required by delicacy than by a due regard to health and comfort, to the preservation of the teeth themselves, and as a means of escape from the racking torments of the tooth-ache. What an advantage and a blessing is a good set of teeth! With many people they are one of the principal marks of beauty; and so long as they remain sound, are, we all know, most useful, as well as handsome; and, by care and attention, especially in the season of youth, they may remain sound, and useful, and beautiful, all your days. It may be asked, Why are not children born with teeth? We reply, because teeth would be useless to the new-born infant; and would cause pain to the mother in suckling it. It is therefore wisely provided that the teeth shall not appear till about the time of weaning the child.

There are other distinct bones which might be mentioned, such as the small and delicate bones of the ear, which we must now pass over.

9. The various limbs and bones which constitute the human frame are all severally united together by numerous JOINTS.

These are to be found at the neck, shoulders, elbows, wrists, fingers, hips, knees, ankles, insteps, feet, and toes. There are, in general, two kinds of joints, the hinge joint, and the balland-socket joint; in the latter, the end of one bone is formed into a rounded head or ball; and this is received into a corresponding socket or cup in the other. Of the hinge joint we have examples in the elbow, the knee, and the joints of the fingers and toes. Of the perfect ball-and-socket joint, we have in Man only two examples,-the shoulder and the hip. In the former, the socket is much shallower than in the latter, and therefore is more liable to dislocation. These joints are connected together by a strong supple ligament,—a white shining substance,-attached to, or growing out of the bone. This may easily notice at any time in severing a shoulder or leg of mutton. "Now what prevents the joints of the human body from rapidly wearing out, when we walk much, or run swiftly? The Father of the universe is the Preserver, as well as the Creator, of this 'wondrous frame.' Were there not something done to keep these joints oiled, if we may so call it, they would not last long. Take the knee, for instance, and think what a vast deal of friction or rubbing together of the end of the thigh bone and of the two leg bones there must be! Now the

C

you

Author of the human frame has so contrived it, that a substance, called SYNOVIA, (a Greek word, signifying the white of an egg, which it resembles,) which answers all the purpose of oil, continually oozes out in the inside of the ligaments at the joints, and keeps the ligaments themselves, and the joints, soft and moist. Can anything be more curious? Can anything prove more clearly the wisdom and goodness of a great Designer?"

In speaking of the joints of the human frame as exhibiting a proof of the existence and wisdom of the Creator, I am reminded of an anecdote which I once heard the eminent Missionary, Mr. Williams, relate. Two captains of an English vessel touched at Raiatea, one of the South Sea Islands, whose inhabitants had recently been converted to Christianity. In conversation with Mr. Williams, these gentlemen wished particularly to know whether the natives embraced Christianity on the bare representations of the Missionaries, or whether they really understood its principles. Mr. W. called some of the converts together to answer for themselves. One of them, on being asked what reason he had to believe in the existence of God, as the Creator of all things, replied, "When I look at myself, I find that I have HINGES all over me,-hinges at my fingers; at my elbows; at my jaws; at my knees, and at my feet. If a thought arises in my mind, it moves these hinges. If a thought comes into my mind that I must go somewhere, it moves the hinges of my feet. If I want to speak, it moves the hinges of my jaws, and so on." This reply, though coming from a lately untutored savage, was philosophy worthy of a Bacon or a Paley.

"In considering the joints," says Paley, "there is nothing, perhaps, which ought to move our gratitude more than the reflection, how well they wear. A limb shall swing upon its hinge, or play in its socket, many hundred times in an hour, for sixty years together, without diminution of agility; which is a long time for any thing to last, for any thing so much worked as the joints are."

Upon the skeleton, with all its bones, which is the framework of the human body, and which, not being intended to be seen, possesses no qualities pleasing to the eye, the whole remaining substance of the body is arranged and supported.

*"House I Live in,” p. 76.

V. We now proceed to

THE MUSCLES.

A great portion of the soft substance of the body consists of what is termed fleshy or muscular fibre. In popular language, the muscles are the flesh, that is, the lean part of it, which is of a red colour, caused by the blood which tinges the whole substance. The beef and mutton that we eat are the muscular substances of the ox and the sheep. The muscles themselves are thready, stringy, or fibrous. They, with what is termed their TENDONS, or sinews, are the instruments by which animal motion is performed. They are wonderfully susceptible of contraction and relaxation; or of being drawn in or stretched out. These muscles may be distinctly seen and understood by looking at the bony end of a leg of mutton or veal. Those pieces which appear to be united together by a glutinous substance, and which may be easily separated, are muscles. The largest and most visible muscles of the human frame are those of the calf of the leg, and of the upper part of the arm. Now these muscles in the human body are divided into upwards of four hundred bundles, forming several layers placed over each other, infinitely varied in size and strength according to the purposes which they are designed to serve.

The TENDONS, which are the beginnings or endings of the muscles, and in general connect muscles to bones, are distinguished from the flesh by being smaller, firmer, and stronger: they are a kind of straps, and are of a glittering silver-colour. These tendons may be traced under the skin on the back of the hand, and in the very powerful specimen at the heel, called the "tendon of Achilles." 66 The muscles are those parts by which the head and limbs are moved, and by which locomotion generally is effected. In short, from the most rapid and energetic movements which we are capable of performing, to the slightest motion of the little finger, or the eye-lid, all is performed by the aid of the muscles." The study of the muscles is called MYOLOGY, from Mʊs, a muscle, and λoyos, a discourse.

VI. The next subject we briefly notice is

THE CARTILAGES.

By these are meant what we commonly call Gristle, which is

a smooth, solid, flexible, elastic substance, softer than bone, of a pearly colour, without cells or cavities. The nose, ears, and windpipe are the principal cartilaginous or gristly parts of the human body. The cartilage does not, in ordinary cases, unite when torn or divided. "These injuries, however, are sometimes repaired in various ways. The uniting medium is never found to be new cartilaginous tissue, but is a substance sometimes like ligament, and sometimes of a bony structure." Cartilage serves to connect the bones of the vertebræ, and is essential to their various movements. Its general uses are to prevent the bones from being injured by continual friction, and to join them together: it also contributes, in a great measure, to the well-forming of several parts of the body, as the nose, ears, &c.

VII. A few words on

THE NERVES.

The Nerves are small, firm, white, pulpy cords; and are prolongations of the medullary or marrowy substance of the brain and spinal marrow, which ramify and extend chiefly in pairs to every part of the body, endowing it with sensation and voluntary motion. They serve at once to convey the information of the senses to the mind, and to transmit the will of the mind to the muscles. The brain itself, the spinal marrow, and the nerves, are collectively called the NERVOUS SYSTEM, because they are apparently united in one order of functions. The nerves are divided into nerves of motion and nerves of sensation; nerves of the special senses, nerves serving for nutrition, respiratory nerves, &c. Most of the nerves are exquisitely fine in their texture; a few only-for example, the sciatic nerve, or that pertaining to the hip-being of larger diameter. They divide as minutely as do the arteries and veins, which is proved by the fact that we have feeling almost everywhere, externally and internally. A puncture with the point of the smallest needle gives us pain; but this could not be, unless there were nerves in the part which is wounded. The uses of these nerves are, as we have just hinted, to convey sensation from the various parts of the body to the brain, which may be considered as their common centre.

There are, in some parts of the body, what are called GANGLIONS, or knots of nerves, which are whitish-red bodies, of various sizes and figures, the use of which is wholly unknown.

The study of the nerves is called NEUROLOGY, from Neugov, a nerve, and λoyos, a discourse. Hence also the word NEURALGIA, or pain in a nerve, given to that distressing malady, the TIC DOULOUREUX, the cause of which is unknown, and often baffles the skill of the physician.

VIII. The next subject which comes under consideration is

ence.

THE SKIN.

very

This, to give a general definition, is the natural covering of animal bodies. It consists of three layers or coverings. First, the EPIDERMIS, cuticle, or scarf-skin, is the outermost of the three layers. A blister on your hand would easily show you this. It is a thin insensible membrane, has no blood-vessels or nerves, and consequently neither bleeds nor feels pain when cut or abraded. This skin considerably varies in thickness: it is extremely delicate, for example, in the lips and tongue; very thin at the finger-ends and on the face; and thick on the soles of the feet and palms of the hands. "This latter is manifestly the intentional work of the Creator, for it is perceptible even at birth, before use can have exercised any influWhen a part is much used, the cuticle covering it becomes thicker and thicker within certain limits; till, in extreme cases, it becomes as thick, hard, and resisting as horn. It is this thickening of the epidermis on the lady's finger that alone enables her to ply with impunity that important instrument the needle." The same effect is produced on the fingers in playing the harp. "And it is the same thickening that fits the blacksmith and the mason, the stone-breaker and the boatman, to ply their trades, without that painful blistering which the young apprentice or unaccustomed labourer so regularly undergoes."* The second skin, or MUCOUS COAT, is a thin layer of soft or pulpy matter, which performs the secretions, or the separation of matter from the blood, and is the seat of colour. The outer skin is in colour exactly alike in all people, whether black, red, copper, or white; yet this second under skin in the African is black; in the native American, it is red or coppercoloured; in the Asiatic it is tawny or yellow; and in the European white. If a Hottentot were to blister his hand, the skin that would rise would be as white as yours. Here, then,

* Combe's "Principles of Physiology," p. 45.