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additions may hereafter be made to these discoveries it is impossible to say, but at present our knowledge is stopt exactly where I have stated. We know the entrance, the path, and the place of destination; the mode of proceeding, and the effects after it has reached its goal, we do not know.

There are two common errors respecting our sensations which those who have been in any degree accustomed to these sort of speculations will hardly remember, and those who have not, will find, perhaps, some trifling difficulty in correcting,-I mean, the reference of our sensations fo the objects which cause them, and to the senses which convey them. I say that I feel with my hand, and that I see with my eye; but what are seeing and feeling? They are affections of the mind, not of the body. My eye conveys to me the notion that this paper is white, and my hand is an instrument to inform me this table is hard; but the notions themselves exist only in my mind, and cannot exist in my eye or my hand, which are mere brute matter, and quite incapable of intelligence. There are many things which we can only see through a microscope, but it would be very absurd to suppose that the microscope sees;-put away the microscope, and it is just as absurd to suppose the eye sees. The eye is a mere machine, like the other, to convey knowledge to the mind; the only difference is, when we use a microscope we use two optical machines, when we use the eye alone we employ only one. suppose the thought itself to exist in the mere instrument of thinking, we must, in the case of feeling, suppose mind to be spread over all the body. There is a mind in each foot and in every finger, and we kneel upon mind and sit down upon it; and the old proverb,

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many men, many minds," may with equal propriety be asserted of a single individual. The second popular mistake which I specified is, that of attributing our own sensations to the bodies which occasion them. If I speak

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of the smell of a rose, I mean that that flower affects my mind through the organs of smelling in that particular manner; the smell is not in the rose, it is in my mind; there is an unknown cause in the rose which excites this feeling of the inind called smell. There is an organ through which that effect is produced; but the effect itself is in my mind. Just so, the colour is not in the table, for the word colour means nothing more than an affection of my mind; but there is an unknown cause in this wood which produces that effect upon my mind through the medium of my eye. And, in general, we must always carry it in our recollection, that in speaking of sensation, we are speaking of what exists in our minds; and that when we refer these to the objects by which, or the instruments through which, they are excited, it is a mere fashion of speaking, and not an accurate statement of the fact.

I decline to discuss the question of the difference between the primary and secondary qualities of bodies; and I assume, with Dr. Reid, the existence of matter as a first principle not proved by reason, and not proveable by reason.

Almost all the senses are possessed by some one animal or another, in greater perfection than by man, though perhaps there is none that inherits such excel lence in all the five senses. We are not to judge of the degree of sensation with which nature has endowed us from the blunted condition of these organs in a state of society. An American Indian has such an acute sight, that he can discover the prints of his enemies' feet, can ascertain their number with the greatest exactness, and the length of time which has elapsed since their passage; they can discover the fires and hear the noises of their enemies, when no sign of the contiguity of any human being can be discovered by the most vigilant European. Nothing can be plainer than that a life of society is unfavourable to all the animal powers of man. Such a

minute and scrupulous exercise of his senses is not necessary to his safety or his support, and he gradually subsides into that mediocrity of organs, which is sufficient for his altered condition. One of the immediate effects of civilisation is to render such excessive bodily perfection entirely useless. A Choctaw could run from here to Oxford without stopping: I go in the mail coach; and the time that the savage has been employed in learning to run so far, I have employed in something else. It would not only be useless in me to run like a Choctaw, but foolish and disgraceful.

An irresistible proof of the vast improvement of which the senses are capable, is, the education of the deaf and dumb, and the blind; which proceeds upon the principle that, after one sense is taken away, the others may be made much more acute in their exercise, and much more extensive in their employment. The sense of touch became so acute in Professor Saunderson, who had been blind from one year old, that he could discover with the greatest exactness the slightest inequality of surface, and could distinguish, in the most finished works, the slightest oversight in the polish. In the cabinet of medals at Cambridge he could single out the Roman medals with the utmost exactness. When any object passed before his face, though at some distance, he discovered it, and could guess its size with considerable accuracy. When he walked, he knew when he passed by a tree, a wall, or a house. His ear had become so accurate from habit, that he could not only recognise those with whom he was acquainted, by the sound of their voices, but could judge with the utmost accuracy of the size of any room into which he was conducted.

The most singular instance of this substitution of one sense for another, and the degree of perfection to which particular senses can be carried, is recorded in the Transactions of the Manchester Society, from whence I have taken it. "John Metcalf, a native of the neigh

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"bourhood of Manchester, became blind," says Dr. Bew, "at a very early age, so as to be quite unconscious of 'light and its various effects. This man passed the younger part of his life as a waggoner, and occasionally "as a guide during the night in intricate roads, when "the tracks were covered with snow. Strange as this may appear to those who can see, the employment he "has since undertaken is still more extraordinary; it is 66 one of the last to which we should ever suppose a blind "man would turn his attention;-his present occupa"tion is that of a projector and surveyor of highways "in difficult and mountainous parts. With the assist"ance only of a long staff, I have several times met this "man traversing the roads, ascending precipices, exploring valleys, and investigating their several extents, "forms, and situations, so as to answer his design in the "best manner. The plans which he designs, and the estimates which he makes, are done in a manner pecu"liar to himself, and of which he cannot well convey the "meaning to others. His abilities, nevertheless, in this

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way are so great, that he finds constant employment. "Most of the roads over the Peak in Derbyshire have "been altered by his direction, particularly those in the " vicinity of Buxton; and he is at this time constructing "a new one between Wilmslow and Congleton, with a "view to open a communication with the great London "road, without being obliged to pass over the moun"tains."

To these very remarkable cases, may be added that of Stanley the organist; the blind at Paris, who are taught to read, write, and print; and the equally extraordinary Institution for the Deaf and Dumb, which I dare say many persons here present have visited. All these valuable and useful institutions, which do honour to the ingenuity and humanity of man, merely avail themselves of that superfluity of senses (if I may use the expression) which nature has given us, and make those which

survive, do the duties of that which is deceased. It seems, at first sight, very singular that a blind child should be taught to read; but observe what the common process is with every child: a child sees certain marks upon a plain piece of paper, which he is taught to call A, B, C; but if you were to raise certain marks in relief upon pasteboard, as you may of course do, and teach a blind child to call these marks which he felt A, B, C, a blind child would as easily learn his alphabet by his fingers as another would do by his eyes, and might go on feeling through Homer or Virgil as we do by persevering in looking at the book. Just in the same manner, I should not be surprised if the alphabet could be taught by a series of well-contrived flavours; and we may even live to see the day when men may be taught to smell out their learning, and when a fine scenting day shall be, (which it certainly is not at present) considered as a day peculiarly favourable to study.

A curious question may be agitated as to the resemblance of the senses to each other. All the ideas of seeing bear a resemblance to each other, and all of hearing, and so forth; or do we only conceive them to resemble each other because they enter the mind by the same channel? Is there any more resemblance in the taste of vinegar and the taste of a peach, than there is between the taste of vinegar and the sound of an Æolian harp? I am very much inclined to think there is not; and that the only reason of supposing a resemblance is, that they affect the same organ. I believe there is a much greater analogy between those ideas of every sense which produce a similar tone of mind, whether of excitement, or soothing, or dislike, or horror, than there is between ideas of the same sense which stand in very different degrees of favour with the mind. The resemblance seems to be much more intimate between soft sounds, fragrant smells, smooth surfaces, pleasant tastes, and refreshing colours, than between soft sounds and

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