It is for the same reason that we become giddy on looking down from the battlements of a high tower, as we have no familiar object on a level with us, whence we may regulate our position; and, hence, Saussure advises those who wish to look down Alpine precipices with safety, to lie flat on their belly. The inability of infants to walk, arises, we think, more from their ignorance of perpendicular position, than from weakness of their muscles.

A

healthy infant of a few weeks old, can, for the most part, support himself firmly on his legs; and nothing hinders him from standing and walking, but want of knowledge. In the West Indies, the Negro children who are put down to tumble and crawl naked a few days after birth, learn to walk by the sixth or seventh month. In this country, it is commonly twelve months before they can walk. Those who were swaddled, according to the absurd custom once universal in Europe, could seldom walk under two years of age. When a person is giddy, he is very liable to fall, and also to become sick, and even to vomit. Sickness, on the other hand, induces giddiness from the connection, whatever it is, between the stomach and the head. This affords an explanation of the sickness experienced at sea; the pitching of the vessel causing those who are unaccustomed to it, to employ a different set of muscles, from what they used on land, to preserve their balance. Agreeably to this opinion, it is known, that the sickness is

increased by looking at the sea rolling past the vessel, and, also, when the motion of the vessel becomes greater. The sickness, likewise, is relieved, by keeping near the centre of the vessel, where the motion is least, and from lying in a horizontal position. This wa found, in the author's case, to be very effectual. Strong doses of opium he found not to have the least power in allaying the irritation of the stomach.

CRADLES REPREHENDED.

As similar effects are produced in people of irritable habits, by swinging, and even by riding in a coach, we infer, that rocking infants in a cradle must tend to derange their stomachs, and cause sickness and vomiting, till they are habituated to it, as sailors are to the motion of a ship. It must, unquestionably, influence the system, and may, we have no doubt, injure the brain, by producing water in the head. The practice we, therefore, think very reprehensible.

EXPERIMENT BY CHESELDEN.

Having now briefly detailed the mechanism of the eyes, and the theory of vision, so far as our knowledge extends on this difficult but interesting subject, we shall confirm it by a case which has for so many years been given in almost every work on optics and on the eye, that it could not here be properly omitted. Not that it is unique and solitary; but because

it is so well stated, and accords exactly with others of the same kind, except in a single instance, given by Mr. Ware, with a few trifling differences.

The case is that of a young man who had been blind from his birth, (probably, in consequence of the membrane of the pupil persisting?) and who was restored to sight by Mr. Cheselden by a surgical operation. When he first saw, he was so far from making any judgment of distances, that he thought, "all objects whatever touched his eyes, as what he touched did his skin." This was his own expression.

He knew not the shape of any thing, nor any one thing from another, however different in shape and magnitude. All the things which he saw, he thought extremely large; but, upon seeing things larger than the first, he conceived the first to be less. The room he was in, he said, he conceived to be part of the house; yet he could not conceive that the whole house should look bigger, for the picture of the room filled the whole area of his eye.

He was exceedingly anxious to recognise the things which he had formerly known by touch, but, upon being told, he very soon forgot them, and, at first, learned and forgot again, as he said, a thousand things a day. It was some time before he could distinguish the cat from the dog, and, being ashamed to ask often, he was observed to catch the cat, which he knew by feeling, and, after looking at her atten

He liked scarlet, and said, it was the most beautiful of all colours. At first, black excited great uneasiness; and he was struck with horror at the sight of a Negro-woman. It was long before he could be reconciled to this colour. This is a very strong fact, we think, against the theory of beauty, advocated by Mr. Alison and Mr. Jeffrey, who maintain, that no colour, nor any thing else, is agreeable or disagreeable of itself, and that all is referable to association. (See the Theory of Beauty, in this work.)

About two months after he could see, he discovered, that pictures represented solid objects; though, up to that time, he had considered them as only party-coloured planes. Upon making the discovery, he expected that the pictures would feel like the things which they represented; and amazed, that objects painted in perspective felt flat and level, he asked, with much simplicity, which was the lying sense, touching or seeing? The proper answer would be, "Neither;" for sight and touch mutually assist each other, and we must learn to compare thein by patient and repeated trials. These, indeed, we have all made, but most of them in infancy, some of them when only a few months old. As Voltaire well remarks, we learn to see in a similar manner as we learn to speak, to read, or to walk. Mr. Travers, indeed, thinks, with some

plausibility, that, if a person were deprived of touch, he could have no idea of visible objects, no more than a deaf man has of sounds. Dr. T. Brown, on the contrary, thinks this explanation is a begging of the question. "We pace around our circle," he says, "and believe that we have advanced." He himself offers no explanation.

It may not be out of place to mention here a case observed by Cabanis, of a youth whose brain was exceedingly small, and whose skull never had had sutures. He was deaf from birth, but all his other senses were sound and acute. He ate and smelt with great keenness, and was ever anxious to catch at every thing, particularly animals, whose soft feet pleased him; yet he had no idea of distances. James Mitchell, the Scots' boy, born deaf and blind, whose case excited so much attention a few years ago, had his touch, taste, and smell, preternaturally acute. By touch and smell he examined every thing within his reach. Large objects, such as furniture, he felt over with his hands; smaller objects he examined with his teeth and the point of his tongue. It was interesting to observe, in what a delicate and precise manner he applied the tips of his fingers; and with what ease and flexibility he would insinuate his tongue into the inequalities of objects.

In illustration of several of the preceding facts, we have incidentally stated some of the changes which the eyes undergo from infancy to old age. It may