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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"> </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—Characters by which animals are -distinguished from plants—Actions common to plants and -animals—Actions peculiar to animals—Actions included -in the <span class="smcap">ORGANIC</span> circle—Actions included in the <span class="smcap">ANIMAL</span> -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</td> -<td class="tdl"> </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—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</td> -<td class="tdl"> </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—Sources</td> -</tr> -<tr> -<td class="tdl">of pleasure—Special provision by which the organic -organs influence consciousness and afford pleasure—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—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</td> -<td class="tdl"> </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—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</td> -<td class="tdl"> </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— -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</td> -<td class="tdl"> </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—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</td> -<td class="tdl"> </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—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</td> -<td class="tdl"> </td> -<td class="tdr"><a href="#Page_357">357</a></td> -</tr> - -<tr> -<td class="tdchap">FOOTNOTES.</td> -<td class="tdl"> </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—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—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.</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,—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,—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—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,—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;—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:—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—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.</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 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.</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—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.</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,—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, &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,—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—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!</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—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>—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—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—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—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.</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—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—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"> 11,494</td> -</tr> -<tr> -<td class="tdl"> </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"> 17,071</td> -</tr> -<tr> -<td class="tdl"> </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"> 21,960</td> -</tr> -<tr> -<td class="tdl"> </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"> 30,493</td> -</tr> -<tr> -<td class="tdl"> </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"> 40,708</td> -</tr> -<tr> -<td class="tdl"> </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"> 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—"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"> </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"> 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"> " </td> -</tr> -<tr> -<td class="tdl"> </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"> " </td> -</tr> -<tr> -<td class="tdl"> </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"> " </td> -</tr> -<tr> -<td class="tdl"> </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"> " </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">————</td> -<td class="tdl"> </td> -<td class="tdr"> </td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> 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"> " </td> -</tr> -<tr> -<td class="tdl"> </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"> " </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"> " </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"> </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—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 - -<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:—</p> - -<table summary="Roman"> - -<tr> -<td class="tdl">At</td> -<td class="tdr"> birth</td> -<td class="tdr"> 41½</td> -<td class="tdr">years.</td> -</tr> -<tr> -<td class="tdl">At</td> -<td class="tdr">12</td> -<td class="tdr">46¾</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">17</td> -<td class="tdr">41½</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">22</td> -<td class="tdr">38⅜</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">27</td> -<td class="tdr">35¼</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">32</td> -<td class="tdr">32 </td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">37</td> -<td class="tdr">28¾</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">42</td> -<td class="tdr">25½</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">47</td> -<td class="tdr">22¼</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">52</td> -<td class="tdr">19 </td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">57</td> -<td class="tdr">16 </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">62</td> -<td class="tdr">13 </td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">67</td> -<td class="tdr">10½</td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">72</td> -<td class="tdr">8 </td> -<td class="tdr"> </td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdr">77</td> -<td class="tdr">6 </td> -<td class="tdr"> </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%;">33¼ 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%;">14¼ 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%;">34¾<span style="margin-left: 9.3em;">37½ 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"> </td> -<td class="tdr">│</td> -<td class="tdr">50│</td> -<td class="tdr">55│</td> -<td class="tdr">60│</td> -<td class="tdr">65│</td> -<td class="tdr">70│</td> -<td class="tdr">75│</td> -<td class="tdr">80│</td> -<td class="tdr">85│</td> -</tr> - -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr">Yrs.│</td> -<td class="tdr">Yrs.│</td> -<td class="tdr">Yrs.│</td> -<td class="tdr">Yrs.│</td> -<td class="tdr">Yrs.│</td> -<td class="tdr">Yrs.│</td> -<td class="tdr">Yrs.│</td> -<td class="tdr">Yrs.│</td> -</tr> -<tr> -<td class="tdl">The average duration of Human Life of both sexes collectively</td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</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"> </td> -<td class="tdr">│</td> -<td class="tdr">23│</td> -<td class="tdr">19│</td> -<td class="tdr">16│</td> -<td class="tdr">13│</td> -<td class="tdr">11│</td> -<td class="tdr">8│</td> -<td class="tdr">6│</td> -<td class="tdr">3│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">–</td> -<td class="tdr">———</td> -<td class="tdr">———</td> -<td class="tdr">———</td> -<td class="tdr">———</td> -<td class="tdr">———</td> -<td class="tdr">———</td> -<td class="tdr">———</td> -<td class="tdr">———</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"> </td> -</tr> -<tr> -<td class="tdc">Answer.</td> -<td class="tdc"> Name of the </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"> </td> -<td class="tdc">Observer.</td> -<td class="tdr">│</td> -<td class="tdr">Wks.│</td> -<td class="tdr">Wks.│</td> -<td class="tdr">Wks.│</td> -<td class="tdr">Wks.│</td> -<td class="tdr">Wks.│</td> -<td class="tdr">Wks.│</td> -<td class="tdr">Wks.│</td> -<td class="tdr">Wks.│</td> -</tr> -<tr> -<td class="tdc"><span class="large"><b>Among the higher classes of people exclusively.</b></span></td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -</tr> - -<tr> -<td class="tdl">In England—Among the Government Annuitants,</td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</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">│</td> -<td class="tdr">35│</td> -<td class="tdr">1│</td> -<td class="tdr">7│</td> -<td class="tdr">10│</td> -<td class="tdr">47│</td> -<td class="tdr">11│</td> -<td class="tdr">14│</td> -<td class="tdr">53│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -</tr> - -<tr> -<td class="tdl"><span style="margin-left: 5.5em;">Among the Lives assured at the Equitable</span></td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</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">│</td> -<td class="tdr">119│</td> -<td class="tdr">83│</td> -<td class="tdr">87│</td> -<td class="tdr">81│</td> -<td class="tdr">96│</td> -<td class="tdr">33│</td> -<td class="tdr">10│</td> -<td class="tdr">27│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</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"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -</tr> -<tr> -<td class="tdl"><span style="margin-left: 5.5em;">—between that year and 1775</span></td> -<td class="tdc">John Finlaison.</td> -<td class="tdr">│</td> -<td class="tdr">269│</td> -<td class="tdr">195│</td> -<td class="tdr">170│</td> -<td class="tdr">141│</td> -<td class="tdr">157│</td> -<td class="tdr">110│</td> -<td class="tdr">90│</td> -<td class="tdr">89│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -</tr> -<tr> -<td class="tdl">In France — Among the Nominees of the Tontine of 1693</td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -</tr> -<tr> -<td class="tdl"><span style="margin-left: 5.5em;">—between that year and 1745</span></td> -<td class="tdc">M. de Parcieux.</td> -<td class="tdr">│</td> -<td class="tdr">133│</td> -<td class="tdr">88│</td> -<td class="tdr">87│</td> -<td class="tdr">86│</td> -<td class="tdr">118│</td> -<td class="tdr">70│</td> -<td class="tdr">55│</td> -<td class="tdr">65│</td> -</tr> - -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -</tr> -<tr> -<td class="tdl">In Holland — Among the Public Annuitants, between 1615 and 1740</td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</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">│</td> -<td class="tdr">186│</td> -<td class="tdr">118│</td> -<td class="tdr">104│</td> -<td class="tdr">75│</td> -<td class="tdr">96│</td> -<td class="tdr">61│</td> -<td class="tdr">48│</td> -<td class="tdr">84│</td> -</tr> - -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -</tr> - -<tr> -<td class="tdc"><span class="large"><b>In regard to the mass of the people.</b></span></td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc"> </td> -<td class="tdr">│</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -<td class="tdr"> │</td> -</tr> -<tr> -<td class="tdl">In Breslau in Silesia, between 1700 and 1725,</td> -<td class="tdc">Dr. Halley.</td> -<td class="tdr">│</td> -<td class="tdr">275│</td> -<td class="tdr">211│</td> -<td class="tdr">181│</td> -<td class="tdr">150│</td> -<td class="tdr">166│</td> -<td class="tdr">100│</td> -<td class="tdr">36│</td> -<td class="tdr">137│</td> -</tr> - -<tr> -<td class="tdl">In Sweden, between 1775 and 1795,</td> -<td class="tdc">M. Nicander,</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc">and Mr. Milne.</td> -<td class="tdr">│</td> -<td class="tdr">207│</td> -<td class="tdr">161│</td> -<td class="tdr">164│</td> -<td class="tdr">146│</td> -<td class="tdr">156│</td> -<td class="tdr">94│</td> -<td class="tdr">60│</td> -<td class="tdr">60│</td> -</tr> - -<tr> -<td class="tdl">In Northampton, in England, between 1735 and 1780,</td> -<td class="tdc">Dr. Price.</td> -<td class="tdr">│</td> -<td class="tdr">209│</td> -<td class="tdr">178│</td> -<td class="tdr">145│</td> -<td class="tdr">110│</td> -<td class="tdr">125│</td> -<td class="tdr">76│</td> -<td class="tdr">65│</td> -<td class="tdr">85│</td> -</tr> - -<tr> -<td class="tdl">In Carlisle, in England, between 1779 and 1787,</td> -<td class="tdc">Dr. Heysham,</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -<td class="tdr">│</td> -</tr> -<tr> -<td class="tdl"> </td> -<td class="tdc">and Mr. Milne.</td> -<td class="tdr">│</td> -<td class="tdr">98│</td> -<td class="tdr">74│</td> -<td class="tdr">86│</td> -<td class="tdr">63│</td> -<td class="tdr">94│</td> -<td class="tdr">52│</td> -<td class="tdr">26│</td> -<td class="tdr">46│</td> -</tr> - -<tr> -<td class="tdl">In all England and Wales, between 1811 and 1831,</td> -<td class="tdc">John Finlaison.</td> -<td class="tdr">│</td> -<td class="tdr">100│</td> -<td class="tdr">59│</td> -<td class="tdr">65│</td> -<td class="tdr">58│</td> -<td class="tdr">87│</td> -<td class="tdr">48│</td> -<td class="tdr">37│</td> -<td class="tdr">49│</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">│</td> -<td class="tdr">276│</td> -<td class="tdr">210│</td> -<td class="tdr">184│</td> -<td class="tdr">146│</td> -<td class="tdr">143│</td> -<td class="tdr">76│</td> -<td class="tdr">50│</td> -<td class="tdr">75│</td> -</tr> - -<tr> -<td class="tdl">In all Belgium, between 1725 and 1832,</td> -<td class="tdc"> M. Quetelet.</td> -<td class="tdr">│</td> -<td class="tdr">183│</td> -<td class="tdr">133│</td> -<td class="tdr">133│</td> -<td class="tdr">117│</td> -<td class="tdr">112│</td> -<td class="tdr">84│</td> -<td class="tdr">50│</td> -<td class="tdr">61│</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—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.</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— -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,—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—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,—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—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.</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—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, &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 fœtal 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 -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.</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 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 - -<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, &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—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—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—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,—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,—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—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!"</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—Process of coagulation—Constituents -of the blood: proportions—Constituents of -the body contained in the blood—Vital properties of the -blood—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 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.</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"> 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"> potash</td> -<td class="tdr">6·00</td> -</tr> -<tr> -<td class="tdl">Subcarbonate and phosphate of</td> -</tr> -<tr> -<td class="tdl"> soda, and sulphate of potash </td> -<td class="tdr">2·10</td> -</tr> -<tr> -<td class="tdl">Phosphate of lime, magnesia,</td> -</tr> -<tr> -<td class="tdl"> and iron, with subcarbonate</td> -</tr> -<tr> -<td class="tdl"> 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 </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"> </td> -<td class="tdr">————</td> -</tr> -<tr> -<td class="tdl"> </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,—</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"> </td> -<td class="tdl"> </td> -<td class="tdl"> </td> -<td class="tdc">Minutes.</td> -<td class="tdc"> 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"> " </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"> " </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"> " </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"> </td> -<td class="tdl"> </td> -<td class="tdl"> </td> -<td class="tdr">Minutes.</td> -<td class="tdr"> 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"> " </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"> " </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, -—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—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.</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,—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,—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;—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—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. 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