THE PEOPLE'S

COMMON SENSE

MEDICAL ADVISER

IN PLAIN ENGLISH:

OR,

MEDICINE SIMPLIFIED.

BY

R.V. PIERCE, M.D.

ONE OF THE STAFF OF CONSULTING PHYSICIANS AND SURGEONS

AT THE INVALIDS' HOTEL AND SURGICAL INSTITUTE, AND

PRESIDENT OF THE WORLD'S DISPENSARY

MEDICAL ASSOCIATION.

FIFTY-FOURTH EDITION.

One Million, Six Hundred and Fifty Thousand.

Carefully Revised by the Author, assisted by his full Staff of Associate Specialists in Medicine and Surgery, the Faculty of the Invalids' Hotel and Surgical Institute.

Entered according to Act of Congress, in the year 1895, by the WORLD'S DISPENSARY MEDICAL ASSOCIATION, In the office of the Librarian of Congress, at Washington, D.C.

TO
MY PATIENTS,
WHO HAVE SOLICITED MY PROFESSIONAL SERVICES,
FROM THEIR HOMES
IN EVERY STATE, CITY, TOWN, AND ALMOST EVERY HAMLET,
WITHIN THE AMERICAN UNION;
ALSO TO THOSE DWELLING IN EUROPE, MEXICO, SOUTH AMERICA,
THE EAST AND WEST INDIES, AND OTHER
FOREIGN LANDS,
I RESPECTFULLY DEDICATE
THIS WORK.

TABLE OF CONTENTS

PREFACE TO THE PRESENT EDITION
PREFACE TO THE FIRST EDITION
INTRODUCTORY WORDS

PART I

CHAPTER I. BIOLOGY
CHAPTER II. PHYSIOLOGICAL ANATOMY. THE BONES.
CHAPTER III. PHYSIOLOGICAL ANATOMY. THE MUSCLES.
CHAPTER IV. PHYSIOLOGICAL ANATOMY. THE DIGESTIVE ORGANS.
CHAPTER V. PHYSIOLOGICAL ANATOMY. ABSORPTION.
CHAPTER VI. PHYSICAL AND VITAL PROPERTIES OF THE BLOOD.
CHAPTER VII. PHYSIOLOGICAL ANATOMY. CIRCULATORY ORGANS.
CHAPTER VIII. PHYSIOLOGICAL ANATOMY. THE ORGANS OF RESPIRATION.
CHAPTER IX. PHYSIOLOGICAL ANATOMY. THE SKIN.
CHAPTER X. PHYSIOLOGICAL ANATOMY. SECRETION.
CHAPTER XI. PHYSIOLOGICAL ANATOMY. EXCRETION.
CHAPTER XII. PHYSIOLOGICAL ANATOMY. THE NERVOUS SYSTEM.
CHAPTER XIII. THE SPECIAL SENSES. SIGHT.
CHAPTER XIV. CEREBRAL PHYSIOLOGY.
CHAPTER XV. THE HUMAN TEMPERAMENTS.
CHAPTER XVI. MARRIAGE. LOVE.
CHAPTER XVII. REPRODUCTION.

PART II. HYGIENE.

CHAPTER I. HYGIENE DEFINED.—PURE AIR.
CHAPTER II. FOOD. BEVERAGES. ALCOHOLIC LIQUORS. CLOTHING.
CHAPTER III. PHYSICAL EXERCISE. MENTAL CULTURE. SLEEP. CLEANLINESS.
CHAPTER IV. HYGIENE OF THE REPRODUCTIVE ORGANS.
CHAPTER V. PRACTICAL SUMMARY OF HYGIENE.

PART III. RATIONAL MEDICINE.

CHAPTER I. THE PROGRESS OF MEDICINE.
CHAPTER II. REMEDIES FOR DISEASE.
CHAPTER III. BATHS AND MOTION AS REMEDIAL AGENTS.
CHAPTER IV. HYGIENIC TREATMENT OF THE SICK.

PART IV. DISEASES AND THEIR REMEDIAL TREATMENT.

INDEX

FOOTNOTES

PREFACE TO THE PRESENT EDITION

PREFACE TO THE FIRST EDITION.

While instruction is imparted for the care of the body, those diseases (alas how prevalent!) are investigated which are sure to follow as a consequence of certain abuses, usually committed through ignorance. That these ills do exist is evident from the fact that the Author is consulted by multitudes of unfortunate young men and women, who are desirous of procuring relief from the weaknesses and derangements incurred by having unwittingly violated physiological laws.

Although some of these subjects may seem out of place in a work designed for every member of the family, yet they are presented in a style which cannot offend the most fastidious, and with a studied avoidance of all language that can possibly displease the chaste, or disturb the delicate susceptibilities of persons of either sex.

This book should not be excluded from the young, for it is eminently adapted to their wants, and imparts information without which millions will suffer untold misery. It is a false modesty which debars the youth of our land from obtaining such information.

As its title indicates, the Author aims to make this book a useful and practical Medical Adviser. He proposes to express himself in plain and simple language, and, so far as possible, to avoid the employment of technical words, so that all his readers may readily comprehend the work, and profit by its perusal. Written as it is amid the many cares attendant upon a practice embracing the treatment of thousands of cases annually, and therefore containing the fruits of a rich and varied experience, some excuse exists for any literary imperfections which the critical reader may observe.

THE AUTHOR.

BUFFALO, N.Y., July, 1875.

INTRODUCTORY WORDS.

We, as a people, are becoming idle, living in luxury and ease, and in the gratification of artificial wants. Some indulge in the use of food rendered unwholesome by bad cookery, and think more of gratifying a morbid appetite than of supplying the body with proper nourishment. Others devote unnecessary attention to the display of dress and a genteel figure, yielding themselves completely to the sway of fashion. Such intemperance in diet and dress manifests itself in the general appearance of the unfortunate transgressor, and exposes his folly to the world, with little less precision than certain vices signify their presence by a tobacco-tainted breath, beer-bloated body, rum-emblazoned nose, and kindred manifestations. They coddle themselves instead of practicing self-denial, and appear to think that the chief end of life is gratification, rather than useful endeavor.

I purpose to express myself candidly and earnestly on all topics relating to health, and appeal to the common sense of the reader for justification. Although it is my aim to simplify the work, and render it a practical common-sense guide to the farmer, mechanic, mariner, and day-laborer, yet I trust that it may not prove less acceptable to the scholar, in its discussion of the problems of Life. Not only does the method adopted in this volume of treating of the Functions of the Brain and Nervous System present many new suggestions, in its application to hygiene, the management of disease, generation and the development and improvement of man, but the conclusions correspond with the results of the latest investigations of the world's most distinguished savants. My object is to inculcate the facts of science rather than the theories of philosophy.

Unto us are committed important health trusts, which we hold, not merely in our own behalf, but for the benefit of others. If we discharge the obligations of our trusteeship, we shall enjoy present strength, usefulness, and length of days; but if we fail in their performance, then inefficiency, incapacity, and sickness, will follow, the sequel of which is pain and death. Let us, then, prove worthy of this generous commission, that we may enjoy the sweetest of all pleasures, the delicious fruitage of honest toil and faithful obedience.

PART I.

CHAPTER I.

Latent Life is contained in a small globule, a mere atom of matter, in the sperm-cell. This element is something which, under certain conditions, develops into a living organism. The entire realm of nature teems with these interesting phenomena, thus manifesting that admirable adjustment of internal to external relations, which claims our profound attention. We are simply humble scholars, waiting on the threshold of nature's glorious sanctuary, to receive the interpretation of her divine mysteries.

Some have conjectured that chemical and physical forces account for all the phenomena of life, and that organization is not the result of vital forces. Physical science cannot inform us what the beginning was, or how vitality is the result of chemical forces; nor can it tell us what transmutations will occur at the end of organized existence. This mysterious life-principle eludes the grasp of the profoundest scientists, and its presence in the world will ever continue to be an astonishing and indubitable testimony of Divine Power.

The physical act of generation is accomplished by the union of two cells; and as this conjugation is known to be so generally indispensable to the organization of life, we may fairly infer that it is a universal necessity. Investigations with the microscope have destroyed the hypothesis of "spontaneous generation." These show us that even the minutest living forms are derived from a parent organization.

Generation. So long as the vital principle remains in the sperm-cell, it lies dormant. That part of the cell which contains this principle is called the spermatozoön, which consists of a flattened body, having a long appendage tapering to the finest point. If it be remembered that a line is the one-twelfth part of an inch in length, some idea may be formed of the extreme minuteness of the body of a human spermatozoön, when we state that it is from 1/800 to 1/600 part of a line, and the filiform tail 1/50 of a line, in length. This life-atom, which can be discerned only with a powerful magnifying glass, is perfectly transparent, and moves about by executing a vibratile motion with its long appendage. Within this speck of matter are hidden the multifarious forces which, under certain favorable conditions, result in organization. Magnify this infinitesimal atom a thousand times, and no congeries of formative powers is perceived wherewith to work out the wonders of its existence. Yet it contains the principle, which is the contribution on the part of the male toward the generation of a new being.

The ovum or germ-cell, is the special contribution on the part of the female for the production of another being. The human ovum, though larger than the spermatozoön, is also extremely small, measuring not more than from 1/20 to 1/10 of a line, or from 1/240 to 1/120 of an inch, in diameter.

Fig. 1. A. Human Spermatozoön magnified about 3,800 diameters. B. Vertical and lateral views of spermatozoa of man. C, D, E, F. Development of spermatozoa within the vesicles of evolution. G. Cell of the sponge resembling a spermatozoön. H. Vesicles of evolution from the seminal fluid of the dog in the parent cell I. Single vesicles of different sizes. J. Human spermatozoön forming in its cell. K. Rupture of the cell and escape of the spermatozoön.

The sperm and the germ-cells contain the primary elements of all organic structures, and both possess the special qualities and conditions by which they may evolve organic beings. Every cell is composed of minute grains, within which vital action takes place. The interior of a cell consists of growing matter; the exterior, of matter which has assumed its form and is less active.

When the vital principle is communicated to it, the cell undergoes a rapid transformation. While this alteration takes place within the cell, deteriorating changes occur in the cell-wall. Although vital operations build up these structures, yet the animal and nervous functions are continually disintegrating, or wasting, them.

Throughout the animal kingdom, germ-cells present the same external aspect when carefully examined with the microscope. No difference can be observed between the cells of the flowers of the oak and those of the apple, but the cells of the one always produce oak trees, while those of the other always produce apple trees. The same is true of the germs of animals, there being not the slightest apparent difference. We are unable to perceive how one cell should give origin to a dog, while another exactly like it becomes a man. For aught we know, the ultimate atoms of these cells are identical in physical character; at least we have no means of detecting any difference.

Species. The term species is generally used merely as a convenient name to designate certain assemblages of individuals having various striking points of resemblance. Scientific writers, as a rule, no longer hold that what are usually called species are constantly unvarying and unchangeable quantities. Recent researches point to the conclusion that all species vary more or less, and, in some instances, that the variation is so great that the limits of general specific distinctness are sometimes exceeded.

Our space will not permit us to do more than merely indicate the two great fundamental ideas upon which the leading theories of the time respecting the origin of species are based. These are usually termed the doctrine of Special Creation and the doctrine of Evolution. According to the doctrine of Special Creation, it is thought that species are practically immutable productions, each species having a specific centre where it was originally created, and from which it spread over a certain area until its further progress was obstructed by unfavorable conditions. The advocates of the doctrine of Evolution hold, on the contrary, that species are not permanent and immutable, but that they are subject to modification, and that "the existing forms of life are descendants by true generation of pre-existing forms."^[1] Most naturalists are now inclined to admit the general truth of the theory of evolution, but they differ widely respecting the mode in which it occurred.

THE PROCESS OF GENERATION.

The vital principle, represented in the sperm-cell by a spermatozoön, must be imparted to a germ-cell in order to effect impregnation. After touching each other, separate them immediately, and observe the result. If, with the aid of a powerful lens, we directly examine the spermatozoön, it will be perceived that, for a short time, it preserves its dimensions and retains all its material aspects. But it does not long withstand the siege of decay, and, having fulfilled its destiny, loses its organic characteristics, and begins to shrink.

If we examine the fertilized germ, we discover unusual activity, the result of impregnation. Organic processes succeed one another with wonderful regularity, as if wrought out by inexplicable intelligence. Here begin the functions which constitute human physiology.

Generation requires that a spermatozoön be brought into actual contact with a germ that fecundation may follow. If a spermatic cell, or spermatozoön, together with several unimpregnated ova, no matter how near to one another, if not actually touching, be placed on the concave surface of a watch-crystal, and covered with another crystal, keeping them warm, and even though the vapor of the ova envelops it, no impregnation will occur. Place the spermatozoön in contact with an ovum, and impregnation is instantly and perfectly accomplished. Should this vitalizing power be termed nerve-force, electricity, heat, or motion? It is known that these forces may be metamorphosed; for instance, nervous force may be converted into electricity, electricity into heat, and heat into motion, thus illustrating their affiliation and capability of transformation. But nothing is explained respecting the real nature of the vital principle, if we assert its identity with any of these forces; for who can reveal the true nature of any of these, or even of matter?

ALTERNATE GENERATION.

In several insect families, the species is not wholly represented in the adult individuals of both sexes, or in their development, but, to complete this series, supplementary individuals, as it were, of one or of several preceding generations, are required. The son may not resemble the father, but the grandfather, and in some instances, the likeness re-appears only in latter generations. Agassiz states: "Alternate generation was first observed among the Salpæ. These are marine mollusks, without shells, belonging to the family Tunicata. They are distinguished by the curious peculiarity of being united together in considerable numbers so as to form long chains, which float in the sea, the mouth(m) however being free in each.

Fig. 2.

Fig. 3.

"Fig. 2. The individuals thus joined in floating colonies produce eggs; but in each animal there is generally but one egg formed, which is developed in the body of the parent, and from which is hatched a little mollusk.

"Fig. 3, which remains solitary, and differs in many respects from the parent. This little animal, on the other hand, does not produce eggs, but propagates, by a kind of budding, which gives rise to chains already seen in the body of their parent(a), and these again bring forth solitary individuals, etc."

It therefore follows that generation in some animals require? two different bodies with intermediate ones, by means of which and their different modes of reproduction, a return to the original stock is effected.

Universality of Animalcular Life.—Living organisms are universally diffused over every part of the globe. The gentle zephyr wafts from flower to flower invisible, fructifying atoms, which quicken beauty and fragrance, giving the promise of a golden fruitage, to gladden and nourish a dependent world. Nature's own sweet cunning invests all living things constraining into her service chemical affinities, arranging the elements and disposing them for her own benefit, in such numberless ways that we involuntarily exclaim,

"The course of Nature is the art of God."

The microscope reveals the fact that matter measuring only 1/120000 of an inch diameter may be endowed with vitality, and that countless numbers of animalcules often inhabit a single drop of stagnant water. These monads do not vary in form, whether in motion or at rest. The life of one, even, is an inexplicable mystery to the philosopher. Ehrenberg writes: "Not only in the polar regions is there an uninterrupted development of active microscopic life, where larger animals cannot exist, but we find that those minute beings collected in the Antarctic expedition of Captain James Ross exhibit a remarkable abundance of unknown, and often most beautiful forms."

Even the interior of animal bodies is inhabited by animalcules. They have been found in the blood of the frog and the salmon, and in the optic fluid of fishes. Organic beings are found in the interior of the earth, into which the industry of the miner has made extensive excavations, sunk deep shafts, and thus revealed their forms; likewise, the smallest fossil organisms form subterranean strata many fathoms deep. Not only do lakes and inland seas abound with life, but also, from unknown depths, in volcanic districts, arise thermal springs which contain living insects. Were we endowed with a microscopic eye, we might see myriads of ethereal voyagers wafted by on every breeze, as we now behold drifting clouds of aqueous vapor. While the continents of earth furnishes evidences of the universality of organic beings, recent observations prove that "animal life predominates amid the eternal night of the depths of the liquid ocean."

THE ORIGIN OF LIFE.

The ancients, rude in many of their ideas, referred the origin of life to divine determination. The thought was crudely expressed, but well represented, in the following verse:

"Then God smites his hands together,
And strikes out a soul as a spark,
Into the organized glory of things.
From the deeps of the dark."

According to a Greek myth, Prometheus formed a human image from the dust of the ground, and then, by fire stolen from heaven, animated it with a living soul. Spontaneous generation once held its sway, and now the idea of natural evolution is popular. Some believe that the inpenetrable mystery of life is evolved from the endowments of nature, and build their imperfect theory on observations of her concrete forms and their manifestations, to which all our investigations are restricted. But every function indicates purpose, every organism evinces intelligent design, and all proclaim a Divine Power. Something cannot come out of nothing. With reason and philosophy, chance is an impossibility. We, therefore, accept the display of wisdom in nature as indicative of the designs of God. Thus "has He written His claims for our profoundest admiration and homage all over every object that He has made." If you ask: Is there any advantage in considering the phenomena of nature as the result of DIVINE VOLITION? we answer, that this belief corresponds with the universally acknowledged ideas of accountability; for, with a wise, and efficient Cause, we infer there is an intelligent creation, and the desire to communicate, guide and bless, is responded to by man, who loves, obeys, and enjoys. Nothing is gained by attributing to nature vicegerent forces. Is it not preferable to say that she responds to intelligent, loving Omnipotence? Our finiteness is illustrated by our initiation into organized being. Emerging from a rayless atom, too diminutive for the sight, we gradually develop and advance to the maturity of those conscious powers, the exercise of which furnishes indubitable evidence of our immortality. We are pervaded with invisible influences, which, like the needle of the compass trembling on its pivot, point us to immortality as our ultimate goal, where in the sunny clime of Love, even in a spiritual realm of joy and happiness, we may eternally reign with Him who is all in all.

CHAPTER II.

Fig. 4. Nucleated cell. From Goeber. 1. Periphery of the cell, or cell-wall. 2. Nucleus. 3. Nucleolus in the center.

A variety of tissues enters into the composition of an animal structure, yet their differences are not always distinctly marked, since the characteristics of some are not unlike those of others. We shall notice, however, only the more important of the tissues.

The Areolar, or Connective Tissue, is a complete network of delicate fibers, spread over the body, and serves to bind the various organs and parts together. The fibrous and serous tissues are modifications of the areolar.

The Nervous Tissue is of two kinds: The gray, which is pulpy and granulated, and the white fibrous tissue. The Adipose Tissue is an extremely thin membrane, composed of closed cells which contain fat. It is found principally just beneath the skin, giving it a smooth, plump appearance.

Fig. 5. Arrangement of fibers in the Areolar Tissue. Magnified 135 diameters.

The Cartilaginous Tissue consists of nucleated cells, and, with the exception of bone, is the hardest part of the animal frame. The Osseous Tissue, or bone, is more compact and solid than the cartilaginous, for it contains a greater quantity of lime. The Muscular Tissue is composed of bundles of fibers, which are enclosed in a cellular membrane.

Fig. 6. Human Adipose Tissue.

Various opinions have been entertained in regard to the formation, or growth, of bone. Some anatomists have supposed that all bone is formed in cartilage. But this is not true, for there is an intra-membranous, as well as an intra-cartilaginous, formation of bone, as may be seen in the development of the cranial bones, where the gradual calcification takes place upon the inner layers of the fibrous coverings. Intra-cartilaginous deposit is found in the vicinity of the blood-vessels, within the cartilaginous canals; also, there are certain points first observed in the shafts of long bones, called centers of ossification. These points are no sooner formed than the cartilage corpuscles arrange themselves in concentric zones, and, lying in contact with one another, become very compact. As ossification proceeds, the cup-shaped cavities are converted into closed interstices of bone, with extremely thin lamellæ, or layers. These, however, soon increase in density, and no blood-vessels can be observed within them.

Fig. 7. Vertical section of cartilage near the surface of ossification. 1. Ordinary appearance of the temporary cartilage. 1'. Portion of the same more highly magnified. 2. The cells beginning to form into concentric zones. 2'. Portion more magnified. 3. The ossification is extending in the inter-cellular spaces, and the rows of cells are seen resting in the cavities so formed, the nuclei being more separated than above. 3'. Portion of the same more highly magnified.

Fig. 8. Thigh-bone, sawn open lengthwise.

Fig. 9. Lower end of the thigh-bone sawn across, showing its central cavity.

The bony plates form the boundaries of the Haversian, or nutritive canals of the bones. In the second stage of ossification, the cartilage corpuscles are converted into bone. Becoming flattened against the osseous lamellæ already formed, they crowd upon one another so as to entirely obliterate the lines that distinguish them; and, simultaneously with these changes, a calcareous deposit takes place upon their interior. Bones grow by additions to their ends and surfaces. In the child, their extremities are separated from the body of the bone by layer of cartilage, and the cancellated, or cellular structure, which remains for a time in the interior, represents the early condition of the ossifying substances.

The bones contain more earthy matter in their composition than any other part of the human body, being firm, hard, and of a lime color. They compose the skeleton or frame work, and, when united by natural ligaments, form what is known as the natural skeleton; when they are wired together, they are called an artificial skeleton. The number of bones in the human body is variously estimated; for those regarded as single by some anatomists are considered by others to consist of several distinct pieces. There are two hundred distinct bones in the human skeleton besides the teeth. These may be divided into those of the Head, Trunk, Upper Extremities, and Lower Extremities.

Fig. 10. The bones of the skull separated. 1. Frontal, only half is seen. 2. Parietal. 3. Occipital, only half is seen. 4. Temporal. 5. Nasal. 6. Malar. 7. Superior maxillary (upper jaw). 8. Lachrymal. 9. Inferior maxillary (lower jaw). Between 4 and 6 a part of the sphenoid or wedge-shaped bone, is seen. Another bone assisting to form the skull, but not here seen, is called the ethmoid (sieve-like, from being full of holes), and is situated between the sockets of the eyes, forming the roof of the nose.

The Bones of the Head are classed as follows: eight belonging to the Cranium, and fourteen to the Face. The bones of the Cranium are the occipital, two parietal, two temporal, frontal, sphenoid, and ethmoid. Those composing the face are, the two nasal, two superior maxillary, two lachrymal, two malar two palate, two inferior turbinated, vomer, and inferior maxillary. The cranial bones are composed of two dense plates, between which there is, in most places a cancellated or cellular tissue. The external plate is fibrous, the internal, compact and vitreous. The skull is nearly oval in form, convex externally, the bone being much thicker at the base than elsewhere, and it is, in every respect admirably adapted to resist any injury to which it may be exposed, thus affording ample protection to the brain substance which it envelops. The internal surface of the cranium presents eminences and depressions for lodging the convolutions of the brain, and numerous furrows for the ramifications of the blood-vessels. The bones of the cranium are united to one another by ragged edges called sutures, which are quite distinct in the child but which in old age are nearly effaced. Some authorities suppose that by this arrangement the cranium is less liable to be fractured by blows; others think that the sutures allow the growth of these bones, which takes place by a gradual osseous enlargement at the margins. The bones of the Face are joined at the lower part and in front of the cranium, and serve for the attachment of powerful muscles which assist in the process of mastication. Although the soft parts of the face cover the bony structure, yet they do not conceal its principal features, or materially change its proportions. The form of the head and face presents some remarkable dissimilarities in different races.

Fig. 11. 1. The first bone of the sternum (breast-bone). 2. The second bone of the sternum. 3. The cartilage of the sternum. 4. The first dorsal vertebra (a bone of the spinal column). 5. The last dorsal vertebra. 6. The first rib. 7. Its head. 8. Its neck. 9. Its tubercle. 10. The seventh or last true rib. 11. The cartilage of the third rib. 12. The floating ribs.

Fig. 12. A vertebra of the neck. 1. The body of the vertebra. 2. The spinal canal. 4. The spinous process cleft at its extremity. 5. The transverse process. 7. The interior articular process. 8. The superior articular process.

The Trunk has fifty-four bones, which are as follows: The Os Hyoides, the Sternum, twenty-four Ribs, twenty-four vertebræ or bones of the Spinal Column, the Sacrum, the Coccyx, and two Ossa Innominata. The Os Hyoides, situated at the base of the tongue, is the most isolated bone of the skeleton, and serves for the attachment of muscles. The Sternum, or breast-bone, in a child is composed of six pieces, in the adult of three, which in old age are consolidated into one bone. The Ribs are thin, curved bones, being convex externally. There are twelve on each side, and all are attached to the spinal column. The seven upper ribs, which are united in front of the sternum, are termed true ribs; the next three, which are not attached to the sternum, but to one another are called false ribs; and the last two, which are joined only to the vertebræ, are designated as floating ribs. The first rib is the shortest, and they increase in length as far as the eighth, after which this order is reversed.

Fig. 13. 1. The cartilaginous substance which connects the bodies of the vertebræ. 2. The body of the vertebra. 3. The spinous process. 4,4. The transverse processes. 5,5. The articular processes. 6,6. A portion of the bony bridge which assists in forming the spinal canal (7).

Fig. 14. Backbone, spinal column, or vertebral column. All animals possessing such a row of bones are called vertebrates. Above b are the cervical (neck) vertebræ; b to c, dorsal (back) or chest vertebræ; c to d, lumbar (loins) vertebræ; d to e, sacrum; e to f, coccyx.

The Spinal Column or backbone, when viewed from the front presents a perpendicular appearance, but a side view shows four distinct curves. The bones composing it are called vertebræ. The body part of a vertebra is light and spongy in texture, having seven projections called processes, four of which are the articular processes, which furnish surfaces to join the different vertebræ of the spinal column. Two are called transverse, and the remaining one is termed the spinous. The transverse and spinous processes serve for the attachment of the muscles belonging to the back. All these processes are more compact than the body of the vertebra, and, when naturally connected, are so arranged as to form a tube which contains the medulla spinalis, or spinal cord. Between the vertebræ is a highly-elastic, cartilaginous and cushion-like substance, which freely admits of motion, and allows the spine to bend as occasion requires. The natural curvatures of the spinal column diminish the shock produced by falling, running or leaping, which would otherwise be more directly transmitted to the brain. The ribs at the sides, the sternum in front, and the twelve dorsal bones of the spinal column behind, bound the thoracic cavity, which contains the lungs, heart, and large blood-vessels.

Fig. 15. A representation of the pelvic bones. e. The lumbo-sacral joint. 2. The sacrum. 3. Coccyx. 1, 1. The innominata. 4,4. Acetabula.

The Pelvis is an open bony structure, consisting of the Os Innominata, one on either side, and the Sacrum and Coccyx behind. The Sacrum, during childhood, consists of five bones, which in later years unite to form one bone. It is light and spongy in texture, and the upper surface articulates with the lowest vertebra, while it is united at its inferior margin to the coccyx. The Coccyx is the terminal bone of the spinal column. In infancy it is cartilaginous and composed of several pieces, but in the adult these unite and form one bone. The Innominata, or nameless bones, during youth, consist of three separate pieces on each side; but as age advances they coalesce and form one bone. A deep socket, called the acetabulum, is found near their junction, which serves for the reception of the head of the thigh-bone.

Fig. 16. 1. Portions of the backbone. 2. Cranial bones. 4. Breast-bone. 5. Ribs. 7. Collar-bone. 8. Arm-bone (humerus). 9. Shoulder-joint. 10, 11. Bones of the fore-arm (ulna and radius). 12. Elbow-joint. 13. Wrist-joint. 14. Bones of the hand. 15, 16. Pelvic bones. 17. Hip-joint. 18. Femur. 19, 20. Bones of the knee-joint. 21, 22. Fibula and tibia. 23. Ankle bone. 24. Bones of the foot.

The Bones of the Upper Extremities are sixty-four in number, and are classified as follows: The Scapula, Clavicle, Humerus, Ulna, Radius, Carpus, Metacarpus, and Phalanges. The Scapula, or shoulder-blade, is an irregular, thin, triangular bone, situated at the posterior part of the shoulder, and attached to the upper and back part of the chest. The Clavicle, or collar-bone, is located at the upper part of the chest, between the sternum and scapula, and connects with both. Its form resembles that of the italic letter f, and it prevents the arms from sliding forward. The Humerus, the first bone of the arm, is long, cylindrical, and situated between the scapula and fore-arm. The Ulna is nearly parallel with the radius, and situated on the inner side of the fore-arm. It is the longer and larger of the two bones, and in its articulation with the humerus, forms a perfect hinge-joint. The Radius, so called from its resemblance to a spoke, is on the outer side of the fore-arm, and articulates with the bones of the wrist, forming a joint. The ulna and radius also articulate with each other at their extremities. The Carpus, or wrist, consists of eight bones, arranged in two rows. The Metacarpus, or palm of the hand, is composed of five bones situated between the carpus and fingers. The Phalanges, fourteen in number, are the bones of the fingers and thumb, the fingers each having three and the thumb two.

The Bones of the Lower Extremities, sixty in number, are classed as follows: The Femur, Patella, Tibia, Fibula, Tarsus, Metatarsus, and Phalanges. The Femur, or thigh-bone, is the longest bone in the body. It has a large round head, which is received into the acetabulum, thus affording a good illustration of a ball and socket joint. The Patella, or knee-pan, is the most complicated articulation of the body. It is of a round form, connects with the tibia by means of a strong ligament, and serves to protect the front of the joint, and to increase the leverage of the muscles attached to it, by causing them to act at a greater angle. The Tibia, or shin bone, is enlarged at each extremity and articulates with the femur above and the astragalus, the upper bone of the tarsus, below. The Fibula, the small bone of the leg, is situated on the outer side of the tibia, and is firmly bound to it at each extremity. The Tarsus, or instep, is composed of seven bones, and corresponds to the carpus of the upper extremities. The Metatarsus, the middle of the foot, bears a dose resemblance to the metacarpus, and consists of five bones situated between the tarsus and the phalanges. The tarsal and the metatarsal bones are so united as to give an arched appearance to the foot, thus imparting elasticity. The Phalanges, the toes, consist of fourteen bones, arranged in a manner similar to that of the fingers.

We are not less interested in tracing the formation of bone through its several stages, than in considering other parts of the human system. The formation of the Haversian canals for the passage of blood-vessels to nourish the bones, the earlier construction of bony tissue by a metamorphosis of cartilaginous substance, and also the commencement of ossification at distinct points, called centers of ossification, are all important subjects, requiring the student's careful attention. The bones are protected by an external membranous envelope, which, from its situation is called the periosteum. The bones are divided into four classes, long, short, flat and irregular, being thus adapted to subserve a variety of purposes.

The Long Bones are found in the limbs, where they act as levers to sustain the body and aid in locomotion. Eachlong bone is composed of a cylinder, known as the shaft, and two extremities. The shaft is hollow, its wails being thickest in the middle and growing thinner toward the extremities. The extremities are usually considerably enlarged, for convenience of connection with other bones, and to afford a broad surface for the attachment of muscles. The clavical, humerus, radius, ulna, femur, tibia, fibula, the bones of the metacarpus, metatarsus and the phalanges, are classed as long bones.

Where the principal object to be attained is strength, and the motion of the skeleton is limited, the individual bones are short and compressed, as the bones of the carpus and tarsus. The structure of these bones is spongy, except at the surface, where there is a thin crust of compact matter.

Fig. 17. Anatomy of a joint, 1, 1. Bones of a joint. 2, 2. Cartilage. 3, 3, 3, 3. Synovial membrane.

Fig. 18. Anatomy of knee joint. 1. Lower end of thigh-bone. 3. Knee-pan. 2, 4 Ligaments of the knee-pan. 5. Upper end of the tibia, or shin-bone. 6, 12. Cartilages.

When protection is required for the organs of the body, or a broad flat surface for the attachment of the muscles, the bones are expanded into plates, as in the cranium and shoulder-blades.

The irregular or mixed bones are those which, from their peculiar shape, cannot be classed among any of the foregoing divisions. Their structure is similar to the others, consisting of cancellar tissue, surrounded by a crust of compact matter.

The vertebræ, sacrum, coccyx, temporal, sphenoid, ethmoid, malar, two maxillary, palate, inferior turbinated, and hyoid are known as irregular bones.

The formation of the joints requires not only bones, but also cartilages, ligaments, and the synovial membrane, to complete the articulation. Cartilage is a smooth, elastic substance, softer than bone, and invested with a thin membrane, called perichondrium. When cartilage is placed upon convex surfaces, the reverse is true. The Ligaments are white, inelastic, tendinous substances, softer than cartilage, but harder than membrane. Their function is to bind together the bones. The Synovial Membrane covers the cartilages, and is then reflected upon the ligaments, thus forming a thin, closed sac, called the synovial capsule.

All the synovial membranes secrete a lubricating fluid, termed synovia, which enables the surfaces of the bones and ligaments to move freely upon one another. When this fluid is secreted in excessive quantities, it produces a disease known as "dropsy of the joints." There are numerous smaller sacs besides the synovial, called bursæ mucosæ, which in structure are analogous to them, and secrete a similar fluid. Some joints permit motion in every direction, as the shoulders, some in two directions only, as the elbows, while others do not admit of any movement. The bones, ligaments, cartilages, and synovial membrane, are supplied with nerves, arteries, and veins.

When an animal is provided with an internal bony structure, it indicates a high rank in the scale of organization. An elaborate texture of bone is found in no class below the vertebrates. Even in the lower order of this sub-kingdom, which is the highest of animals, bone does not exist, as is the case in some tribes of fishes, such as sharks, etc., and in all classes below that of the cartilaginous fishes, the inflexible substance which sustains the soft parts is either shell or some modification of bone, and is usually found on the outside of the body. True bone, on the contrary, is found in the interior, and, therefore, in higher animals, the skeleton is always internal, while the soft parts are placed external to the bony frame. While many animals of the lowest species, being composed of soft gelatinous matter, are buoyant in water, the highest type of animals requires not only a bony skeleton, but also a flexible, muscular system, for locomotion in the water or upon the land. Each species of the animal kingdom is thus organically adapted to its condition and sphere of life.

CHAPTER III.