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We conclude this subject with the following beautiful observations on the eye, from the pen of Addison.
Our sight is the most perfect and most delightful of all our senses. It fills the mind with the largest variety of ideas, converses with its object at the greatest distance, and continues the longest in action without being tired or satiated with its proper enjoyments. The sense of feeling can indeed give us a notion of extension, shape, and all other ideas that enter at the eye, except colours ; but, at the same time, it is very much straightened and confined in its operations, to the number, bulk, and distance of its particular objects. Our sight seems designed to supply all these defects, and may be considered as a more delicate and diffusive kind of touch, that spreads itself over an infinite multitude of bodies, comprehends the largest figures, and brings within our reach some of the most remote parts of the universe.
It is this sense which furnishes the imagination with its ideas. We cannot, indeed, have a single image in the fancy that did not make its first entrance through the sight; but we have the power of retaining, altering, and compounding those images, which we have once received, into all the varieties of picture and vision that are most agreeable to the imagination; for, by this faculty, a man in a dungeon is capable of entertaining himself with scenes and landscapes more beautiful than can be found in the whole compass of nature. A beautiful prospect delights the soul, as much as a demonstration; and a description in Homer has charmed more readers than a chapter of Aristotle. Besides, the pleasures of the imagination have this advantage above those of the understanding, that they are more obvious, and more easy to be acquired. It is but opening the eye, and the scene enters. The colours paint themselves on the fancy with very little attention of thought or application of mind in the beholder. We are struck, we know not how, with the symmetry of anything we
see, and immediately assent to the beauty of an object, without inquiring into the particular causes and occasions of it A man of polite imagination is let into a great many pleasures that the vulgar are not capable of receiving. He can converse with a picture, and find an agreeable companion in a statue. He meets with a secret refreshment in a description, and often feels a greater satisfaction in the prospect of fields and meadows, than another does in the possession. It gives him, indeed, a kind of property in everything he sees, and makes the most uncultivated parts of nature administer to his pleasures ; so that he looks upon the world, as it were, in another light, and discovers in it a multitude of charms, that conceal themselves from the generality of mankind.
ANIMAL LIFE. Living bodies are usually divided into the animal and vegetable kingdoms. It may seem at first sufficiently easy to make the distinctions between an animal and a plant; and, as long as we confine our views to the higher orders of animated beings there is no room for doubt. But when we descend in the scale to the radiated animals, which present no distinct nervous system, no organs of sensation, no observable mode of communication with the external world—it then becomes necessary to inquire more accurately into the peculiar points which should decide us to arrange them under the one class or the other. Perhaps the most certain of these, is the presence of a digestive organ. Cuvier mentions three other marks of distinction, which, however, are by no means so general. They are, the presence of nitrogen, as one of the chemical components of all animal bodies; the existence of a circulation; and respiration. Nitrogen does exist in all animal bodies, but some vegetables contain it, as the extensive classes of fungi and cruciformia, and in cafein, a principle extracted from coffee, there is actually a greater quantity of it than in most animal substances, Circulation is not found to exist in the lowest class of ani. mals; as for respiration, the leaves of plants so exactly resemble in their action the lungs of animals, that they are now familiarly spoken of by vegetable physiologists as respiratory organs.
What life is, we know not; what life does, we know well. Life counteracts the laws of gravity. If the fluids of our bodies followed the natural tendency of fluids, they would descend to our feet when we stood, or to our backs when we lay. The cause why they do not may be referred immediately to the action of the heart and vessels ; but it is evident that they derive that power from life.
Life resists the effects of mechanical power. Friction, which will thin and wear a dead body, actually is the cause of thickening a living one. The skin on a labourer's hand is thickened and hardened to save it from the effects of a constant contact with rough and hard substances. The feet of the African, who, without any defence, walks over the burning sands, exhibit always a thickened covering; and a layer of fat, a bad conductor of heat, is found deposited between it and the sentient extremities of the nerves. Pressure, which thins inorganic matter, thickens living matter. A tight shoe produces a corn, which is nothing more than thickened cuticle. The same muscle, that with ease raised a hundred pounds when alive, is torn through by ten, when dead. Life prevents chemical egency. The body when left to itself soon begins to putrify; the several parts of which it is composed, no longer under the influence of a higher controlling power, yield to their chemical affinities; new combinations are formed ; ammoniacal, sulphuretic, carburetted, and other gases are
given off, and nothing remains but dust. This never happens during life.
Life modifies the power of heat. Beneath a tropical sun, or within the arctic circle, the temperature of the human body is found unaltered, when examined by the thermometer. Some have exposed themselves to air, heated above the point at which water boils; yet a thermometer placed under the tongue, stood at the usual height of about 98°; and the sailors, who, under Capt. Parry wintered so near the north pole, when examined in the same way, constantly afforded the same results.
Finally, life is the cause of the constant changes that are going forward in our bodies. From the moment that our being commences, none of the materials of which we are composed continue stationary Foreign matter is taken in, and, by the action of what are termed the assimilating functions, becomes part of our composition; while on the other hand, the materials of which our frame has been built up, being now unfit any longer for the performance of the necessary duties, are dissolved, as it were, into a liquid or gaseous form, —conveyed by the absorbents from the place which the new matter comes to occupy, and finally expelled from the system.
TRIUMPH OF RELIGION.
To follow thee. He follows on in awe,