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and the consequent muscular tension needed to withstand or overcome this resistance. Without, perhaps, being peculiar to this sense, the cognition of space, and its several modes and diversities that is to say, the magnitude, the distance and direction (which, taken together, gives the position) of objects, their form, &c.—may no doubt be gained by consciousness of differences in the sweep and contraction of the muscular movements. The nicety of discrimination acquired by the blind in regard to these qualities has received many illustrations. Diderot says of the celebrated blind man of Puesseaux, a visit to whom occasioned his Lettre sur les Aveugles: "He appreciates with wonderful accuracy the weights of bodies and the capacities of vessels; and he has made of his arms balances so exact, and of his fingers compasses so well tested, that on occasions on which this sort of static is called into play, I would always back our blind man against twenty who see. The lady patient of Sir Hans Sloane, who became blind, deaf, and dumb, through confluent small-pox, manifested the same fineness of muscular sensibility. "To amuse herself in the mournful and perpetual solitude and darkness to which her disorder had reduced her, she used to work much at her needle; and it is remarkable that her needlework was uncommonly neat and exact. . . . . . She used also sometimes to write; and her writing was yet more extraordinary than her needlework; it was executed with the same regularity and exactness; the character was very pretty, the lines were all even, and the letters placed at equal distances from each other: but the most astonishing particular of all, with respect to her writing is, that she could by some means discover when a letter had by some mistake been omitted, and would place it over that part of the word where it should have been inserted, with a caret under it."*

This last-mentioned circumstance requires stronger faith or stronger testimony than we possess to convince us of the fact. There is nothing improbable in the other assertions. The blind in general, indeed, are obliged to have recourse to a special apparatus in writing, to prevent the pen from wandering over the paper. But the case of the American girl, Laura Bridgman (blind, deaf, and dumb), as well as that of Sir Hans Sloane's patient, proves that the muscular sense may be brought to a degree of perfection which enables it to dispense with artificial aids. Mr. Dickens, in his American Notes, says of Laura Bridgman, who wrote in his presence: "No line was indicated by any contrivance; but she wrote straight and freely." Laura Bridgman appears to have used one set of muscular movements to watch over, and correct if needful, the set in action. "I * Encyclopædia Britannica, original edition, art. “Blind."

observed," says Mr. Dickens, "that she kept her left hand always touching and following up her right, in which of course she held the pen." The left hand in this way discharged for her the functions of superintendence and control, which with the seeing are rendered by the eye. John Metcalf (of whom an account has already been given) must in his surveying expeditions have relied principally upon the same sense. From the direction and degree of inclination of his staff, and the various amounts of resistance it encountered, he drew his inferences as to the physical features and soil of the districts he examined; and he could only know the position of the staff by the experience of the muscular tension and contraction consequent upon its changes as he shifted it about. The great number of blind persons who have been able to practise with success various manual trades and mechanical arts, from shoemaking and plain carpentry up to the making of watches and the manufacture of organs and pianos, and the pupils in almost every blind-school in which useful handicrafts are taught, are all dependent on the same faculty. Only from it can they learn the right mode of handling their tools, and the proper range, direction, and force to be given to their movements.

From the muscular feelings we proceed to the Sense of Touch. We assign it the second place among the modes of external perception, not only on account of its close connection with the muscular sensations (which until recently were confounded with it, and are so still by "popular" writers), but because, while any or all of the remaining senses may be lost, we cannot conceive touch absent from a sentient organism. Beings who possess only this sense and the muscular feelings have existed, and do exist; but the entire paralysis of the nervous system which would be necessary to destroy tactile feeling could scarcely be distinguished from death. According to Cabanis, whose doctrine on this point is adopted by Sir William Hamilton, and his able disciple and expositor Mr. Mansel, all the commonly-admitted five senses may be resolved into modifications of touch. This sense is diffused over the entire surface of the body, and has its seat in the papilla of the skin. The exquisite sensibility which it habitually attains in the blind, is perhaps the bestknown feature of their condition. Many, however, of the phenomena commonly attributed to it really belong to the muscular sense. That the two orders of feeling are distinct, is shown by the fact, that the susceptibility of the former is often very faint, when that of the latter is most keen and discriminating. This is the case with most handicraft labourers, the skin of whose hands is generally hard and callous, while their perceptions of weight, distance, figure, &c., are wonderfully delicate and exact. An

example, if one is needed, is presented by the blind deaf-mute Edward Meyster. Before entering the Blind Asylum at Lausanne, he had been employed in cutting wood, in consequence of which "his fingers never acquired the delicacy of touch of the other pupils." Nevertheless he excelled all his companions in mechanical skill, and was unusually dextrous in the use of the turning-lathe.

One of the most remarkable instances of the power which this sense may acquire is presented in the history of John Gough, who lost his sight through small-pox when in his third year. He devoted himself with great ardour to the study of natural history, and made considerable progress both in zoology and botany, especially in the latter science. The sensibility of touch in his fingers was sufficient to enable him to recognise, classify, and arrange ordinary plants. "It is mentioned, that towards the end of his life a rare plant was put into his hands, which he very soon called by its name, observing that he had never met with more than one specimen of it, and that was fifty years ago." When he failed to recognise a plant by his fingers, he used to apply it to his lips and tongue; and was generally able in this way to identify it, or refer it to its botanical order. The explanation of this expedient is as follows. The experiments of Weber have shown that the tactile sensibility of the skin varies in different parts. Placing the points of a pair of compasses, blunted with sealing-wax, on the tip of the tongue, he found that the points could be recognised as different at the distance of the twentieth part of an English inch; on the lower surface of the finger, they required to be widened to the tenth part of an inch in order to be distinguished. The tactile discrimination of the tongue is therefore twice as great as that of the finger-ends; an object placed on the former appears twice as great as it does when examined by the fingers. Gough's use of his tongue corresponded strictly to the use of a glass of double magnifying power by the seeing.

"The lips," says Dr. Bull, "are almost as liberally supplied with the nerves of touch as the tips of the fingers [Weber's experiments show that they have greater tactile discrimination than the fingers, and very nearly as great as that of the tongue], and in one instance have done good service to a fellow-sufferer. A poor blind girl, residing in one of the provinces of France, had for many years, as her greatest comfort, perused her embossed Bible with her finger; getting out of health, and becoming partially paralysed, the hand also was affected, and gradually all power of touch was lost. Her agony of mind at her deprivation was great, and in a moment of despair she took up her Bible, bent down her head, and kissed the open leaf, by

* Bull, p. 182.

way, as she supposed, of a last farewell. In the act of doing so, to her great surprise and sudden joy, she felt the letters distinctly with her lips; and from that day this poor child has thus been reading in the Word of God, words more precious to her than silver or gold,—even fine gold." (p. 68.)

The discriminating sensibility of the fingers may, however, be indefinitely improved by practice. It varies very much in individuals. In the interesting account of Mdlle. de Salignac, which forms the postscript of Diderot's Lettre sur les Aveugles (and was, indeed, written more than thirty years after), several illustrations of this are given. She could read books in the ordinary type (embossed printing had not then been invented) which were printed on only one side of the page. We have also heard of a blind German who was able to read books printed on the coarse rough paper used in that country. Mdlle. de Salignac's nicety of touch enabled her to play at cards with perfect accuracy. Marks were made on each card, which she was able to distinguish, though they escaped both the eye and touch of those who saw. Dr. Guillié gives an account of a blind Dutchman who could recognise the differences of the figures on cards without this aid; the different textures of the colours, black and red, and the different forms of club and spade, heart and diamond, were palpable to his feeling. In consequence, whenever he dealt he always won. Touching all the cards of the pack as he gave them out, he had virtually seen his opponent's hands. The evidence of this power possessed by some of the blind to discern differences of colours is indeed irresistible: Sir Hans Sloane's patient,* the blind Highland tailor Maguire (mentioned in the Philosophical Transactions), who made tartan (parti-coloured) dresses without mistake, Madam von Paradis, the Dutchman alluded to by Leibnitz and the Count of Mansfeldt, of whom Keckermann gives an account, are instances. A more recent example is given by Dr. Bull, on the testimony of a friend. Two eminent blind men, Dr. Blacklock and M. Ro

"She could distinguish the different colours of silk and flowers. . . . A lady who was nearly related to her having an apron on that was embroidered with silk of different colours, asked her, in the manner which has been described, if she could tell what colour it was; and after applying her fingers attentively to the figures of the embroidery, she replied, that it was red, blue, and green, which was true. The same lady having a pink-coloured ribbon on her head, and being willing still further to satisfy her curiosity and her doubts, asked what colour that was. Her cousin, after feeling some time, answered that it was pink. Her answer was yet more astonishing, because it showed not only a power of distinguishing different colours, but different kinds of the same colour; the ribbon was discovered not only to be red, but the red was discovered to be of the pale kind called pink."-Encyc. Britan., article "Blind."

"Visiting, in 1847, some friends in Gloucestershire, one morning a man about twenty-five, perfectly blind, for the eyes were entirely gone, called to return thanks for his admission into a blind asylum, in which he had been residing for some years

denbach, have declared themselves totally destitute of this power, and sceptical as to its existence. But the fact that most blind people are without it, does not prove that some few do not possess it. It is not pretended that it is any thing but an exceptional faculty. Mr. Johns's remark, that "if the testimony of all the inmates of the largest blind school in Europe is to be believed, they have not the least power of detecting colour," does not prove much. The pupils in the Southwark school, to which he refers, are habitually employed in handicraft trades, the effect of which is to harden and blunt the sensibility of the skin. M. Dufau mentions that the blind have often complained to him, that the sensibility of the finger-ends diminishes as they grow up, and renders reading and similar tasks more difficult to them; and he wisely insists on the necessity of the blind guarding their touch from injury as carefully as the seeing do their eyes.*

Other examples of tactile sensibility in the blind to which we may briefly refer are the power possessed by Dr. Saunderson and Madame Paradis of distinguishing false from genuine Roman medals, which connoisseurs with eyes were unable to do; and the still more astonishing circumstance related of Dr. Moyse, who with his fingers measured the length of a stroke, which was invisible to the eye, made by an etching tool on a plate of steel. Even in the case of the seeing, minute inequalities of past. In giving an account of what he had learnt there, he mentioned the power of distinguishing colours by the touch, and begged those present to try him. I made him feel my dress, a French merino, and he replied, I should say this is a reddish brown,' which it was. The next given him was one of the Rob-Roy tartan; he said, 'This is a material of two colours, red and black.' Another person made him feel her blue gauze veil. This is blue, but a very thin dress for the time of the year,' was the reply. The only other trial to which he was put was a printed cotton, which he pronounced to be of various colours. Being asked how he attained this power, he replied, 'A piece of cloth was given me, and its colour named, which I felt till quite familiar with it; then another, which I continued to examine until I could correctly distinguish one from the other; and so on until I knew all the colours,' and as it seemed to us, even shades of some. The darkest colours appeared to him to have most body in them. He said it required a very sensitive touch, and great patience and perseverance, and that consequently very few attain the power" (Bull, pp. 54, 55).

* M. Rodenbach relates that, while at the Musée des Aveugles in Paris, M. Fournier and he, in order to develop their sense of touch, procured some pumicestone, with which they rubbed the index-finger, taking care to wear on the finger a covering of fine leather (un doigtier de peau). In the Annual Report of the Boston Institution for 1842 (p. 20), it is said that "an old blind soldier, in order to render the hardened skin of his fingers capable of perceiving characters in relief, applied blisters to them on several occasions." The following passage from M. Dufau's Souvenirs d'une Aveugle-née may be added: Every substance likely to injure the delicate susceptibility of the epidermis was withdrawn from my habitual contact; and my hands even were usually covered with a fine and supple skin-glove, which preserved their tactile envelope without hindering free movement. This expedient took the place with me of the glasses worn by those who wish to take precautions against the loss or enfeeblement of their sight. Had not nature, in fact, in my case placed my eyes at my finger-ends?" (p. 19.)

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