just made, speaks of a certain blind man in that city as follows: "I had an opportunity of repeatedly observing the peculiar inanner in which he arranged his ideas, and acquired his information. Whenever he was introduced into company, I remarked that he continued some time silent. The sound directed him to judge of the dimensions of the room, and the different voices of the number of persons that were present. His distinction in these respects was very accurate; and his memory so retentive that he was seldom mistaken. I have known him instantly recognise a person on first hearing him, though more than two years had elapsed since the time of their last meeting. He determined pretty nearly the stature of those he was conversing with by the direction of their voices; and he made tolerable conjectures respecting their tempers and dispositions by the manner in which they conducted their conversation.'

§ 102. Of certain universal habits based on sounds.

There are certain habits of hearing (perhaps we should say classes of habits) which all men, by the aid of the other senses, combined with that of the judgment, form at an early period of life. The first class of habits here referred to are those which have relation to the particular cause and the distance of sounds. The manner in which we learn these has been pointed out in a previous section (§ 66). The mere sensations of sound are entirely a distinct thing from the ideas of cause, place, and direction, which we generally combine with them. Owing to frequent repetition from early life, this combination is effected so rapidly, that we are unable to retrace the successive steps of the process, and the whole seems to be involved in a single sensation. Perhaps it may be said that the effect of repetition (that is to say, the HABIT) has more direct and special relation to the act of judgment, which combines the reference with the sensation, than to the sensation itself. However that may be, it may still be proper to speak of habits of hearing in the respect now under consideration, when we remember that the reference has been so long and closely interwoven with the sensation as to be apparently and practically, though not really, identical with it.

In respect to spoken language also, our habits are so laboriously and deeply founded, that we may almost consider ourselves as having a new sense superadded to that of hearing. In our ordinary conversation with others, we seem to hear the whole of what is said; nothing is lost, as we imagine. But that this is not the fact, and that we are sustained in such cases not wholly by an actual sensation of sound, but in part, at least, by an acquired power or HABIT, is evident from this. When we

hear proper names, whether of persons, places, or natural objects, pronounced for the first time, we often hesitate in respect to them; are not certain that we possess the syllables intended to be conveyed, and ask for the repetition of them. We experience the same difficulty and uncertainty, as every one must have known who has tried it, when we hear a person read or converse in a foreign language. But when the conversation is in our own language, and relates to persons and objects we are acquainted with, it is altogether different, as has already been intimated. But what is the ground of the difference? Why are we perplexed in one case and not in the other?—In our intercourse with others in conversation, it almost constantly happens (at least as much so as on any other occasions), that the ear catches nothing but imperfect syllables, half-uttered words, sounds jumbled and commingled together; but we are nevertheless not commonly at a loss and perplexed, as in the cases before mentioned. By the aid of judgment, and the power of conception, whose action has in this case, by long repetition, formed itself into a prompt and decisive habit, we at once separate these confused elements, supply the breaks in their connexion, fill up the deficiencies, and make out a continuous and significant whole. And yet this is done so rapidly, and is so common, that in most cases we imagine there is nothing more than the pure and unmixed sensation.

§ 103. Application of habit to the touch.

The sense of touch, like the others, may be exceedingly improved by habit. The more we are obliged to call it into use, the more attention we pay to its intimations. By the frequent repetition, therefore, under such circum

stances, these sensations not only acquire increased intenseness in themselves, but particularly so in reference to our notice and remembrance of them. But it is desirable to confirm this, as it is all other principles from time to time laid down, by an appeal to facts, and by careful inductions from them.

Diderot relates of the blind man of Puiseaux mentioned in a former section, that he was capable of judging of his distance from the fireplace by the degree of heat, and of his approach to any solid bodies by the action or pulse of the air upon his face. The same thing is recorded of many other persons in a similar situation;* and it may be regarded as a point well established, that blind people, who are unable to see the large and heavy bodies presenting themselves in their way as they walk about, generally estimate their approach to them by the increased resistance of the atmosphere. A blind person, owing to the increased accuracy of his remaining senses, especially of the touch, would be better trusted to go through the apartments of a house in the darkness of midnight, than one possessed of the sense of seeing without any artificial light to guide him.

In the celebrated Dr. Saunderson, who lost his sight in very early youth, and remained blind through life, although he occupied the professorship of mathematics in the English University of Cambridge, the touch acquired such acuteness that he could distinguish, by merely let

It is a singular circumstance, that something similar to what is here stated of the ability of blind men to discover the nearness or distance of objects by changes in the resistance of the atmosphere, has been noticed by the naturalist Spallanzani in respect to bats. He discovered that bats, when perfectly blinded and afterward set at liberty, had the extraordinary faculty of guiding themselves through the most complicated windings of subterraneous passages, without striking against the walls, and they avoided with great skill cords, branches of trees, and other obstacles, placed by design in their way.

This ability is probably owing to an extreme delicacy in the wing, which is of a very large size in proportion to that of the animal, and is covered with an exceedingly fine network of nerves. The bat, as it strikes the air with its wing, receives sensations of heat, cold, and resistance, and, in consequence, is enabled to avoid objects which would otherwise obstruct its flight, apparently in the same way that blind persons perceive a door or a wall by a change in the temperature or in the resistance of the air.

ting them pass through his fingers, spurious coins, which were so well executed as to deceive even skilful judges who could see. *

The case of a Mr. John Metcalf, otherwise called Blind Jack, which is particularly dwelt upon by the author of the Article in the Memoirs just referred to, is a striking one. The writer states that he became blind at an early period; but, notwithstanding, followed the profession of a wagoner, and occasionally of a guide in intricate roads during the night, or when the tracks were covered with snow. At length he became a projector and surveyor of highways in difficult and mountainous districts; an employment for which one would naturally suppose a blind man to be but indifferently qualified. But he was found to answer all the expectations of his employers, and most of the roads over the peak in Derbyshire, in England, were altered by his directions. Says the person who gives this account of Blind Jack, "I have several times met this man, with the assistance of a long staff traversing the roads, ascending precipices, exploring valleys, and investigating their several extents, forms, and situations, so as to answer his designs in the best manner."

In the interesting Schools for the Blind which have recently been established in various parts of the world, the pupils read by means of the fingers. They very soon learn by the touch to distinguish one letter from another, which are made separately for that purpose of wood, metals, or other hard materials. The printed sheets which they use are conformed to their method of studying them. The types are much larger than those ordinarily used in printing; the paper is very thick, and, being put upon the types while wet, and powerfully pressed, the letters on it are consequently raised, and appear in relief. The pupils, having before learned to distinguish one letter from another, and also to combine them into syllables and words, are able, after a time, to pass their fingers along the words and sentences of these printed sheets, and ascertain their meaning with a good degree of rapidity.

Perhaps it may occasion some surprise when we add, that men may not only read by the touch, but may even * Memoirs of Manchester Philos. Society, vol. i., p. 164. VOL. I-N

find a substitute for the hearing in that sense. Persons who were entirely deaf have in some instances discovered a perception of the proportion and harmony of sounds.

"It will scarcely be credited," says an English writer, speaking of one in that situation, "that a person thus circumstanced should be fond of music; but this was the fact in the case of Mr. Arrowsmith. He was at a gentlemen's glee club, of which I was president at that time, and, as the glees were sung, he would place himself near some article of wooden furniture, or a partition, door, or window-shutter, and would fix the extreme end of his finger nails, which he kept rather long, upon the edge of some projecting part of the wood, and there remain until the piece under performance was finished, all the while expressing, by the most significant gestures, the pleasure he experienced from the perception of musical sounds. He was not so much pleased with a solo as with a pretty full clash of harmony; and if the music was not very good, or I should rather say, if it was not correctly executed, he would show no sensation of pleasure. But the most extraordinary circumstance in this case is, that he was most evidently delighted with those passages in which the composer displayed his science in modulating the different keys. When such passages happened to be executed with precision, he could scarcely repress the emotions of pleasure which he received within any bounds; for the delight he evinced seemed to border on ecstasy."*

senses.

◊ 104. Other striking instances of habits of touch.

The power of the touch will increase in proportion to the necessity of a reliance on it. The more frequent the resort to it, the stronger will be the habit; but the necessity of this frequent reference to it will be found to be peculiarly great where a person is deprived of two of his other It is noticed of James Mitchell, whose case has been already referred to, that he distinguished such articles as belonged to himself from the property of others by this sense. Although the articles were of the same form and materials with those of others, it would seem that he was not at a loss in identifying what was his own.

* London Quarterly Review, vol. xxvi., p. 404.