Изображения страниц
PDF
EPUB

PART II.

CHAPTER I.

THE NATURE OF THE HUMAN BODY.

THE human body is worthy of our attention in a philosophical point of view; because it contains evidences of the profoundest wisdom and contrivance. The knowledge of our corporeal frame is also essential to our welfare, because we may thereby avoid injury, and remove many ailments that "flesh is heir to."

It is said of Albertus Magnus, that he employed thirty years in attempting to form a human being; and he laboured on the various parts, under different aspects and constellations, that the whole might be complete; but, after all his toil and expenditure of skill, he produced a substance without sense or motion, and as much unlike a human being, as the idols of the Brahmins, or of the South Sea Islanders, are dissimilar to the gods they are intended to represent.

The human body is an inexhaustible source of wonder.A piece of living mechanism, composed of bones, cartilages, tendons, ligaments, muscles, nerves, and vessels of various kinds; with the heart working in the centre; the lungs purifying the blood; the arteries taking this vital fluid to the

[ocr errors]

remotest parts, and the veins bringing it back; the mouth receiving food; the œsophagus conducting it to the stomach; the stomach dissolving, and conveying it to the next laboratory for the second digestion, when it passes by the lacteals into the circulation. And this curious structure is capable of various movements. The eye is most curiously contrived for receiving the semblance of external objects, whether distant or near, varying regularly from closeness and distinctness, to distance and obscurity; the ear, for collecting a variety of sounds harsh and mellifluous, discordant and harmonious; while it clearly distinguishes the one sort from the other; the sense of smelling, for all kinds of odours, pleasant and unpleasant, as a guide to wholesome nutriment, and a preventive of harm; the taste, for the qualities of substances which pass over the palate; the feeling, for impressions from innumerable objects of hardness and softness, roughness and smoothness, bluntness and sharpness. This human mechanism is gifted with powers of sensation, neither too acute nor too dull; for an extra acuteness in one sense would diminish the action of the other senses, and occasion more pain than pleasure. If the ear, for instance, received every sound with ten times its usual power, it would occasion a continual uneasiness.

- –

There is a surprising variety among human beings; and yet there is a beautiful harmony. Every eye varies a little from every other; and yet the impressions of form and colour, of extension and distance, are exceedingly similar. The coun

tenances of all men are marked with peculiarities, and yet the generic character is preserved. The height and the bulk of human beings vary, and yet a certain standard regulates both. Why is not a man as large as an elephant? What prevents him from continually growing, or why does he not remain a few inches in length? What prevents him from living to the age of Methuselah? Or what enables him to live a single day? Considerations of this kind show us very distinctly that there must be a wise and powerful Principle, who "rules, sustains, and governs all;" who brings harmony out of discord, and the welfare of mankind out of what would otherwise occasion confusion and disadvantage. The eminent Galen was an atheist; but an examination of the human body, in its structure and singular operations, convinced him that there must be a "Great First Cause."

The senses communicate impressions to the mind; and the mental faculty, in return, affords that energy which is necessary for their office. When the mind purposes to receive information through the organs of feeling, it erects the papillæ of the fingers, that the acuteness of the touch may be increased. Sometimes the intellect will operate so powerfully on one sense, and give it such a capability of acting, as to take the place of some other sense which may be defective or absent. And thus the blind man may not only distinguish colours, but he may (by the sense of feeling) trace out the impressions of large printing type, and read the contents of a book!

Nature has favoured us with two eyes: how is it that we perceive objects singly? By the same rule we possess two ears, and yet we have only one impression of a sound. Is it because two communications of a similar kind appear to the mind as one? And thus, with regard to seeing, when we alter the communication by distorting one of the organs of vision, do we make both visible, because they disagree? One thing is certain, that, if all substances appeared double with the use of both eyes, we should have an endless confusion. Besides, our sphere of vision must be increased to twice its present extent, or every object must occupy only half the space it does now. We perceive, also, every thing in its erect or natural position. How is this, when the representation on the retina is inverted? There must be some contrivance (by the great Author of nature) whereby the figure shall again become changed and restored to its proper position. All distant objects to an infant, or a person recently restored to sight, appear equally near; they seem to touch the eye: but experience discovers their size and character, so as to judge accurately of the distance. A landsman at sea, in a dark night, would be incapable of discovering, with the same facility as a sailor, the distance of any light, merely because he had not been accustomed to it.

At birth, the human body is exceedingly imperfect. It is scarcely capable of seeing, feeling, tasting, smelling, or hearing. It can only cry, and express its wants. The statue of Memnon in Egypt sighed when the sun rose, and shone upon

it; and the child enters the world, and begins with tears. It has no instinctive knowledge to preserve it from danger. It would lie on the brink of a precipice without fear. It would grasp the flame of a candle with a smiling countenance. It would roll into the fire, or into the cradle, or into a pail of water, with equal willingness. The body, at this period, is extremely feeble: it is formed of cartilage, ligaments, muscles, and other substances, all in an imperfect state. Every part indicates but the germ or commencement of being. As it advances to youth, the cartilage, in many parts, becomes changed into bone; the muscles become more rigid; firmness and strength accompany each other; and as middle age approaches, there is a still further transformation of soft substances to solids; while the decline of life is distinguished by a more general rigidity: small vessels become united, and constitute larger vessels, or cease altogether from their functions; the larger arteries are covered with a bony substance, and the smaller ones are closed. As the withdrawing of the sun from the northern to the southern regions occasions coldness, chilliness, and hardness the fluid which heaved and glistened in the sunbeams becoming congelated; so the withdrawing of the principle of life produces sterility, stiffness, and inactivity. An old man cannot run nor walk; his senses become dim: the ear refuses the "concord of sweet sounds;" the eye is not pleased with the beauties which nature and art have distributed around it; the palate despises delicious food; the nostrils are unsusceptible of grateful odours;

[ocr errors]
« ПредыдущаяПродолжить »