gives man the sensation of pain, and thus, when once taught what produces this effect, we learn by experience to shun it. On the other hand, when the application conveys agreeable sensations, it is termed pleasure.

The animal machine thus moved, guided, and protected, stands in need only of one more power, and one which proves to be of the highest importance to the system, for without it, the fabric decays and dies. All things must, from daily use, suffer some diminution or injury, and stand in need of repairs and enlargement. It is certain that the best contrived machinery, which human ingenuity has invented, constantly requires the assisting hand of wheelwrights, carpenters, and joiners: in one place a wheel being injured, in another, a rope broken, a pulley worn out, a pin lost, or a pillar loosened. It is just so in the human structure, but it is provided with an apparatus which effects all these repairs within itself. Here is a mechanical contrivance to cut and divide certain substances, before they enter a chemical laboratory to dissolve, decompose, and reunite; pipes to convey such prepared substances to the great reservoir, where a powerful machine forces the liquid containing all these substances, either mixed or chemically combined, into a number of other pipes, to the remotest part of the system, where they pass again into vessels which separate from them such properties as they want for the parts they pass through: here another set of vessels receives the exhausted fluid, and carries it back

to the reservoir again for a fresh supply: while another apparatus conveys out of the system any thing which is no longer wanted.

To be a little more explanatory. The teeth masticate and cut the food, which the hands, assisted by the eye, the nose, and the taste, have directed them to, and which they convey to the mouth; it then passes into the stomach, the great chemical laboratory, where it undergoes the necessary changes. The lacteals take up this substance, convey it to the heart, which, by its powerful action, drives it with impetuosity to the most remote parts of the system;* where it passes through vessels, which run into substances of very different natures, into muscle, tendon, cartilage, fat, skin; all of which separate such proportions of their respective substances as they need; while the veins receive the impoverished blood, and reconvey it to the heart for a fresh supply. Another set of vessels, termed absorbents, take away such of the component parts of bones, muscles, tendons, &c., as are no longer necessary, convey them into the general circulation, where, arriving at the skin, they are thrown off by perspiration, or

* According to the best calculations, the heart alone exerts a power equal to the pressure of fifty-one and a half pounds, which propels the blood through the arteries at the velocity of one hundred and forty-nine feet in a minute, in which time it expels from its cavities about one hundred and sixty ounces. The quantity of blood in the human body is difficult to be ascertained. Some physiologists think, that, in an adult, the quantity is nearly equal to twenty-five, others to thirty pounds.

deposited into the intestines, to mix with those fæculæ which remain of the food after the stomach and lacteals have deprived it of its nutritious qualities. Thus is the animal body supported, the waste of parts resupplied, and all performed almost without our knowledge within our own system; the calls of hunger being so imperious, as to rouse the most torpid into ac-. tion, and make the most indolent do something to satisfy its craving.

These complete the principal part of the animal structure, and only one thing now remains to be noticed. We have hitherto attended to the body with respect to naked muscles, prominent bones, sharp angles, and ghastly cavities: without the skin and cellular membrane, the beauty and symmetry of the exterior would have been much diminished. We should have seen the raw muscles in all their actions, and the naked nerves exposed to the air and to injury. There would have existed deep fissures between the muscles, cavities in almost every part, and the body would have presented the sad appearance it now does in consumption. But the cellular substance in some places only separates one part from another, or affords a slippery surface for one muscle to slide over the other: in others forming membranes, or fascia, to hide, to bind down and strengthen different organs; while in others admitting into its cells an oily substance, it becomes fat, and fills up all the interstices, rounds off all prominences, softens acute lines, and gives a graceful softness and contour to the

whole; while the skin, enveloping in a close case, keeps all compact, and hides from the eye whatever might be offensive: at the same time that the cutis, or true skin, serves as a surface for the nerves and exhalent vessels to terminate, the cuticle, or scarf skin, defends them from harm, and moderates their excessive sensibility. After this short view, it will excite our wonder that any person, gifted with common sense and common observation, could for a moment doubt the existence of an almighty Creator, blindly affirming that all these wondrous works sprung into form by chance alone; and that an accidental application of shapeless atoms, rushing together without design, gave rise to a creation in which such intimate knowledge of every branch of philosophy is exhibited, and such a nice adaptation of principles to conduce to a certain end. This wonderful system, which by its uniform and harmonious action, contributes so essentially and largely to our terrestrial enjoyment, is most certainly the work of a Being who is infinitely intelligent, active, powerful, and good.

Without health, how insufficient are all the smiles of fortune? What a dreary void is life, a path beset with misery, dissolving every charm with its potent spell, and divesting the gayest and fairest prospects of their loveliness. When the inquiring mind dispassionately contemplates this curious structure, is it not lost in astonishment, that a harp of a thousand strings should keep in tune so long? On what apparently

trivial causes do our choicest blessings depend! How soon may the derangement of one little fibre, in this multitude of fibres, deduct from our comforts; and the paralysis of one muscle hurry us into that awful eternity, which it behoves us to contemplate as the certain lot of human kind. For instance, should the fibres which elevate the eye-lid only cease to contract, a circumstance which does occur, the consequence would be a total blindness of that eye: although the eye be perfect, and capable of conveying to the sensorium every impression of object, still the falling of this trifling curtain would veil nature's brightest prospect from our view, and deduct from our enjoyment more than we can possibly imagine, till such a circumstance be experienced.

Again; the simple obstruction of a little tube not so long as a crow's quill, cuts us off, as it were, from society, and makes us feel as aliens amidst our nearest friends and relations: I mean the Eustachian tube, which communicates with the inner side of the tympanum, and keeps up within that cavity the equilibrium of atmospheric pressure, without which the drum, and its chain of bones, must cease to act, and consequently produce complete deafness. The irksomeness of this great defect, we can sufficiently imagine; but when this misfortune occurs in infancy, before the infant tongue has gained the powers of speech, total dumbness is the consequence; which is one of the greatest afflictions in the whole catalogue of human calamities. Cut off from all communication with mankind, unable