VISION. 425 



off from the posterior part of the eye of an ox, or 

 any other large quadruped, leaving only the retina, 

 and the eye so prepared be placed in a hole in a 

 window-shutter, in a darkened room, with the cornea 

 on the outside, all the illuminated objects of the 

 external scene will be beautifully depicted, in an 

 inverted position, on the retina. 



Few spectacles are more calculated to raise our 

 admiration than this delicate picture, which nature 

 has, with such exquisite art, and with the finest 

 touches of her pencil, spread over the smooth 

 canvass of this subtle nerve ; a picture, which, 

 though scarcely occupying a space of half an inch 

 in diameter, contains the delineation of a boundless 

 scene of earth and sky, full of all kinds of objects, 

 some at rest, and others in motion, yet all accu- 

 rately represented as to their forms, colours and 

 positions, and followed in all their changes, with- 

 out the least interference, irregularity, or confusion. 

 Every one of those countless and stupendous orbs 

 of fire, whose light, after traversing immeasurable 

 regions of space, at length reaches our eye, is 

 collected on its narrow curtain into a luminous 

 focus of inconceivable minuteness; and yet this 

 almost infinitesimal point shall be sufficient to 

 convey to the mind, through the medium of the 

 optic nerve and brain, a knowledge of the exist- 

 ence and position of the far distant luminary, from 

 which that light has emanated. How infinitely 

 surpassing all the limits of our conception must be 

 the intelligence, and the power of that Being, who 

 planned and executed an instrument comprising, 

 within such limited dimensions, such vast powers 

 as th(^ eye, of which the perceptions comprehend 



