DEFENCES OF THE EYE. 209 organ on which we thus depend for so many enjoyments, should be guarded with peculiar care accordingly we find it lodged in a strong, deep, bony socket, where it lies imbedded in fat; it is sheltered by the eyebrows, and still better protected by the eyelid, a moveable curtain, ever ready to fall over it at a moment's warning, and always closing to secure it from danger, during sleep. To keep it moist and clean, a wash is constantly supplied, which, when it has performed its office, passes into the nose, through a hole prepared for it in the solid bone. This contrivance, like the other arrangements of the great Artificer, is only found in those animals that need it; fish, living in an element that supplies a constant lotion to preserve the moisture of the eye, are without this provision.* The view we have now taken of the structure of the eye, slight and imperfect as it is, may yet, I hope, convince you of the infinite superiority of the works of nature, to the most ad * Paley, 23. 210 THE EYE MERELY AN INSTRUMENT. mired productions of human ingenuity. But the eye, though beautiful and important, perfect in design and execution, is still only an instrument, an unperceiving instrument. It is not the eye that sees, but the mind which perceives the image formed in the eye, and which may be formed there when life is extinct; if the eye of a recently killed bullock or sheep be taken out, and the opaque sclerotica carefully cut away, then, by going with it to a dark place, and turning the pupil towards any object which is brightly illuminated, you might see, through the half-transparent retina, a perfect picture of the object; the dead eye would show itself to be a complete camera-obscura.* So far, then, as the eye is concerned, we see it to be a machine, and that we can account for the formation of the image, by causes purely mechanical-causes, which will, for a little space, continue to operate even after life has departed. *Arnott, ii. 213. This fact was proved to the young audience, and the structure of the eye more clearly shown, by the examination of some sheep's eyes, wbich were procured from the butcher, and dissected after the Lecture had been read. MACHINERY THE RESULT OF CONTRIVANCE. 211 Why, think you, was all this machinery requisite? Could not the Author of our being have endued us with the faculty of sight, without this apparatus of refracting lenses and reflecting mirrors? No doubt he could; but then he would have deprived us of a most striking example of his power, wisdom, and goodness. He dwells in light, which no man can approach; but it has pleased him, ever since the creation of man, to suffer his invisible perfections to be understood by the things that he has made. How could we understand them, if we were not allowed to see the manner in which they operate? But we are permitted to see this in numberless instances, and to learn many things in another way respecting His will, and our duty. If we are reasonable creatures, we shall not shut our eyes when we may so clearly perceive that all things are ordered by his providence, and subject to his power. "Nothing, O child of reason, is without God; let Him therefore be in all thy thoughts!" THE END. By the same Author, PUBLISHED BY DARTON AND HARVEY, GRACECHURCH-STREET. GEOLOGICAL SKETCHES and GLIMPSES of the ANCIENT EARTH; With Maps and Illustrations. 12mo. Price 9s. in coloured cambric. "In this admirably executed work, we have only another specimen of the power of art and industry in facilitating the study of sciences, which appear to a beginner pedantic and repulsive. This work, though very acceptable, and very well suited to the youthful mind, is well worth the attention of all to whom the subject of Geology is still a novelty. Those who desire to combine, in their New Year's Presents, the valuable with the beautiful, will find it their interest to look after the very attractive work which we have now described" Monthly Review, January, 1832. ENGLISH STORIES; Illustrating some of the most interesting Events and Characters from the accession of Alfred to the Reformation. 3 vols. Price 1. 18. in boards; or 78. each volume. "The volumes are entitled to our most unqualified praise. We know of no work on English History so proper to be put into the hands of young persons, or so well adapted to render the study of history subservient to moral improvement." Eclectic Review, October, 1822. "These volumes impart correct historical knowledge, and at the same time convey beautiful lessons of morality, the highest and best use of history." Journal of Education, April, 1831. GRECIAN STORIES; Taken from the works of eminent Historians. A new edition, in which the explanatory Remarks formerly given in Conversation are incorporated in the Narrative, as a Class-book for Schools. 18mo. Price 38. in cloth lettered. FAMILIAR ILLUSTRATIONS Of the principal Evidences and Design of Christianity. 18mo. in cloth lettered. Price 3s. |