge it from its socket and
-drive it upwards, inwards, and backwards (fig.
-LXV.), the directions in which force is most commonly
-applied to it. By these processes of bone
-the joint is greatly strengthened, especially in those
-directions. Moreover, a strong ligament, termed
-the fibrous capsule (fig. LXVIII. 10) envelops the
-joint. This ligament, arising from the neck of the
-scapula (fig. LXVIII. 10), expands itself in such
-a manner as completely to surround the head of
-the humerus (fig. LXVIII. 10); and then again
-contracts in order to be inserted into the neck of
-the bone (fig. LXVIII. 10). This ligament is
-strengthened by the tendons of no less than four
-muscles which are expanded over it, as well as by
-the powerful substance termed fascia which is reflected
-upon it from both the processes and ligaments
-of the scapula. In addition to all these expedients
-for fortifying the joint, it receives a further
-security in the position of the scapula, which is
-loose and unattached; which slides easily over the
-ribs upon its cushion of flesh; which thus obtains,
-by its facility of yielding, some compensation for
-its want of strength, eluding the force which it
-cannot resist.</p>
-
-<p>148.  The arm consists of numerous and powerful
-
-<span class="pagenum"><a name="Page_264" id="Page_264">[Pg 264]</a></span>
-
-muscles, and of a single bone, the humerus,
-which belongs to the class of bones termed cylindrical
-(185).</p>
-
-<p>149.  The upper end of the humerus terminates
-in a circular head (fig. LXV. 9), which is received
-into the socket of the scapula (fig. LXV. 9. 7)
-
-<span class="pagenum"><a name="Page_265" id="Page_265">[Pg 265]</a></span>
-
-termed, as has been stated (141), its glenoid
-cavity. The middle portion of the bone, or what is
-termed its shaft (fig. LXV. 8), diminishes considerably
-in magnitude, and becomes somewhat
-rounded (fig. LXV. 8), while its lower end again
-enlarges, and is spread out into a flattened surface of
-great extent (fig. LXIX. 1, 3, 2, 4). Of this broad
-flattened surface, the middle portion is grooved
-(fig. LXIX. 2): it is covered with cartilage; it forms
-the articulating surface by which the arm is connected
-with the fore-arm. On each side of this
-groove there is a projection of bone or tubercle,
-termed condyle (fig. LXIX. 3, 4), the inner (fig.
-LXIX. 3) being much larger than the outer (fig.
-LXIX. 4). The inner condyle gives origin to the
-muscles that bend, the outer to those that extend
-the fore-arm and the fingers (figs. LXXXIV.
-1, 2, and LXXXV. 1).</p>
-
-<p><span class="pagenum"><a name="Page_266" id="Page_266">[Pg 266]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_264.png" alt="Fig. LXIX." />
-<div class="caption">1.  Lower extremity of the humerus; 2. grooved surface;<br />
-3. internal condyle; 4. external condyle; 5. the upper part<br />
-of the ulna; 6. the head; 7. the neck; 8. the tubercle of<br />
-the radius.</div>
-</div>
-
-<p>150. The muscles that act upon the arm arise
-from the back (fig. LXXII. 2), the chest (fig.
-LXXI. 1), the clavicle (fig. LXXI. 1), and the
-scapula (fig. LXXI. 3); and they move the arm
-with freedom and power upwards, downwards, forwards,
-backwards, inwards, and outwards. The
-chief muscle that raises the arm is the deltoid (fig.
-LXXI. 3), which arises partly from the clavicle
-and partly from the scapula (fig. LXXI. 3). It has
-the appearance of three muscles proceeding in different
-directions, the different portions being separated
-by slight fissures (figs. LXXI. 3, and
-
-LXXII. 3). The fibres converging unite and form
-a powerful muscle which covers the joint of the
-humerus (fig. LXXI. 3). It is implanted by a short
-and strong tendon into the middle of the humerus
-(fig. LXXI. 4). Its manifest action is to pull the
-arm directly upwards. Its action is assisted by the
-muscles that cover the back of the scapula, which
-are in like manner inserted into the humerus, and
-
-<span class="pagenum"><a name="Page_267" id="Page_267">[Pg 267]</a></span>
-
-which, at the same time that they elevate the arm,
-support it when raised.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_266.png" alt="Fig. LXXI." />
-<div class="caption">View of the muscles on the fore part of the chest that<br />
-act upon the arm. 1. The muscle called the great pectoral;<br />
-2. the small pectoral; 3. the deltoid; 4. the humerus.</div>
-</div>
-
-<p>151. The principal muscle that carries the arm
-downwards is the latissimus dorsi (fig. LXXII. 2),
-the broadest muscle of the body, which, after having
-covered all the lower part of the back and loins,
-terminates in a thin but strong tendon which
-stretches to the arm, and is implanted into the humerus
-(fig. LXXII. 2), near the tendon of a
-muscle immediately to be described,&mdash;the great
-pectoral. When the arm is raised by the deltoid
-and its assistant muscles, the latissimus dorsi carries
-it downwards with force, and its powerful action
-is increased by that of other muscles which arise
-from the scapula and are inserted into the arm.</p>
-
-<p>152. The principal muscle that carries the arm
-forwards towards the chest, is the great pectoral
-(fig. LXXI. 1), which, arising partly from the clavicle
-(fig. LXXI. 1), partly from the sternum (fig.
-LXXI. 1), and partly from the cartilages of the
-second, third, fourth, fifth, and sixth ribs (fig.
-LXXI. 1), covers the greater part of the breast
-(fig. LXXI. 1). Its fibres, converging, terminate
-in a strong tendon, which is inserted near the
-tendon of the longissimus dorsi into the humerus,
-about four inches below its head (fig. LXXI. 1).
-These two muscles form the axilla or armpit,
-the anterior border of the axilla consisting of the
-pectoral muscle. Though each of these muscles
-has its own peculiar office, yet they often act in
-concert, thereby greatly increasing their power, and
-the result of their combined action is to carry the
-arm either directly downwards or to the side of the
-chest.</p>
-
-<p><span class="pagenum"><a name="Page_268" id="Page_268">[Pg 268]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_268.png" alt="Fig. LXXII." />
-<div class="caption">View of the muscles seated on the back part of the trunk<br />
-that act upon the shoulder and arm. 1. The muscle called<br />
-the trapezius; 2. the latissimus dorsi; 3. the deltoid.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_269" id="Page_269">[Pg 269]</a></span></p>
-
-<p>153. Some of the muscles that elevate the arm
-carry it inwards, and others outwards; the muscles
-that carry it forwards likewise carry it inwards;
-while of the muscles that pull it downwards, some
-direct it forwards and inwards, and others backwards
-and outwards (151 and 152).</p>
-
-<p>154. It has been already stated that the shoulder-joint
-is completely surrounded by the muscular
-fibres or the tendinous expansions of several of
-these powerful muscles, which have a far greater
-effect in maintaining the head of the humerus in
-its socket than the fibrous capsule of the joint;
-the latter being necessarily loose, in order to allow
-of the extended and varied motions of the arm,
-whereas the muscles that encompass the joint adhere
-closely and firmly to it. Moreover, by virtue
-of their vital power these muscles act with an
-efficiency which a mere ligamentous band is incapable
-of exerting; for they apportion the strength
-of resistance to the separating force, and react
-with an energy proportioned to the violence
-applied.</p>
-
-<p>155. The bones of the fore-arm are two, the
-ulna and the radius (figs. LXIX. and LXXIII.).
-The ulna is essentially the bone of the elbow (figs.
-LXIX. 5, and LXXIII. 3); the radius that of the
-
-<span class="pagenum"><a name="Page_270" id="Page_270">[Pg 270]</a></span>
-
-hand (fig. LXXV.). Supposing the arm to hang
-by the side of the body, and the palm of the
-hand to be turned forwards, the ulna, in apposition
-with the little finger, occupies the inner; and the
-radius, in apposition with the thumb, occupies the
-outer part of the fore-arm (fig. XXXIV. 3).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_270.png" alt="Fig. LXXIII." />
-<div class="caption">1. The internal condyle of the humerus; 2. the external<br />
-condyle of the humerus; 3. the olecranon process of the<br />
-ulna; 4. the head of the radius.</div>
-</div>
-
-<p>156. The upper end of the ulna belonging to
-the elbow is large (figs. LXIX. 5, and LXXIII. 3).
-It sends backwards the large projection commonly
-named the elbow or <i>olecranon</i> (fig. LXXII. 3),
-
-<span class="pagenum"><a name="Page_271" id="Page_271">[Pg 271]</a></span>
-
-in the centre of which there is a smooth and
-somewhat triangular surface (fig. LXXIII. 3)
-which is always covered by skin of a coarse texture,
-like that placed over the lower part of the
-knee-pan, as if nature intended this for a part
-on which we may occasionally lean and rest.
-Large at the elbow, the ulna gradually grows
-smaller and smaller as it descends towards the
-wrist, where it ends in a small round head (fig.
-LXXXII. 2), beyond which, on the inner side, or
-that corresponding to the little finger, it projects
-downwards a small rounded point, termed the
-styloid process (fig. LXXXII. 3). As the styloid
-process and the olecranon, the two extremities of
-the ulna (figs. LXXIII. 3, and LXXII. 3), are
-easily and distinctly felt, the length of this bone
-was primitively used as a measure, called a cubit,
-which was the ancient name of the bone.</p>
-
-<p>157. The radius, the second bone of the fore-arm,
-placed along its outer part next the thumb, is
-small at its upper end (figs. LXIX. 6, and
-LXXIII. 4); but its body is larger than that of
-the ulna; while its lower end, next the wrist to
-which it properly belongs, is very bulky (fig.
-LXXXII. 1). Its upper end is formed into a small
-circular head, which is united by distinct joints
-both to the humerus and to the ulna (fig. LXIX. 6).
-The top of its rounded head is excavated into
-a shallow cup (figs. LXIX. 6, and LXXIII. 4)
-which receives a corresponding convexity of the
-
-<span class="pagenum"><a name="Page_272" id="Page_272">[Pg 272]</a></span>
-
-humerus (fig. LXIX. 2), and its lower extremity
-is excavated into an oblong cavity, which receives
-two of the bones of the wrist (fig. LXXXIII. 1. 4).</p>
-
-<p>158. The joint of the elbow is composed above
-of the condyles of the humerus (fig. LXIX. 3. 2),
-and below by the heads of the ulna and radius
-(fig. LXIX. 5. 6).</p>
-
-<p>159. The upper surface of the ulna is so accurately
-adapted to the lower surface of the humerus
-that the one seems to be moulded on the other
-(figs. LXIX. 5, and LXXIII. 3), and the form of
-these corresponding surfaces, which are everywhere
-covered with cartilage, is such as to admit of free
-motion backwards and forwards, that is, of extension
-and flexion; but to prevent any degree of motion
-in any other direction. The joint is therefore
-a hinge-joint, of which the two motions of flexion
-and extension are the proper motions. This hinge
-is formed on the part of the humerus by a grooved
-surface, with lateral projections (fig. LXIX. 2,
-3, 4), and on the part of the ulna by a middle projection
-with lateral depressions (fig. LXIX. 5): the
-middle projection of the ulna turning readily on the
-grooved surface of the humerus (fig. LXIX. 2).</p>
-
-<p>160. The bones are held in their proper situation,
-first, by a ligament on the fore part of the arm,
-called the anterior (fig. LXXIV. 6), which arises
-from the lower extremity of the humerus, and is
-inserted into the upper part of the ulna and the
-coronary ligament of the radius (fig. LXXIV. 6.
-
-<span class="pagenum"><a name="Page_273" id="Page_273">[Pg 273]</a></span>
-
-8); secondly, by another ligament on the back part
-of the arm, called the posterior ligament (fig.LXXV.
-8), placed in the cavity of the humerus that receives
-the olecranon of the ulna (fig. LXXV. 8); and
-thirdly, by two other ligaments at the sides of the
-ulna (fig. LXXV. 6, 7). The ulna and radius are
-united, first, by a ligament called the coronary,
-which, arising from the ulna, passes completely
-
-<span class="pagenum"><a name="Page_274" id="Page_274">[Pg 274]</a></span>
-
-around the head of the radius (fig. LXXVI. 3),
-and the attachment of which, while sufficiently
-close to prevent the separation of the two bones, is
-yet not adherent to the radius, for a reason immediately
-to be assigned; secondly, by another ligament
-which passes in an oblique direction from one
-bone to the other (fig. LXXVI. 4); and thirdly,
-by a dense and broad ligament, termed the <i>interosseous</i>
-(figs. LXXIV. 10, and LXXVI. 5), which
-fills up the space between the two bones nearly in
-
-<span class="pagenum"><a name="Page_275" id="Page_275">[Pg 275]</a></span>
-
-their whole extent. This ligament serves other
-offices besides that of forming a bond of union,
-affording, more especially, a greater extent of surface
-for the attachment of muscles, and separating
-the muscles on the anterior from those on the posterior
-part of the limb.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_273.png" alt="Fig. LXXIV." />
-<div class="caption">Anterior view of the ligaments of the elbow-joint. 1. The<br />
-lower portion of the humerus; 2. the upper portion of the<br />
-radius; 3. the upper portion of the ulna; <br />
-4. the internal condyle; 5. the external condyle; 6. the anterior<br />
-ligament; 7. portion of the internal lateral ligament;<br />
-8. portion of the coronary ligament; 9. the oblique ligament;<br />
-10. upper portion of the interosseous ligament.</div>
-</div>
-
-<div class="topspace2"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_274.png" alt="Fig. LXXV." />
-<div class="caption">Posterior view of the ligaments of the elbow-joint.<br />
-1. Lower end of the humerus; 2. internal condyle; 3. external<br />
-condyle; 4. the olecranon process of the ulna;<br />
-5. the upper portion of the radius; 6. the internal lateral ligament;<br />
-7. the external lateral ligament; 8. the posterior<br />
-ligament.</div>
-</div>
-
-<div class="topspace2"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_275.png" alt="Fig. LXXVI." />
-<div class="caption">View of the ligaments connecting the ulna and radius at<br />
-their upper part. 1. The radius; 2. the ulna; 3. the coronary<br />
-ligament surrounding the head of the radius; 4. the<br />
-oblique ligament passing from the ulna to the tubercle of<br />
-the radius; 5 the upper portion of the interosseous ligament.</div>
-</div>
-
-<p>161. At their inferior extremities the ulna and
-radius are united partly by the interosseous ligament
-(fig. LXXVII. 1) and partly by ligamentous
-fibres which pass transversely from one bone to
-the other (fig. LXXVII. 2) on the anterior and
-the posterior surface of the fore-arm.</p>
-
-<p><span class="pagenum"><a name="Page_276" id="Page_276">[Pg 276]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_276.png" alt="Fig. LXXVII." />
-<div class="caption">1. Interosseous ligament; 2. transverse fibres passing<br />
-between the radius and ulna, and uniting the two bones;<br />
-3. 4. 5. posterior and lateral ligaments of the wrist joint;<br />
-6. ligaments uniting the bones of the wrist with one another;<br />
-7. 8. ligaments which attach the metacarpal to the<br />
-carpal bones; 9. transverse ligaments for the attachment<br />
-of the phalanges of the fingers; 10. lateral ligaments for<br />
-the attachment of the phalanges of the fingers 11. ligaments<br />
-of the thumb.</div>
-</div>
-
-<p>162. The lower extremity of the radius is also
-united to the wrist; and the hand being attached
-to the wrist, the junction of the hand and the fore-arm
-is effected by the articulation of the wrist with
-the radius (fig. LXXVII.). The ligaments which
-
-<span class="pagenum"><a name="Page_277" id="Page_277">[Pg 277]</a></span>
-
-connect the bones of the wrist with the radius are
-bands of exceeding strength (fig. LXXVII. 3).</p>
-
-<p>163. The muscles that act upon the fore-arm are
-placed upon the arm (fig. LXXVIII.). The joint of
-the elbow being a hinge-joint, the fore-arm can admit
-only of two motions, namely, flexion and extension.
-The muscles by which these motions are effected
-are four, two for each; the two flexors being
-placed on the fore part (fig. LXXVIII. 2. 4), and
-the two extensors on the back part of the arm
-(fig. LXXIX. 5).</p>
-
-<p>164. The two flexor muscles of the fore-arm are
-termed the biceps and the brachialis (fig. LXXVIII.
-2, 4). The biceps is so called because it has two
-distinct heads or points of origin (fig. LXXVIII.
-2), both of which arise from the scapula (fig.
-LXXVIII. 2). About a third part down the humerus
-the two heads meet, unite and form a bulky
-muscle (fig. LXXVIII. 2), which, when it contracts,
-may be felt like a firm ball on the fore part
-of the arm, the upper part of the ball marking the
-point of union of the two heads (fig. LXXVIII. 2).
-The muscle gradually becoming smaller, at length
-terminates in a rounded tendon (fig. LXXVIII. 3),
-which is implanted into the tubercle of the radius
-a little below its neck (fig. LXXVIII. 3). It is
-an exceedingly thick and powerful muscle, and its
-manifest action is to bend the fore-arm with great
-strength. But since its tendon is inserted into the
-radius, besides bending the fore-arm, it assists other
-
-muscles that also act upon the radius in the performance
-of a function to be described immediately
-(168).</p>
-
-<p><span class="pagenum"><a name="Page_278" id="Page_278">[Pg 278]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_278.png" alt="Fig. LXXVIII." />
-<div class="caption">View of the flexor muscles of the fore-arm. 1. The anterior<br />
-surface of the scapula; 2. the muscle called biceps;<br />
-3. tendon of the biceps passing to the tubercle of the radius;<br />
-4. the muscle called brachialis.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_279" id="Page_279">[Pg 279]</a></span></p>
-
-<p>165. The second flexor of the fore-arm, termed
-the brachialis, is placed immediately under the
-biceps, and is concealed by it for a considerable
-part of its course (fig. LXXVIII. 4). Arising from
-the humerus, on each side of the insertion of the
-deltoid, it continues its attachment to the bone all
-the way down the fore part of the humerus, to
-within inch of the joint; it then passes over
-the joint, adhering firmly to the anterior ligament
-(fig. LXXVIII. 4), and is inserted by a strong
-tendon into the ulna (fig. LXXVIII. 4). It is a
-thick and fleshy muscle, powerfully assisting the
-action of the biceps.</p>
-
-<p>166. The two extensor muscles are named the
-triceps and the anconeous (fig. LXXIX.). The
-triceps, seated on the back part of the arm, derives
-its name from having three distinct points of origin,
-or three separate heads (fig. LXXIX. 5); one of
-which arises from the scapula and two from
-the humerus (fig. LXXIX. 5). All these heads
-adhere firmly to the humerus, as the brachialis
-does on the fore part of the arm, down to within
-an inch of the joint (fig. LXXIX. 5), where they
-form a strong tendon, which is implanted into the
-olecranon of the ulna (fig. LXXIX. 3); the projection
-of which affords a lever for increasing the action
-of the muscle. In all animals that leap and bound,
-this process of the ulna is increased in length
-in proportion to their power of performing these
-movements. The triceps forms an exceedingly thick
-and strong muscle, which envelops the whole of
-the back part of the arm (fig. LXXIX.); its
-action is simple and obvious; it powerfully extends
-the fore-arm. The anconeous, a small muscle of a
-triangular form, arising from the external condyle
-of the humerus, and inserted into the ulna a little
-below the olecranon, assists the action of the
-triceps.</p>
-
-<p><span class="pagenum"><a name="Page_280" id="Page_280">[Pg 280]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_280.png" alt="Fig. LXXIX." />
-<div class="caption">View of the extensor muscles of the fore-arm. 1. The<br />
-scapula; 2. the upper part of the humerus; 3. upper end<br />
-of the ulna; 4. upper end of the radius; 5. the muscle<br />
-called <i>triceps</i>, the extensor of the fore-arm.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_281" id="Page_281">[Pg 281]</a></span></p>
-
-<p>167. Such are the motive powers which act
-upon the fore-arm, and which produce all the
-motions of which the hinge-joint of the elbow
-renders it capable. But besides flexion and extension,
-the fore-arm is capable of the motion of
-rotation, which is accomplished by means of the
-radius. It has been shown (157) that the top of
-the rounded head of the radius is excavated into
-a shallow cup (figs. LXIX. 6, and LXXIII. 4)
-which receives a corresponding convexity of the
-humerus (figs. LXIX. 2, and LXXIII. 2). In
-consequence of this articulation with the humerus,
-the radius, like the ulna, can move backwards
-and forwards in flexion and extension, the proper
-movements of the hinge-joint; but that portion of
-the margin of the hinge of the radius which is
-in apposition with the ulna is convex (fig. LXIX.
-6), and is received into a semilunar cavity hollowed
-out in the ulna (fig. LXIX. 5). In this
-cavity the rounded head of the radius revolves,
-the two bones being held together by the ligament
-
-<span class="pagenum"><a name="Page_282" id="Page_282">[Pg 282]</a></span>
-
-already described (160), which surrounds
-the head of the radius (fig. LXXVI. 3), and
-which holds it firmly without being adherent to
-it, and without impeding in any degree the rotatory
-motion of the radius. Below, the surface
-of the radius next the ulna is hollowed out into a
-semilunar cavity (fig. LXXXII. 1), which receives
-a corresponding convex surface of the ulna (fig.
-LXXXII. 2), upon which convex surface the radius
-rolls (fig. LXXXII. 1). Thus, by the mode in
-which it is articulated with the ulna above, the
-radius turns upon its own axis. By the mode in
-which it is articulated with the ulna below, the
-radius revolves upon the head of the ulna; and, in
-consequence of both articulations, is capable of
-performing the motion of rotation. Moreover, the
-hand being attached to the radius through the
-medium of the wrist (figs. LXXXII. 1. 4. and
-LXXXIII. 1. 4) must necessarily follow every
-movement of the radius; the rotation of which
-brings the hand into two opposite positions. In
-the one, the palm of the hand is directed upwards
-(fig. LXXXII.); in the other, it is turned
-downwards (fig. LXXXIII.). When the hand is
-turned upwards, it is said to be in the state of
-<i>supination</i> (fig. LXXXII.); when downwards,
-in that of <i>pronation</i> (fig. LXXXIII.). A distinct
-apparatus of muscles is provided for effecting
-the rotation of the radius, in order to bring the
-hand into these opposite states: one set for producing
-its supination, and another its pronation.</p>
-
-<p><span class="pagenum"><a name="Page_283" id="Page_283">[Pg 283]</a></span></p>
-
-<p>168.  The principal supinators arise from the
-external condyle of the humerus (fig. LXXX.),
-and are called long and short (fig. LXXX. 4, 5).
-The long supinator extends as far as the lower end
-of the radius, into which it is inserted (fig. LXXX.
-4): the short supinator surrounds the upper part
-of the radius, and is attached to it in this situation
-(fig. LXXX. 5.). Moreover, the triceps,
-being inserted into the radius (164), often cooperates
-with the supinators and powerfully assists
-their action.</p>
-
-<p>169. The principal pronators are also two, called
-the round and the square (figs. LXXXI. and
-LXXXVI. 1). The round pronator arises from the
-internal condyle, and passing downwards, is inserted
-into the middle of the radius (fig. LXXXI.
-4); the square pronator is a small muscle between
-the radius and ulna, at their lower extremities
-being attached to each (fig. LXXXVI. 1).</p>
-
-<p><span class="pagenum"><a name="Page_284" id="Page_284">[Pg 284]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_284.png" alt="Fig. LXXX." />
-<div class="caption">View of the supinators of the radius and hand. 1. The<br />
-humerus; 2. the ulna; 3. the radius; 4. the muscle called<br />
-the long supinator passing to be inserted into the lower portion<br />
-of the radius; 5. the muscle, called the short supinator,<br />
-surrounding the upper part of the radius.</div>
-</div>
-
-<p>170. The action of these muscles in producing
-the rotation of the radius, and so rendering the
-hand supine or prone, is sufficiently manifest from
-the mere inspection of the diagrams (fig. LXXXI. 4).</p>
-
-<p><span class="pagenum"><a name="Page_285" id="Page_285">[Pg 285]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_286.png" alt="Fig. LXXXI." />
-<div class="caption">View of the pronators of the hand. 1. Lower end of the<br />
-humerus; 2. the radius; 3. the ulna; 4. the muscle called<br />
-the round <i>pronator</i>, one of the powerful pronators of the hand.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_286" id="Page_286">[Pg 286]</a></span></p>
-
-<p>171. The hand is composed of the carpus, metacarpus,
-and fingers.</p>
-
-<p>172. The carpus (fig. LXXXII. 4) consists of
-eight small wedge-shaped bones, placed in a double
-row, each row containing an equal number, and
-the whole disposed like stones in an arch (fig.
-LXXXII. 4). They do in fact form an arch, the
-convexity of which is upwards, on the dorsal surface
-(fig. LXXXIII. 4); and the concavity downwards,
-on the palmar surface (fig. LXXXII. 4).
-But they differ from the stones of an arch in this,
-that each bone is joined to its fellow by a distinct
-moveable joint, each being covered with a smooth
-articulating cartilage. At the same time all of
-them are tied together by ligaments of prodigious
-strength, which cross each other in every direction
-(fig. LXXVII. 6), so that the several separate
-joints are consolidated into one great joint. The
-consequence of this mechanism is that some
-degree of motion is capable of taking place between
-the several bones, which, when multiplied
-together, gives to the two rows of bones such an
-extent of motion, that when the wrist is bent the
-arch of the carpus forms a kind of knuckle. By
-this construction a facility and ease of motion, and
-a power of accommodation to motion and force,
-are obtained, such as belong to no arch contrived
-by human ingenuity.</p>
-
-<p><span class="pagenum"><a name="Page_287" id="Page_287">[Pg 287]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_287.png" alt="Fig. LXXXII" />
-<div class="caption">1. Lower extremity of the radius; 2. lower extremity of<br />
-the ulna; 3. styloid process of the ulna; 4. bones of the<br />
-carpus or wrist; 5. metacarpal bones; 6. first phalanges<br />
-of the fingers; 7. second phalanges of the fingers; 8. third<br />
-phalanges of the fingers.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_288" id="Page_288">[Pg 288]</a></span></p>
-
-<p>173. The metacarpus (fig. LXXXII. 5), the
-middle portion of the hand, interposed between
-the wrist and the fingers, is composed of five
-bones, which are placed parallel to each other (fig.
-LXXXII. 5). They are convex outwardly, forming
-the back (fig. LXXXIII. 5), and concave inwardly,
-forming the hollow of the hand (fig.
-LXXXII. 5). They are large at each end, to form
-the joints by which they are connected with the
-wrist and fingers (figs. LXXXII. and LXXXIII.):
-they are small in the middle, in order to afford
-room for the lodgment and arrangement of the
-
-<span class="pagenum"><a name="Page_289" id="Page_289">[Pg 289]</a></span>
-
-muscles, that move the fingers from side to side (fig.
-LXXXVI. 2). Their ends, which are joined to the
-carpus, are connected by nearly plane surfaces (figs.
-LXXXII. and LXXXIII.): their ends, which
-support the fingers, are formed into rounded heads,
-which are received into corresponding cup-shaped
-cavities, excavated in the top of the first bones
-of the fingers (fig. LXXXII. 5.). The powerful
-ligaments that unite these bones pass, both on the
-dorsal and the palmar surface, from the inferior
-extremity of the second row of the carpal to the
-bases of the metacarpal bones (fig. LXXVII, 7, 8).
-The ligaments are arranged in such a manner as
-to limit the motions of the joints chiefly to those
-of flexion and extension, allowing, however, a
-slight degree of motion from side to side.</p>
-
-<p>174.  Each of the fingers is composed of three
-separate pieces of bone, called phalanges; the
-thumb has only two (fig. LXXXII. 6, 7, 8): the
-phalanges are convex outwardly (fig. LXXXII. 6,
-7, 8) for increasing their strength, and flattened
-inwardly (fig. LXXXIII. 6, 7, 8) for the convenience
-of grasping. The last bones of the fingers,
-which are small, terminate at their under ends,
-in a somewhat rounded and rough surface (fig.
-LXXXIII. 8), on which rests the vascular, pulpy,
-and nervous substance, constituting the special
-organ of touch, placed at the points of the fingers,
-and guarded on the upper surface by the nail (fig.
-LXXXII. 8).</p>
-
-<p><span class="pagenum"><a name="Page_290" id="Page_290">[Pg 290]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_288.png" alt="Fig. LXXXIII." />
-<div class="caption">1. Lower extremity of the radius; 2. lower extremity of<br />
-the ulna; 3. styloid process of the ulna; 4. bones of the<br />
-carpus; 5. metacarpal bones; 6. 7. 8. first, second, and<br />
-third phalanges of the fingers.</div>
-</div>
-
-<p>175. The round inferior extremity of the metacarpus
-is admitted into the cavity of the superior
-extremity of the first phalanx of the five fingers
-(figs. LXXXII. and LXXXIII.), and their joints
-are connected by lateral and transverse ligaments
-of great strength (fig. LXXVII. 9). The situation
-and direction of the ligaments which unite the
-several phalanges of the fingers (fig. LXXVII. 9)
-are precisely the same as those of the articulation of
-the phalanges with the metacarpus (fig. LXXVII.
-7, 8); and the articulation of these bones with one
-another is such as to admit only of the motions of
-flexion and extension.</p>
-
-<p>176. The muscles which perform these motions
-are seated for the most part on the fore-arm. Independently
-of the supinators and pronators which
-have been already described (167 et seq.), there
-are distinct sets of muscles for bending and extending
-the wrist and the fingers. The flexors
-arise from the internal, and the extensors from the
-external, condyle of the humerus (fig. LXIX. 3,
-4). The internal condyle is larger and longer
-than the external (fig. LXIX. 3, 4); for the
-flexors require a larger point of origin and a
-longer fulcrum than the extensor muscles; because
-to the actions of flexion, such as grasping,
-bending, pulling, more power is necessary than to
-the action of extension, which consists merely in
-the unfolding or the opening of the hand previously
-to the renewal of the grasp.</p>
-
-<p>177. For the same reason, two muscles are provided
-
-<span class="pagenum"><a name="Page_291" id="Page_291">[Pg 291]</a></span>
-
-for flexing, while only one is provided for
-extending the fingers. The flexors, bulky, thick,
-and strong, are placed on the fore part of the fore-arm
-(fig. LXXXIV.). The first, named the
-superficial flexor (fig. LXXXIV. 1), about the
-middle of the arm, divides into four fleshy portions,
-each of which ends in a slender tendon (fig.
-LXXXIV. 1). As these tendons approach the
-fingers they expand (fig. LXXXIV. 1), and when
-in apposition with the first phalanx, split and form
-distinct sheaths for the reception of the tendons
-of the second flexor (fig. LXXXIV. 3). After
-completing the sheath, the tendons proceed forward
-along the second phalanx, into the fore part
-of which they are implanted, and the chief office
-of this powerful muscle is to bend the second joint
-of the fingers upon the first, and the first upon
-the metacarpal bone. Its action is assisted by a
-second muscle, called the deep or profound flexor
-(fig. LXXXIV. 2), because it lies beneath the
-former; or the perforans, because it pierces it.
-Bulky and fleshy, this second flexor, like the first,
-about the middle of the arm, divides into four tendons,
-which, entering the sheaths prepared for
-them in the former muscle (where the tendons are
-small and rounded for their easy transmission and
-play), pass to the root of the third phalanx of
-the fingers into which they are implanted (fig.
-LXXXIV. 3).</p>
-
-<p><span class="pagenum"><a name="Page_292" id="Page_292">[Pg 292]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_292.png" alt="Fig. LXXXIV." />
-<div class="caption">View of the flexor muscles of the fingers. 1. The superficial<br />
-flexor, divided and turned aside, to show, 2. the deep<br />
-flexor; 3. sheaths for the tendons of the deep flexor,<br />
-formed by the splitting of the tendons of the superficial<br />
-flexor; 4. the anterior annular ligament, divided and turned<br />
-aside.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_293" id="Page_293">[Pg 293]</a></span></p>
-
-<p>118. The muscle that extends the fingers, called
-the common extensor, is placed on the back part of
-the fore-arm (fig. LXXXV.), about the middle of
-which it divides into four portions which terminate
-in so many tendons (fig. LXXXV. 2). When
-they reach the back of the metacarpal bones, these
-tendons become broad and flat, and send tendinous
-expansions to each other, forming a strong tendinous
-sheath which surrounds the back of the
-fingers (fig. LXXXV. 2). These tendinous expansions
-are inserted into the posterior part of the
-bones of the four fingers (fig. LXXXV. 2); and
-their office is powerfully to extend all the joints of
-all the fingers (fig. LXXXV. 2).</p>
-
-<p>179. On both the palmar and dorsal regions of
-the wrist are placed ligaments for tying down these
-tendons, and preventing them from starting from
-their situation during the action of the muscles
-(figs. LXXXIV. and LXXXV.). On the palmar
-region an exceedingly strong ligament passes
-anteriorly to the concave arch of the carpus (fig.
-LXXXIV. 4) for the purpose of tying down the
-tendons of the flexor muscles. On the dorsal surface
-(fig. LXXXV.), a similar ligament, passing
-in an oblique direction from the styloid process of
-the radius to the styloid process of the ulna (fig.
-LXXXV. 3), performs the same office in tying
-down the tendons of the extensor muscle. Both
-these ligaments are called annular.</p>
-
-<p><span class="pagenum"><a name="Page_294" id="Page_294">[Pg 294]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_294.png" alt="Fig. LXXXV." />
-<div class="caption">View of the extensor muscles of the fingers. 1. The<br />
-common extensor, sending (2 2 2 2) tendons to each<br />
-finger; 3. the posterior annular ligament.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_295" id="Page_295">[Pg 295]</a></span></p>
-
-<p>180. In the palm of the hand are placed additional
-muscles which assist the flexors of the
-fingers (fig. LXXXVI. 2), being chiefly useful in
-enabling the fingers to perform with strength and
-precision short and quick motions. There are
-especially four small and rounded muscles (fig.
-LXXXVI. 2), resembling the earth worm in form
-and size, and hence called lumbricales; but as
-their chief use is to assist the fingers in executing
-short and rapid motions, they have also received
-the better name of the musculi fidicinales.</p>
-
-<p><span class="pagenum"><a name="Page_296" id="Page_296">[Pg 296]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_295.png" alt="Fig. LXXXVI." />
-<div class="caption">1. The muscle called the square pronator; 2. muscles<br />
-seated in the palm of the hand, by which, chiefly, the<br />
-fingers execute short and rapid motions.</div>
-</div>
-
-<p>181. The thumb, in consequence of the comparative
-looseness of its ligaments, is capable of a
-much greater extent of motion than the fingers, and
-can be applied to any part of each of the fingers, to
-different parts of the hand, and in direct opposition
-to the power exerted by the whole of the fingers and
-hand, in the act of grasping. The muscles which
-enable it to perform these varied motions, and
-which act powerfully in almost every thing we do
-with the hand, form a mass of flesh at the ball of
-the thumb (fig. LXXXVII. 1), almost entirely surrounding
-it. The little finger is also provided with
-a distinct apparatus of muscles (fig. LXXXVII. 2),
-which surrounds its root, just as those of the
-thumb surround its ball, in order to keep it firm
-in opposition to the power of the thumb in the act
-of grasping, and in various other motions.</p>
-
-<p><span class="pagenum"><a name="Page_297" id="Page_297">[Pg 297]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_297.png" alt="Fig. LXXXVII." />
-<div class="caption">1. The mass of muscles forming the ball of the thumb;<br />
-2. the mass of muscles forming the ball of the little finger;<br />
-3. tendons of one of the flexor muscles of the fingers;<br />
-4. sheaths formed by the tendons of the superficial flexor<br />
-for the reception of the tendons of the deep flexor.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_298" id="Page_298">[Pg 298]</a></span></p>
-
-<p>182. The upper extremity is covered by a tendinous
-expansion or fascia which envelopes the whole
-arm, encloses its muscles as in a sheath, and affords
-them, in their strong actions, "that kind of support
-which workmen feel in binding their arms with
-thongs." This fascia likewise descends between
-many of the muscles, forming strong partitions between
-them, and affording points of origin to many
-of their fibres, scarcely less fixed than bone itself.</p>
-
-<p>183. From the whole, it appears, that the
-first joint of the upper extremities, that of the
-shoulder, is a ball and socket joint, a joint admitting
-of motion in every direction; that the second
-joint, that of the elbow, is partly a hinge-joint,
-admitting of flexion and extension, and partly a
-rotation joint, admitting of a turning or rotatory
-motion; and that the joints of the wrist and of the
-fingers are likewise hinge-joints, admitting at the
-same time of some degree of lateral motion. When
-these various motions are combined, the result is
-that the hand can apply itself to bodies in almost
-every direction, in any part of the area described
-by the arm, when all the joints are moved to their
-utmost extent. There is thus formed an instrument
-of considerable strength, capable of a surprising
-variety and complexity of movements,
-capable of seizing, holding, pulling, pushing and
-striking with great power, yet at the same time
-capable of apprehending the minutest objects, and
-of guiding them with the utmost gentleness, precision,
-and accuracy, so that there are few conceptions
-of the designing mind which cannot be executed
-by the skilful hand.</p>
-
-<p>184. The lower extremities consist of the thigh,
-leg, and foot.</p>
-
-<p>185. The osseous part of the thigh consists of
-a single bone, called the femur (fig. XXXIV. 4),
-the longest, thickest, and strongest bone in the
-body. It sustains the entire weight of the trunk,
-and occasionally much heavier loads superimposed
-upon it. It is constructed in such a manner as
-to combine strength with lightness. This is
-effected by rendering the bone what is technically
-
-<span class="pagenum"><a name="Page_299" id="Page_299">[Pg 299]</a></span>
-
-called cylindrical; that is, a bone in which the
-osseous fibres are arranged around a hollow cylinder.
-There are two varieties of osseous matter,&mdash;the
-compact, in which the fibres are dense and solid
-(fig. LXXXVIII. 1), and the spongy, in which
-the fibres are comparatively tender and delicate
-(fig. LXXXVIII. 2). Both varieties are, indeed,
-combined, more or less, in every bone, the compact
-substance being always external, and the spongy
-internal; but in the cylindrical bones the arrangement
-is peculiar. Every long or cylindrical bone
-consists of a body or shaft (fig. LXXXVIII. 4.),
-and of two extremities (fig. LXXXVIII. 5). The
-body is composed principally of compact substance,
-which on the external surface is so dense
-and solid, that scarcely any distinct arrangement
-is visible; but towards the interior this density
-diminishes; the fibres become distinct (fig.
-LXXXVIII. 5), and form an expanded tissue
-of a cellular appearance (fig. LXXXVIII. 5), the
-cells being called cancelli, and the structure cancellated.
-In the centre of the bone even the cancelli
-disappear; the osseous fibres terminate; and a
-hollow space is left filled up, in the natural state,
-by an infinite number of minute membranous bags
-which contain the marrow (fig. LXXXVIII. 3).
-In the body of the bone, to which strength is requisite,
-that part being the most exposed to external
-violence, the compact matter is arranged around a
-central cavity. By this means strength is secured
-
-<span class="pagenum"><a name="Page_300" id="Page_300">[Pg 300]</a></span>
-
-without any addition of weight; for the resisting
-power of a cylindrical body increases in proportion
-to its diameter; consequently the same number of
-osseous fibres placed around the circumference of a
-circle produce a stronger bone than could have been
-constructed had the fibres been consolidated in the
-centre, and had the diameter been proportionally
-diminished. The hollow space thus gained in its
-centre, renders the bone lighter by the subtraction
-of the weight of as many fibres as would have gone
-to fill up that space; while its strength is not only
-not diminished by this arrangement, but positively
-increased. On the other hand, at the extremities
-of the bone, space, not strength, is required; required
-for the attachment and arrangement of the
-tendons of the muscles that act upon it, and for the
-formation of joints (fig. LXXXVIII. 5). Accordingly,
-at its extremities the bone swells out into
-bulky surfaces; but these surfaces are composed,
-not of dense and solid substance, but of spongy
-tissue, covered by an exceedingly thin crust of
-compact matter, and so, as by the former expedient
-strength is secured without increase of weight, by
-this, space is obtained without increase of weight.</p>
-
-<p><span class="pagenum"><a name="Page_301" id="Page_301">[Pg 301]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_300.png" alt="Fig. LXXXVIII." />
-<div class="caption">A section of the femur, showing, 1. the compact bony<br />
-substance; 2. the spongy or cancellated structure; 3. the<br />
-internal cavity containing the marrow; 4. body; 5, extremities<br />
-of the bone.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_302" id="Page_302">[Pg 302]</a></span></p>
-
-<p>186. The thigh-bone, placed at the under and
-outer part of the pelvis, has an oblique direction,
-the under being considerably nearer its fellow than
-the upper end (fig. XXXIV. 4), in order to afford
-space for the passages at the bottom of the pelvis,
-and also to favour the action of walking. The
-body of the bone, which is of a rounded form (fig.
-XXXIV. 4), is smooth on its anterior surface
-(fig. XXXIV. 4), where it is always slightly convex,
-the convexity being forwards (fig. XXXIV.
-4), while its posterior surface is irregular and
-rough, and forms a sharp prominent line, termed
-the linea aspera (fig. XXXV. 4), giving attachment
-to numerous muscles.</p>
-
-<p>187. The superior extremity of the femur terminates
-in a large ball or head, which forms nearly
-two-thirds of a sphere (fig. LXXXIX. 4.). It
-is smooth, covered with cartilage, and received into
-the socket of the ilium called the acetabulum,
-which, deep as it is, is still further deepened by the
-cartilage which borders the brim (fig. LXXXIX.
-3). The brim is particularly high in the upper
-and outer part, because it is in this direction that
-the reaction of the ground against the descending
-weight of the trunk tends to dislodge the ball from
-its socket.</p>
-
-<p>188. Passing obliquely downwards and outwards
-from the ball, is that part of the femur which is
-called the neck (fig. LXXXIX. 5). It spreads
-out archlike between the head and the body of the
-bone, and is more than an inch in length (fig.
-LXXXIX. 5). It is thus long in order that
-the head of the bone may be set deep in its socket,
-and that its motions may be wide, free, and unembarrassed.</p>
-
-<p><span class="pagenum"><a name="Page_303" id="Page_303">[Pg 303]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_303.png" alt="Fig. LXXXIX." />
-<div class="caption">1. Lower portion of the ilium; 2. tuberosity of the<br />
-ischium: 3. socket for the head of the femur, or thigh-bone;<br />
-4. head of the femur; 5. neck of the femur; 6. the<br />
-great process of the femur called the trochanter major;<br />
-7. the body of the femur.</div>
-</div>
-
-<p>189. From the external surface of the femur,
-nearly in a line with its axis, proceeds the largest
-and strongest bony process of the body which gives
-insertion to its most powerful muscles, namely,
-those that extend the thigh and that turn it upon
-its axis (fig. LXXXIX. 6). Because, from its
-oblique direction, it rotates the thigh, this process
-is called the trochanter, and, from its size, the
-trochanter major. At the under and inner part of
-the neck on the posterior surface of the bone, is
-a similar process, but much smaller, called the
-trochanter minor (fig. XXXV. 4), into which are
-inserted the muscles that bend the thigh.</p>
-
-<p><span class="pagenum"><a name="Page_304" id="Page_304">[Pg 304]</a></span></p>
-
-<p>190.  The inferior extremity of the femur, much
-broader and thicker than the superior (fig.
-XC. 1), is terminated by two eminences, with
-smooth surfaces, termed condyles (fig. XC. 2),
-which, articulated with the tibia, and the patella,
-form the joint of the knee (figs. XC. 2, 4, 5, and
-XCI. 1, 2, 3).</p>
-
-<p><span class="pagenum"><a name="Page_305" id="Page_305">[Pg 305]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_304.png" alt="Fig. XC." />
-<div class="caption">1. Lower end of the femur; 2. condyles of the femur;<br />
-3. upper end of the tibia; 4. articular surfaces on the head<br />
-of the tibia on which the thigh-bone plays; 5. the patella,<br />
-or knee-pan; 6. upper end of the fibula, not entering into<br />
-the knee-joint.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_306" id="Page_306">[Pg 306]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_305.png" alt="Fig. XCI." />
-<div class="caption">Posterior view of the bones forming the knee-joint.<br />
-1. Lower end of the femur; 2. upper end of the tibia;<br />
-3. articular surfaces on the head of the tibia, on which<br />
-the thigh-bone plays; 4. upper end of the fibula, not entering<br />
-into the knee joint.</div>
-</div>
-
-<p>191. The bones of the leg, two in number,
-consist of the tibia (fig. XC. 3) and fibula (fig.
-XC. 6). The tibia, next to the femur, the longest
-bone in the body, is situated at the inner side of
-the leg (fig. XC. 3). Its superior extremity is
-bulky and thick (fig. XC. 3). The top of it forms
-two smooth and slightly concave surfaces, adapted
-to the convex surfaces of the condyles of the femur
-(fig. XC. 4, 2). On its outer side there is a smooth
-surface, to which the head of the fibula is attached
-(fig. XC. 6). Its lower extremity, which is small,
-forms a concavity adapted to the convexity of the
-bone of the tarsus, called the astragalus, with which
-it is articulated (fig. XCII. 4.) Its inner part is
-produced so as to form the inner ankle (figs. XCII.
-2, and XCIII. 3): its outer side is excavated into
-a semilunar cavity, for receiving the under end of
-the fibula, which forms the outer ankle (figs. XCII.
-3, and XCIII. 4).</p>
-
-<p>192. The fibula, in proportion to its length
-the most slender bone of the body, is situated at
-the outer side of the tibia (fig. XC. 6). Its
-upper end formed into a head, with a flat surface
-on its inner side (figs. XC. 6, and XCI. 4), is
-firmly united to the tibia (fig. XC. 4). Its lower
-end forms the outer ankle, which is lower and
-farther back than the inner (fig. XCII. 3, 2).</p>
-
-<p><span class="pagenum"><a name="Page_307" id="Page_307">[Pg 307]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_307.png" alt="Fig. XCII." />
-<div class="caption">Anterior view of the bones forming the ankle-joint.<br />
-1. Lower end of the tibia; 2. production of the tibia, forming<br />
-the inner ankle; 3. lower end of the fibula, forming the<br />
-outer ankle; 4. upper part of the astragalus: these three<br />
-bones form the ankle-joint; 5 5 5, other bones of the tarsus;<br />
-6 6 6 6 6 metatarsal bones.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_308" id="Page_308">[Pg 308]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_308.png" alt="Fig. XCIII." />
-<div class="caption">Posterior view of the bones forming the ankle-joint.<br />
-1. Lower end of the tibia; 2. lower end of the fibula; 3. internal<br />
-malleolus or ankle; 4. external malleolus or ankle;<br />
-5. one of the tarsal bones, called the astragalus, with which<br />
-the tibia and fibula are articulated; 6. the os calcis or heel.</div>
-</div>
-
-<p>193. The patella, or knee-pan (fig. XC. 5), is
-a light but strong bone, of the figure of the heart
-as painted on playing-cards, placed at the fore part
-of the joint of the knee, and attached by a strong
-ligament to the tibia, the motions of which it
-follows (fig. XC. 5). It is lodged, when the
-knee is extended, in a cavity formed for it in the
-femur (fig. XC.); when bent, in a cavity formed
-for it at the fore part of the knee (fig. XC. 5).</p>
-
-<p><span class="pagenum"><a name="Page_309" id="Page_309">[Pg 309]</a></span></p>
-
-<p>194. The foot consists of the tarsus, metatarsus,
-and toes.</p>
-
-<p>195. The tarsus, or instep, is composed of seven
-strong, irregular-shaped bones, disposed like those
-of the carpus, in a double row (fig. XCII. 4, 5).
-The arrangement of the tarsal bones is such as to
-form an arch, the convexity of which above, constitutes
-the upper surface of the instep (fig. XCII.
-4, 5): in the concavity below are lodged the
-muscles, vessels, and nerves that belong to the sole.</p>
-
-<p>196. The metatarsus consists of five bones,
-which are placed parallel to each other (fig. XCII.
-6), and which extend between the tarsus and the
-proper bones of the toes (fig. XCII. 6). Their extremities,
-especially next the tarsus, are large, in
-order that they may form secure articulations with
-the tarsal bones (fig. XCII. 6). Their bodies are
-arched upwards (fig. XCII. 6), slightly concave
-below, and terminate forwards in small, neat,
-round heads, which receive the first bones of the
-toes, and with which they form joints, admitting
-of a much greater degree of rotation than is ever
-actually exercised, in consequence of the practice
-of wearing shoes. The natural, free, wide-spreading
-form of the toes, and the consequent security
-with which they grasp the ground, is greatly
-impaired by this custom. Taken together, the
-bones of the metatarsus form a second arch corresponding
-to that of the tarsus (fig. XCVIII. 2).</p>
-
-<p>197. Each toe consists of three distinct bones,
-
-<span class="pagenum"><a name="Page_310" id="Page_310">[Pg 310]</a></span>
-
-called, like those of the fingers, phalanges (fig.
-XCVIII.), but the great toe, like the thumb, has
-only two (fig. XCVIII.). That extremity of the
-first phalanges which is next the metatarsal bones
-is hollowed into a socket for the head of the metatarsal
-bones.</p>
-
-<p>198. Besides the bones already described, there
-are other small bones, of the size and figure of
-flattened peas, found in certain parts of the extremities,
-never in the trunk, called sesamoid,
-from their resemblance to the seed of the sesamum.
-They belong rather to the tendons of the muscles
-than to the bones of the skeleton. They are
-embedded within the substance of tendons, are
-found especially at the roots of the thumb and of
-the great toe, and are always placed in the direction
-of flexion. Their office, like that of the
-patella, which is, in truth, a bone of this class,
-is to increase the power of the flexor muscles by
-altering the line of their direction, that is, by removing
-them farther from the axis of the bone on
-which they are intended to act.</p>
-
-<p>199. The ligaments which connect the bones of
-the lower extremities are the firmest and strongest
-in the body. Of these, the fibrous capsule of the
-hip-joint (fig. XCIV. 1), which secures the head
-of the femur in the cavity of the acetabulum (fig.
-XCIV.), is the thickest and strongest. It completely
-surrounds the joint (fig. XCIV. 1). It
-arises from the whole circumference of the acetabulum,
-
-<span class="pagenum"><a name="Page_311" id="Page_311">[Pg 311]</a></span>
-
-and, proceeding in a direction outwards
-and backwards, is attached below to the neck of
-the femur (fig. XCIV. 1). It is thicker, stronger,
-and much more closely attached to the bones than
-the fibrous capsule of the shoulder-joint (144),
-because the hip-joint is formed, not like the shoulder-joint,
-for extent of motion, but for strength.
-Its internal surface is lined by synovial membrane,
-and its external surface is covered and
-strengthened by the insertion of muscles that
-move the thigh-bone. The joint is strengthened
-by another ligament, which passes from the inner
-and fore part of the cavity of the acetabulum (fig.
-XCV.) to be inserted into the head of the femur
-(fig. XCIV.), called the round ligament, the office
-of which obviously is to hold the head of the
-femur firmly in its socket.</p>
-
-<p><span class="pagenum"><a name="Page_312" id="Page_312">[Pg 312]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_311.png" alt="Fig. XCIV." />
-<div class="caption">1. The fibrous capsule of the hip-joint, laid open and<br />
-turned aside to show, 2. the round ligament in its natural<br />
-position.</div>
-</div>
-<div class="topspace4"></div>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_312.png" alt="Fig. XCV." />
-<div class="caption">A view of the head of the femur drawn out of its socket,<br />
-and suspended by the round ligament, to show more clearly<br />
-the action of the ligament in retaining the head of the<br />
-femur in its socket.</div>
-</div>
-
-<p>200. Numerous and complicated ligaments connect
-the bones that form the knee-joint (fig.
-XCVI.), and the strength of these powerful bands
-
-<span class="pagenum"><a name="Page_313" id="Page_313">[Pg 313]</a></span>
-
-is greatly increased by the tendons that move the
-leg (fig. XCVI. 5), which pass over, and more or
-less surround, the joint.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_313.png" alt="Fig. XCVI." />
-<div class="caption">General view of the ligaments of the knee-joint. 1. Lower<br />
-end of the femur; 2. upper end of the tibia; 3. upper end<br />
-of the fibula; 4. the patella; 5. united tendons of the<br />
-extensor muscles; 6. ligaments of the patella; 7. the capsular<br />
-investment of the knee; 8. the internal lateral ligament;<br />
-9. the external lateral ligaments; 10. the posterior<br />
-ligament; 11. the ligament connecting the tibia and fibula;<br />
-12. a portion of the interosseous ligament.</div>
-</div>
-
-<p>201. Strong ligaments maintain in their proper
-position the bones that form the ankle-joint (fig.
-
-<span class="pagenum"><a name="Page_314" id="Page_314">[Pg 314]</a></span>
-XCVII.), connect the bones of the tarsus and metatarsus
-with one another (fig. XCVIII. 1), and
-articulate the several phalanges of the toes (fig.
-XCVIII. 2).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_314.png" alt="Fig. XCVII." />
-<div class="caption">General view of the posterior ligaments of the ankle-joint.<br />
-1. Lower end of the tibia; 2. lower end of the<br />
-fibula; 3. astragalus; 4. os calcis; 5. ligament between<br />
-the tibia and fibula; 6. ligament passing from the fibula<br />
-to the astragalus; 7. ligament passing from the fibula to<br />
-the os calcis; 8. ligament passing from the tibia to the<br />
-astragalus.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_315" id="Page_315">[Pg 315]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_315.png" alt="Fig. XCVIII." />
-<div class="caption">General view of the ligaments of the sole of the foot.<br />
-1. Ligaments connecting the bones of the tarsus; 2. ligaments<br />
-connecting the bones of the toes.</div>
-</div>
-
-<p>202. The joint of the hip, like that of the
-shoulder, is capable of flexion, extension, and
-rotation; but its rotatory motions are to a much
-less extent, on account of the greater depth of the
-acetabulum and the stronger and shorter fibrous
-capsule. When the femur is flexed, the thigh is
-bent upon the pelvis, and its inferior extremity is
-
-<span class="pagenum"><a name="Page_316" id="Page_316">[Pg 316]</a></span>
-
-carried forwards. When it is extended, the thigh
-is carried backwards. The two thighs may be
-separated from each other laterally (abduction),
-or brought near to each other (adduction), or the
-one may be made to cross the other, and they may
-be rotated outwards or inwards.</p>
-
-<p>203. The apparatus of muscles that produces
-these varied motions is seated partly on the trunk
-and partly on the pelvis. Thus, the powerful
-muscle that flexes the thigh, or that carries it forwards,
-termed the psoas (fig. XCIX. 1), arises
-from the last vertebra of the back, and successively
-from each vertebra of the loins (fig. XCIX. 1),
-and is inserted into the lesser trochanter of the
-femur (fig. XCIX. 3). Its action is assisted
-first by a large and strong muscle named the
-iliacus (fig. XCIX. 2), which occupies the whole
-concavity of the ilium (fig. XCIX. 2), and which,
-like the psoas, is inserted into the lesser trochanter
-of the femur (fig. XCIX. 3).</p>
-
-<p><span class="pagenum"><a name="Page_317" id="Page_317">[Pg 317]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_316.png" alt="Fig. XCIX." />
-<div class="caption">View of the muscles that bend the thigh. 1. The<br />
-muscle called psoas; 2. the muscle called iliacus; 3. tendons<br />
-of these muscles, going to be inserted into the trochanter<br />
-minor of the femur.</div>
-</div>
-
-<p>204. The muscles that extend the thigh, or that
-carry it backwards, named the glutæi, the most
-powerful muscles of the body, are placed in successive
-layers, one upon the other, on the back
-part of the ilium (fig. C. 1, 2, 3), and are inserted
-into the linea aspera of the femur. They constitute
-the mass of flesh which forms the hip, and
-their powerful action in drawing the thigh backwards
-is assisted by several other muscles (fig.
-C. 4, 5, 6). Their action is never perfectly simple
-and direct; for those which move the thigh forwards
-sometimes carry it inwards, and sometimes
-outwards; and in like manner, those which move
-it backwards, at one time carry it inwards and at
-
-<span class="pagenum"><a name="Page_318" id="Page_318">[Pg 318]</a></span>
-
-another outwards, according to the direction of the
-fibres of the muscle and the position of the limb
-when those fibres act; while some of them, and
-more especially those which carry it backwards, at
-the same time rotate it, or roll it upon its axis.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_318.png" alt="Fig. C." />
-<div class="caption">View of the muscles that extend the thigh. 1. The<br />
-muscle called glutæus maximus, removed from its origin,<br />
-2,  2, to show the muscles which lie beneath it; 2. cut edge<br />
-showing the origin of the same muscle; 3. the muscle<br />
-called glutæus medius; 4, 5, 6. smaller muscles, assisting<br />
-the action of the glutæi.</div>
-</div>
-
-<p>205. The knee is a hinge-joint, admitting only
-of flexion and extension, and is therefore provided
-only with two sets of muscles, one for bending and
-the other for extending the leg. The flexors of
-
-<span class="pagenum"><a name="Page_319" id="Page_319">[Pg 319]</a></span>
-
-the leg arise from the under and back part of the
-pelvis, are seated on the back part of the thigh,
-
-<span class="pagenum"><a name="Page_320" id="Page_320">[Pg 320]</a></span>
-
-and are inserted into the upper part either of the
-tibia or of the fibula (fig. CI). They consist for
-the most part of three muscles, named the semi-tendinosus,
-the semi-membranosus (fig. CI. 3), and
-the biceps of the leg (fig. CI. 1). The tendons of
-the two former muscles, in passing to be inserted
-into the leg, form the inner, and that of the latter
-the outer, hamstrings (fig. CI. 4, 5).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_319.png" alt="Fig. CI." />
-<div class="caption">View of the flexor and extensor muscles of the leg.<br />
-1. The biceps of the leg; 2. tendon of the biceps, inserted<br />
-into the head of the fibula; 3. the semi-membranosus,<br />
-passing to be inserted into the head of the fibula; 4. tendon<br />
-of the semi-membranosus forming the inner, and<br />
-5. tendon of the biceps forming the outer, hamstring;<br />
-6. upper part of the gastrocnemius muscle; 7. the four large<br />
-muscles which unite to form the great extensor muscle of<br />
-the leg, inserted into 8. the patella; 9. a portion of the<br />
-glutæus maximus concealing the other muscles of the hip.</div><br />
-</div>
-
-<p>206. Four large muscles, blended together in
-such a manner as to form one muscle of prodigious
-size, termed the quadriceps cruris (fig. CI. 7),
-occupying nearly all the forepart and the sides,
-and a considerable portion of the back part of the
-thigh, constitute the great flexor of the thigh.
-This enormous mass of muscle arises partly from
-the ischium, and partly from the upper part of the
-femur (fig. CI. 7), and is all inserted into the
-patella (fig. CI. 8), which constitutes a pulley for
-the purpose of assisting the action of these powerful
-muscles.</p>
-
-<p>207. The muscles which bend the toes and extend
-the foot, termed the gastrocnemii (fig. CII.
-1, 2), are placed on the back part of the leg, and
-form the mass of muscle which constitutes the calf
-
-<span class="pagenum"><a name="Page_321" id="Page_321">[Pg 321]</a></span>
-
-of the leg (fig. CII. 1, 2). They arise partly from
-the lower extremity of the femur (fig. CII.) and
-partly from the upper and back part of the fibula
-and tibia; and they form the largest and strongest
-tendon in the body, termed the tendo achillis (fig.
-CII. 3), which is implanted into the heel (fig.
-CII. 4).</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_321.png" alt="Fig. CII." />
-<div class="caption">View of the muscles which bend the toes, and which, by<br />
-lifting the heel, extend the foot. 1. The muscle called<br />
-gastrocnemius externus, which, uniting with 2. the gastrocnemius<br />
-internus, forms 3. the tendo achillis, which is inserted<br />
-into 4. the heel.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_322" id="Page_322">[Pg 322]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_322.png" alt="Fig. CIII." />
-<div class="caption">View of the muscles which extend the toes and bend the<br />
-foot. 1. The common extensor; 2. the tendons of the same<br />
-muscle inserted into the toes; 3. the anterior annular<br />
-ligament of the foot.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_323" id="Page_323">[Pg 323]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_323.png" alt="Fig. CIV." />
-<div class="caption">View of the muscles in the sole of the foot. 1 The<br />
-muscle which draws the great toe from the other toes; 2. the<br />
-muscle which draws the little toe from the other toes;<br />
-3. the muscle called the short flexor of the toes, which<br />
-assists in bending the four smaller toes.</div>
-</div>
-
-<p>208. The muscles which extend the toes and
-bend the foot are seated on the fore part of the leg
-
-<span class="pagenum"><a name="Page_324" id="Page_324">[Pg 324]</a></span>
-
-(fig. CIII.); split into tendons like the analogous
-muscles of the fingers (fig. CIII. 2); and are
-bound down by a ligament (fig. CIII. 3), exactly
-the same in name, disposition, and office, as that
-which belongs to the hand (fig. CIII. 3). Numerous
-minute muscles are placed in the sole of the
-foot (fig. CIV.), which act on the toes as the
-small muscles in the palm of the hand act on the
-fingers (fig. LXXXVI.).</p>
-
-<p>209. Such are the moving powers which put in
-action the complicated mechanism provided for
-the function of locomotion. And these powers
-are adequate to their office; but they are what
-may be termed expensive powers; agents requiring
-a high degree, of organization and the utmost resources
-of the economy to support and maintain
-them. Hence in the construction of the framework
-of the machine which they have to move,
-whatever mechanical contrivance may economize
-their labour, is adopted. The construction, form,
-and disposition of the several parts of that framework
-have all reference to two objects: first, the
-combination of strength with lightness; and secondly,
-security to tender organs, with the power
-of executing rapid, energetic, and, sometimes, violent
-motions. The combination is effected and
-the object attained in a mode complicated in the
-detail, simple in the design, and perfect in the
-result. The weight of the body transmitted from
-the arch of the pelvis to a second arch, formed by
-
-<span class="pagenum"><a name="Page_325" id="Page_325">[Pg 325]</a></span>
-
-the neck of the thigh-bone, and from this, in a
-perpendicular direction, to a third arch formed
-by the foot, is ultimately received by the heel
-behind, and by the metatarsal bones and the first
-phalanges of the toes before, and more especially
-by the metatarsal joints belonging to the great
-and little toe, which have a special apparatus
-of muscles, for the purpose of preserving steadily
-their relative situation to the heel. The weight
-of the body is thus sustained on a series of arches,
-from which it is, in succession, transmitted to
-the ground, where it ultimately rests upon a
-tripod: forms known and selected as the best
-adapted to afford support, and to give security
-of position. Columns of compact bone superimposed
-one upon another, and united at different
-points by bands of prodigious strength, form the
-pillars of support. But these bony columns never
-touch each other; are never in actual contact; are
-all separated by layers of elastic matter which, while
-they assist in binding the columns together, enable
-them to move one upon another, as upon so many
-pliant springs. The layers of cartilage interposed
-between the several vertebræ; the layer of cartilage
-interposed between the vertebral column and the
-pelvis; the layer of cartilage that lines the acetabulum
-and that covers the head of the femur; the
-layer of cartilage that covers the lower extremity
-of the femur and the upper extremity of the
-tibia and fibula and the tarsus; the successive
-
-<span class="pagenum"><a name="Page_326" id="Page_326">[Pg 326]</a></span>
-
-layers of cartilage interposed between the
-several bones of the tarsus; and finally, the layer of
-cartilage that covers both the tarsal and the digital
-extremities of the metatarsal bones; are so many
-special provisions to prevent the weight of the
-body from being transmitted to the ground with a
-shock; and, at the same time, so many barriers
-established between the ground and the spinal
-cord, the brain and the soft and tender organs
-contained in the thoracic and abdominal cavities,
-to prevent these organs from being injured by the
-reaction of the ground upon the body. The excellence
-of this mechanism is seen in its results;
-in contemplating "from what heights we can
-leap&mdash;to what heights we can spring&mdash;to what
-distances we can bound&mdash;how swiftly we can run&mdash;how
-firmly we can stand&mdash;how nimbly we can
-dance&mdash;and yet how perfectly we can balance
-ourselves upon the smallest surfaces of support!"</p>
-
-<p>210. It is necessary, in order to complete this
-general view of the structure of the human body,
-and of the combination and arrangement of its
-various parts, to denote the several regions into
-which, for the purpose of describing with accuracy
-the situation and relation of its more important
-organs, the body is divided. It is not needful to
-the present purpose to describe the regions of the
-head, because its internal cavity contains only one
-organ, the brain, and its external divisions do not
-differ materially from those which are common
-
-<span class="pagenum"><a name="Page_327" id="Page_327">[Pg 327]</a></span>
-
-and familiar; but the chest, the abdomen, and the
-upper and lower extremities are mapped out into
-regions, of which it is very important to have an
-exact knowledge, which may be acquired by the
-study of the annexed diagrams.</p>
-
-<p><span class="pagenum"><a name="Page_328" id="Page_328">[Pg 328]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_328.png" alt="Fig. CV." />
-<div class="caption">Anterior view of the regions of the body. 1. Region of the neck;<br />
-2. region of the chest or thorax. Abdominal regions: 3. epigastric;<br />
-4. umbilical; 5. hypogastric region. Regions of the upper extremities.<br />
-6. shoulder; 7. arm; 8. elbow; 9. fore-arm; 10. wrist; 11. ball of<br />
-thumb; 12. the axilla or armpit. Regions of the lower extremities:<br />
-13. thigh; 14. knee; 15. leg; 16. ankle; 17. instep and foot.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_329" id="Page_329">[Pg 329]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_329.png" alt="Fig. CVI." />
-<div class="caption">Posterior view of the regions of the body: 18. region to<br />
-the scapula; 19. of the back; 20. of the loins; 21. of the<br />
-hips; 22. of the ham; 23. of the calf of the leg; 24. of the<br />
-heel and foot.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_330" id="Page_330">[Pg 330]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_330.png" alt="Fig. CVII." />
-<div class="caption">Lateral view of the regions of the body: 25. arch of<br />
-the foot.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_331" id="Page_331">[Pg 331]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_331.png" alt="Fig. CVIII." />
-<div class="caption">Anterior view of the situation of the more important internal<br />
-organs: 1. lungs, right and left; 2. heart; 3. line<br />
-representing the edge of the diaphragm; 4. liver; 5. stomach;<br />
-6. small intestines; 7. colon; 8. urinary bladder.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_332" id="Page_332">[Pg 332]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_332.png" alt="Fig. CIX." />
-<div class="caption">Posterior view of the situation of the more important<br />
-internal organs: 9. kidnies, right and left; 10. the course<br />
-of the spinal cord.</div>
-</div>
-<div class="topspace4"></div>
-
-<p><span class="pagenum"><a name="Page_333" id="Page_333">[Pg 333]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_333.png" alt="Fig. CX." />
-<div class="caption">Lateral view of the situation of the more important<br />
-internal organs.</div>
-</div>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_334" id="Page_334">[Pg 334]</a></span></p>
-
-<h2>CHAPTER VI.
-<br />
-<br />
-<span class="smaller">OF THE BLOOD.</span>
-</h2>
-</div>
-
-<blockquote>
-
-<p>Physical characters of the blood: colour, fluidity, specific
-gravity, temperature: quantity&mdash;Process of coagulation&mdash;Constituents
-of the blood: proportions&mdash;Constituents of
-the body contained in the blood&mdash;Vital properties of the
-blood&mdash;Practical applications.</p></blockquote>
-
-
-<p>211. Supposing the human body to have been
-built up in the manner now described, and to be
-in the full exercise of all its functions, the integrity
-of its various structures is maintained, and their
-due action excited by the blood. Out of this substance
-is formed the blandest fluid, as the milk,
-and the firmest solid, as the compact bone. The
-heart, capable of untiring action, as long as the
-blood is in contact with its internal surface, becomes
-immovable soon after the supply of this
-fluid is withdrawn; and in less than one minute
-from the time it ceases to flow in due quantity
-and of proper quality through the vessels of the
-brain, the eye is no longer capable of seeing, nor
-the ear of hearing, nor the brain of carrying on
-any intellectual operation.</p>
-
-<p>212. At the moment, and for some time after it
-has issued from its vessel, the appearance of the
-
-<span class="pagenum"><a name="Page_335" id="Page_335">[Pg 335]</a></span>
-
-blood is that of a thick, viscid, and tenacious fluid;
-yet it is essentially a solid, composed of several
-substances, each possessing its own distinct and
-peculiar properties, the relation and combination
-of which cannot be considered without exciting the
-feeling that our admiration of the structure of the
-animal frame ought not to be confined to the mechanism
-of its solid parts, but that the whole is
-admirable, from the common material of which it
-is composed, to its most delicate and elaborate
-instrument.</p>
-
-<p>213. The colour of redness is universally associated
-with the idea of blood; but redness of
-colour is not essential to blood. There are many
-animals with true, yet without red, blood; and
-there is no animal in which the blood is red in all
-the parts of its body. The blood of the insect is
-transparent; that of the reptile is of a yellowish
-colour; that of the fish, in the greater part of its
-body, is colourless. Even the red blood of the
-human body is not equally red in every part of it,
-there being two distinct systems of blood-vessels,
-distinguished from each other by carrying blood
-of different colours.</p>
-
-<p>214. In the state of health, the specific gravity
-of human blood, water being 1000, is 1080; from
-which standard it is capable of varying from 1120,
-the maximum, to 1026, the minimum.</p>
-
-<p>215. The natural temperature of the human
-blood is 98°. From this it is capable of varying
-
-<span class="pagenum"><a name="Page_336" id="Page_336">[Pg 336]</a></span>
-
-from 104°, the maximum, to 86°, the minimum;
-these changes being always the effect of disease.</p>
-
-<p>216. It is estimated that the fluids circulating
-in the adult man amount to about fifty pounds; of
-these it is calculated that twenty-eight consist of
-red blood.</p>
-
-<p>217. Fluid and homogeneous as the blood
-appears while flowing in its vessel, when a mass of
-it is collected and allowed to stand at rest, it soon
-undergoes a very remarkable change. First, a thin
-film is formed upon its surface; this is followed
-by the conversion of the whole mass into a soft
-jelly: this jelly separates into two portions, a fluid
-and a solid portion. The solid portion again separates
-into two parts, into a substance of a yellowish-white
-colour, occupying the upper surface,
-and into a red mass always found at the under
-surface.</p>
-
-<p>218. The process by which the constituents of the
-blood are thus spontaneously disunited, and afforded
-in a separate form, is denominated <span class="smcap">COAGULATION</span>;
-the fluid portion separated by the process is termed
-the <span class="smcap">SERUM</span>; the solid portion the <span class="smcap">COAGULUM</span> or
-<span class="smcap">CLOT</span>; the white substance forming the upper part
-of the clot, the <span class="smcap">FIBRIN</span>; and the red mass forming
-the under part of it, the <span class="smcap">RED PARTICLES</span>.</p>
-
-<p>219. Probably the process of coagulation commences
-the moment the blood leaves its living
-vessel. In three minutes and a half it is visible
-to the eye; in seven minutes the mass is formed
-
-<span class="pagenum"><a name="Page_337" id="Page_337">[Pg 337]</a></span>
-
-into a jelly; in from ten to twelve minutes the
-serum separates from the clot; in about twenty
-the clot is divided into fibrin and red particles,
-when the coagulation is complete; but occasionally
-the clot continues to grow firmer and firmer for
-the space of twenty-four hours.</p>
-
-<p>220.  As soon as the coagulation commences, and
-during all the time the blood preserves its heat, an
-aqueous vapour arises from it, termed the <span class="smcap">HALITUS</span>.
-The halitus consists of water holding in solution a
-small quantity of animal and saline matter, which
-communicate to it a f&oelig;tid odour of a strong and peculiar
-nature, manifest on approaching a slaughter-house,
-and still more manifest in the slaughter-house
-of human beings, a field of battle.</p>
-
-<p>221.  During the process of coagulation, as in
-every other in which a fluid is converted into a
-solid, caloric is evolved.</p>
-
-<p>222.  During the process of coagulation carbonic
-acid is also extricated.</p>
-
-<p>223.  The process of coagulation affords three
-distinct substances, the chief constituents of the
-blood, namely, serum, fibrin, and red particles.</p>
-
-<p>224.  The serum, the fluid portion of the blood,
-when obtained perfectly pure, is of a light straw
-colour, tinged with green. Its taste is saline, and
-its consistence adhesive. It is composed principally
-of water holding in solution animal and saline
-matter. The animal matter gives it its adhesive
-
-<span class="pagenum"><a name="Page_338" id="Page_338">[Pg 338]</a></span>
-
-consistence, and the saline its peculiar salt
-taste. The chief animal matter contained in it is
-the proximate principle termed albumen, which
-may be separated from the water that holds it in
-solution by the application of heat and by certain
-chemical agents. Heat being applied, when the
-temperature reaches 160°, fluid serum is converted
-into a white opaque solid substance of firm consistence.
-This is found to be albumen, which may
-be also separated from the watery portion by the
-application of spirits of wine, acids, oxymuriate of
-mercury, and several other chemical substances.
-The quantity of albumen contained in 1000 parts
-of serum varies from about 78, the maximum, to
-58, the minimum.</p>
-
-<p>225. If the albumen yielded by the serum be
-subjected to pressure, or be cut into small pieces,
-there flows from it a watery fluid which is termed
-the serosity. In meat dressed for the table, the
-serum of the blood contained in the blood-vessels
-is converted by the heat into solid albumen, from
-which, when cut, the serosity flows in the form of
-gravy.</p>
-
-<p>226. Besides albumen, serum holds in solution
-both a fatty and an oily matter, in the proportion
-of about one part of each to 1000 parts of serum.
-The proportion of its saline substances is about
-ten in 1000 parts. According to M. le Canu,
-who has made the most recent chemical analysis
-of serum, 1000 parts contain, of</p>
-
-<p><span class="pagenum"><a name="Page_339" id="Page_339">[Pg 339]</a></span></p>
-
-<table summary="blood">
-<tr>
-<td class="tdl">Water</td>
-<td class="tdr">906·00</td>
-</tr>
-<tr>
-<td class="tdl">Albumen</td>
-<td class="tdr">78·00</td>
-</tr>
-<tr>
-<td class="tdl">Animal matter, soluble in water</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp; &nbsp; and alcohol</td>
-<td class="tdr">1·69</td>
-</tr>
-<tr>
-<td class="tdl">Albumen combined with soda</td>
-<td class="tdr">2·10</td>
-</tr>
-<tr>
-<td class="tdl">Crystallizable fatty matter</td>
-<td class="tdr">1·20</td>
-</tr>
-<tr>
-<td class="tdl">Oily matter</td>
-<td class="tdr">1·00</td>
-</tr>
-<tr>
-<td class="tdl">Hydrochlorate of soda and</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp; &nbsp; potash</td>
-<td class="tdr">6·00</td>
-</tr>
-<tr>
-<td class="tdl">Subcarbonate and phosphate of</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;soda, and sulphate of potash&nbsp;</td>
-<td class="tdr">2·10</td>
-</tr>
-<tr>
-<td class="tdl">Phosphate of lime, magnesia,</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;and iron, with subcarbonate</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;of lime and magnesia</td>
-<td class="tdr">·91</td>
-</tr>
-<tr>
-<td class="tdl">Loss</td>
-<td class="tdr">1·00</td>
-</tr>
-</table>
-
-<p>227. All the animal and saline matter held in
-solution in the serum being removed, the fluid
-that remains is water, the proportion of which in
-1000 parts varies from 853, the maximum, to 779,
-the minimum.</p>
-
-<p>228. The second constituent of the blood, the
-fibrin, is the most essential portion of it, being
-invariably present, whatever other constituent be
-absent. While circulating in the living vessel,
-fibrin is fluid and transparent; by the process of
-coagulation, it is converted into a solid and opaque
-substance of a yellowish white colour, consisting
-of stringy fibres, disposed in striæ, which occasionally
-form a complete net-work (fig. CXI.).
-These fibres are exceedingly elastic. In their
-
-<span class="pagenum"><a name="Page_340" id="Page_340">[Pg 340]</a></span>
-
-general aspect and their chemical relations they
-bear a close resemblance to pure muscular fibre,
-that is, to muscular fibre deprived of its enveloping
-membrane and of its colouring matter, and they
-form the basis of muscle. According to M. le
-Canu, the proportion of the fibrin varies from
-seven parts in 1000, the maximum, to one part in
-1000, the minimum, the medium of twenty experiments
-being four parts in 1000.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_340.png" alt="Fig. CXI." />
-<div class="caption">A portion of the fibrin of the blood, showing its fibrous<br />
-structure and the striated or net-like arrangement of its<br />
-fibres.</div>
-</div>
-
-<p>229.  The third constituent of the blood, the
-matter upon which its red colour depends, though,
-as has been stated, entirely absent in certain classes
-of animals, and in all animals in some parts of
-their body, seems to be essential, at least to the
-organic organs, whenever they perform their functions
-with a high degree of perfection. Thus in
-the lowest class of vertebrated animals, the fish,
-
-<span class="pagenum"><a name="Page_341" id="Page_341">[Pg 341]</a></span>
-
-while the principal part of its body receives only a
-colourless fluid, its organic organs, as the heart,
-the gills, the liver, are provided with red blood.</p>
-
-<p>230. The red matter, wherever present, is invariably
-heavier than the fibrin, and consequently,
-during the process of coagulation, it gradually subsides
-to the lower surface, and is always found
-forming the bottom of the clot. Its proportion to
-the other constituents varies very remarkably, the
-maximum being 148, the minimum 68, and the
-medium 108, in 1000 parts of blood.</p>
-
-<p>231. All observers are agreed that the red matter
-of the blood consists of minute particles, having a
-peculiar and definite structure; but in regard to
-the nature of that structure, there is considerable
-diversity of opinion, which is not wonderful, since
-the particles in question are so minute that they
-can be distinguished only by the microscope, and
-since, of all microscopical objects, they are perhaps
-the most difficult to examine, because, being soft
-and yielding, their figure is apt to change, and
-because there is reason to suppose that their substance
-is not uniform in its refractive power.</p>
-
-<p>232. The earlier observers describe the red particles
-as being of a globular figure, and accordingly
-name them globules. They conceive that each
-globule consists of a central solid particle, enveloped
-in a transparent vesicle. Recently, Sir Everard
-Home and Mr. Bauer in this country, and MM.
-Prevost and Dumas on the continent, have revived
-
-<span class="pagenum"><a name="Page_342" id="Page_342">[Pg 342]</a></span>
-
-this opinion, and describe the red particle as consisting
-of a central solid white corpuscle contained
-in an external envelop of a red colour. When the
-blood is observed with the microscope in a living
-animal, flowing in its vessels, only two substances
-can be distinguished, namely, a transparent fluid
-and the red corpuscles. MM. Prevost and Dumas
-contend that these two substances are the only
-component parts of the blood. When the blood
-coagulates, they conceive that the red envelop
-separates from the central white corpuscle; that
-these white corpuscles unite together; that the
-aggregates resulting from this combination are disposed
-in the form of filaments, which filaments
-constitute the fibrin, while the red matter at the
-bottom of the clot is nothing but the disintegrated
-envelops of the central particle. But this view is
-not the common one. In general, physiologists
-conceive the fibrin to be one constituent and the
-red particles to be another constituent of the blood.
-Mr. Lister, who has successfully laboured to improve
-the microscope, and who, together with his
-friend Dr. Hodgkin, have very carefully examined
-with their improved instrument the red particles,
-contend that the figure of these bodies is not globular,
-although they state that the instant the
-particles are removed from the living blood-vessels
-many things are capable of making them assume
-a globular appearance; such, for example, as the
-application of water. With a rapidity which, in
-
-<span class="pagenum"><a name="Page_343" id="Page_343">[Pg 343]</a></span>
-
-spite of every precaution, the eye in vain attempts
-to follow, the particles change their real figure for
-a globular form on the application of the smallest
-quantity of pure water; while, if the water contain
-a solution of saline matter, little alteration is occasioned
-in the figure of the particles. According to
-these observers, the red particles are flattened cakes,
-having rounded and very slightly thickened margins
-(fig. CXII. 1). The thickness of the margin
-gives to both surfaces the appearance of a slight
-depression in the middle (fig. CXII. 1), so that
-the particles bear a close resemblance to a penny
-piece. There is no appearance of an external
-envelop. The circular and flattened cake is transparent;
-when seen singly it is nearly if not quite
-colourless (fig. CXII. 1); it assumes a reddish
-tinge only when aggregated in considerable masses.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_343.png" alt="Fig. CXII." />
-<div class="caption">1. A particle of the human blood as it appears when<br />
-transparent and floating; 2. the same dry, seen as opaque,<br />
-illuminated by a leiberkuhn; 3. the same as it appears<br />
-when half the leiberkuhn is darkened; 4. a particle of the<br />
-frog's blood floating; 5. the same seen on its edge. All<br />
-the above objects are magnified 500 diameters<a name="FNanchor_5_5" id="FNanchor_5_5"></a><a href="#Footnote_5_5" class="fnanchor">[5]</a></div>
-</div>
-
-<p>233. The red particle of the human blood is circular (fig. CXII. 1, 2, 3).
-
-<span class="pagenum"><a name="Page_344" id="Page_344">[Pg 344]</a></span>
-
-It is circular also in all
-animals belonging to the class mammalia; but in
-the three lower classes of vertebrated animals, the
-bird, the reptile, and the fish, it is elliptical (fig.
-CXII. 4, 5).</p>
-
-<p>234. The magnitude of the red particle of the
-human blood is variously estimated from the two-thousandth
-to the six-thousandth part of an inch
-in diameter. Bauer estimates it at the two-thousandth,
-Hodgkin and Lister at the three-thousandth,
-Kater at the four-thousandth, Wollaston
-at the five-thousandth, and Young at the six-thousandth
-part of an inch. Its magnitude is
-uniformly the same in all individuals of the same
-species, but differs exceedingly in the different
-classes. The elliptical particles are larger than the
-circular, but proportionally thinner; larger in fishes
-than in any other class of animals, and largest of
-all in the skate.</p>
-
-<p>235. When perfect and entire, the red particles
-indicate a disposition to arrange themselves in a
-definite mode. They combine spontaneously into
-columns of variable length (fig. CXIII.). In
-order to observe this tendency, a small quantity
-of blood, the moment it is taken from its
-living vessel, should be placed between two strips
-of glass or covered with a bit of talc and placed
-under the microscope. When thus arranged, a
-considerable agitation at first takes place among
-the particles. As soon as this motion subsides, the
-
-<span class="pagenum"><a name="Page_345" id="Page_345">[Pg 345]</a></span>
-
-particles apply themselves to each other by their
-broad surfaces, and thus form piles or columns of
-Considerable length (fig. CXIII.). The columns
-often again combine one among another, the end
-of one being attached to the side of another,
-sometimes producing very curious ramifications
-(fig. CXIII.). In like manner, the elliptical particles
-apply themselves to each other by their
-broad surfaces, but they are not so exactly matched
-as the circular, one particle partially overlapping
-another, so that they form less regular columns
-than the circular.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_345.png" alt="Fig. CXIII." />
-<div class="caption">Columnar arrangement which the particles of the human<br />
-blood assume immediately after it is drawn from its vessel.</div>
-</div>
-
-<p>236. The red particles, as far as is known, constitute
-a distinct and peculiar form of animal matter:
-the red colour, according to some, depending
-on an impregnation of iron; according to others, on
-an animal substance of a gelatinous nature.</p>
-
-<p>237. The exact proportion of the different substances
-
-<span class="pagenum"><a name="Page_346" id="Page_346">[Pg 346]</a></span>
-contained in the blood, according to the
-most recent analysis of it, that by M. le Canu, is
-as follows, namely,</p>
-
-<table summary="proportion">
-<tr>
-<td class="tdl">Water</td>
-<td class="tdr">786·500</td>
-</tr>
-<tr>
-<td class="tdl">Albumen</td>
-<td class="tdr">69·415</td>
-</tr>
-<tr>
-<td class="tdl">Fibrin</td>
-<td class="tdr">3·565</td>
-</tr>
-<tr>
-<td class="tdl">Colouring matter</td>
-<td class="tdr">119·626</td>
-</tr>
-<tr>
-<td class="tdl">Crystallizable fatty matter</td>
-<td class="tdr">4·300</td>
-</tr>
-<tr>
-<td class="tdl">Oily matter&nbsp;</td>
-<td class="tdr">2·270</td>
-</tr>
-<tr>
-<td class="tdl">Extractive matter, soluble in</td>
-</tr>
-<tr>
-<td class="tdl">alcohol and water</td>
-<td class="tdr">1·920</td>
-</tr>
-<tr>
-<td class="tdl">Albumen combined with soda</td>
-<td class="tdr">2·010</td>
-</tr>
-<tr>
-<td class="tdl">Chloruret of sodium and potassium,</td>
-</tr>
-<tr>
-<td class="tdl">alkaline phosphate,</td>
-</tr>
-<tr>
-<td class="tdl">sulphate, and subcarbonates</td>
-<td class="tdr">7·304</td>
-</tr>
-<tr>
-<td class="tdl">Subcarbonate of lime and magnesia,</td>
-</tr>
-<tr>
-<td class="tdl">phosphates of lime,</td>
-</tr>
-<tr>
-<td class="tdl">magnesia and iron, peroxide</td>
-</tr>
-<tr>
-<td class="tdl">of iron</td>
-<td class="tdr">1·414</td>
-</tr>
-<tr>
-<td class="tdl">Loss</td>
-<td class="tdr">2·586</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">&mdash;&mdash;&mdash;&mdash;</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">1000·</td>
-</tr>
-
-</table>
-
-<p>238. From the results of this analysis it is manifest
-that all the proximate principles of which the
-different tissues are composed exist in the blood,
-namely, albumen, the proximate principle forming
-the basis of membrane; fibrin, the proximate principle
-forming the basis of muscle; fatty matter,
-forming the basis of nerve and brain; and various
-
-<span class="pagenum"><a name="Page_347" id="Page_347">[Pg 347]</a></span>
-
-saline and mineral substances, forming a large part
-of bone, and entering more or less into the composition
-of every fluid and solid.</p>
-
-<p>239. The blood, which contains all the proximate
-constituents of the body, and which, by distributing
-them to the various tissues and organs, maintains
-their integrity and life, is itself alive. The vitality
-of the blood is proved,&mdash;</p>
-
-<p>240. i. By its undergoing the process of death,
-which it does just as much as the heart or the
-brain, every time it is removed from the body.
-While flowing in its living vessel, the blood is
-permanently fluid. Its fluidity depends on a force
-of mutual repulsion exerted by its particles on each
-other. That repulsive force is a vital endowment,
-probably derived from the organic nerves so abundantly
-distributed to the inner coat of the blood-vessels.
-When this vital influence is withdrawn,
-which happens on the removal of the blood from its
-vessel, the mass is no longer capable of remaining
-fluid; the fibrin is converted into a solid; the red
-particles, instead of repelling, attract each other,
-forming the crude aggregate at the bottom of the
-clot; coagulation is thus a process of death; its
-commencement indicates a diminution of the vital
-energy of the blood; during its progress that energy
-is constantly growing less and less; the blood is
-dying; and when complete, the blood is dead.</p>
-
-<p>241. Hence in every state of the system in which
-the vital energy of the blood is preternaturally
-
-<span class="pagenum"><a name="Page_348" id="Page_348">[Pg 348]</a></span>
-
-increased, coagulation is proportionably slow; in
-every state in which its energy is diminished,
-coagulation is rapid. By copious and repeated
-blood-letting, the vital energy is rapidly exhausted.
-The effect of blood-letting on coagulation is determined
-by experiments instituted for the express
-purpose of ascertaining it. Blood was received
-from a horse at four periods, about a minute and a
-half intervening between the filling of each cup.</p>
-
-<table summary="coagulation time 2">
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdc">Minutes.</td>
-<td class="tdc">&nbsp; Seconds.</td>
-</tr>
-<tr>
-<td class="tdl">In cup No.</td>
-<td class="tdl"> 1.</td>
-<td class="tdl">coagulation began in</td>
-<td class="tdc">11</td>
-<td class="tdc">10</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"&nbsp;</td>
-<td class="tdl"> 2.</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdc">10</td>
-<td class="tdc">5</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"&nbsp;</td>
-<td class="tdl"> 3.</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdc">9</td>
-<td class="tdc">55</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"&nbsp;</td>
-<td class="tdl"> 4.</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdc">3</td>
-<td class="tdc">10</td>
-</tr>
-</table>
-
-<p>242. In like manner three cups were filled with
-the blood of a sheep, at the interval of half a
-minute.</p>
-
-
-
-<table summary="coagulation time 2">
-<tr>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdl">&nbsp;</td>
-<td class="tdr">Minutes.</td>
-<td class="tdr">&nbsp; Seconds.</td>
-</tr>
-<tr>
-<td class="tdl">In cup No.</td>
-<td class="tdl"> 1.</td>
-<td class="tdl">coagulation began in</td>
-<td class="tdc"> 2</td>
-<td class="tdc">10</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"&nbsp;</td>
-<td class="tdl"> 2.</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdc"> 1</td>
-<td class="tdc">45</td>
-</tr>
-<tr>
-<td class="tdl">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;"&nbsp;</td>
-<td class="tdl"> 3.</td>
-<td class="tdl"><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span><span style="margin-left: 2em;">"</span></td>
-<td class="tdc"> 0</td>
-<td class="tdc">55</td>
-</tr>
-</table>
-
-<p>The same result was obtained in blood taken
-from a human subject. A pound and a half of
-blood was removed from the arm of a woman
-labouring under fever, a portion of which, received
-into a tea-cup on the first effusion, remained fluid
-for the space of seven minutes; a similar quantity,
-taken immediately before tying up the arm,
-was coagulated in three minutes thirty seconds.
-These experiments demonstrate that coagulation
-
-<span class="pagenum"><a name="Page_349" id="Page_349">[Pg 349]</a></span>
-
-is rapid or slow as the vital energy of the blood is
-exhausted or unexhausted, or that in proportion
-to the degree of life possessed by the blood is the
-space of time it takes in dying.</p>
-
-<p>243. This result is referable to the principle
-already shown to be characteristic of living substance,
-&mdash;namely, the power of resisting, within a
-certain range, the ordinary influence of physical
-agents. The operation of this power is illustrated
-in a beautiful manner in a series of experiments
-performed by Mr. Hunter on the egg and on blood.
-This physiologist exposed a live, that is, a fresh
-egg to the temperature of the 17th and the 15th
-degrees of Fahrenheit; it took half an hour to
-freeze it. The egg was then thawed and exposed
-to 10° less cold, namely, to the 25th degree of
-Fahrenheit; it was now frozen in a quarter of an
-hour. A living egg and one that had been killed
-by having been first frozen and then thawed, were
-put together into a freezing mixture at 15°: the
-dead was frozen twenty-five minutes sooner than
-the living egg. The undiminished vitality of the
-fresh egg enabled it to resist the low temperature
-for the space of twenty-five minutes; the vitality
-of the frozen egg having been destroyed, it yielded
-at once to the influence of the physical agent. On
-subjecting blood to analogous experiments, the
-result was found to be the same. Blood immediately
-taken from the living vessel, and blood
-previously frozen and then thawed, being exposed
-
-<span class="pagenum"><a name="Page_350" id="Page_350">[Pg 350]</a></span>
-
-to a freezing mixture, a much shorter period and
-a much less degree of cold were required to freeze
-the latter than the former.</p>
-
-<p>244. ii. The vitality of the blood is proved by the
-change it undergoes in becoming a constituent
-part of an organized tissue. The blood conveys
-to the several tissues the constituents of which they
-are composed; each tissue selects from the mass
-of blood its own constituents and converts them
-into its own substance, in which conversion, since
-the blood always goes to the tissue in a fluid form,
-the blood must necessarily pass from a fluid into a
-solid. In the vessels the vital endowment of the
-blood maintains it permanently fluid; in the structures
-the same power makes it and keeps it solid.
-One and the same substance in one and the same
-body, in one part is always fluid, in another
-always solid; the fluid is every moment passing
-into the solid and the solid into the fluid, without
-intermixture and without interference. Nothing
-analogous to this is ever witnessed in inorganic
-matter, in physical mechanism; it is peculiar to
-the organized body and distinctive of the mechanism
-of life. Sometimes in physical mechanism
-we can perceive the mechanical arrangements and
-distinctly trace them from beginning to end: in
-vital mechanism, even when we can discern the
-mechanical arrangements, we can seldom trace
-them beyond a step or two, and never from beginning
-to end; but arrangement and adaptation we
-
-<span class="pagenum"><a name="Page_351" id="Page_351">[Pg 351]</a></span>
-
-know there must be in that which goes beyond,
-no less than in that which keeps within, our perception,
-and we ought scarcely to question the
-existence of adjustments, because they elude our
-sense, when probably the very reason why they do
-so is that their delicacy and perfection immeasurably
-exceed any with which sense has made us
-acquainted.</p>
-
-<p>245. iii. The vitality of the blood is proved by
-the process of organization. We can trace only a
-few steps of this process, but these are sufficient
-to establish the point in question. Blood effused
-from living vessels into the substance, or upon the
-surface of living organs, solidifies without losing
-vitality. If a clot of blood be examined some
-time after it has thus become solid, it is found to
-abound with blood-vessels. Some of these vessels
-are obviously derived from the surrounding living
-parts. The minute vessels of these parts, as can
-be distinctly traced, elongate and shoot into the
-clot. The clot thus acquires blood-vessels of its
-own. By degrees a complete circulation is established
-within it. The blood-vessels of the clot
-act upon the blood they receive just as the vessels
-of any other part act upon their blood, that is
-transform it into the animal matter it is their office
-to elaborate. In this manner a clot of blood is
-converted into a component part of the body, and
-acquires the power of exercising its own peculiar
-and appropriate functions in the economy.</p>
-
-<p><span class="pagenum"><a name="Page_352" id="Page_352">[Pg 352]</a></span></p>
-
-<p>246. But while, in this process, some of the
-vessels of the clot can be distinctly traced from the
-surrounding living parts, others appear to have no
-communication with those parts, at all events no
-such communication can be traced. These vessels,
-the origin of which cannot be found external to the
-clot, are supposed by some physiologists to be
-formed within it. Within the living egg, during
-incubation, certain motions or actions are observed
-spontaneously to arise, which terminate in the
-development of the chick. Analogous motions
-arising within the clot terminate, it is conceived,
-in the development of blood-vessels. According to
-this view, a simultaneous action takes place in the
-clot, and in the living part with which it is in
-contact; each shooting out vessels which elongate,
-approximate, unite, and thus establish a direct
-vital communication. Whether this view of the
-process of organization be the correct one or not
-does not affect the present argument. It is certain
-that a clot of blood surrounded by living parts
-becomes organized; it is certain that no dead substance
-surrounded by living parts becomes organized;
-it follows that the blood possesses life.</p>
-
-<p>247. Health and life depend on the quantity,
-quality, and distribution of the blood. The chief
-source from which the blood itself is derived is the
-chyle: hence too much or too little food, or too
-great or too little activity of the organs that digest
-it, may render the quantity of the blood preternaturally
-
-<span class="pagenum"><a name="Page_353" id="Page_353">[Pg 353]</a></span>
-
-abundant or deficient; or though there be
-neither excess nor deficiency in the quantity of
-nourishment formed, parts of the blood which
-ought to be removed may be retained, or parts
-which ought to be retained may be removed, and
-hence the actual quantity in the system may be
-superabundant or insufficient.</p>
-
-<p>248. The relative proportion of every constituent
-of the blood is capable of varying; and of course
-in the degree in which the healthy proportion is
-deranged, the quality of the mass must undergo
-a corresponding deterioration. The watery portion
-is sometimes so deficient, that the mass is obviously
-thickened; while at other times the fluid preponderates
-so much over the solid constituents, that
-the blood is thin and watery. The albumen, the
-quantity of which varies considerably even in
-health, in disease is sometimes twice as great, and
-at other times is less than half its natural proportion.
-In some cases the fibrin preponderates so
-much, that the coagulum formed by the blood is
-exceedingly coherent, firm and dense; in other cases
-the quantity of fibrin is so small, that the coagulation
-is imperfect, forming only a soft, loose and
-tender coagulum, and in extreme cases the blood
-remains wholly fluid. When the vital energy of
-the system is great, the red particles abound;
-when it is depressed, they are deficient. In the
-former state, they are of a bright red colour; in
-the latter, dusky, purple, or even black. When
-
-<span class="pagenum"><a name="Page_354" id="Page_354">[Pg 354]</a></span>
-
-the depression of the vital energy is extreme, the
-power of mutual repulsion exerted by the particles
-would seem to be so far destroyed as to admit of
-their adhering to each other partially in certain
-organs; while in other cases they seem to be
-actually disorganised, and to have their structures
-so broken up, that they escape from the current of
-the circulation as if dissolved in the serum, through
-the minute vessels intended only for the exhalation
-of the watery part of the blood. This fearful change
-is conceived to have an intimate connexion with a
-diminution of the proportion of the saline constituents.
-Out of the body, as has been shown, the
-red particles change their figure instantaneously,
-and are rapidly dissolved when in contact with pure
-water; while they undergo little change of form if
-the water hold saline matter in solution. It would
-seem that one use of the saline constituents of the
-blood is to preserve entire the figure and constitution
-of the red particles. It is certain that any
-change in the proportion of the saline constituents
-produces a most powerful effect on the condition of
-the red particles. It is no less certain that changes
-do take place in the proportion of the saline constituents.
-In the state of health, the taste of the
-blood is distinctly salt, depending chiefly on the
-quantity of muriate of soda contained in it. In
-certain violent and malignant diseases, such, for
-example, as the malignant forms of fever, and
-more especially that form of it termed pestilential
-
-<span class="pagenum"><a name="Page_355" id="Page_355">[Pg 355]</a></span>
-
-cholera, this salt taste is scarcely, if at all, perceptible;
-and it is ascertained that, in such cases,
-the proportion of saline matter is sensibly diminished.</p>
-
-<p>249. The quality of the blood may be also essentially
-changed by the disturbance of the balance
-of certain organic functions: digestion, absorption,
-circulation, respiration, are indispensable to the
-formation of the blood and to the nourishment of
-the tissues. Absorption, nutrition, secretion, circulation,
-render the blood impure, either by directly
-communicating to it hurtful ingredients, or by
-allowing noxious matters to accumulate in it, or
-by destroying the relative proportion of its constituents.
-Organs are specially provided, the main
-function of which is to separate and remove from
-the blood these injurious substances. Organs of
-this class are called depurating, and the process
-they carry on is denominated that of depuration.
-The lungs, the liver, the kidneys, are depurating
-organs, and one result at least of the functions they
-perform is the purification or depuration of the
-blood. If the lung fail to eliminate carbon, the
-liver bile, the kidney urine, carbon, bile, urine, or
-at least the constituents of which these substances
-are composed, must accumulate in the blood,
-contaminate it, and render it incapable of duly
-nourishing and stimulating the organs.</p>
-
-<p>250. But though the blood be good in quality
-and just in quantity, health and life must still
-
-<span class="pagenum"><a name="Page_356" id="Page_356">[Pg 356]</a></span>
-
-depend upon its proper distribution. It may be
-sent out to the system too rapidly or too slowly.
-It may be distributed to different portions of the
-system unequally; too much may be sent to one
-organ, and too little to another: consequently,
-while the latter languishes, the former may be oppressed,
-overwhelmed or stimulated to violent and
-destructive action. In either case health is disturbed
-and life endangered.</p>
-
-<p>251. Of the mode and degree in which food,
-air, moisture, temperature, repletion, abstinence,
-exercise, indolence, influence the quantity, quality,
-and distribution of the blood; of the mode in
-which the condition of the blood modifies the actions
-both of the organic and the animal organs;
-of the reason why health and disease are wholly
-dependent on those states and actions, a clear and
-just conception may be formed when the several
-functions have been described, and the precise
-office of each is understood.</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_357" id="Page_357">[Pg 357]</a></span></p>
-<h2><a name="CHAPTER_VII" id="CHAPTER_VII">CHAPTER VII.</a>
-<br />
-<br />
-<span class="smaller">OF THE CIRCULATION.</span></h2>
-</div>
-
-<blockquote>
-
-<p>Vessels connected with the heart: chambers of the heart&mdash;Position
-of the heart&mdash;Pulmonic circle: systemic circle&mdash;Structure
-of the heart, artery, and vein&mdash;Consequences
-of the discovery of the circulation to the discoverer&mdash;Action
-of the heart: sounds occasioned by its different
-movements&mdash;Contraction: dilatation&mdash;Disposition and
-action of the valves&mdash;Powers that move the blood&mdash;Force
-of the heart&mdash;Action of the arterial tubes: the pulse: action
-of the capillaries: action of the veins&mdash;Self-moving
-power of the blood&mdash;Vital endowment of the capillaries:
-functions&mdash;Practical applications.</p></blockquote>
-
-
-<p>252. The blood, being necessary to nourish the
-tissues and to stimulate the organs, must be in
-motion in order to be borne to them. An apparatus
-is provided partly for the purpose of originating
-an impelling force to put the blood in motion,
-and partly for the purpose of conveying the blood
-when in motion to the different parts of the body.</p>
-
-<p>253. The heart is the impelling organ; the great
-vessels in immediate connexion with it are the
-transmitting organs (fig. CXIV. 1, 2). The heart
-is divided into two sets of chambers (fig. CXIV.
-3, 4, 10, 11), one for the reception of the blood
-from the different parts of the body (fig. CXIV.
-3, 10); the other for the communication of the
-
-<span class="pagenum"><a name="Page_358" id="Page_358">[Pg 358]</a></span>
-
-impulse which keeps the blood in motion (fig.
-CXIV. 4, 11). The chamber which receives the
-blood is termed an auricle (fig. CXIV. 3, 10), and
-is connected with a vessel termed a vein (fig. CXIV.
-1, 2, 9); that which communicates impulse to the
-blood is termed a ventricle (fig. CXIV. 4, 11),
-and is connected with a vessel termed an artery
-(fig. CXIV. 7, 12). The vein carries blood to the
-auricle; the auricle transmits it to the ventricle;
-the ventricle propels it into the artery; the artery,
-carrying it out from the ventricle, ultimately sends
-
-<span class="pagenum"><a name="Page_359" id="Page_359">[Pg 359]</a></span>
-
-it again into the vein, the vein returns it to the
-auricle, the auricle to the ventricle, the ventricle
-to the artery, and thus the blood is constantly
-moving in a circle; hence the name of the process,
-the circulation of the blood.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_358.png" alt="Fig. CXIV." />
-<div class="caption">View of the heart with its several chambers exposed, and<br />
-the great vessels in connection with them. 1. The superior<br />
-vena cava; 2. the inferior vena cava; 3. the chamber called<br />
-the right auricle; 4. the chamber called the right ventricle;<br />
-5. the line marking the passage between the two chambers,<br />
-and the points of attachment of one margin of the valve;<br />
-6. the septum between the two ventricles; 7. the pulmonary<br />
-artery arising from the right ventricle, and dividing at 8, into<br />
-right and left for the corresponding lungs; 9. the four pulmonary<br />
-veins bringing the blood from the lungs into 10,<br />
-the left auricle; 11. the left ventricle; 12. the aorta arising<br />
-from the left ventricle, and passing down behind the heart<br />
-to distribute blood, by its divisions and subdivisions, to<br />
-every part of the body.</div>
-</div>
-
-<p>254. In nourishing the tissues and stimulating
-the organs, the blood parts with its nutritive and
-stimulating constituents, and receives in return
-some ingredients which can no longer be usefully
-employed in the economy, and others which are positively
-injurious. An apparatus is established for
-its renovation and depuration; this organ is termed
-the lung (fig. LIX. 5), and to this organ the
-blood must in like manner be conveyed. Thus the
-blood moves in a double circle, one from the heart
-to the body and from the body back to the heart,
-termed the systemic circle; the other from the
-heart to the lung and from the lung back to the
-heart, termed the pulmonic circle. Hence in the
-human body the heart is double, consisting of two
-corresponding parts precisely the same in name,
-in nature, and in office; the one appropriated to
-the greater, or the systemic, and the other to the
-lesser, or the pulmonic circulation (fig. CXIV.).</p>
-
-<p>255. There is a complete separation between
-these two portions of the heart (fig. CXIV. 6),
-formed by a strong muscular partition which prevents
-any communication between them except
-through the medium of vessels.</p>
-
-<p>256. The heart is situated between the two lungs
-(fig. LIX. 2, 5), in the lower and fore part of
-
-<span class="pagenum"><a name="Page_360" id="Page_360">[Pg 360]</a></span>
-
-the chest, nearly in the centre, but inclining a
-little to the left side. Its position is oblique (fig.
-LIX. 2, 5). Its basis is directed upwards, backwards,
-and towards the right (fig. LIX. 2); its
-apex is directed downwards, forwards, and towards
-the left, opposite to the interval between the cartilages
-of the fifth and sixth ribs (fig. LIX. 2).
-It is inclosed in a bag termed the pericardium
-(fig. CXV.), which consists of serous membrane.
-
-<span class="pagenum"><a name="Page_361" id="Page_361">[Pg 361]</a></span>
-
-The pericardium is considerably larger than the
-heart, allowing abundant space for the action of
-the organ (fig. CXV.). One part of the pericardium
-forms a bag around the heart (fig. CXV.);
-the other part is reflected upon the heart so as
-to form its external covering (fig. CXV.), and is
-continued for a considerable distance upon the
-great vessels that go to and from the heart in
-such a manner that this bag, like all the serous
-membranes, constitutes a shut sac. Both that
-portion of the pericardium which is reflected upon
-the heart, and that which forms the internal surface
-of the bag around it, is moistened during life
-by a serous fluid, which, after death, is condensed
-into a small quantity of transparent water. That
-portion of the pericardium which rests on the
-diaphragm (fig. LXX. 1) is so firmly attached to
-it that it cannot be separated without laceration,
-and by this attachment, together with the great
-vessels at its base, the heart is firmly held in its
-situation, although in the varied movements of the
-body it is capable of deviating to a slight extent
-from the exact position here described.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_360.png" alt="Fig. CXV." />
-<div class="caption">View of the heart enveloped in its pericardium, the fore part<br />
-of the latter being cut open and reflected back.</div>
-</div>
-
-<p>257. When the interior of the heart is laid
-open there are brought into view four chambers
-(fig. CXIV. 3, 4, 10, 11), two for each circle.
-Those belonging to the pulmonic circle are on the
-right (fig. CXIV. 3, 4), those to the systemic on
-the left side of the body (fig. CXIV. 10, 11);
-
-<span class="pagenum"><a name="Page_362" id="Page_362">[Pg 362]</a></span>
-
-hence the terms right and left are applied to these
-respective parts of the heart.</p>
-
-<p>258. The veins which carry the blood to the right
-or the pulmonic chambers are two, one of which
-brings it from the upper, and the other from the
-lower parts of the body: the first is called the superior
-and the second the inferior vena cava (fig.
-CXIV. 1, 2). Both pour their blood into the first
-chamber, termed the right auricle (fig. CXIV. 3);
-from the right auricle the blood passes into the
-second chamber, denominated the right ventricle
-(fig. CXIV. 4): from which springs the artery
-which carries the blood from the heart to the lung,
-the pulmonary artery (fig. CXIV. 7). This is
-the pulmonic circle. From the lung the blood is
-returned to the heart by four veins, termed the
-pulmonary veins (fig. CXIV. 9), which pour
-the blood into the third chamber of the heart, the
-left auricle (fig. CXIV. 10). From the left auricle
-it passes into the fourth chamber, the left ventricle
-(fig. CXIV. 11), from which springs the artery
-which carries out the blood to the system, termed
-the aorta (figs. CXIV. 12, and CXVII. 11).
-This is the systemic circle. In the system the
-minute branches of the aorta unite with the minute
-branches that form the venæ cavæ, which return
-the blood to the right auricle of the heart, and thus
-the double circle is completed.</p>
-
-<p>259. The two chambers called the auricles
-
-<span class="pagenum"><a name="Page_363" id="Page_363">[Pg 363]</a></span>
-
-occupy the basis of the heart (fig. CXIV. 3, 10).
-The right auricle is situated at the basis of the
-right ventricle (figs. CXIV. 3, and CXVI. 4). It
-
-<span class="pagenum"><a name="Page_364" id="Page_364">[Pg 364]</a></span>
-
-is partly membranous and partly muscular. At its
-upper and back part is the opening of the vena
-cava superior (fig. CXVI. 1), which returns the
-blood to the heart from the head, neck, and all
-the upper parts of the body. At its lower part is
-the opening of the vena cava inferior (fig. CXVI.
-2), which returns the blood from all the lower
-parts of the body.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_363.png" alt="Fig. CXVI." />
-<div class="caption">View of the heart with the great vessels in connection<br />
-with it, on the right side, its different chambers being laid<br />
-open and its structure shown. 1. The vena cava superior;<br />
-2. the vena cava inferior; 3. cut edge of the right auricle<br />
-turned aside to show, 4. the cavity of the right auricle into<br />
-which the two venæ cavæ pour the blood returned from all<br />
-parts of the body; 5. hook suspending the reflected portion<br />
-of the wall of the auricle; 6. the right ventricle; 7. cut<br />
-edge of the wall of the ventricle, a portion of which has<br />
-been removed to show 8. the cavity of the ventricle; 9.<br />
-situation of the opening between the auricle and ventricle,<br />
-called the auricular orifice of the ventricle; 10. valve placed<br />
-between the auricle and ventricle, one margin being firmly<br />
-attached to the auriculo-ventricular opening in its entire<br />
-extent, the other lying loose in the cavity of the ventricle;<br />
-11. probe passed from the auricle into the ventricle underneath<br />
-the valve, showing the course of the blood from the<br />
-former chamber to the latter; 12. the columnæ carneæ<br />
-attached by one extremity to the walls of the ventricle, the<br />
-other extremity ending in tendinous threads attached to the<br />
-loose margin of the valve; 13. passage to the pulmonary<br />
-artery; 14. the three semilunar valves placed at the commencement<br />
-of 15. the pulmonary artery; 16. the two great<br />
-branches into which the trunk of the pulmonary artery<br />
-divides, one branch going to each lung.</div>
-</div>
-
-<p>260. The auricle communicates with its corresponding
-ventricle by a large opening, termed the
-auricular orifice of the ventricle (figs. CXIV. 5,
-and CXVI. 9). All around the opening is placed
-a thin but strong membrane (fig. CXVI. 10), one
-margin of which is firmly attached to the wall of
-the ventricle (figs. CXIV. 5, and CXVI. 9), while
-the other is free (fig. CXVI. 10). This membrane
-receives the name, and, as will be seen
-immediately, performs the office of a valve.</p>
-
-<p><span class="pagenum"><a name="Page_365" id="Page_365">[Pg 365]</a></span></p>
-
-<p>261. The ventricle is much thicker and proportionally
-stronger than the auricle (fig. CXVI. 3,
-6). It is composed almost entirely of muscular
-fibre. Over nearly the whole extent of its internal
-surface are placed irregular masses of muscular
-fibres, many of which stand out from the wall of
-the ventricle like columns or pillars (fig. CXVI.
-12); hence they are called fleshy columns (columnæ
-carneæ). Some of these fleshy columns are
-adherent by one extremity to the wall of the ventricle,
-while the other extremity terminates in tendinous
-threads which are attached to the membrane
-that forms the valve (fig. CXVI. 12).</p>
-
-<p>262. From the upper and right side of this
-chamber springs the pulmonary artery (fig. CXVI.
-15); at the entrance of which are placed three
-membranes of a crescent or semilunar shape,
-termed the semilunar valves (fig. CXVI. 14).</p>
-
-<p>263. The structure of the left side of the heart is
-perfectly analogous to that of the right. Its auricle,
-like that on the left side, is placed at the base of
-the ventricle (figs. CXIV. 10, and CXVII. 2), and
-like it also is thin, being composed chiefly of membrane.
-At its upper and back part (figs. CXIV.
-9, and CXVII. 1) are the openings of the four
-pulmonary veins, two from the right, and two from
-the left lung.</p>
-
-<p>264. At the passage of communication between
-the left auricle and ventricle is placed a valve analogous
-to that on the right side (fig. CXVII. 7).</p>
-
-<p><span class="pagenum"><a name="Page_366" id="Page_366">[Pg 366]</a></span></p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_366.png" alt="Fig. CXVII." />
-<div class="caption">View of the heart with the great vessels in connection<br />
-with it, on the left side, its chambers being laid open as in<br />
-the preceding figure. 1. The four pulmonary veins opening<br />
-into, 2. the cavity of the left auricle; 3. the cut edge of the<br />
-wall of the auricle; 4. the appendix of the auricle; 5. the<br />
-cavity of the left ventricle; 6. the cut edge of the wall of<br />
-the ventricle, the greater portion of the wall having been<br />
-removed to show the interior of the chamber; 7. valve<br />
-placed between the auricle and ventricle; 8. columnæ carneæ<br />
-terminating in tendinous threads attached to the loose<br />
-margin of the valve; 9. probe passed underneath the valve<br />
-and its tendinous threads, raising them from the wall of<br />
-the ventricle similar to a refluent current of blood; 10.<br />
-passage to 11. the aorta; 12. two of the semilunar valves<br />
-placed at the mouth of the aorta, the third having been cut<br />
-away; 13. arch of the aorta; 14. the three semilunar valves<br />
-at the commencement of the pulmonary artery seen in<br />
-action, completely closing the mouth of the vessel.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_367" id="Page_367">[Pg 367]</a></span></p>
-
-<p>265. The walls of the left ventricle are nearly
-as thick again as those of the right, and its fleshy
-columns are much larger and stronger. From the
-upper and back part of this fourth chamber (fig.
-CXVII. 11) springs the great systemic artery, the
-aorta, around the mouth of which are placed three
-semilunar valves (fig. CXVII. 12), similar to those
-at the mouth of the pulmonary artery.</p>
-
-<p>266. The partition which divides the two sets
-of chambers from each other (fig. CXIV. 6) is
-wholly composed of muscular fibres, and is called
-the septum of the heart.</p>
-
-<p>267. The external surface of the heart is covered
-by a thin but strong membrane continued over it
-from the pericardium. Between this membranous
-covering and its fleshy substance is lodged, even
-when the body is reduced to the greatest degree of
-thinness, a quantity of fat. Immediately beneath
-this fat are the fleshy fibres that compose the main
-bulk of the organ. These fibres are arranged in a
-peculiar manner. The arrangement is not perceptible
-when the heart is examined in its natural
-state, but after it has been subjected to long-continued
-boiling, which, besides separating extraneous
-matters from the fibres, hardens and loosens without
-displacing them, the manner in which they are
-disposed is manifest. Just at the point where the
-muscular fibres that constitute the septum of the
-auricles are set upon those which form the septum
-of the ventricles, and parallel with the origin of the
-
-<span class="pagenum"><a name="Page_368" id="Page_368">[Pg 368]</a></span>
-
-aorta, the heart is not muscular but tendinous.
-The substance called tendon, it has been shown,
-is often employed in the body to afford origin or
-insertion to muscular fibres, performing, in fact, the
-ordinary office of bone, and substituted for it in
-situations where bone would be inconvenient.
-From the tendinous matter just indicated most of
-the fibres that constitute the muscular walls of the
-heart take their origin. From this point the fibres
-proceed in different directions: those which go to
-form the wall of the auricles ascend; those which
-form the wall of the ventricles pursue an oblique
-course downwards, and the arrangement of the
-whole is such, that a general contraction of the
-fibres must necessarily bring all the parts of the
-heart towards this central tendinous point. The
-object and the result of this arrangement will be
-manifest immediately.</p>
-
-<p>268. The internal surface of the chambers of the
-heart, in its whole extent, is lined by a fine transparent
-serous membrane, which renders it smooth
-and moist; and, like all other organs which have
-important functions to perform, it is plentifully
-supplied with blood-vessels and nerves.</p>
-
-<p>269. Such is the structure of the organ that
-moves the blood. The artery, the tube that
-carries it out from the heart, is a vessel composed
-of three distinct layers of membrane superimposed
-one upon another, and intimately united
-by delicate cellular tissue. These layers are termed
-
-<span class="pagenum"><a name="Page_369" id="Page_369">[Pg 369]</a></span>
-
-tunics or coats. The external coat (fig. CXVIII.
-3), which is also called the cellular, consists
-of minute whitish fibres, which are dense and
-tough, and closely interlaced together in every direction.
-They form a membrane of great strength,
-the elasticity of which, especially in the longitudinal
-direction, is such that, in addition to its
-other names, it has received that of the elastic
-coat.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_369.png" alt="Fig. CXVIII." />
-<div class="caption">Portion of an artery, showing the several coats of which<br />
-it is composed separated from each other. 1. The internal<br />
-or serous coat; 2. the middle or fibrous coat; 3. the external<br />
-or cellular coat.</div>
-</div>
-
-<p>270. The middle or the fibrous tunic is composed
-of yellowish flattened fibres which pass in an
-oblique direction around the calibre of the vessel,
-forming segments of circles, which, uniting, produce
-complete rings (fig. CXVIII. 2). This tunic
-is thick, consisting of several layers of fibres which
-it is easy to peel off in succession. They form a
-firm, solid, elastic, but, at the same time, brittle
-membrane.</p>
-
-<p><span class="pagenum"><a name="Page_370" id="Page_370">[Pg 370]</a></span></p>
-
-<p>271. The inner tunic, thin, colourless, nearly
-transparent, and perfectly smooth, is moistened by
-a serous fluid, and is thence called the serous
-coat (fig. CXVIII. 1). To the naked eye it presents
-no appearance of fibres, yet notwithstanding
-its extreme delicacy, it is so strong that, after the
-other coats of the artery have been entirely removed
-in a living animal, it is capable of resisting the impetus
-of the circulation, and of preventing the dilatation
-of the artery. The arteries themselves are
-supplied with arteries, vessels that nourish their
-tissues, and which are sent to them from neighbouring
-branches, seldom or never from the vessel
-itself to which they are distributed. Each individual
-part of an artery is supplied by its own appropriate
-vessels, which form but few communications
-above and below, so that if care be not
-taken in surgical operations to disturb these nutrient
-arteries very little, the vessel will perish for
-want of sustenance.</p>
-
-<p>272. The vein, the tube that carries back the
-blood to the heart, is composed of the same number
-of tunics as the artery, which, with the exception
-of the middle, are essentially the same in structure,
-but they are all much thinner. The external
-tunic consists of a less dense and strong cellular
-membrane; the middle tunic, instead of being
-formed of elastic rings, is composed of soft and
-yielding fibres, disposed in a longitudinal direction;
-while the inner coat, which is still more delicate
-
-<span class="pagenum"><a name="Page_371" id="Page_371">[Pg 371]</a></span>
-
-than that of the artery, is arranged in a peculiar
-manner. The inner coat of most veins, at slight
-intervals, is formed into folds (fig. CXX. 5), one
-margin of which is firmly adherent to the circumference
-of the vessel, while the other margin is free
-and turned in the direction of the heart. These
-membranous folds are termed valves. In all veins
-the diameter of which is less than a line the valves
-are single; in most veins of greater magnitude
-they are placed in pairs, while in some of the
-larger trunks they are triple, and in a few instances
-quadruple, and even quintuple. The veins, like
-the arteries, are supplied with nutrient vessels and
-nerves.</p>
-
-<p>273. All the arteries of the body proceed from
-the two trunks already described; that connected
-with the pulmonic circle, the pulmonary artery, and
-that connected with the systemic circle, the aorta.
-These vessels, as they go out from the heart and
-proceed to their ultimate termination, are arborescent,
-that is, they successively increase in number
-and diminish in size, like the branches of a tree
-going off from the trunk (fig. CXIX. 1, 2, 3).
-Each trunk usually ends by dividing into two or
-more branches (fig. CXIX. 1, 2), the combined
-area of which is always greater than that of the
-trunk from which they spring, in the proportion
-of about one and a half to one. As the branch
-proceeds to its ultimate termination it divides and
-subdivides, until at length the vessel becomes so
-
-<span class="pagenum"><a name="Page_372" id="Page_372">[Pg 372]</a><br /><a name="Page_373" id="Page_373">[Pg 373]</a></span>minute, that it can no longer be distinguished
-
-by the eye. These ultimate branches are called
-capillary vessels, from their hair-like smallness
-(fig. CXIX. 4); but this term does not adequately
-express their minuteness. It has been stated
-(234) that the red particle of the blood, at the
-medium calculation, is not more than the three-thousandth
-part of an inch in diameter; yet vast
-numbers of the capillary vessels are so small that
-they are incapable of admitting one of these particles,
-and receive only the colourless portion of
-the blood.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_372.png" alt="Fig. CXIX." />
-<div class="caption">View of the manner in which an artery divides and subdivides<br />
-into its ultimate branches. 1. Trunk of the artery;<br />
-2. large branches into which it subdivides; 3. small<br />
-branches, successively becoming smaller and smaller until<br />
-they terminate in 4. the capillary branches.</div>
-</div>
-
-<p>274. Every portion of an artery, by reason of the
-elasticity of its coats, preserves nearly a cylindrical
-form, and as the area of the branches is greater
-than that of the trunks, the blood, in proceeding
-from the heart to the capillaries, though passing
-through a series of descending cylinders, is really
-flowing through an enlarging space.</p>
-
-<p>275.  The disposition of the veins, like that of
-the arteries, is arborescent, but in an inverse order;
-for the course of the veins is from capillary vessels
-to visible branches, and from visible branches to
-large trunks (fig. CXX. 1, 2, 3). In every part
-of the body where the capillary arteries terminate
-the capillary veins begin, and the branches uniting
-to form trunks, and the small to form large trunks,
-and the trunks always advancing towards the heart,
-and always increasing in magnitude as they approach
-it, form at length the two veins which it
-
-<span class="pagenum"><a name="Page_374" id="Page_374">[Pg 374]</a></span>
-
-has been stated (258) return all the blood of the
-body to the right auricle of the heart.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_374.png" alt="Fig. CXX." />
-<div class="caption">View of the manner in which the minute branches of the<br />
-vein unite to form the larger branches and the trunks.<br />
-1. Capillary venous branches; 2. small branches formed by<br />
-the union of the capillary; 3. larger branches formed by<br />
-the union of the smaller and gradually increasing in size,<br />
-to form the great trunk, 4. a portion of which is laid open<br />
-to show its inner surface and the arrangement of 5. the<br />
-valves formed by its inner coat.</div>
-</div>
-
-<p><span class="pagenum"><a name="Page_375" id="Page_375">[Pg 375]</a></span></p>
-
-<p>276. The veins are very much more numerous
-than the arteries, for they often consist of double
-sets, and they are at the same time more capacious
-and more extensible. Reckoning the whole of the
-blood at one-fifth of the weight of the body, it is
-estimated that, of this quantity, about one-fourth
-is in the arterial and the remaining three-fourths
-in the venous system. The combined area of the
-branches of the veins is much greater than that of
-the two trunks in which they terminate (fig. CXX.
-1, 2, 3, 4): the blood, therefore, in returning to
-the heart, is always flowing from a large into a
-smaller space.</p>
-
-<p>277. The divisions and subdivisions of the artery
-freely communicate in all parts of the body by
-means of what are called anastomosing branches,
-and this communication of branch with branch
-and trunk with trunk is termed anastomosis. The
-same intercommunication, but with still greater
-freedom and frequency, takes place among the
-branches of veins. In both orders of vessels the
-communication is frequent in proportion to the
-minuteness of the branch and its distance from
-
-<span class="pagenum"><a name="Page_376" id="Page_376">[Pg 376]</a></span>
-
-the heart. It is also more frequent in proportion
-as a part is exposed to pressure; hence the minute
-arteries and veins about a joint are distinguished
-for the multitude of their anastomosing branches;
-and above all, it is frequent in proportion to the
-importance of the organ; hence the most remarkable
-anastomosis in the body is in the brain. By
-this provision care is taken that no part be deprived
-of its supply of blood; for if one channel
-be blocked up, a hundred more are open to the
-current, and the transmission of it to any particular
-region or organ by two or more channels,
-instead of through one trunk, is a part of the same
-provision. Thus the fore-arm possesses four principal
-arteries with corresponding veins, and the
-brain receives its blood through four totally independent
-canals<a name="FNanchor_6_6" id="FNanchor_6_6"></a><a href="#Footnote_6_6" class="fnanchor">[6]</a>.</p>
-
-<p><span class="pagenum"><a name="Page_377" id="Page_377">[Pg 377]</a></span></p>
-
-<p>278. That the blood is really a flowing stream,
-and that it pursues the course described (258),
-is indubitable. For,</p>
-
-<p>(1.) With the microscope, in the transparent
-parts of animals, the blood can be seen in motion
-(fig. CXXI.); and if its course be attentively
-observed, its route may be clearly traced.</p>
-
-<div class="topspace2"></div>
-<div class="figcenter">
-<img src="images/i_378.png" alt="Fig. CXXI." />
-<div class="caption">View of the circulation of the blood as seen under the<br />
-microscope in the web of the frog's foot.</div>
-</div>
-
-<p>(2.) The membranes termed valves are so
-placed as to allow of the freest passage to the
-blood in the circle described, while they either
-altogether prevent or exceedingly impede its movement
-in any other direction.</p>
-
-<p>(3.) The effect of a ligature placed around a
-vein and an artery, and of a puncture made above
-the ligature in the one vessel and below it in the
-other, demonstrate both the motion of the blood
-and the course of it. When a ligature is placed
-around a vein, that part of the vessel which is
-most distant from the heart becomes full and
-turgid on account of the accumulation of blood in
-it; while the part of the vessel which is between
-the ligature and the heart becomes empty and
-
-<span class="pagenum"><a name="Page_378" id="Page_378">[Pg 378]</a></span>flaccid, because it has carried on its contents to
-
-the heart, and it can receive no fresh supply from
-the body. When, on the contrary, a ligature is
-placed around an artery, that portion of the vessel
-which lies between the ligature and the heart
-becomes full and turgid, and the other portion
-
-<span class="pagenum"><a name="Page_379" id="Page_379">[Pg 379]</a></span>
-
-empty and flaccid. This can only be because the
-contents of the two vessels move in opposite directions,&mdash;from
-the heart to the artery, from the
-artery to the vein, and from the vein to the heart.
-At the same time, if the vein be punctured above
-the ligature, there will be little or no loss of blood;
-while if it be punctured below the ligature, the
-blood will continue to flow until the loss of it
-occasions death, which could not be unless the
-blood were in motion, nor unless the direction of
-its course were from the artery to the vein and
-from the vein to the heart.</p>
-
-<p>(4.) If fluids be injected into the veins or
-arteries, whether of the dead or of the living body,
-they readily make their way and fill the vessels, if
-thrown in the direction stated to be the natural
-course of the circulation; but they are strongly
-resisted if forced in the opposite direction.</p>
-
-<p>279. Such is the description, and with the exception
-of the first proof, such the evidence of the
-circulation of the blood in the human body, pretty
-much as it was given by the discoverer of it, the
-illustrious Harvey. Before the time of Harvey, a
-vague and indistinct conception that the blood was
-not without motion in the body had been formed
-by several anatomists. It is analogous to the
-ordinary mode in which the human mind arrives
-at discovery (chap. iii., p. 103), that many minds
-should have an imperfect perception of an unknown
-truth, before some one mind sees it in its completeness
-
-<span class="pagenum"><a name="Page_380" id="Page_380">[Pg 380]</a></span>
-
-and fully discloses it. Having, about
-the year 1620, succeeded in completely tracing the
-circle in which the blood moves, and having at
-that time collected all the evidence of the fact,
-with a rare degree of philosophical forbearance,
-Harvey still spent no less than eight years in re-examining
-the subject, and in maturing the proof
-of every point, before he ventured to speak of it in
-public. The brief tract which at length he published
-was written with extreme simplicity, clearness,
-and perspicuity, and has been justly characterised
-as one of the most admirable examples of
-a series of arguments deduced from observation
-and experiment that ever appeared on any subject.</p>
-
-<p>280. Cotemporaries are seldom grateful to discoverers.
-More than one instance is on record
-in which a man has injured his fortune and lost
-his happiness through the elucidation and establishment
-of a truth which has given him immortality.
-It may be that there are physical truths
-yet to be brought to light, to say nothing of new
-applications of old truths, which, if they could
-be announced and demonstrated to-day, would be
-the ruin of the discoverer. It is certain that there
-are moral truths to be discovered, expounded, and
-enforced, which, if any man had now penetration
-enough to see them, and courage enough to express
-them, would cause him to be regarded by the
-present generation with horror and detestation.
-Perhaps, during those eight years of re-examination,
-
-<span class="pagenum"><a name="Page_381" id="Page_381">[Pg 381]</a></span>
-
-the discoverer of the circulation sometimes
-endeavoured in imagination to trace the effect
-which the stupendous fact at the knowledge of
-which he had arrived would have on the progress
-of his favourite science; and, it may be, the hope
-and the expectation occasionally arose that the
-inestimable benefit he was about to confer on his
-fellow men would secure to him some portion of
-their esteem and confidence. What must have
-been his disappointment when he found, after the
-publication of his tract, that the little practice he
-had had as a physician, by degrees fell off. He
-was too speculative, too theoretical, not practical.
-Such was the view taken even by his friends. His
-enemies saw in his tract nothing but indications
-of a presumptuous mind that dared to call in
-question the revered authority of the ancients;
-and some of them saw, moreover, indications of a
-malignant mind, that conceived and defended doctrines
-which, if not checked, would undermine the
-very foundations of morality and religion. When
-the evidence of the truth became irresistible, then
-these persons suddenly turned round and said,
-that it was all known before, and that the sole
-merit of this vaunted discoverer consisted in having
-circulated the circulation. The pun was not fatal
-to the future fame of this truly great man, nor
-even to the gradual though slow return of the
-public confidence even during his own time; for
-he lived to attain the summit of reputation.</p>
-
-<p><span class="pagenum"><a name="Page_382" id="Page_382">[Pg 382]</a></span></p>
-
-<p>281. It is then indubitably established that the
-whole blood of the body in successive streams is
-collected and concentrated at the heart. The
-object of the accumulation of a certain mass of it
-at this organ is to subject it to the action of a
-strong muscle, and thereby to determine its transmission
-with adequate force and precision through
-the different sets of capillary vessels.</p>
-
-<p>282. In the accomplishment of this object the
-heart performs a twofold action; that of contraction
-and that of dilatation. The auricles contract
-and thereby diminish their cavities, then dilate and
-thereby expand them, and the one action alternates
-with the other. There is the like alternate
-contraction and dilatation of the ventricles. The
-first action is termed systole, the second diastole,
-and both are performed with force.</p>
-
-<p>283. When the heart is laid open to view in a
-living animal, and its movements are carefully observed,
-it is apparent that the two auricles contract
-together; that the two ventricles contract together;
-that these motions alternate with each other, and
-that they proceed in regular succession. The interval
-between these alternate movements is, however,
-exceedingly short, and can scarcely be perceived
-when the heart is acting with full vigour;
-but it is evident when its action is somewhat
-languid.</p>
-
-<p>284. When the ventricles contract, the apex of
-the heart is drawn upwards, and at the same time
-
-<span class="pagenum"><a name="Page_383" id="Page_383">[Pg 383]</a></span>
-
-raised or tilted forwards. It is during this systole
-of the ventricles, and in consequence of this result
-of their action, that the apex of the heart gives
-that impulse against the walls of the chest which
-is felt in the natural state between the fifth and
-sixth ribs, and which just perceptibly precedes the
-pulse at the wrist.</p>
-
-<p>285. When the ear is applied to the human
-chest, over the situation of the heart, a dull and
-somewhat prolonged sound is heard, which precedes
-and accompanies the impulse of the heart against
-the chest. This dull sound is immediately succeeded
-by a shorter and sharper sound: after this
-there is a short pause; and then the dull sound
-and impulse are again renewed. The duller sound
-and stronger impulse are ascribed to the contraction
-of the ventricles, and the sharper sound and
-feebler impulse to that of the auricles.</p>
-
-<p>286. The movement of the heart is effected by
-the contraction of its muscular fibres. Those
-fibres rest, as upon a firm support, on the tendinous
-matter to which they are attached, from which
-they diverge, and towards which their contraction
-must necessarily bring all the parts of the heart
-(267). The result of their contraction is the
-powerful compression of all the chambers of the
-heart, and thereby the forcible ejection of their
-contents through the natural openings.</p>
-
-<p>287. But the chambers, alternately with forcible
-contraction, perform the action of forcible dilatation.
-
-<span class="pagenum"><a name="Page_384" id="Page_384">[Pg 384]</a></span>
-
-This movement of dilatation is effected by
-the reaction of the elasticity of the tendinous
-matter on which the muscular fibres are supported
-(267). This highly elastic substance, by the contraction
-of the fibres, is brought into a state of
-extreme tension. The contraction of the fibres
-ceasing, that moment the tense tendon recoils with
-a force exactly proportionate to the degree of
-tension into which it had been brought. Thus the
-very agent that is employed forcibly to close the
-chamber is made the main instrument of securing
-its instantaneous re-opening. A vital energy is
-appointed to accomplish what is indispensable,
-and what nothing else can effect, the origination
-of a motive power; a physical agent is conjoined
-to perform the easier task to which it is competent;
-and the two powers, the vital and the physical,
-work in harmony, each acting alternately, and
-each, with undeviating regularity and unfailing
-energy, fulfilling its appropriate office.</p>
-
-<p>288. When the chambers of the heart which open
-into each other, and which as freely communicate
-with the great vessels that enter and proceed from
-them, are forcibly closed, and the blood they contain
-is projected from them, how is one uniform forward
-direction given to the current? Why, when
-the right ventricle contracts, is the blood not sent
-back into the right auricle, as well as forward into
-the pulmonary artery? There is but one mode of
-preventing such an event, which is to place a flood-gate
-
-<span class="pagenum"><a name="Page_385" id="Page_385">[Pg 385]</a></span>
-
-between the two chambers; and there a flood-gate
-is placed, and that flood-gate is the valve. As
-long as the blood proceeds onwards in the direct
-course of the circulation, it presses this membrane
-close to the side of the heart, and thereby prevents
-it from occasioning any impediment to the current.
-When, on the contrary, the blood is forced backwards,
-and attempts to re-enter the auricle, being
-of course driven in all directions, some of it passes
-between the wall of the ventricle and the valve.
-The moment it is in this situation it raises up the
-valve, carries it over the mouth of the passage,
-and shuts up the channel. There cannot be a
-more perfect flood-gate.</p>
-
-<p>289. This is beautiful mechanism; but there
-is another arrangement which surpasses mere mechanism,
-however beautiful. It has been shown
-(260) that one edge of the membrane that forms
-the valve is firmly adherent to the wall of the ventricle,
-while the other edge, when not in action,
-appears to lie loosely in the ventricle (fig. CXVI.
-10). Were this edge really loose the refluent
-current would carry it back completely into the
-auricle, and so counteract its action as a valve;
-but it is attached to the tendinous threads proceeding
-from the fleshy columns that stand along
-the wall of the ventricle (fig. CXVI. 12). By
-these tendinous threads, as by so many strings,
-the membrane is firmly held in its proper position
-(fig. CXVI. 10, 12); and the refluent current
-
-<span class="pagenum"><a name="Page_386" id="Page_386">[Pg 386]</a></span>
-
-cannot carry it into the auricle. Thus far the
-arrangement is mechanical. But each of these
-fleshy columns is a muscle, exerting a proper muscular
-action. Among the stimulants which excite
-the contractility of the muscular fibre, one of the
-most powerful is distension. The refluent current
-distends the membrane; the distension of the membrane
-stretches the tendinous threads attached to
-it; the stretching of its tendinous threads stretches
-the fleshy column; by this distension of the column
-it is excited to contraction; by the contraction of
-the column its thread is shortened; by the shortening
-of the thread the valve is tightened, and that
-in the exact degree in which the thread is shortened.
-So, the greater the impetus of the refluent blood,
-the greater the distension of the membrane; and
-the greater the distension of the membrane, the
-greater the excitement of the fleshy column; the
-greater the energy with which it is stimulated to
-act, the greater, therefore, the security that the
-valve will be held just in the position that is required,
-with exactly the force that is needed. Here,
-then, is a flood-gate not only well constructed as
-far as regards the mechanical arrangement, but so
-endowed as to be able to act with additional force
-whenever additional force is requisite; to put
-forth on every occasion, as the occasion arises, just
-the degree of strength required, and no more.</p>
-
-<p>290. The contraction of the heart is the power
-that moves the blood; and this contraction generates
-
-<span class="pagenum"><a name="Page_387" id="Page_387">[Pg 387]</a></span>
-
-a force which is adequate to impel it through
-the circle. From experiments performed by Dr.
-Hales it appears that if the artery of a large animal,
-such as the horse, be made to communicate with
-an upright tube, the blood will ascend in the tube
-to the height of about ten feet above the level of
-the heart, and will afterwards continue there rising
-and falling a few inches with each pulsation of the
-heart. In this animal, then, the heart acts with a
-force capable of maintaining a column of ten feet.
-Now a column of ten feet indicates a pressure of
-about four pounds and a half in a square inch of
-surface. Suppose the human heart to be capable
-of supporting a column of blood eight feet high,
-this will indicate a pressure of four pounds to the
-square inch; but the left ventricle of the heart,
-while it injects its column of blood into the aorta,
-has to overcome the inertia of the quantity of blood
-projected; of the mass already in the artery, and of
-the elasticity of the vessel yielding to a momentary
-increase of pressure: it is probable, therefore, that
-the heart acts with a force of six pounds on the
-inch. The left ventricle, when distended, has about
-ten square inches of internal surface; consequently
-the whole force exerted by it may be about sixty
-pounds. According to the calculation of Hales, it
-is fifty-one and a half. Now, it is proved by numerous
-experiments, that, after death, a slight impulse
-with the syringe, certainly much less than
-that which is acting upon the blood in the same
-
-<span class="pagenum"><a name="Page_388" id="Page_388">[Pg 388]</a></span>
-
-artery during life, is sufficient to propel a solution
-of indigo, or fresh drawn blood, from a large artery
-into the extreme capillary. If, therefore, after
-death, a slight force will fill the capillaries, a force
-during life equal to sixty pounds must be adequate
-to do so.</p>
-
-<p>291. The heart, with a force equal to the pressure
-of sixty pounds, propels into the artery two
-ounces of blood at every contraction. It contracts
-four thousand times in an hour. There passes
-through the heart, therefore, every hour, eight
-thousand ounces or seven hundred pounds of
-blood. It has been stated (216) that the whole
-mass of blood in an adult is about twenty-eight
-pounds: on an average the entire circulation is
-completed in two minutes and a half; consequently
-a quantity of blood equal to the whole
-mass passes through the heart from twenty to
-twenty-four times in an hour. But though the average
-space of time requisite to accomplish a complete
-circulation may be two minutes and a half, yet
-when a stream of blood leaves the heart, different
-portions of it must finish their circle at very different
-periods, depending in part upon the length of the
-course which they have to go, and in part upon the
-degree of resistance that obstructs their passage. A
-part of the stream, it is obvious, finishes its course
-in circulating through the heart itself; another
-portion takes a longer circuit through the chest;
-another extends the circle round the head; and
-
-<span class="pagenum"><a name="Page_389" id="Page_389">[Pg 389]</a></span>
-
-another visits the part placed at the remotest
-distance from the central moving power. Such is
-the velocity with which the current sometimes
-goes, that, in the horse, a fluid injected into the
-great vein of the neck, on one side, has been detected
-in the vein on the opposite side, and even
-in the vein of the foot, within half a minute.</p>
-
-<p>292. It has been shown (282) that the different
-chambers of the heart have a tendency to perform
-their movements in a uniform manner, and in a successive
-order; that they contract and dilate in regular
-alternation, and at equal intervals; but, moreover,
-they continue these movements equally without
-rest and without fatigue. On go the motions,
-night and day, for eighty years together, at the rate
-of a hundred thousand strokes every twenty-four
-hours, alike without disorder, cessation, or weariness.
-The muscles of the arm tire after an hour's exertion,
-are exhausted after a day's labour, and can
-by no effort be made to work beyond a certain
-period. There is no appreciable difference between
-the muscular substance of the heart and
-that of the arm. It is true that the heart is
-placed under one condition which is peculiar.
-Muscles contract on the application of stimuli;
-and different muscles are obedient to different
-stimuli,&mdash;the voluntary muscles to the stimulus
-of volition, and the heart to that of the blood.
-The exertion of volition is not constant, but
-occasional; the muscle acts only when it is excited
-
-<span class="pagenum"><a name="Page_390" id="Page_390">[Pg 390]</a></span>
-
-by the application of its stimulus: hence
-the voluntary muscle has considerable intervals of
-rest. The blood, on the contrary, is conveyed to
-the heart without ceasing, in a determinate manner,
-in a successive order; and this is the reason why
-through life its action is uniform: it uniformly
-receives a due supply of its appropriate stimulus.
-But why it is unwearied, why it never requires
-rest, we do not know. We know the necessities
-of the system which render it indispensable that it
-should be capable of untiring action, for we know
-that the first hour of its repose would be the last
-of life; but of the mode in which this wonderful
-endowment is communicated, or of the relations
-upon which it is dependent, we are wholly ignorant.</p>
-
-<p>293. The force exerted by the heart is vital. It
-is distinguished from mechanical force in being
-produced by the very engine that exerts it. In
-the best-constructed machinery there is no real
-generation of power. There is merely concentration
-and direction of it. In the recoil of the
-spring, in the reaction of condensed steam, the
-energy of the expansive impulse is never greater
-than the force employed to compress or condense,
-and the moment this power is expended all capacity
-of motion is at an end. But the heart
-produces a force equal to the pressure of sixty
-pounds by the gentlest application of a bland fluid.
-Here no force is communicated to be again given
-
-<span class="pagenum"><a name="Page_391" id="Page_391">[Pg 391]</a></span>
-
-out, as in every mechanical moving power; but it
-is new power, power really and properly generated;
-and this power is the result of vital action, and is
-never in any case the result of action that is not
-vital.</p>
-
-<p>294. The heart projects the blood with a given
-force into the arterial tubes. The arteries in the
-living body are always filled to distension, and
-somewhat beyond it, by the quantity of blood that
-is in them. It has been shown that the elasticity
-of their coats is such as to give to them, even after
-death, the form of open hollow cylinders (274).
-During life they are kept in a state of distension by
-the quantity of blood they contain. By virtue of
-their elasticity they react upon their contents with
-a force exactly proportioned to the degree of their
-distension, that is, with a force at least adequate
-to keep them always open and rigid.</p>
-
-<p>295. These open and rigid tubes, already filled
-to distension, and somewhat beyond it, receive at
-every contraction of the heart a forcible injection
-of a new wave of blood. The first effect of the injection
-of this new wave into a tube previously full
-to distension, is to cause the current to proceed by
-jerks or jets, each jerk or jet corresponding to the
-contraction of the heart. And, accordingly, by this
-jet-like motion, the flow of the blood in the artery
-is distinguished from that in the vein, in which
-latter vessel the current is an equal and tranquil
-stream.</p>
-
-<p><span class="pagenum"><a name="Page_392" id="Page_392">[Pg 392]</a></span></p>
-
-<p>296. The second effect of this new wave is to
-occasion some further distension of the already
-distended artery, and accordingly, when the vessel
-is exposed in a living animal, and its action carefully
-observed, a slight augmentation of its diameter
-is distinguishable at every contraction of the
-heart. This new wave while it distends must at
-the same time slightly elongate the vessel; cause
-its straight portions to bend a little, and its curved
-portions to bend still more; and, consequently, in
-some situations, to lift it a little from its place,
-giving it a slight degree of locomotion;&mdash;and these
-two causes combined produce the pulse. When
-the finger is pressed gently on an artery, at the instant
-of the contraction of the heart, the vessel is
-felt to bound against the finger with a certain
-degree of force: this, as just stated, is owing to
-a slight distension of the vessel by the new wave
-of blood, together with a slight elongation of it,
-and a gentle rising from its situation.</p>
-
-<p>297. The blood, in flowing through the arterial
-trunks and branches to the capillaries, through
-the arterial to the venous capillaries, and through
-the venous branches and trunks back to the heart,
-is exposed to numerous and powerful causes of
-retardation: such, for example, as the friction
-between the blood and the sides of the vessels, the
-numerous curves and angles formed by the branches
-in springing from the trunks, the tortuous course
-of the vessels in many parts of the body, and the
-
-<span class="pagenum"><a name="Page_393" id="Page_393">[Pg 393]</a></span>
-
-increasing area of the arterial branches as they
-multiply and subdivide. Yet the extraordinary
-fact has been recently discovered, that the blood
-moves with the same momentum or force in every
-part of the arterial system, in the aorta, in the
-artery in the neck which carries the blood to the
-head (the carotid artery), in the artery of the arm
-(the humeral artery), in the artery of the lower
-extremity (the femoral artery); in a word, in the
-minute and remote capillary, and in the large trunk
-near the heart. Having contrived an instrument
-by which the force of the blood as it flows in its
-vessel could be accurately indicated by the rise of
-mercury in a tube, M. Poiseuille found that the
-elevation of the mercury is uniformly the same in
-the different arteries of the same animal, whatever
-the size of the artery and its distance from the
-heart. This tube was inserted, for example, into
-the common carotid artery of a horse: the diameter
-of the vessel was 34/100ths of an inch; its distance
-from the heart was thirty-nine inches; the height
-to which the mercury rose in the graduated tube
-was accurately marked. The tube was then inserted
-into a muscular branch of the artery in
-the thigh: the diameter of this vessel was 7/100ths
-of an inch, and its distance from the heart 67½
-inches. According to the mean of nine observations,
-the mercury rose in both tubes to precisely
-the same elevation. Here is another instance of
-the beautiful adjustments everywhere established
-
-<span class="pagenum"><a name="Page_394" id="Page_394">[Pg 394]</a></span>
-
-in the living economy. The blood is sent by a
-living engine, moving under laws peculiar to the
-state of life, into living vessels, which in their turn
-acting under laws peculiar to the state of life, so
-accommodate themselves to the current as absolutely
-to offer no resistance to its progress; so
-accommodate themselves to the moving power, as
-completely and everywhere to obviate the physical
-impediments to motion inseparable from inorganic
-matter.</p>
-
-<p>298. That the arterial tubes do possess and exert
-a truly vital power, modifying the current of the
-blood they contain, is indubitably established.</p>
-
-<p>1. If in a living animal the trunk of an artery be
-laid bare, the mere exposure of it to the atmospheric
-air causes it to contract to such a degree, that its
-size becomes obviously and strikingly diminished.
-This can result only from the exertion of a vital
-property, for no dead tube is capable in such a
-manner of diminishing its diameter.</p>
-
-<p>2. If during life an artery be opened and the
-animal be largely bled, the arteries become progressively
-smaller and smaller as the quantity of
-blood in the body diminishes. If the bleeding be
-continued until the animal dies, and the arteries of
-the system be immediately examined, they are
-found to be reduced to a very small size; if again
-examined some time after death, they are found to
-have become larger, and they go on growing successively
-larger and larger until they regain nearly
-
-<span class="pagenum"><a name="Page_395" id="Page_395">[Pg 395]</a></span>
-
-their original magnitude, which they retain until
-they are decomposed by putrefaction.</p>
-
-<p>3. M. Poiseuille distended with water the artery
-of an animal just killed. This water was urged by
-the pressure of a given column of mercury. The
-force of the reaction of the artery was now measured
-by the height of a column of mercury which
-the water expelled from the artery could support.
-It was found that the artery reacted with a force
-greater than that employed to distend it, and
-greater than the same artery could exert some
-time after death; but since mechanical reaction
-can never be greater than the force previously
-exerted upon it (293), it follows that the excess of
-the reaction indicated in this case was vital.</p>
-
-<p>4. If an artery be exposed and a mechanical or
-chemical stimulus be applied to it, its diameter is
-altered, sometimes becoming larger and sometimes
-smaller, according to the kind of agent employed.</p>
-
-<p>299. Any one of these facts, taken by itself,
-affords a demonstration that the arterial trunks
-and branches are capable of enlarging and diminishing
-their diameter by virtue of a vital endowment.
-There is complete evidence that the exertion
-of this vital power on the part of the arterial
-trunk is not to communicate to the blood the
-smallest impulsive force; the engine constructed
-for the express purpose of working the current
-generates all the force that is required; but the
-labour of the engine is economized by imparting
-
-<span class="pagenum"><a name="Page_396" id="Page_396">[Pg 396]</a></span>
-
-to the tubes that receive the stream a vital property,
-by which they wholly remove the physical
-obstructions to its motion.</p>
-
-<p>300. Driven by the heart through the arterial
-branches into the capillaries, the blood courses
-along these minute vessels urged by the same
-power. The most careful observers, from Haller
-and Spalanzani down to the present time, concur
-in stating that the pulsatory movement communicated
-by the heart to the blood in the great arteries
-is distinctly visible under the microscope in
-the capillaries. "I have often observed in frogs
-and tadpoles, and once in the bat," says Wedemeyer,
-"that when the circulation was becoming
-feeble, the blood in the finest capillaries advanced
-by jerks, corresponding with the contractions of the
-heart. I remarked the same appearance in the
-fine veins several times in the toad and tadpole,
-and once in the frog." If an experimenter so dispose
-the circulation of the limb of an animal that
-the flow of blood be confined to the branches of a
-single artery, and a corresponding vein, it is found
-that the blood stagnates in the vein whenever the
-current in the artery is stopped by a ligature, but
-no sooner is the ligature removed from the artery,
-than the blood begins again to flow freely along
-the vein, the capillaries of the artery which have
-to send on the current to those of the vein being
-now again within the influence of the heart. And
-if the impulse of the heart be removed from the
-
-<span class="pagenum"><a name="Page_397" id="Page_397">[Pg 397]</a></span>
-
-capillary system, by placing a ligature around the
-aorta, the capillary circulation is uniformly and
-completely stopped.</p>
-
-<p>301. It was found by Dr. Hales, that, under
-ordinary circumstances, the blood rises in a tube
-connected with a vein to the height only of six
-inches, while it has been shown (290) that in the
-artery it ascends as high as ten feet. This prodigious
-difference between the venous and the
-arterial tension led to the conclusion that the impulsive
-force of the heart was all but exhausted
-before the blood reached the veins, and set physiologists
-on the search for other powers to carry on
-the venous circulation. It was overlooked that
-the blood has an open and ready escape from the
-great trunks of the veins through the right
-chambers of the heart, and that in consequence of
-this free escape of their fluid, these vessels indicate
-no greater tension than is just sufficient to lift the
-blood to the heart, and to overcome friction<a name="FNanchor_7_7" id="FNanchor_7_7"></a><a href="#Footnote_7_7" class="fnanchor">[7]</a>.
-M. Magendie having laid bare the chief artery and
-vein of a living limb, and having raised the vessels
-in such a manner that he could place a ligature
-around the former, without including the latter,
-found that the flow of blood from a puncture made
-below a ligature on the vein, was rapid or slow,
-according as the heart was allowed to produce a
-greater or less degree of tension in the artery,
-
-<span class="pagenum"><a name="Page_398" id="Page_398">[Pg 398]</a></span>which tension was regulated by compressing the
-
-artery between the fingers. After a similar preparation
-of a limb, a ligature was placed around the
-vein; a tube was then inserted into it; it was
-found that the blood ascended in the tube from
-the obstructed vein just as high as from the
-artery.</p>
-
-<p>302. Thus we are able to trace the action of the
-heart from the beginning to the end of the circle.
-Of this circle it is the sole moving power; but it
-is a living engine acting in combination with living
-vessels. The force it exerts is a vital force, economized
-by the agency of a vital property communicated
-to the vessels, by virtue of which they spontaneously
-and completely remove all physical obstruction
-to the progress of the stream through its
-channels.</p>
-
-<p>303. Some German physiologists of great eminence,
-after a careful and patient observation of
-the blood, have satisfied themselves that in addition
-to the contraction of the heart, it is necessary
-to admit a second original and independent motive
-force, namely, a self-moving power inherent in
-the particles of the blood itself. The blood we
-know is a living substance. No reason can be assigned
-why the power of originating motion should
-not be communicated to such a substance as well
-as to the muscular fibre, of which, indeed, one constituent
-of the blood affords the basis. Such a
-power, if found to be inherent in the particles of the
-
-<span class="pagenum"><a name="Page_399" id="Page_399">[Pg 399]</a></span>
-
-blood, would explain some phenomena connected
-with the circulation not yet clearly elucidated; but
-the proof of the self-moving power of the blood
-does not yet seem to be complete. It is, however,
-impossible to explain the phenomena of the circulation,
-or to obtain a satisfactory view of some of
-the other functions of the economy, without supposing
-the particles of the blood to be endowed
-with a vital power of repulsion, in consequence
-of which they are prevented from uniting when
-in contact, and the fluidity of the mass is maintained.</p>
-
-<p>In this account of the powers that move the
-blood, no notice has been taken of the physical
-agents supposed to act as auxiliaries to the heart,
-in carrying on the circulation, such as the suction
-power of the thorax, and of the auricles of the
-heart, and the capillary attraction of the vessels;
-because, without questioning the existence of such
-agents, or denying that advantage may be taken of
-them, it seems pretty clear that their influence is
-but trivial, and they assumed importance only
-when the vital endowments of the tissues were
-not well understood.</p>
-
-<p>304. The ultimate end for which the apparatus
-of the circulation is constructed, and for which all
-its action is exerted, is to convey arterial blood to
-the capillary arteries. These vessels are totally
-distinct in structure and in office from the larger
-arterial tubes. All the tunics of these minute
-
-<span class="pagenum"><a name="Page_400" id="Page_400">[Pg 400]</a></span>
-
-vessels diminish in thickness and strength as the
-tubes lessen in size, but more especially the middle
-or the fibrous coat; which, according to Wedemeyer,
-may still be distinguished by its colour in
-the transverse section of any vessel whose internal
-diameter is not less than the tenth of a line; but
-that it entirely disappears in vessels too small and
-too remote to receive the wave of blood in a manifest
-jet. But while the membranous tunics diminish,
-the nervous filaments distributed to them
-increase: the smaller and thinner the capillary,
-the greater the proportionate quantity of its nervous
-matter; and this is most manifest in organs of the
-greatest irritability. The coats of the capillaries
-successively becoming thinner and thinner, at
-length disappear altogether, and the vessels ultimately
-terminate in membraneless canals formed
-in the substance of the tissues. "The blood in the
-finest capillaries," says Wedemeyer, "no longer
-flows within actual vessels; it is not contained in
-tubes whose parietes are formed by a membranous
-substance distinguishable by its texture and compactness
-from the adjoining cellular tissue: it is
-contained in the different tissues in channels which
-it forms in them for itself; and, under the microscope,
-the stream is seen easily and rapidly to
-work out for itself a new passage in the tissues
-which it penetrates."</p>
-
-<p>305. Some of these fine capillaries, before they
-entirely lose their membranous tunics, communicate
-
-<span class="pagenum"><a name="Page_401" id="Page_401">[Pg 401]</a></span>
-
-directly with veins. Of the capillaries which
-terminate by direct communication with veins,
-some are large enough to admit of three or four
-of the red particles of the blood abreast; the
-diameter of others is sufficient to admit only of
-one; while others are so small that they can transmit
-nothing but the serum of the blood. As long
-as the capillary is of sufficient magnitude to receive
-three or four of the particles abreast, it is evident
-that it possesses regular parietes; but by far the
-greater number, before they communicate with
-veins, lose altogether their membranous coats.
-There are no visible openings or pores in the sides
-or ends of the capillaries by means of which the
-blood can be extravasated, preparatory to its being
-imbibed by the veins. There is nowhere apparent
-a sudden passage of the arterial into the venous
-stream; no abrupt boundary between the division
-of the two systems. The arterial streamlet winds
-through long routes, and describes numerous turns
-before it assumes the nature and takes the direction
-of a venous streamlet. The ultimate capillary
-rarely passes from a large arterial into a large
-venous branch.</p>
-
-<p>306. The vital power which it has been shown
-(298) is possessed by the arterial trunks and
-branches, is still more intense in the minute capillaries.
-If alcohol, strong acetic acid, naphtha,
-and other stimulating fluids, be injected into the
-arteries of a living animal, it is found that they
-
-<span class="pagenum"><a name="Page_402" id="Page_402">[Pg 402]</a></span>
-
-are not transmitted through the capillaries at all,
-or, at all events, that they make their way through
-them with extreme difficulty; whereas mild,
-unirritating fluids pass with rapidity and ease.
-Wedemeyer exposed and divided the main artery
-in the fore-leg of a horse, together with the corresponding
-vein in the shoulder. Several syringes-full
-of tepid water were now injected into the
-lower end of the artery. The gentlest pressure
-was sufficient to force the fluid through the capillaries.
-At each injection the water issued in a
-full stream from the aperture of the vein, the flow
-of the fluid ceasing as soon as the injection was
-stopped. Next, instead of water, four syringes-full
-of pure cold brandy were injected. To propel
-this fluid through the capillaries, so as to render its
-smell and taste perceptible at the aperture of the
-vein, required a great degree of pressure; and
-when at last the fluid issued from the vein, it
-merely trickled in a feeble stream.</p>
-
-<p>The experiment being repeated on another horse
-with vinegar, six syringes-full of which being injected
-in rapid succession, at first this fluid passed
-as easily as water, afterwards it flowed with greater
-difficulty and in a small stream; before long
-the force required to propel it was extreme, and
-at last the obstruction to its passage became
-complete, so that no fluid whatever issued from
-the vein.</p>
-
-<p>These experiments, whenever repeated, afforded
-
-<span class="pagenum"><a name="Page_403" id="Page_403">[Pg 403]</a></span>
-
-the same result, and they demonstrate that the
-capillaries are capable of being stimulated to contract
-upon their contents, and that they can contract
-with such force as to stop the current. It is
-manifest that the power by which they do this is
-vital, because after death all fluids, the mildest
-and the most acrid, pass through them with equal
-facility.</p>
-
-<p>307.  Drs. Thompson, Philip, Hastings, and
-others in this country, have applied stimulants of
-various kinds to the capillary arteries, in order to
-observe with the microscope the changes which
-the vessels undergo. The results of these experiments,
-performed independently, agree with each
-other; and all the observers concur in stating that
-those results are so obvious and decisive as to
-admit of no question. Wedemeyer, fully aware
-of all that had been done on this subject by the
-English physiologists, repeated their experiments
-with his usual patience and care, vigilantly watching
-the effects with his microscope. His observations
-completely coincide with those of our
-countrymen. The circulation being observed in
-the mesentery of the frog and in the web of its
-foot, it was apparent that no change whatever took
-place in the diameter of the small arteries, nor in
-that of the capillaries, as long as the circulation
-was allowed to go on in its natural state; but as
-soon as stimulants were applied to them, an alteration
-of their diameter was visible. Alcohol,
-
-<span class="pagenum"><a name="Page_404" id="Page_404">[Pg 404]</a></span>
-
-without much apparent contraction of the vessels,
-stopped the flow of the blood. Muriate of soda,
-in the course of three or four minutes, caused the
-vessels to contract one-fifth of their calibre, which
-contraction was followed by dilatation and gradual
-retardation and stoppage of the blood. Ammonia
-caused immediate and direct dilatation, and the
-effect of galvanism was still more striking. In a
-space of time varying from ten to thirty seconds,
-nay, sometimes immediately after the completion
-of the galvanic circle, the vessels contracted, some
-a fourth, others half, and others three-fourths, of
-their calibre. The flow of the blood through the
-contracted vessels was accelerated. The contraction
-sometimes lasted a considerable time, occasionally
-several hours; in other instances the contraction
-ceased in ten minutes, and the vessels
-resumed their natural diameter. A second application
-of galvanism to the same capillaries seldom
-caused any material contraction.</p>
-
-<p>308. The evidence, then, is abundant that stimulants
-are capable of modifying to a great extent
-the action of the capillary arteries, sometimes
-causing them to contract, at other times to dilate;
-sometimes quickening the flow of blood through
-them, at other times retarding it, and frequently
-altogether arresting its motion. This contractile
-power of the capillaries must be a vital endowment,
-for no such property is possessed by any
-substance destitute of life, and there is satisfactory
-
-<span class="pagenum"><a name="Page_405" id="Page_405">[Pg 405]</a></span>
-
-evidence that it is communicated, regulated, and
-controlled by the organic nerves, which, as has
-been shown, increase as the size of the vessels and
-the thickness of their membranous tunics diminish.
-The powerful influence of these nerves upon the
-capillary vessels is placed beyond doubt or controversy
-by the obvious local changes produced in
-the capillary circulation by sudden, and even by
-mental, impressions, by the flush of the cheek
-and the sparkle of the eye, at a thought conceived
-or a sound heard; changes which can be effected,
-as far as we have any knowledge, by no medium
-excepting that of the nerves. The part performed
-by electricity, the physical agent by which it is
-conceived the nerves operate, will be considered
-hereafter.</p>
-
-<p>309. Exerting upon each other a vital force of
-repulsion, under a vital influence derived from the
-organic nerves, urged by the vital contraction of
-the heart, the particles of the blood reach the extreme
-capillaries. Most of these capillaries terminate
-(304) in canals, which they work out for
-themselves in the substance of the tissues. The
-tissues are endowed with a vital attractive force,
-which they exert upon the blood&mdash;an elective as
-well as an attractive force: for in every part of
-the body, in the brain, the heart, the lung, the
-muscle, the membrane, the bone, each tissue
-attracts only those constituents of which it is
-
-<span class="pagenum"><a name="Page_406" id="Page_406">[Pg 406]</a></span>
-
-itself composed. Thus the common current, rich
-in all the proximate constituents of the tissues,
-flows out to each. As the current approaches the
-tissue, the particles appropriate to the tissue feel its
-attractive force, obey it, quit the stream, mingle
-with the substance of the tissue, become identified
-with it, and are changed into its own true and
-proper nature. Meantime, the particles which are
-not appropriate to that particular tissue, not being
-attracted by it, do not quit the current, but passing
-on, are borne by other capillaries to other tissues,
-to which they are appropriate, and by which they
-are apprehended and assimilated, When it has
-given to the tissues the constituents with which it
-abounded, and received from them particles no
-longer useful, and which would become noxious,
-the blood flows into the veins to be returned by
-the pulmonic heart to the lung, where, parting
-with the useless and noxious matter it has accumulated,
-and, replenished with new proximate
-principles, it returns to the systemic heart, by
-which it is again sent back to the tissues.</p>
-
-<p>310. Particles of blood are seen to quit the
-current and mingle with the tissues; particles are
-seen to quit the tissues and mingle with the
-current. But all that we can see, with the best
-aid we can get, does but bring us to the confines
-of the grand operations that go on, of which we
-are altogether ignorant. Arterial blood is conveyed
-
-<span class="pagenum"><a name="Page_407" id="Page_407">[Pg 407]</a></span>
-
-by the arteries to the capillaries; but before
-it has passed from under the influence of the capillaries
-it has ceased to be arterial blood. Arterial
-blood is conveyed by the carotid artery to the
-brain; but the cerebral capillaries do not deposit
-blood, but brain. Arterial blood is conveyed by its
-nutrient arteries to bone, but the osseous capillaries
-do not deposit blood, but bone. Arterial
-blood is conveyed by the muscular arteries to
-muscle, but the muscular capillaries do not deposit
-blood, but muscle. The blood conveyed by the
-capillaries of brain, bone, and muscle is the same,
-all comes alike from the systemic heart, and is alike
-conveyed to all tissues; yet in the one it becomes
-brain, in the other bone, and in the third muscle.
-Out of one and the same fluid these living chemists
-manufacture cuticle, and membrane, and muscle,
-and brain, and bone; the tears, the wax, the fat,
-the saliva, the gastric juice, the milk, the bile, all
-the fluids, and all the solids of the body.</p>
-
-<p>311. And they do still more; for they are architects
-as well as chemists; after they have manufactured
-the tissue, they construct the organ. The
-capillaries of the eye not only form its different
-membranes and humours, but arrange them in
-such a manner as to constitute the optical instrument;
-and the capillaries of the brain not
-only form cerebral matter, but build it up
-into the instrument of sensation, thought, and
-motion.</p>
-
-<p>312. The practical applications of these phenomena
-are numerous and most important; but
-they can be clearly and impressively stated only
-when the operation of the physical agents which
-influence the circulation, and which proportionally
-affect life and health, has been explained.</p>
-
-<hr class="chap" />
-
-<div class="chapter">
-<p><span class="pagenum"><a name="Page_408" id="Page_408">[Pg 408]</a></span></p>
-<h2>FOOTNOTES.</h2>
-</div>
-
-<div class="topspace1"></div>
-<div class="footnotes">
-<blockquote>
-<div class="footnote">
-<p><a name="Footnote_1_1" id="Footnote_1_1"></a><a href="#FNanchor_1_1"><span class="label">[1]</span></a> Computationi in alimentis faciendæ hanc formam esse Ulpianus
-scribit, ut <i>à primâ ætate</i> usque ad annum vicesimum
-quantitas alimentorum triginta annorum computetur, ejusque
-quantitatis Falcidia præstetur: <i>ab annis verò viginti</i> usque
-ad annum vicesimumquintum annorum viginti octo: <i>ab
-annis vigintiquinque</i> usque ad annos triginta, annorum
-vigintiquinque: <i>ab annis triginta</i> usque ad annos trigintaquinque
-annorum viginti duo; <i>ab annis trigintaquinque</i> usque
-ad annos quadraginta annorum viginti: <i>ab annis quadraginta</i>
-usque ad annos quinquaginta tot annorum computatio
-fit quot ætate ejus ad annum sexagesimum deerit, remisso
-uno anno: <i>ab anno verò quinquagesimo</i> usque ad annum
-quinquagesimumquintum annorum novem: <i>ab annis quinquagintaquinque</i>
-usque ad annum sexagesimum annorum
-septem: <i>ab annis sexaginta</i>, cujuscunque ætatis sit, annorum
-quinque; eoque nos jure uti Ulpianus ait, et circa compu
-tationem ususfructus faciendam. Solitum est tamen <i>à
-primâ ætate</i> usque ad annum trigesimum computationem
-annorum triginta fieri: <i>ab annis verò triginta</i> tot annorum
-computationem inire, quot ad annum sexagesimum deesse
-videntur; nunquam ergo amplius quam triginta aunorum
-computatio initur. Sic denique, et si Reipublicæ ususfructus
-egetur, sive simpliciter, sive ad ludos, triginta annorum
-computatio fit. Si quis ex heredibus rem propriam esse
-contendat, deinde hereditariam esse convincatur: quidem
-putant ejus quoque Falcidiam non posse retineri; quià
-nihil intersit, subtraxerit an hereditariam esse negaverit.
-Quod Ulpianus rectè improbat. (Vide Justin. Pandect.
-lib. 35, tit. 2, ad Legem Falcidiam.)</p></div>
-
-<div class="footnote">
-
-<p><a name="Footnote_2_2" id="Footnote_2_2"></a><a href="#FNanchor_2_2"><span class="label">[2]</span></a> Which maximum is a little above the highest point hitherto any where attained.</p></div>
-
-<div class="footnote">
-
-<p><a name="Footnote_3_3" id="Footnote_3_3"></a><a href="#FNanchor_3_3"><span class="label">[3]</span></a> Hence in the preparation of jelly as an article of diet,
-the parts of young animals, as the feet of the calf, are principally
-employed; whereas soups made from beef contain
-a large proportion of albumen, while in those made from
-veal the proportion of jelly preponderates.</p></div>
-
-<div class="footnote">
-
-<p><a name="Footnote_4_4" id="Footnote_4_4"></a><a href="#FNanchor_4_4"><span class="label">[4]</span></a> Treatise on Ligaments, by Bransby B. Cooper, Esq.</p></div>
-
-<div class="footnote">
-
-<p><a name="Footnote_5_5" id="Footnote_5_5"></a><a href="#FNanchor_5_5"><span class="label">[5]</span></a> For these illustrations I am indebted to Mr. Lister, who
-has been so kind as to make drawings of the objects for me.</p></div>
-
-<div class="footnote">
-
-<p><a name="Footnote_6_6" id="Footnote_6_6"></a><a href="#FNanchor_6_6"><span class="label">[6]</span></a> Whenever there is any interruption to the ordinary
-flow of the circulating fluids, the powers of the anastomosing
-circulation are capable of being increased to a surprising
-extent. The aorta itself has frequently been tied
-in animals of considerable size without destroying life; in
-the human body it has also been found obliterated by
-disease in different parts of its course, in one case as high
-as the termination of its curvature. In the cure for aneurism
-the external iliac artery has been tied by Mr. Abernethy
-with success; the subclavian artery below the clavicle by
-Mr. Keate; the common carotid by Sir Astley Cooper; the
-subclavian artery above the clavicle by Mr. Ramsden; the
-internal iliac artery by Dr. Stevens; the arteria innominata
-by Dr. Mott, of New York; and lastly, the abdominal aorta itself,
-by Sir A. Cooper. Mr. Grainger tied the
-abdominal aorta of a dog; when the animal had recovered
-from that operation, the carotids and the great trunks of
-the anterior extremities were tied: in this manner the whole
-course of the circulation was altered. The dog, which was
-of very large size, survived all these operations, and appeared
-to enjoy its ordinary health. Grainger's General
-Anatomy, p. 251-253.</p></div>
-
-<div class="footnote">
-
-<p><a name="Footnote_7_7" id="Footnote_7_7"></a><a href="#FNanchor_7_7"><span class="label">[7]</span></a> See this matter very ably discussed in Dr. Arnott's
-excellent work on the Elements of Physics, vol. i.</p></div>
-
-</blockquote>
-</div>
-<div class="topspace1"></div>
-
-<p class="center large">END OF VOL. I.</p>
-
-<p class="center">London: Printed by <span class="smcap">W. Clowes</span> and <span class="smcap">Sons</span>, Stamford Street.</p>
-
-<hr class="chap" />
-
-<div class="transnote">
-<p><span class="smcap">Transcriber's Notes.</span></p>
-<p>1. (Figure LXXIV.) was incorrectly labeled as (Figure LXXVI.). This has been corrected.</p>
-<p>2. No Figure LXX in original book.</p>
-</div>
-
-<hr class="full" />
-
-
-
-
-
-
-
-
-<pre>
-
-
-
-
-
-End of the Project Gutenberg EBook of The Philosophy of Health; Volume 1 (of
-2), by Thomas Southwood-Smith
-
-*** END OF THIS PROJECT GUTENBERG EBOOK PHILOSOPHY OF HEALTH, VOLUME 1 ***
-
-***** This file should be named 60773-h.htm or 60773-h.zip *****
-This and all associated files of various formats will be found in:
-        http://www.gutenberg.org/6/0/7/7/60773/
-
-Produced by Chris Curnow, Brian Wilsden and the Online
-Distributed Proofreading Team at http://www.pgdp.net (This
-file was produced from images generously made available
-by The Internet Archive)
-
-Updated editions will replace the previous one--the old editions will
-be renamed.
-
-Creating the works from print editions not protected by U.S. copyright
-law means that no one owns a United States copyright in these works,
-so the Foundation (and you!) can copy and distribute it in the United
-States without permission and without paying copyright
-royalties. Special rules, set forth in the General Terms of Use part
-of this license, apply to copying and distributing Project
-Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm
-concept and trademark. Project Gutenberg is a registered trademark,
-and may not be used if you charge for the eBooks, unless you receive
-specific permission. If you do not charge anything for copies of this
-eBook, complying with the rules is very easy. You may use this eBook
-for nearly any purpose such as creation of derivative works, reports,
-performances and research. They may be modified and printed and given
-away--you may do practically ANYTHING in the United States with eBooks
-not protected by U.S. copyright law. Redistribution is subject to the
-trademark license, especially commercial redistribution.
-
-START: FULL LICENSE
-
-THE FULL PROJECT GUTENBERG LICENSE
-PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK
-
-To protect the Project Gutenberg-tm mission of promoting the free
-distribution of electronic works, by using or distributing this work
-(or any other work associated in any way with the phrase "Project
-Gutenberg"), you agree to comply with all the terms of the Full
-Project Gutenberg-tm License available with this file or online at
-www.gutenberg.org/license.
-
-Section 1. General Terms of Use and Redistributing Project
-Gutenberg-tm electronic works
-
-1.A. By reading or using any part of this Project Gutenberg-tm
-electronic work, you indicate that you have read, understand, agree to
-and accept all the terms of this license and intellectual property
-(trademark/copyright) agreement. If you do not agree to abide by all
-the terms of this agreement, you must cease using and return or
-destroy all copies of Project Gutenberg-tm electronic works in your
-possession. If you paid a fee for obtaining a copy of or access to a
-Project Gutenberg-tm electronic work and you do not agree to be bound
-by the terms of this agreement, you may obtain a refund from the
-person or entity to whom you paid the fee as set forth in paragraph
-1.E.8.
-
-1.B. "Project Gutenberg" is a registered trademark. It may only be
-used on or associated in any way with an electronic work by people who
-agree to be bound by the terms of this agreement. There are a few
-things that you can do with most Project Gutenberg-tm electronic works
-even without complying with the full terms of this agreement. See
-paragraph 1.C below. There are a lot of things you can do with Project
-Gutenberg-tm electronic works if you follow the terms of this
-agreement and help preserve free future access to Project Gutenberg-tm
-electronic works. See paragraph 1.E below.
-
-1.C. The Project Gutenberg Literary Archive Foundation ("the
-Foundation" or PGLAF), owns a compilation copyright in the collection
-of Project Gutenberg-tm electronic works. Nearly all the individual
-works in the collection are in the public domain in the United
-States. If an individual work is unprotected by copyright law in the
-United States and you are located in the United States, we do not
-claim a right to prevent you from copying, distributing, performing,
-displaying or creating derivative works based on the work as long as
-all references to Project Gutenberg are removed. Of course, we hope
-that you will support the Project Gutenberg-tm mission of promoting
-free access to electronic works by freely sharing Project Gutenberg-tm
-works in compliance with the terms of this agreement for keeping the
-Project Gutenberg-tm name associated with the work. You can easily
-comply with the terms of this agreement by keeping this work in the
-same format with its attached full Project Gutenberg-tm License when
-you share it without charge with others.
-
-1.D. The copyright laws of the place where you are located also govern
-what you can do with this work. Copyright laws in most countries are
-in a constant state of change. If you are outside the United States,
-check the laws of your country in addition to the terms of this
-agreement before downloading, copying, displaying, performing,
-distributing or creating derivative works based on this work or any
-other Project Gutenberg-tm work. The Foundation makes no
-representations concerning the copyright status of any work in any
-country outside the United States.
-
-1.E. Unless you have removed all references to Project Gutenberg:
-
-1.E.1. The following sentence, with active links to, or other
-immediate access to, the full Project Gutenberg-tm License must appear
-prominently whenever any copy of a Project Gutenberg-tm work (any work
-on which the phrase "Project Gutenberg" appears, or with which the
-phrase "Project Gutenberg" is associated) is accessed, displayed,
-performed, viewed, copied or distributed:
-
-  This eBook is for the use of anyone anywhere in the United States and
-  most other parts of the world at no cost and with almost no
-  restrictions whatsoever. You may copy it, give it away or re-use it
-  under the terms of the Project Gutenberg License included with this
-  eBook or online at www.gutenberg.org. If you are not located in the
-  United States, you'll have to check the laws of the country where you
-  are located before using this ebook.
-
-1.E.2. If an individual Project Gutenberg-tm electronic work is
-derived from texts not protected by U.S. copyright law (does not
-contain a notice indicating that it is posted with permission of the
-copyright holder), the work can be copied and distributed to anyone in
-the United States without paying any fees or charges. If you are
-redistributing or providing access to a work with the phrase "Project
-Gutenberg" associated with or appearing on the work, you must comply
-either with the requirements of paragraphs 1.E.1 through 1.E.7 or
-obtain permission for the use of the work and the Project Gutenberg-tm
-trademark as set forth in paragraphs 1.E.8 or 1.E.9.
-
-1.E.3. If an individual Project Gutenberg-tm electronic work is posted
-with the permission of the copyright holder, your use and distribution
-must comply with both paragraphs 1.E.1 through 1.E.7 and any
-additional terms imposed by the copyright holder. Additional terms
-will be linked to the Project Gutenberg-tm License for all works
-posted with the permission of the copyright holder found at the
-beginning of this work.
-
-1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm
-License terms from this work, or any files containing a part of this
-work or any other work associated with Project Gutenberg-tm.
-
-1.E.5. Do not copy, display, perform, distribute or redistribute this
-electronic work, or any part of this electronic work, without
-prominently displaying the sentence set forth in paragraph 1.E.1 with
-active links or immediate access to the full terms of the Project
-Gutenberg-tm License.
-
-1.E.6. You may convert to and distribute this work in any binary,
-compressed, marked up, nonproprietary or proprietary form, including
-any word processing or hypertext form. However, if you provide access
-to or distribute copies of a Project Gutenberg-tm work in a format
-other than "Plain Vanilla ASCII" or other format used in the official
-version posted on the official Project Gutenberg-tm web site
-(www.gutenberg.org), you must, at no additional cost, fee or expense
-to the user, provide a copy, a means of exporting a copy, or a means
-of obtaining a copy upon request, of the work in its original "Plain
-Vanilla ASCII" or other form. Any alternate format must include the
-full Project Gutenberg-tm License as specified in paragraph 1.E.1.
-
-1.E.7. Do not charge a fee for access to, viewing, displaying,
-performing, copying or distributing any Project Gutenberg-tm works
-unless you comply with paragraph 1.E.8 or 1.E.9.
-
-1.E.8. You may charge a reasonable fee for copies of or providing
-access to or distributing Project Gutenberg-tm electronic works
-provided that
-
-* You pay a royalty fee of 20% of the gross profits you derive from
-  the use of Project Gutenberg-tm works calculated using the method
-  you already use to calculate your applicable taxes. The fee is owed
-  to the owner of the Project Gutenberg-tm trademark, but he has
-  agreed to donate royalties under this paragraph to the Project
-  Gutenberg Literary Archive Foundation. Royalty payments must be paid
-  within 60 days following each date on which you prepare (or are
-  legally required to prepare) your periodic tax returns. Royalty
-  payments should be clearly marked as such and sent to the Project
-  Gutenberg Literary Archive Foundation at the address specified in
-  Section 4, "Information about donations to the Project Gutenberg
-  Literary Archive Foundation."
-
-* You provide a full refund of any money paid by a user who notifies
-  you in writing (or by e-mail) within 30 days of receipt that s/he
-  does not agree to the terms of the full Project Gutenberg-tm
-  License. You must require such a user to return or destroy all
-  copies of the works possessed in a physical medium and discontinue
-  all use of and all access to other copies of Project Gutenberg-tm
-  works.
-
-* You provide, in accordance with paragraph 1.F.3, a full refund of
-  any money paid for a work or a replacement copy, if a defect in the
-  electronic work is discovered and reported to you within 90 days of
-  receipt of the work.
-
-* You comply with all other terms of this agreement for free
-  distribution of Project Gutenberg-tm works.
-
-1.E.9. If you wish to charge a fee or distribute a Project
-Gutenberg-tm electronic work or group of works on different terms than
-are set forth in this agreement, you must obtain permission in writing
-from both the Project Gutenberg Literary Archive Foundation and The
-Project Gutenberg Trademark LLC, the owner of the Project Gutenberg-tm
-trademark. Contact the Foundation as set forth in Section 3 below.
-
-1.F.
-
-1.F.1. Project Gutenberg volunteers and employees expend considerable
-effort to identify, do copyright research on, transcribe and proofread
-works not protected by U.S. copyright law in creating the Project
-Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm
-electronic works, and the medium on which they may be stored, may
-contain "Defects," such as, but not limited to, incomplete, inaccurate
-or corrupt data, transcription errors, a copyright or other
-intellectual property infringement, a defective or damaged disk or
-other medium, a computer virus, or computer codes that damage or
-cannot be read by your equipment.
-
-1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right
-of Replacement or Refund" described in paragraph 1.F.3, the Project
-Gutenberg Literary Archive Foundation, the owner of the Project
-Gutenberg-tm trademark, and any other party distributing a Project
-Gutenberg-tm electronic work under this agreement, disclaim all
-liability to you for damages, costs and expenses, including legal
-fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT
-LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE
-PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE
-TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE
-LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR
-INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH
-DAMAGE.
-
-1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a
-defect in this electronic work within 90 days of receiving it, you can
-receive a refund of the money (if any) you paid for it by sending a
-written explanation to the person you received the work from. If you
-received the work on a physical medium, you must return the medium
-with your written explanation. The person or entity that provided you
-with the defective work may elect to provide a replacement copy in
-lieu of a refund. If you received the work electronically, the person
-or entity providing it to you may choose to give you a second
-opportunity to receive the work electronically in lieu of a refund. If
-the second copy is also defective, you may demand a refund in writing
-without further opportunities to fix the problem.
-
-1.F.4. Except for the limited right of replacement or refund set forth
-in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO
-OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
-LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE.
-
-1.F.5. Some states do not allow disclaimers of certain implied
-warranties or the exclusion or limitation of certain types of
-damages. If any disclaimer or limitation set forth in this agreement
-violates the law of the state applicable to this agreement, the
-agreement shall be interpreted to make the maximum disclaimer or
-limitation permitted by the applicable state law. The invalidity or
-unenforceability of any provision of this agreement shall not void the
-remaining provisions.
-
-1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the
-trademark owner, any agent or employee of the Foundation, anyone
-providing copies of Project Gutenberg-tm electronic works in
-accordance with this agreement, and any volunteers associated with the
-production, promotion and distribution of Project Gutenberg-tm
-electronic works, harmless from all liability, costs and expenses,
-including legal fees, that arise directly or indirectly from any of
-the following which you do or cause to occur: (a) distribution of this
-or any Project Gutenberg-tm work, (b) alteration, modification, or
-additions or deletions to any Project Gutenberg-tm work, and (c) any
-Defect you cause.
-
-Section 2. Information about the Mission of Project Gutenberg-tm
-
-Project Gutenberg-tm is synonymous with the free distribution of
-electronic works in formats readable by the widest variety of
-computers including obsolete, old, middle-aged and new computers. It
-exists because of the efforts of hundreds of volunteers and donations
-from people in all walks of life.
-
-Volunteers and financial support to provide volunteers with the
-assistance they need are critical to reaching Project Gutenberg-tm's
-goals and ensuring that the Project Gutenberg-tm collection will
-remain freely available for generations to come. In 2001, the Project
-Gutenberg Literary Archive Foundation was created to provide a secure
-and permanent future for Project Gutenberg-tm and future
-generations. To learn more about the Project Gutenberg Literary
-Archive Foundation and how your efforts and donations can help, see
-Sections 3 and 4 and the Foundation information page at
-www.gutenberg.org
-
-
-
-Section 3. Information about the Project Gutenberg Literary Archive Foundation
-
-The Project Gutenberg Literary Archive Foundation is a non profit
-501(c)(3) educational corporation organized under the laws of the
-state of Mississippi and granted tax exempt status by the Internal
-Revenue Service. The Foundation's EIN or federal tax identification
-number is 64-6221541. Contributions to the Project Gutenberg Literary
-Archive Foundation are tax deductible to the full extent permitted by
-U.S. federal laws and your state's laws.
-
-The Foundation's principal office is in Fairbanks, Alaska, with the
-mailing address: PO Box 750175, Fairbanks, AK 99775, but its
-volunteers and employees are scattered throughout numerous
-locations. Its business office is located at 809 North 1500 West, Salt
-Lake City, UT 84116, (801) 596-1887. Email contact links and up to
-date contact information can be found at the Foundation's web site and
-official page at www.gutenberg.org/contact
-
-For additional contact information:
-
-    Dr. Gregory B. Newby
-    Chief Executive and Director
-    gbnewby@pglaf.org
-
-Section 4. Information about Donations to the Project Gutenberg
-Literary Archive Foundation
-
-Project Gutenberg-tm depends upon and cannot survive without wide
-spread public support and donations to carry out its mission of
-increasing the number of public domain and licensed works that can be
-freely distributed in machine readable form accessible by the widest
-array of equipment including outdated equipment. Many small donations
-($1 to $5,000) are particularly important to maintaining tax exempt
-status with the IRS.
-
-The Foundation is committed to complying with the laws regulating
-charities and charitable donations in all 50 states of the United
-States. Compliance requirements are not uniform and it takes a
-considerable effort, much paperwork and many fees to meet and keep up
-with these requirements. We do not solicit donations in locations
-where we have not received written confirmation of compliance. To SEND
-DONATIONS or determine the status of compliance for any particular
-state visit www.gutenberg.org/donate
-
-While we cannot and do not solicit contributions from states where we
-have not met the solicitation requirements, we know of no prohibition
-against accepting unsolicited donations from donors in such states who
-approach us with offers to donate.
-
-International donations are gratefully accepted, but we cannot make
-any statements concerning tax treatment of donations received from
-outside the United States. U.S. laws alone swamp our small staff.
-
-Please check the Project Gutenberg Web pages for current donation
-methods and addresses. Donations are accepted in a number of other
-ways including checks, online payments and credit card donations. To
-donate, please visit: www.gutenberg.org/donate
-
-Section 5. General Information About Project Gutenberg-tm electronic works.
-
-Professor Michael S. Hart was the originator of the Project
-Gutenberg-tm concept of a library of electronic works that could be
-freely shared with anyone. For forty years, he produced and
-distributed Project Gutenberg-tm eBooks with only a loose network of
-volunteer support.
-
-Project Gutenberg-tm eBooks are often created from several printed
-editions, all of which are confirmed as not protected by copyright in
-the U.S. unless a copyright notice is included. Thus, we do not
-necessarily keep eBooks in compliance with any particular paper
-edition.
-
-Most people start at our Web site which has the main PG search
-facility: www.gutenberg.org
-
-This Web site includes information about Project Gutenberg-tm,
-including how to make donations to the Project Gutenberg Literary
-Archive Foundation, how to help produce our new eBooks, and how to
-subscribe to our email newsletter to hear about new eBooks.
-
-
-
-</pre>
-
-</body>
-</html>
diff --git a/old/60773-h/images/cover.jpg b/old/60773-h/images/cover.jpg
deleted file mode 100644
index e6b4ea8..0000000
--- a/old/60773-h/images/cover.jpg
+++ /dev/null
diff --git a/old/60773-h/images/i_029.png b/old/60773-h/images/i_029.png
deleted file mode 100644
index 013b8cd..0000000
--- a/old/60773-h/images/i_029.png
+++ /dev/null
diff --git a/old/60773-h/images/i_030.png b/old/60773-h/images/i_030.png
deleted file mode 100644
index ad2ae09..0000000
--- a/old/60773-h/images/i_030.png
+++ /dev/null
diff --git a/old/60773-h/images/i_031.png b/old/60773-h/images/i_031.png
deleted file mode 100644
index b94c051..0000000
--- a/old/60773-h/images/i_031.png
+++ /dev/null
diff --git a/old/60773-h/images/i_032.png b/old/60773-h/images/i_032.png
deleted file mode 100644
index 987ae53..0000000
--- a/old/60773-h/images/i_032.png
+++ /dev/null
diff --git a/old/60773-h/images/i_033.png b/old/60773-h/images/i_033.png
deleted file mode 100644
index 04955bd..0000000
--- a/old/60773-h/images/i_033.png
+++ /dev/null
diff --git a/old/60773-h/images/i_034.png b/old/60773-h/images/i_034.png
deleted file mode 100644
index 6b891a5..0000000
--- a/old/60773-h/images/i_034.png
+++ /dev/null
diff --git a/old/60773-h/images/i_036.png b/old/60773-h/images/i_036.png
deleted file mode 100644
index d6f618c..0000000
--- a/old/60773-h/images/i_036.png
+++ /dev/null
diff --git a/old/60773-h/images/i_037.png b/old/60773-h/images/i_037.png
deleted file mode 100644
index 8e3beec..0000000
--- a/old/60773-h/images/i_037.png
+++ /dev/null
diff --git a/old/60773-h/images/i_039a.png b/old/60773-h/images/i_039a.png
deleted file mode 100644
index f4ffd65..0000000
--- a/old/60773-h/images/i_039a.png
+++ /dev/null
diff --git a/old/60773-h/images/i_039b.png b/old/60773-h/images/i_039b.png
deleted file mode 100644
index 820a89f..0000000
--- a/old/60773-h/images/i_039b.png
+++ /dev/null
diff --git a/old/60773-h/images/i_040.png b/old/60773-h/images/i_040.png
deleted file mode 100644
index 9bb80f5..0000000
--- a/old/60773-h/images/i_040.png
+++ /dev/null
diff --git a/old/60773-h/images/i_045.png b/old/60773-h/images/i_045.png
deleted file mode 100644
index 64377e2..0000000
--- a/old/60773-h/images/i_045.png
+++ /dev/null
diff --git a/old/60773-h/images/i_047.png b/old/60773-h/images/i_047.png
deleted file mode 100644
index 31ec475..0000000
--- a/old/60773-h/images/i_047.png
+++ /dev/null
diff --git a/old/60773-h/images/i_078.png b/old/60773-h/images/i_078.png
deleted file mode 100644
index e16c40e..0000000
--- a/old/60773-h/images/i_078.png
+++ /dev/null
diff --git a/old/60773-h/images/i_159.png b/old/60773-h/images/i_159.png
deleted file mode 100644
index 3ba2721..0000000
--- a/old/60773-h/images/i_159.png
+++ /dev/null
diff --git a/old/60773-h/images/i_161.png b/old/60773-h/images/i_161.png
deleted file mode 100644
index 1a37aff..0000000
--- a/old/60773-h/images/i_161.png
+++ /dev/null
diff --git a/old/60773-h/images/i_162.png b/old/60773-h/images/i_162.png
deleted file mode 100644
index fde38d7..0000000
--- a/old/60773-h/images/i_162.png
+++ /dev/null
diff --git a/old/60773-h/images/i_164.png b/old/60773-h/images/i_164.png
deleted file mode 100644
index 206c778..0000000
--- a/old/60773-h/images/i_164.png
+++ /dev/null
diff --git a/old/60773-h/images/i_167.png b/old/60773-h/images/i_167.png
deleted file mode 100644
index 53fdeff..0000000
--- a/old/60773-h/images/i_167.png
+++ /dev/null
diff --git a/old/60773-h/images/i_169.png b/old/60773-h/images/i_169.png
deleted file mode 100644
index f5462d6..0000000
--- a/old/60773-h/images/i_169.png
+++ /dev/null
diff --git a/old/60773-h/images/i_171.png b/old/60773-h/images/i_171.png
deleted file mode 100644
index 1edaea4..0000000
--- a/old/60773-h/images/i_171.png
+++ /dev/null
diff --git a/old/60773-h/images/i_172.png b/old/60773-h/images/i_172.png
deleted file mode 100644
index 88493b5..0000000
--- a/old/60773-h/images/i_172.png
+++ /dev/null
diff --git a/old/60773-h/images/i_174.png b/old/60773-h/images/i_174.png
deleted file mode 100644
index 6a98664..0000000
--- a/old/60773-h/images/i_174.png
+++ /dev/null
diff --git a/old/60773-h/images/i_175.png b/old/60773-h/images/i_175.png
deleted file mode 100644
index c93a44c..0000000
--- a/old/60773-h/images/i_175.png
+++ /dev/null
diff --git a/old/60773-h/images/i_176.png b/old/60773-h/images/i_176.png
deleted file mode 100644
index d37fa60..0000000
--- a/old/60773-h/images/i_176.png
+++ /dev/null
diff --git a/old/60773-h/images/i_177.png b/old/60773-h/images/i_177.png
deleted file mode 100644
index 9ae0f28..0000000
--- a/old/60773-h/images/i_177.png
+++ /dev/null
diff --git a/old/60773-h/images/i_178.png b/old/60773-h/images/i_178.png
deleted file mode 100644
index 254fe6c..0000000
--- a/old/60773-h/images/i_178.png
+++ /dev/null
diff --git a/old/60773-h/images/i_179.png b/old/60773-h/images/i_179.png
deleted file mode 100644
index e4c9f51..0000000
--- a/old/60773-h/images/i_179.png
+++ /dev/null
diff --git a/old/60773-h/images/i_180.png b/old/60773-h/images/i_180.png
deleted file mode 100644
index 30e5e76..0000000
--- a/old/60773-h/images/i_180.png
+++ /dev/null
diff --git a/old/60773-h/images/i_182.png b/old/60773-h/images/i_182.png
deleted file mode 100644
index 7d4d285..0000000
--- a/old/60773-h/images/i_182.png
+++ /dev/null
diff --git a/old/60773-h/images/i_189.png b/old/60773-h/images/i_189.png
deleted file mode 100644
index 9150716..0000000
--- a/old/60773-h/images/i_189.png
+++ /dev/null
diff --git a/old/60773-h/images/i_191.png b/old/60773-h/images/i_191.png
deleted file mode 100644
index 846106e..0000000
--- a/old/60773-h/images/i_191.png
+++ /dev/null
diff --git a/old/60773-h/images/i_192.png b/old/60773-h/images/i_192.png
deleted file mode 100644
index 073dad2..0000000
--- a/old/60773-h/images/i_192.png
+++ /dev/null
diff --git a/old/60773-h/images/i_194.png b/old/60773-h/images/i_194.png
deleted file mode 100644
index 96b7168..0000000
--- a/old/60773-h/images/i_194.png
+++ /dev/null
diff --git a/old/60773-h/images/i_195.png b/old/60773-h/images/i_195.png
deleted file mode 100644
index 1e7a857..0000000
--- a/old/60773-h/images/i_195.png
+++ /dev/null
diff --git a/old/60773-h/images/i_196.png b/old/60773-h/images/i_196.png
deleted file mode 100644
index b5dcc48..0000000
--- a/old/60773-h/images/i_196.png
+++ /dev/null
diff --git a/old/60773-h/images/i_197.png b/old/60773-h/images/i_197.png
deleted file mode 100644
index 1bf1e9d..0000000
--- a/old/60773-h/images/i_197.png
+++ /dev/null
diff --git a/old/60773-h/images/i_198.png b/old/60773-h/images/i_198.png
deleted file mode 100644
index f02f5b8..0000000
--- a/old/60773-h/images/i_198.png
+++ /dev/null
diff --git a/old/60773-h/images/i_199.png b/old/60773-h/images/i_199.png
deleted file mode 100644
index ba4d1b8..0000000
--- a/old/60773-h/images/i_199.png
+++ /dev/null
diff --git a/old/60773-h/images/i_201.png b/old/60773-h/images/i_201.png
deleted file mode 100644
index cc8f021..0000000
--- a/old/60773-h/images/i_201.png
+++ /dev/null
diff --git a/old/60773-h/images/i_205.png b/old/60773-h/images/i_205.png
deleted file mode 100644
index cd43369..0000000
--- a/old/60773-h/images/i_205.png
+++ /dev/null
diff --git a/old/60773-h/images/i_209.png b/old/60773-h/images/i_209.png
deleted file mode 100644
index f387851..0000000
--- a/old/60773-h/images/i_209.png
+++ /dev/null
diff --git a/old/60773-h/images/i_211.png b/old/60773-h/images/i_211.png
deleted file mode 100644
index 4838013..0000000
--- a/old/60773-h/images/i_211.png
+++ /dev/null
diff --git a/old/60773-h/images/i_213.png b/old/60773-h/images/i_213.png
deleted file mode 100644
index 6ed9ea5..0000000
--- a/old/60773-h/images/i_213.png
+++ /dev/null
diff --git a/old/60773-h/images/i_216.png b/old/60773-h/images/i_216.png
deleted file mode 100644
index eba6b7f..0000000
--- a/old/60773-h/images/i_216.png
+++ /dev/null
diff --git a/old/60773-h/images/i_217.png b/old/60773-h/images/i_217.png
deleted file mode 100644
index 45b2d1e..0000000
--- a/old/60773-h/images/i_217.png
+++ /dev/null
diff --git a/old/60773-h/images/i_225.png b/old/60773-h/images/i_225.png
deleted file mode 100644
index a4af22d..0000000
--- a/old/60773-h/images/i_225.png
+++ /dev/null
diff --git a/old/60773-h/images/i_226.png b/old/60773-h/images/i_226.png
deleted file mode 100644
index e47300a..0000000
--- a/old/60773-h/images/i_226.png
+++ /dev/null
diff --git a/old/60773-h/images/i_227.png b/old/60773-h/images/i_227.png
deleted file mode 100644
index e801405..0000000
--- a/old/60773-h/images/i_227.png
+++ /dev/null
diff --git a/old/60773-h/images/i_228.png b/old/60773-h/images/i_228.png
deleted file mode 100644
index c1372ef..0000000
--- a/old/60773-h/images/i_228.png
+++ /dev/null
diff --git a/old/60773-h/images/i_231.png b/old/60773-h/images/i_231.png
deleted file mode 100644
index c01e4a0..0000000
--- a/old/60773-h/images/i_231.png
+++ /dev/null
diff --git a/old/60773-h/images/i_232.png b/old/60773-h/images/i_232.png
deleted file mode 100644
index ea237f6..0000000
--- a/old/60773-h/images/i_232.png
+++ /dev/null
diff --git a/old/60773-h/images/i_234.png b/old/60773-h/images/i_234.png
deleted file mode 100644
index 7a87ff4..0000000
--- a/old/60773-h/images/i_234.png
+++ /dev/null
diff --git a/old/60773-h/images/i_235.png b/old/60773-h/images/i_235.png
deleted file mode 100644
index 201f425..0000000
--- a/old/60773-h/images/i_235.png
+++ /dev/null
diff --git a/old/60773-h/images/i_236.png b/old/60773-h/images/i_236.png
deleted file mode 100644
index 33ebf22..0000000
--- a/old/60773-h/images/i_236.png
+++ /dev/null
diff --git a/old/60773-h/images/i_237.png b/old/60773-h/images/i_237.png
deleted file mode 100644
index d97727a..0000000
--- a/old/60773-h/images/i_237.png
+++ /dev/null
diff --git a/old/60773-h/images/i_240.png b/old/60773-h/images/i_240.png
deleted file mode 100644
index f3af797..0000000
--- a/old/60773-h/images/i_240.png
+++ /dev/null
diff --git a/old/60773-h/images/i_243.png b/old/60773-h/images/i_243.png
deleted file mode 100644
index 8e605be..0000000
--- a/old/60773-h/images/i_243.png
+++ /dev/null
diff --git a/old/60773-h/images/i_244.png b/old/60773-h/images/i_244.png
deleted file mode 100644
index 902e5bc..0000000
--- a/old/60773-h/images/i_244.png
+++ /dev/null
diff --git a/old/60773-h/images/i_248.png b/old/60773-h/images/i_248.png
deleted file mode 100644
index 1347aec..0000000
--- a/old/60773-h/images/i_248.png
+++ /dev/null
diff --git a/old/60773-h/images/i_250.png b/old/60773-h/images/i_250.png
deleted file mode 100644
index 4352f72..0000000
--- a/old/60773-h/images/i_250.png
+++ /dev/null
diff --git a/old/60773-h/images/i_254.png b/old/60773-h/images/i_254.png
deleted file mode 100644
index 50999fc..0000000
--- a/old/60773-h/images/i_254.png
+++ /dev/null
diff --git a/old/60773-h/images/i_255.png b/old/60773-h/images/i_255.png
deleted file mode 100644
index 9dff24a..0000000
--- a/old/60773-h/images/i_255.png
+++ /dev/null
diff --git a/old/60773-h/images/i_259.png b/old/60773-h/images/i_259.png
deleted file mode 100644
index d285c3b..0000000
--- a/old/60773-h/images/i_259.png
+++ /dev/null
diff --git a/old/60773-h/images/i_260.png b/old/60773-h/images/i_260.png
deleted file mode 100644
index 41a988a..0000000
--- a/old/60773-h/images/i_260.png
+++ /dev/null
diff --git a/old/60773-h/images/i_262.png b/old/60773-h/images/i_262.png
deleted file mode 100644
index 95920cb..0000000
--- a/old/60773-h/images/i_262.png
+++ /dev/null
diff --git a/old/60773-h/images/i_264.png b/old/60773-h/images/i_264.png
deleted file mode 100644
index b6a8104..0000000
--- a/old/60773-h/images/i_264.png
+++ /dev/null
diff --git a/old/60773-h/images/i_266.png b/old/60773-h/images/i_266.png
deleted file mode 100644
index c497f3f..0000000
--- a/old/60773-h/images/i_266.png
+++ /dev/null
diff --git a/old/60773-h/images/i_268.png b/old/60773-h/images/i_268.png
deleted file mode 100644
index d50ffcf..0000000
--- a/old/60773-h/images/i_268.png
+++ /dev/null
diff --git a/old/60773-h/images/i_270.png b/old/60773-h/images/i_270.png
deleted file mode 100644
index b90d114..0000000
--- a/old/60773-h/images/i_270.png
+++ /dev/null
diff --git a/old/60773-h/images/i_273.png b/old/60773-h/images/i_273.png
deleted file mode 100644
index b5467eb..0000000
--- a/old/60773-h/images/i_273.png
+++ /dev/null
diff --git a/old/60773-h/images/i_274.png b/old/60773-h/images/i_274.png
deleted file mode 100644
index 9f85cc6..0000000
--- a/old/60773-h/images/i_274.png
+++ /dev/null
diff --git a/old/60773-h/images/i_275.png b/old/60773-h/images/i_275.png
deleted file mode 100644
index 07debac..0000000
--- a/old/60773-h/images/i_275.png
+++ /dev/null
diff --git a/old/60773-h/images/i_276.png b/old/60773-h/images/i_276.png
deleted file mode 100644
index ab1ac4c..0000000
--- a/old/60773-h/images/i_276.png
+++ /dev/null
diff --git a/old/60773-h/images/i_278.png b/old/60773-h/images/i_278.png
deleted file mode 100644
index 5b470df..0000000
--- a/old/60773-h/images/i_278.png
+++ /dev/null
diff --git a/old/60773-h/images/i_280.png b/old/60773-h/images/i_280.png
deleted file mode 100644
index d37e473..0000000
--- a/old/60773-h/images/i_280.png
+++ /dev/null
diff --git a/old/60773-h/images/i_284.png b/old/60773-h/images/i_284.png
deleted file mode 100644
index bd34ebe..0000000
--- a/old/60773-h/images/i_284.png
+++ /dev/null
diff --git a/old/60773-h/images/i_286.png b/old/60773-h/images/i_286.png
deleted file mode 100644
index 621f8a7..0000000
--- a/old/60773-h/images/i_286.png
+++ /dev/null
diff --git a/old/60773-h/images/i_287.png b/old/60773-h/images/i_287.png
deleted file mode 100644
index 24196a5..0000000
--- a/old/60773-h/images/i_287.png
+++ /dev/null
diff --git a/old/60773-h/images/i_288.png b/old/60773-h/images/i_288.png
deleted file mode 100644
index 5ce1de3..0000000
--- a/old/60773-h/images/i_288.png
+++ /dev/null
diff --git a/old/60773-h/images/i_292.png b/old/60773-h/images/i_292.png
deleted file mode 100644
index 6ece6fb..0000000
--- a/old/60773-h/images/i_292.png
+++ /dev/null
diff --git a/old/60773-h/images/i_294.png b/old/60773-h/images/i_294.png
deleted file mode 100644
index fccf5b3..0000000
--- a/old/60773-h/images/i_294.png
+++ /dev/null
diff --git a/old/60773-h/images/i_295.png b/old/60773-h/images/i_295.png
deleted file mode 100644
index fcfd66d..0000000
--- a/old/60773-h/images/i_295.png
+++ /dev/null
diff --git a/old/60773-h/images/i_297.png b/old/60773-h/images/i_297.png
deleted file mode 100644
index 4d8413a..0000000
--- a/old/60773-h/images/i_297.png
+++ /dev/null
diff --git a/old/60773-h/images/i_300.png b/old/60773-h/images/i_300.png
deleted file mode 100644
index 9a5531a..0000000
--- a/old/60773-h/images/i_300.png
+++ /dev/null
diff --git a/old/60773-h/images/i_303.png b/old/60773-h/images/i_303.png
deleted file mode 100644
index 5641c41..0000000
--- a/old/60773-h/images/i_303.png
+++ /dev/null
diff --git a/old/60773-h/images/i_304.png b/old/60773-h/images/i_304.png
deleted file mode 100644
index 31dde07..0000000
--- a/old/60773-h/images/i_304.png
+++ /dev/null
diff --git a/old/60773-h/images/i_305.png b/old/60773-h/images/i_305.png
deleted file mode 100644
index 52e959c..0000000
--- a/old/60773-h/images/i_305.png
+++ /dev/null
diff --git a/old/60773-h/images/i_307.png b/old/60773-h/images/i_307.png
deleted file mode 100644
index 6df03cb..0000000
--- a/old/60773-h/images/i_307.png
+++ /dev/null
diff --git a/old/60773-h/images/i_308.png b/old/60773-h/images/i_308.png
deleted file mode 100644
index e6a3292..0000000
--- a/old/60773-h/images/i_308.png
+++ /dev/null
diff --git a/old/60773-h/images/i_311.png b/old/60773-h/images/i_311.png
deleted file mode 100644
index 607e884..0000000
--- a/old/60773-h/images/i_311.png
+++ /dev/null
diff --git a/old/60773-h/images/i_312.png b/old/60773-h/images/i_312.png
deleted file mode 100644
index cbb4694..0000000
--- a/old/60773-h/images/i_312.png
+++ /dev/null
diff --git a/old/60773-h/images/i_313.png b/old/60773-h/images/i_313.png
deleted file mode 100644
index eccd32a..0000000
--- a/old/60773-h/images/i_313.png
+++ /dev/null
diff --git a/old/60773-h/images/i_314.png b/old/60773-h/images/i_314.png
deleted file mode 100644
index 78854e8..0000000
--- a/old/60773-h/images/i_314.png
+++ /dev/null
diff --git a/old/60773-h/images/i_315.png b/old/60773-h/images/i_315.png
deleted file mode 100644
index d7398be..0000000
--- a/old/60773-h/images/i_315.png
+++ /dev/null
diff --git a/old/60773-h/images/i_316.png b/old/60773-h/images/i_316.png
deleted file mode 100644
index ebd6450..0000000
--- a/old/60773-h/images/i_316.png
+++ /dev/null
diff --git a/old/60773-h/images/i_318.png b/old/60773-h/images/i_318.png
deleted file mode 100644
index 45e037e..0000000
--- a/old/60773-h/images/i_318.png
+++ /dev/null
diff --git a/old/60773-h/images/i_319.png b/old/60773-h/images/i_319.png
deleted file mode 100644
index b31d283..0000000
--- a/old/60773-h/images/i_319.png
+++ /dev/null
diff --git a/old/60773-h/images/i_321.png b/old/60773-h/images/i_321.png
deleted file mode 100644
index a3548d3..0000000
--- a/old/60773-h/images/i_321.png
+++ /dev/null
diff --git a/old/60773-h/images/i_322.png b/old/60773-h/images/i_322.png
deleted file mode 100644
index 7eb6801..0000000
--- a/old/60773-h/images/i_322.png
+++ /dev/null
diff --git a/old/60773-h/images/i_323.png b/old/60773-h/images/i_323.png
deleted file mode 100644
index f63e845..0000000
--- a/old/60773-h/images/i_323.png
+++ /dev/null
diff --git a/old/60773-h/images/i_328.png b/old/60773-h/images/i_328.png
deleted file mode 100644
index 688c56d..0000000
--- a/old/60773-h/images/i_328.png
+++ /dev/null
diff --git a/old/60773-h/images/i_329.png b/old/60773-h/images/i_329.png
deleted file mode 100644
index 68deb11..0000000
--- a/old/60773-h/images/i_329.png
+++ /dev/null
diff --git a/old/60773-h/images/i_330.png b/old/60773-h/images/i_330.png
deleted file mode 100644
index 29937a2..0000000
--- a/old/60773-h/images/i_330.png
+++ /dev/null
diff --git a/old/60773-h/images/i_331.png b/old/60773-h/images/i_331.png
deleted file mode 100644
index 7fc262f..0000000
--- a/old/60773-h/images/i_331.png
+++ /dev/null
diff --git a/old/60773-h/images/i_332.png b/old/60773-h/images/i_332.png
deleted file mode 100644
index 6712397..0000000
--- a/old/60773-h/images/i_332.png
+++ /dev/null
diff --git a/old/60773-h/images/i_333.png b/old/60773-h/images/i_333.png
deleted file mode 100644
index a46edae..0000000
--- a/old/60773-h/images/i_333.png
+++ /dev/null
diff --git a/old/60773-h/images/i_340.png b/old/60773-h/images/i_340.png
deleted file mode 100644
index 1cf7ef5..0000000
--- a/old/60773-h/images/i_340.png
+++ /dev/null
diff --git a/old/60773-h/images/i_343.png b/old/60773-h/images/i_343.png
deleted file mode 100644
index 8285745..0000000
--- a/old/60773-h/images/i_343.png
+++ /dev/null
diff --git a/old/60773-h/images/i_345.png b/old/60773-h/images/i_345.png
deleted file mode 100644
index 61f49fa..0000000
--- a/old/60773-h/images/i_345.png
+++ /dev/null
diff --git a/old/60773-h/images/i_358.png b/old/60773-h/images/i_358.png
deleted file mode 100644
index 4efad2d..0000000
--- a/old/60773-h/images/i_358.png
+++ /dev/null
diff --git a/old/60773-h/images/i_360.png b/old/60773-h/images/i_360.png
deleted file mode 100644
index ab0e4db..0000000
--- a/old/60773-h/images/i_360.png
+++ /dev/null
diff --git a/old/60773-h/images/i_363.png b/old/60773-h/images/i_363.png
deleted file mode 100644
index 4545bf7..0000000
--- a/old/60773-h/images/i_363.png
+++ /dev/null
diff --git a/old/60773-h/images/i_366.png b/old/60773-h/images/i_366.png
deleted file mode 100644
index 58e0de1..0000000
--- a/old/60773-h/images/i_366.png
+++ /dev/null
diff --git a/old/60773-h/images/i_369.png b/old/60773-h/images/i_369.png
deleted file mode 100644
index ff5fcc0..0000000
--- a/old/60773-h/images/i_369.png
+++ /dev/null
diff --git a/old/60773-h/images/i_372.png b/old/60773-h/images/i_372.png
deleted file mode 100644
index 0b96bd6..0000000
--- a/old/60773-h/images/i_372.png
+++ /dev/null
diff --git a/old/60773-h/images/i_374.png b/old/60773-h/images/i_374.png
deleted file mode 100644
index 2ee3a89..0000000
--- a/old/60773-h/images/i_374.png
+++ /dev/null
diff --git a/old/60773-h/images/i_378.png b/old/60773-h/images/i_378.png
deleted file mode 100644
index 022c694..0000000
--- a/old/60773-h/images/i_378.png
+++ /dev/null