Though a small degree of reflection may serve to convince us of the truth of these positions, yet it may not be amiss to corroborate them by facts which cannot be disputed. M. Chesselden, having couched for a cataract a lad of thirteen years of age, who had from his birth been blind, and thus communicated to him the sense of seeing, was at great pains to mark the progress of his visual powers; his observations were afterwards published in the Philosophical Transactions. This youth was not absolutely and entirely blind: Like every other person, whose vision is obstructed by a cataract, he could distinguish day from night and even black from white, but of the figure of bodies he had no idea. At first the operation was performed only upon one of his eyes, and when he saw for the first time, so far was he from judging of distances, that he supposed (as he himself expressed it) every thing he saw touched his eyes, in the same manner as every thing he felt touched his skin. The objects that pleased him most were those whose surfaces were plain and the figures regular, though he could in no degree judge of their different forms, or assign why some were more agreeable to him than others. His ideas of colours during his former dark state were so imperfect, that when he saw them in reality he could hardly be persuaded they were the same. When such objects were shewn him as he had been formerly familiar with by the touch, he beheld them with earnestness, in order to know them again, but as he had too many to retain at once the greatest number were forgotten, and for one thing which he knew, after seeing it, there were a thousand, according to his own declaration, of which he no longer possessed the smallest remembrance. He was very much surprised to find that those persons, and those things, which he had loved best, were not the most pleasing to his sight; nor could he help testifying his disappointment in finding his parents less handsome than he had conceived them to be. Before he could distinguish that pictures resembled solid bodies above two months elapsed; till then he only considered them as surfaces diversified by a variety of colours; but when he began to perceive that these shadings actually represented human beings, he expected also to find their inequalities; and great was his surprise to find smooth and even what he had supposed a very unequal surface; and he inquired whether the deception existed in feeling or seeing. He was then shewn a miniature portrait of his father, which was contained in his mother's watch-case, and though he readily perceived the resemblance, yet he expressed his amazement how so large a face could be comprised in so small a compass; to him it appeared as strange as that a pint vessel should contain a bushel. At first he could bear but a very small quantity of light, and every object appeared larger than the life; but in proportion as he observed objects that were in reality large, he conceived the others