ton is a beautiful object, in the usual sense of the term beauty; but the term beautiful is well applicable to the adaptation of the various parts to one another, and to the manner in which they subserve the object of their existence. When, moreover, the connexion of the different portions of the skeleton, by means of the ligaments, and the action, and mode of action simple and combined, of the various muscles of the machine at large, are considered, when we regard the protection given by the bones to important parts contained within the cavities, and to the blood vessels in the limbs, the strength, and yet comparative lightness of the whole fabric; and lastly, the powers of reparation after injury, the word beautiful in another sense, is that which really expresses the admirable perfection of the structure. The entire skeleton consists of two hundred and forty-six different bones. As the descriptions of the most important of these are given in the separate articles, it is unnecessary to do more here than to point them out by name, on the adjoining figures.Figs. A and B.-Each bone having the same numbers. 1. The skull, or face bones, including the lower jaw. 2. The spine, composed of the vertebræ, which supports the head, and rests on the pelvis. 3. The collar-bones, or clavicles. - See Shoulder. 4. The ribs. 5. The breast-bone, or sternum. 6. The shoulder-blade, or scapula. 7. The arm-bone, or humerus. 8. The fore-arm bones, or radius and ulna. 9. The wrist-bones-eight in number, also called the carpal-bones. 10. The hand, and finger-bones, also called the meta-carpal-bones. 11. The pelvis, or pelvic-bones. 12. The thigh-bone, or femur. 13. The knee-cap, or patella. 14. The leg-bones. The larger, the tibia, the smaller the fibula. 15. The tarsal-bones, seven in number. 16. The foot and toe-bones, also called the metatarsal-bones. The bones above mentioned do not nearly make up the number of two hundred and forty-six bones. To do this, must be added the small bones of the ear, the teeth, a detached bone, the " hyoid" situated near the base of the tongue, and sundry, what are called, sesamoid bones, which are found regularly in the tendons of certain muscles, such as those of the thumb. SKIN. No less wonderful than the bony frame-work of the human body, which we have just considered, is the covering of that body, the skin, which, while it protects, and retains in place the various parts, serves, also, most important purposes in the animal economy. cavities, such as the mouth, nose, &c., its epidermis corresponding to the epithelium of the membranes. The epidermis is a thin, semi-transparent membrane, which is extended over the surface of the true skin of the body. Apparently, it is without structure, and indeed, was long considered to be simply an exudation which became hardened by exposure to the air; it is now known to consist of regular series or layers of cells-fig. B-1. The outermost layers of these cells, which are exposed to general contact, and to the influence of the atmosphere, are comparatively hard, and are flattened as represented, becoming less flat, and softer, inward-fig. B-1,-as the surface of the true skin is approached, at which point the cells are quite soft and granular. This soft layer of the epidermis, used formerly to be regarded as a distinct portion of the skin structure, under the name of "rete mucosum." 66 The intermixture, in this layer, of pigment cells," that is, cells containing colouring matter, gives the varied hues to the skin of different races, as most strongly exemplified in the negro; and the appearance of freckles originates from the same cause. On the surface of the epidermis, the flattened cells lie over one another, as represented-fig. B-2. The outermost The skin consists of two distinct formations, the "epidermis" or cuticle, or scarf, or outer skin-fig. A 1-B 1-2,-and the "derma." Cutis," or true skin-fig. A 2. The skin is continuous with the mucus membranes at the openings of the various becoming continually detached and worn | through the skin, but is a regular secretion, off. When these detached scales are re- and excretion from the blood, by means of tained, as by the hair, or by the clothing, innumerable small glands-fig. A 4-4— they constitute what is called scurf or dan- B 2-which are situated in the deep layers driff. The epidermis is, as all are aware, of the true skin. These "sudiparous" or insensible. It varies considerably in thick- sweat glands, are composed, as represented, ness, on different parts of the body, even of a rounded extremity formed by the conat birth, being much thicker on those, volutions of the tube, which opens to the such as the heel, back, &c., which naturally surface, by means of a spiral duct, about a require greater protection; it however, be- quarter of an inch long. This duct, in comes immensely thickened on any portion many situations-makes its exit, on the of the body which is subject to continual surface of the cuticle, obliquely,-fig. B 2 pressure or friction; of this, the hand of -in such a manner, that it has, as it were, every workman is an example. As all are a valvular covering; it does not pierce the aware, the appearance of the skin varies cuticle, but this latter membrane is conaccording to age, from the soft skin of the tinued down into it, as a lining. In addiinfant, or of the bloom of youth, to the flac- tion to these perspiration glands, the skin cidity and wrinkles of age; constitution, is furnished with another set of excreting also, exerts much influence over the appear- agents, which closely resemble the above, ance of the skin-See Complexion. but which are named the "sebaceous," or oil glands.-fig. A 5-5-See Sebaceous. The office of these glands is to separate certain matters from the blood, and to excrete them in the form of an oily matter from the skin, which oil or grease, although it is doubtless an excretion, serves also to lubricate the skin, and to preserve it from cracking from dryness; on this account probably, the sebaceous glands are more abundant in the skins of natives of warm climates, to shield them from the drying effect of the heat. The sebaceous glands have been already alluded to, under the article sebaceous; they are often lobular in structure, frequently communicate with one another by a common duct, and in such situations as the scalp, one or two of them open into each hair folliclefig. A-6. As already mentioned, the skin in addition to the above, contains blood vessels and nerves abundantly; it The "cutis vera" or "derma" or true skin, which lies underneath the cuticlefig. A 2,-is much thicker than the latter; it consists chiefly of areolar tissue, that is, of interlacing fibres, which inclose the blood vessels, nerves, &c., which make up the substance of the covering. The true skin being abundantly supplied both with blood vessels and nerves, is extremely sensitive, so much so indeed, as to require the protection of the cuticle as a necessity. All are aware of the painful sensibility of the true skin, when the outer skin has been abraded. At its surface, where it is in contact with the cuticle, the true skin is elevated into little eminences, or "papillæ," these are most manifestly developed, on the pulpy extremities of the fingers, and on other places where sensation is acute, each papilla being received into a corresponding hollow, in the soft granular layer of the epidermis. The deeper layer of the true skin is composed of interlacing fibres already mentioned, and with these are mingled, elastic fibres, and a peculiar form of muscular fibre, the latter being evidenced in action, by the occurrence of what is popularly called goose skin. The deeper layer of the skin internally, rests upon the cellular tissue, fat, &c., beneath-fig. A 3-3,-B 4. Were the skin required, simply for an elastic, sensitive, and complete covering to the body, the structures already mentioned might have been sufficient, but it has other functions equally important to perform, for which provision is made, over its wide extent of surface. The most important perhaps of these functions, is the discharge of the perspiration which is going on continually. The perspiration, is not, as might be thought, a simple exudation of fluid also contains absorbent vessels. The number of the sebaceous and sweat glands, particularly of the latter, is almost innumerable, and some curious calculations have been made respecting them, by Mr. Erasmus Wilson, the well known writer upon the skin, who says, "I counted the perspiratory pores on the palm of the hand, and found 3528 in a square inch. Now each of these pores being the aperture of a little tube about a quarter of an inch long, it follows, that in a square inch of skin on the palm of the hand, there exists a length of tube equal to 882 inches, or 73 feet." "To obtain an estimate of the length of the tube of the perspiratory system of the whole surface of the body, 2800 may be taken as a fair average of the number of pores in a square inch, and 700, consequently, of the number of inches in length. Now, the number of square inches of surface in a man of ordinary height and bulk, is 2500; the number of pores therefore, 7,000,000, and the number of inches of perspiratory tube 1,750,000, that is 145,833 feet, or 48,600 yards, or nearly twenty-eight miles." From the above exposition of the perspiratory system, the reader will be prepared to learn, that the skin is often the most abundant excretor of fluid in the body, exceeding in this, except under particular circumstances, even the kidney, and also the lungs. According to the most generally trusted experiments, it is found that the average amount of watery fluid exhaled from the lungs and skin of the human body in twenty-four hours, at an ordinary temperature, is about fifty-four ounces, of which amount, thirty-three ounces are attributable to the skin, the remaining twenty-one to the lungs. This excretion of fluid, is capable however of being largely increased, and it is an ascertained fact, that a stout man undergoing strong muscular exertion, under high temperature, has, in an hour, lost as much as five pounds weight. The perspiration thus depends greatly upon the external temperature of the atmosphere, it is however, considerably influenced by conditions of bodily health. Under ordinary conditions, perspiration takes place insensibly, that is, in the form of vapour, which passing off into the air as it is thrown out, gives no palpable indication of its presence; if, however, it is confined, as by an inverted glass, on the skin, a deposition of moisture at once occurs upon the glass. When the perspiration is so rapidly thrown out, that it cannot be at once evaporated from the surface, it takes the form of sensible perspiration, or sweat, in greater or less abundance. It is evident, that when the external air is greatly laden with moisture, the perspiration will be much less quickly evaporated, and consequently much sooner evidenced than under the reverse circumstances; moreover, that as the kidneys alternate in some measure with the skin, in the excretion of fluid, influences which increase the one must diminish the other, as in hot countries, the cutaneous moisture is much increased, and the flow of urine lessened. There is no doubt that the evaporation of the perspiration is one great means of keeping the temperature of the body down to its proper level, under exposure to heat; indeed, this is the secret, by which persons have been able to endure without injury, the heat of an oven of sufficient intensity to cook meat. It is not, however, a mere exudation of simple water, which takes place in perspiration, the mixed fluid which is thrown out from both the sweat and the oil glands, contains a considerable amount of free acid-lactic acid-and of salts, carbonates of soda, lime, and ammonia, muriatic acid, &c. To these must be added, carbonic acid, and nitrogen, which have also been proved to be excretions from the skin. According to Andral, the sweat is always acid, the sebaceous secretion alkaline, the predominance of one or other giving the characteristic chemical reaction. Simple reasoning might be enough to convince that the extensive perspiratory apparatus spread over so large an extent of skin, and in such active operation, must subserve some very important offices in the animal economy. Moreover, the injurious effects of which all are aware, as the consequences of having this secretion suddenly interfered with, prove that these offices are intimately connected with the health of the system generally; and, lastly, direct experiments have added to the proof. The experiments alluded to, are those of M. Fourcault, who demonstrated, that if the transpiration of the skin of living animals was prevented by means of a coating of varnish, they speedily either died in a state resembling suffocation, or became the subjects of internal congestions of blood, especially of the liver. In addition to its excretory functions, the skin is endowed with the reverse, becoming at times a medium for absorption of fluids, gases, or other substances into the system. The fact of gases being absorbed by the skin, adds to the importance of the body being surrounded by pure air; in fact, by some it is thought, that noxious effluvia, malaria, &c., are more readily absorbed into the constitution through the skin than through the lungs. If the body be immersed for some time in a tepid bath, it gains weight by absorption of water, and if thirst has existed, it is relieved. Certain medicines, again, such as mercury, Spanish flies, rhubarb, &c., affect the constitution through the skin. Probably, as suggested by Dr. Combe, even matter which has been once cast out by the skin, may be re-absorbed by it, and cause disease. Enough, perhaps, has now been said to demonstrate to all, of what immense importance the functions of the skin are to the animal system, to show, that while this most perfect structure fulfils the palpable office of a protector and coverer of the entire system, it constitutes one of the great channels by which, used up, and therefore noxious matters are cast out from the blood, a channel, too, which cannot be interfered with, without its internal coadjutors, the liver, the bowels, the kidneys, the lungs, one or all of them suffering. Again, if it is reflected, that every moment of our lives, this exudation through the skin is going on, that while the watery fluid escapes, it leaves the solids, the salts, the acid, the grease, behind, mingled with the scales and scurf of the epidermis, and added to this, the dust, &c., which must adhere to the skin, it will give some little idea of what there is to remove from the skin to keep it commonly clean, still more to keep it in that state of healthy activity and freedom which is requisite for health. appendages" of the skin are the The " hair, nails, &c. Refer to-Ablution-Absorption-HairNails. SKIN, DISEASES OF.-The diseases and disorders to which an organ-as it may be called like the skin is liable, must necessarily be numerous. It is exposed, not only to many influences from without, to atmospheric vicissitudes, to the effects of neglect and dirt, of contagion and accident, but it is also liable to influences from within, arising from those internal organs, with which it is so intimately connected, both sympathetically and in function, and it is excited by altered conditions of the blood, for which it performs such important offices. Very various classifications of skin diseases have been made by different authorities on the subject, with the view of facilitating their distinction from one another, and their treatment. In the following slight sketch, the author has adopted the divisions best calculated to give a clear general idea of the subject; to attempt more would be quite at variance with the character of this work. The exanthemata, or eruptive fevers, include measles, scarlet fever, small-pox, cowpox, and chicken-pox, some of the most important affections connected with the skin, which have already been noticed, under their separate articles. Many other eruptive diseases are accompanied with febrile symptoms, but not of such marked peculiarity and uniformity as those which characterize the above; some authors, however, include in the class of eruptive fevers, erysipelas and erythema-nettle-rash and rose-rash. Nettle-rash cannot be better described, than as an eruption which closely resembles nettle stings, both in appearance and in the sensations it gives rise to. When acute, it is generally accompanied with more or less fever. The nettle-rash, in almost all cases, arises from disorder of the digestive organs, caused either by indigestible food, or in some persons by particular kinds of food. Kernels or seeds, such as almond, peach, &c., which contain prussic acid, seem especially apt to cause nettle-rash, and in some individuals even the pips of an apple have been known to produce the disorder. Fish, particularly shell-fish, also bring it on, or mushrooms; also certain medicines, such as turpentine; teething, hurry and agitation of mind in adults, and other irritations, also give rise to nettle-rash. The generally known causes of this affection, indicate the remedy. the removal from the alimentary canal of offending matters. If there is tendency to sickness, and if the eruption appears soon after a meal, an emetic is the appropriate remedy, but whether this is given or not, there should be given an aperient. As acid in the bowels often accompanies the condition, a dose of magnesia with rhubarb is very suitable, or some other antacid may be had recourse to, and, afterwards, castor-oil. External remedies are comparatively of little service in the acute forms of nettle-rash. A lotion composed of carbonate of ammonia and sugar of lead, of each one drachm, in half a pint of distilled or rosewater, will give relief. Dr. Watson recommends flour dusted over the surface. If nettle-rash takes a chronic form, that is, continues, and keeps recurring, after the use of such mild aperients as recommended above, and after regulation of the diet, the case should be seen by a medical man. Rose-rash occurs both in children and adults, in the form of rose-red patches, of various sizes, somewhat resembling measles in many cases, but of a redder hue. The disease is generally accompanied with some slight constitutional disorder or fever, but the symptoms differ from those which accompany measles. It is devoid of danger, and generally subsides after the administration of a simple aperient. If either rose-rash or nettle-rash are thought to be connected with teething, the gums should be scarified. A class of skin diseases are called "papular;" they consist essentially, of the elevation of minute "papulæ," or points, upon the surface; to this class of diseases belongs the "red gum," of infants; also, two other diseases named lichen and prurigo, which are both extremely troublesome, from the intense itching with which they are accompanied, and the obstinacy with which at times they resist treatment. The affection named prickly heat, described in a former article, is a species of lichen; and a somewhat similar affection occurs in this country in hot summers. The general directions as to diet, &c., given in the above article, may be useful when the affection occurs. Tepid baths, with or without the |