bodies may occaſion. If this remembrance be very fleeting in us, if we have but little conception how one born blind fixes, recalls, and combines the ſenſation of the touch, it 1 owing to the cuſtom ve derive en, at FRO THE BLIN D. 27 derive from our eyes, of performing every thing in our imagination wich colours. It has, however, been my own caſe, under the agitation of a violent paſſion, to feel a thrilling throughout one of my hands, and the impreſſion of bodies, which it was ſome time ſince I had touched, renewed as ſtrongly as if ſtill actually under my touch: the limits of the ſenſation hkewiſe preciſely correſponding with thoſe abſent bodies, Though ſenſation be of it-ſelf indiviſible, it takes up, if I may be an: allowed the term, a large ſpace, which the We perſon blind from his birth can increaſe or or WW <omtract by thought, enlarging or dimihat niſhing the part affected. Thus he comwe, poſes points, ſurfaces, and ſolids: he will em: even have a ſolid large as the terraqueous globe, by ſuppoſing his fingers ends as large as the globe, and every where in length, breadth, and depth, taken up by the ſenſation.
I do not know any thing which better demonſtrates the reality of internal ſenſation, than this faculty, ſo weak in 1 us, but C0 ſo 28 LETTER O N ſo ſtrong in thoſe who are born blind, of feeling or calling to mind the ſenſation of bodies, even when abſent; and no longer acting on us. We cannot bring one born blind to underſtand how imagination exhibits abſent objects to us as if preſent; but we eaſily perceive in us the ſame faculty of feeling at the fingers ends a body when no longer there, as in one born blind. In order to this, ſqueeze your fore- finger againſt your thumb, ſhut your eyes, ſpread your fingers, and immediately after they are ſeparated, look into yourſelf, and tell me, whether the ſenſation does not laſt a conſiderable time after the compreſſion has ceaſed? whether it, during the compreſſion, your ſoul appears to you to be rather more in your head than at your fingers ends? and whether this compreflion does not, by the ſpace which the ſenſation fills, give you the idea of a ſurface? We diſtinguiſh the preſence of beings out of us, from the imagery of them in our imagination, only through the force or weakneſs of the impreſſion. : 80 THE FEISTY _ 4 8o he, who is born blind, 3 the ſen - ſation from the real preſence of an object at his fingers ends, only by the force or weakneſs of that very ſenſation. Should a philoſopher, who has been blind and deaf from' his birth, ever make a man in imitation of that of Deſcartes, I dare atfirm, Madam, that he will place the foul at the fingers ends; as from thence deriving his principal ſenſations, and all his lights, And who will put him in mind, that his head is the reſidence of his thoughts? If the labours of imagination impair our brain, it is becauſe our effort in | imagining 1s pretty ſimilar to that which ve exert in perceiving very near or very {mall objects. But it will not be ſo with him who has been blind and deaf from his us birth: the ſenſations which he has derived ch trom the touch- will be, as it were, the * WW mould of all his ideas; and I ſhould not oY be ſurprized that, after a deep and cloſe of meditation, his finger ſhould be as much gh tired as our head. It would give me no apprehenſion, were a philoſopher to object C24 to 30 ' LETTER ON to him, that the nerves are the cauſes of our ſenſations, and that all nerves have their origin in the brain. Were theſe two propoſitions fully demonſtrated, which is very far from being the caſe, eſpecially the former, an expoſition of all the dreams of naturaliſts on this head, would be ſufficient to confirm him in his opinion..
But if the imagination of a blind perſon be no more than the faculty of calling to mind, and combining ſenſations of palpable points; and that of a man who ſees, the faculty of combining and calling to mind viſible or. coloured points: the perſon born blind conſequently perceives things in a much more abſtract manner than we; and in.queſtions merely ſpeculative, he 1s, perhaps, leis liable to be deecived. For abſtraction is only ſeparating the ſenſible qualities of bodies, either from one another, or from the body itſelf in which they are inherent; and from this being wrong or improper, ſprings error, wrong in © metaphyſical queſtions, and improper in phy ſico-mathematical queſtions.
G a N oo mo, >. oy / — — +4 — » 1 % &# dl | — Er tons. A way, in which one can ſcarce avoid being miſtaken in metaphyſics, is not ſufficiently ſimplifying the objects under inveſtigation; and an infallible ſecret for coming to falle concluſions in phy ſico-mathematics, is to ſuppoſe them leſs compounded than they are.
There is a kind of abſtraction, of ako 65 very few are capable, that it ſeems reſerved to pure intelligences: the reducing every thing to numerical unities. It muſt be allowed, that the reſults of this geometry would be very exact, and its formulas very general, there being no objects either actually exiſting or poſſible, which theſe imple unities could not repreſent, by points, lines, ſurfaces, ſolids, thoughts, ideas, ſenſations, &c. and, if this ſhauld prove to be the foundation of Pythagoras's doctrine, he might be ſaid to have tailed in his plan, his mode of philoſophizing being too much above us, and too near that of the Supreme Being, who, according to the ingenious expreſſion of Ki | an an Engliſh geometrician, is perpetually geometriſing in the univerſe.
Unity, pure and ſimple, is too vague and general a ſymbol for us. Our ſenſes bring us back to ſigns more analogous to the extent of our intellects, and the conformation of our organs. We have even brought thoſe ſigns to be in common among us, and to ſerve, as it were, for the ſtaple, in the mutual commerce of our ideas: ſome we have appointed for the eye, as characters; ſome for the ear, as articulate ſounds; but for the touch we have none, though there is a proper way of ſpeaking to phat ſenſe, and getting an-ſwers from it. The want of this language precludes all converſation between us and thoſe who are born deaf, blind, and dumb. They grow up, but ſtill in a ſtate of imbecility; whereas. they might, perhaps, acquire ideas, were they, from their childhood, trained in a fixed, determinate, canſtant, and uniform manner to underſtand us: in a word, by tracing on their hand the ſame: characters, which we we we delineate on paper, with the ſame ſignification unalterably annexed to them. Now, Madam, does not this language appear to you as convenient as another; and is it not even ready invented? And would you take upon you to affirm, that you never have been brought to under- ſtand any thing in the like manner? All r that remains then is to fix it, and make e a grammar and diftionaries of it, ſhould $ the expreſſion, by the common characters e of writing, be thought too ſlow for this y purpoſe. 705 There are three avenues for knowledge; but one, from the want of ſigns, is kept barricaded: had the two others been neglected, we ſhould be little better than brutes; as the touch underſtands only by compreſſion, ſo would it have been the only means of ſpeaking to the ear. Madam, it is only the want of one ſenſe, can make us thoroughly acquainted with the advantages of the ſymbols, appointed for thoſe which we enjoy; and what a conſoation would it be to thoſe, whoſe misfor- CE £ dine \ dam, is another blind man, with whom it 34 EEFTTFEEDOY tune it is to be deaf, blind, and dumb, or who ſhould loſe thoſe three ſenſes by any accident, were there a clear and poets e for the touch. | It is much ſhorter to uſe fonbols ready invented, than to invent them, which yet muſt be done when taken unprepared, What an advantage would it not have been for Saunderſon, to find in his ſixth year a tangible arithmetic ready to his hands, inſtead of being put to contrive one when he was twenty-five. This Saunderſon, Mawill not be foreign from my purpoſe to make you acquainted. Wonderful things, indeed, are told of him; and yet there is not one to which, from his improvements in literature, and his ſkill in mathematical ſciences, we may not ſafely give credit. The ſame machine ſerved him for algebraical calculations, and for the deſcription of rectilineał figures. You. would like to have this explained to you, did it come within your underſtanding; and nom 2 ſhall ſee that it 9 no farther know 7.8 9 WN , , E 4 n * * we — 7 U.
= 5 n © wv. „1 : - i +S- J know! and t! ſhoulc work Sup it inte lines a points nl iquare RE ing t length 3 me Thi placed and th except and t! pin pl. ithor yphen jeadec vithou her 2 he ce . Peadec * hi . Il | lil AAA * 0 J E knowledge than what you are miſtreſs of, and that it would be very uſeful to you, ſhould you ever take it into your head towork long calculations by feeling.
Suppoſe a ſquare, as Plate II. Divide it into four equal parts by perpendicular lines at the ſides, ſo as to form the nine points, 1, 2, 3, 4, 5, 6, 7, B, 9. In this ſquare are nine holes, capable of admitting two kinds of pins, all of the fame length and bigneſs, except the heads of bme being a little bigger than others.
The {large headed pins were never placed. but in the center of the ſquare and the ſmall headed always on the ſides, except only in the ſingle caſe of a nought, and this was marked by a large headed. pin placed in the center of the little ſquare, ithout any othes pin on the ſides. The ypher 1, was repreſented by à ſmalk jeaded pin in the center of the ſquare, ithout any other pin On the ſides. Cyher 2, by a large headed pin placed in he center of the ſquare, and a ſmalkxcaded pin placed on one of. the ſides as | © & 3» paint THE BL END: 35 * P F : - + N . : i A v 'SY 7 | point 1. Cypher 3, by a large headed pin placed in the center of the ſquare, and a ſmall headed pin placed on one of the ſides at point 2. Cypher 4, by a large headed pin placed in the center of the ſquare, and by a ſmall headed pin placed on one of the ſides at point 3. Cypher 53, by a large headed pin in the center of the fquare, and a {mall headed one in one of the fides at point 4. Cypher 6, by a large headed pin in the center of the ſquare, and a ſmall headed pin on one of the ſides at point 5, Cypher 7, by a large headed pin placed in the center of the ſquare, and 2 ſmall headed pin placed on one of the ſides at point 6. Cypher 8, by a large headed pin placed in the center of the {quare, and a {mall headed pin placed on one of the ſides at point 7. Cypher q, by a large headed pin placed in the center of the ſquare, and a ſmall headed pin placed on one of the ſides of the ſquare at point 8.
Here are ten different expreſſions for the touch, each * to one of our ten . arith- Au Ll jt il [| ll WI (| (| Will Ul mM WING LK ll [mm Wil e lil Lu Lu ll (Nil ll I" WU £S j ' lll Ii Il ll III | ol , LI Ill TIN Ly um / ww h A I II lil — — — — — = — I U ö [ ll li A he [ 1 Amn. 4 LUCA leni.
arithmetical characters. Now fancy 8 table as large as you pleaſe; divide it into little ſquares horizontally diſpoſed, and ſeparated one from another at the ſame diſtance, as in Plate III. and this gives you.
Saunderſon's machine.
You readily conceive, that there are no numbers which may not be written on that table; and, conſequently, no arithmetica}: operation but what may be performed by it.
Let it be propoſed, for inſtance, to find the ſum of the nine following numbers.
a a8 0-2 8: n r F write them on the table as they are named to. me, The firſt cypher at the left — left of the firſt number, on the firſt ſquare to the left of the firſt line; the ſecond cypher at the left of the firſt number, on the ſecond ſquare, at the left of the ſame line; and ſo on. The ſecond number I place on the ſecond row of {quares, the units under units, the tens under tens, &c.
I place the third number on the third; row of ſquares, and ſo on, as you ee, Plate III. Then, with my fingers going over every vertical row from the top to the bottom, beginning by that which is moſt to my left, I add up the numbers expreſſed in that row, writing the ſurplus. of the tens at the end of the column. I go on to the ſecond column, proceeding towards the left, which I work in the ſame way. From that to the third; and thus. ſucceſſively go through my addition. How the ſame table ſerved. him for demonſtrating the properties of rectilineal figures was thus: ſuppoſing he was to demonſtrate, that parallelograms of the like baſe and height have equal ſurfaces;. be placed his pins as you ſee, Plate IV. annexing #4 mo ar. n —— 5 #4 mo ar. n —— 5 THE BLIND. 7% nexing names to the angular points, and performed the demonſtrations with his fingers.
Had Saunderſon made uſe of only ke headed pins to. denote the limits of his figures, he could place round them ſmalł headed pins diſpoſed in nine different manners, all quite plain and familiar to him; ſo that he was never at a ſtand, but when the great number of angular points to be named in his demonſtration, laid him under a neceſſity of recurring to the letters of the alphabet; and how he made __ of them, we are not informec.
All we know is, that his fingers ran over his table with ſurprizing diſpatch; entering on the longeſt calculations, breaking off, and perceiving when he was out, that 1 be eaſily proved them, and ſo convenient was the arrangement of his table, that this 4 operation did not take him up any thing of the time which we ſhould conceive. This arrangement conſiſted in. placing large headed pins in the center of all the ſquares;, after which, all he had ro i 5 SY 4, 9 7 bi) ——_ N « % he LETTER ON do, was determining their value by the fmall headed pins, except in the caſe of a nought. Then, inſtead of the large headed pin, he placed in the center of the ſquare, a ſmall headed one. Sometimes, inſtead of forming a whole line with his pins, he only placed them at all the angular, or interſecting points, with ſilken threads round them, which completed the limits of his figures. See Plate V.
se has left ſome other machines, which made the ſtudy of geometry eaſier to him. His particular way of uſing them is not known; and, perhaps, the finding it out would require more ſagacity than to ſolve a problem of integral calculation. I wiſh fome geometrician would find out what uſe he made of four ſolid pieces of wood in the form of rectangular parallelopipedes, each eleven inches in length, to a breadth - of five and a half, and little more than half an inch in thickneſs, with the two thick oppoſite ſurfaces divided into ſmall ſquares, like that of the- abacus, before deſcribed, - aa this difference, that they were perforated THE FL IN@A 4r rated only in ſome places where the pins were thruſt in up to the head. Every ſurface repreſented nine ſmall arithmetical tables, each of ten numbers;. and each of thoſe ten numbers was. compoſed of ten cyphers. Plate VL exhibits one of theſe little tables, with its numbers.
9 4 08 4 | 354-4 $5: | He wrote The Elements of Geometry, a very complete work in its kind, and which bears no other marks of his blindneſs, than the ſingularity of ſome demonſtrations, which a man, with his eyes, would perhaps not have hit on. He firſt found out „ VUVETTER:ON out the diviſion of the cube into ſix equal pyramids, with their ſummits 1n the center of the cube, and their baſes each of its faces. It is uſed in a very plain demonſtration, to ſhow that every pyramid is the third of a priſm of the ſame baſe and height.
His own taſte led him to the ſtudy of the mathematics, and the ſmallneſs of his fortune, but chiefly the encouragement of his friends, put him on holding public lectures. They made no queſtion of his ſucceeding beyond his hopes, by his wonderful facility in making himfelf under-ſtood. Saunderſon, indeed, uſed to ſpeak to his pupils as if they had loſt their ſight; but that blind man, who ſpeaks fo as to be clearly underſtood by the blind, muſt go a great way with thoſe who have their fight: it is a teleſcope the more. They who have written his life ſay, that he a. bounded in happy expreſſions; and that is very probable. But, perhaps, you will . © aſk me, what do you mean by happy ex- 7 nga? I anſwer, Madam, that they are — THE BEIND., 32 are ſuch which are proper to, one ſenſe, to the touch, and, at the ſame time, metaphorical to another ſenſe, as the fight; a circumſtance, from which the perſon ſpoken to receives a double light, the real and direct light of the expreſſion, and the reflected light of the metaphor. It is evident, that on theſe occaſions, Saunderſon underſtood himſelf only by halves, as perceiving only half the ideas annexed to the terms he uſed. But who is not now and chen in the like caſe? many a ſmart jeſt baun come from idiots, and perſons of the r. eſt ſenſe drop a filly thing without either K Wl being aware of it.
t; [ have obſerved the want of ER produce the like effect in foreigners, who, in our language, are obliged to lay every thing in very few words, ſome of which they unknowingly place very happily. But every language being to writers of a lively fancy deficient in it words, they are in the fame caſe 3 foreigners of wit; the ſituations in- 3 they rented by them, the delicate gradations.
4 ILE T F oN they perceive in characters, the natural pictures which they draw, are continually leading them from the common ways of ſpeaking. into terms and phraſes, which never fail to charm, when neither obſcure nor affected; and theſe faults are dealt with according to the reader's own wit, and -his little acquaintance with the language. Hence it Is that, of all French writers, M. de M- is beſt liked by the Engliſh; and Tacitus, of all the claſſics, bears the bell among thinkers: they do not attend to the licences of the ſtyle, it is only the truth of the expreſſion which ſtrikes them. Saunderſon was profeſſor of e tics at the univerſity of Cambridge. He read lectures on optics, the nature of light and colours; he explained the theory of viſion, the effects of glaſſes, the phænomena of the rainbow, and ſeveral other points relating to ſight, and its organ. The marvellous of theſe things, Madam, will be found conſiderably to abate, on your taking into conſideration, that ; there THE B E IF INE 45 there are three things to be diſtinguiſhed in every phylico-geometrical queſtion; the phenomenon to be explained, the geometrician's ſuppoſitions, and the calculation reſulting from the ſuppoſitions. Now, it is manifeſt, that to a blind perſon, how great ſoever his penetration be, the phenomena of light and of colours are unknown. The ſuppoſitions he will under-ſtand, as all of them relate to palpable cauſes; but the geometer's reaſon for preferring them to others, will be out of his verge, as in order to that, he muſt be - che blind man takes the ſuppoſitions for Je what they are given him; a ray of light he for an elaſtic and fine thread, or for a ſeof ties of minute bodies ſtriking our eyes 10- MW vith incredible velocity; and he calculates her Wl accordingly. The tranſition from phycs to geometry is now got over, and the Ha- queſtion becomes ſimply mathematical. But what are we to think of the reſults of the calculation? 1. That the coming at able to compare the ſuppoſitions them-. ſelves with the phenomena: therefore, them; +. LETTER-ON them is ſometimes extremely difficult, and that it would be to little purpoſe, that a naturaliſt could form the moſt plauſible hypotheſes, were he not able to verify them by geometry: accordingly, the greateſt natural philoſophers, as Galileo, Deſ. cartes, and Newton, were great geometti. cCians. 2. That theſe reſults are more or leſs certain; as the hypotheſes on which they are built, are more or leſs compli cated. When the calculation is founded on a ſimple hypotheſis, the concluſions acquire the force of geometrical demonſtrations. When the ſuppoſitions are multi. farious, the probability of each hypotheſis being true diminiſhes in proportion to the number of the hypotheſes; but, on the other hand, increaſes from the little probability, that ſo many falſe hypotheſes would exactly correct each other, and produce a reſult confirmed by the phenomena. This would be like an addition, the reſult of which was right, though the par: tial ſum of the numbers added had been all miſcounted. The Poſſibility of ſuch an Opera- THE BLTI1ND. Ge operation cannot be denied; but, at the F ſame time, you ſee, that it would very ſeldom prove ſo. The more numbers are to y be added, the greater the probability of a 5 miſtake in the addition of each; but this probability is likewiſe leſſened, if the re- ſult of the operation be right: ſo that there is a number of hypotheſes, the certaind reſulting from which would be the leaſt " poſſible. If I make A, plus B, plus C, . equal to 50, am I to conclude from 50 being the real quantity of the phænomena that the ſuppoſitions repreſented by * the letters A, B, C, are true, there being ef; WW numberleſs ways of taking from one of thoſe two letters, and adding to the other, and 50 to prove always the reſult? But the caſe of three combined hypotheſes is, perhaps, one of the moſt disfavourable. One advantage of calculation, which I muſt not omit, is, that the contrariety found between the reſult and the phænomenon excludes falſe hypotheſes. A naturaliſt, to find the curve formed by a ray of light in the nn is obliged to | regulate A y regulate himſelf by the denſity of the ſtrata of the air, the law of refraction, the nature and figure of the luminous cor. puſcle, and, perhaps, by other eſſential elements which he does not bring into account, either as voluntarily neglecting them, or being unknown to him. At length he determines the curvature of the ray. If it be otherwiſe in nature, than his calculation makes it, his ſuppoſitions are deficient or falſe; if the determination agrees with the natural curvature of the ray, it follows either, that ſome ſuppoſitions have corrected others, or that they are all exact: but which of the two, he knows not; yet, that is the certitude to which he can attain.
I have carefully peruſed Saunderſon's Elements of Algebra, in hopes of meeting with what I was deſirous of knowing from thoſe who familiarly converſed with him, and who have made us acquainted with ſome particulars of his life; but my cur oſity has been diſappointed, and I thought that elements of geometry from him would 1 have he pri have been a work both more ſingular in ſhould there have been let into his definitions of point, line, ſurface, ſolid, angle, interſections of lines and planes, in Which I make no queſtion but he would have proceeded on principles of very abſtract metaphyſics, and near a-kin to that of the idealiſts. Idealiſts, Madam, are thoſe philoſophers who, being conſcious only „of their exiſtence and a ſucceſſion of in-„e Wl ternal ſenſations, admit nothing elſe. A p- item of ſuch extravagancy, that I ſhould at think it muſt have been the offspring of 0, blindneſs itſelf; and yet, to the diſgrace de of the human mind and of philoſophy, s the moſt difficult to combat, though =; WM the moſt abſurd. Dr. Berkeley, biſhop of ing Cloine, in Ireland, has ſet it forth with great om andour and perſpicuity, in three dia- 10 logues. It were to be wiſhed, that the vi author of the Eſay on our Knowledge, uli. ould take this work into examination; * he would there find matter for uſeful, a- THE B LIND. 49 elf, and much more uſeful to us. We ol grecable, and ingenious obſervations 3; for | hy. 4.4 FI 4— a — 1 n » ET T ER ON ſuch as, in a word, no perſon has a bet. ter talent. Idealiſm deſerves very well of ourſelves, and what we perceive is only foundation of his whole ſyſtem. Would - it muſt be he who ſhould manage them to be reported to him; and this hypotheſis is as a double incentive for him, its ſingularity, and much more the difhculty of refuting its principles, they being preciſely. the ſame as thoſe of Berkeley, According to both, and according to rea. ſon, the terms, eſſence, matter, ſubſtance, agent, &c. of themſelves, convey very little light to the mind. Beſides, as the author of The Eſſay on the Origin of Human Knowledge judiciouſly obſerves, whether we aſcend up to the heavens, or go down into the abyſſes of the earth, we never go out our own thoughts: now this is the very reſult of Berkeley's firſt dialogue, and the it not highly delight you, Madam, to ſee two enemies engaged, whoſe weapons are ſo much alike? If either got the better, with the greater dexterity; and the author of The Ei on the Origin of Human Know ledge Jul the uld lee are ter, hem thor now HE {[B:L-1POW 51 ledge has lately, in a treatiſe on ſyſtems, given freſh proofs of his adroitneſs, and how much he is to be redoubted by ſyltematics. h Here, you will ſay, this is quite loſing ſight of the blind. True, Madam; but you muſt be ſo good as to allow me all theſe digreſſions. I promiſed you a converſation, and, without this indulgence, I cannot keep my word. | I have peruſed, with the utmoſt ſtretch of my attention, what Saunderſon has ſaid concerning infinitude: and I can aſſure you, that he had ſuch very juſt and very clear ideas on this head, that, in his account, moſt of our infinitarians would have been looked on but as blind. You your- ſelf ſnall be judge: though this matter be ſomewhat difficult, and a little beyond your mathematical knowledge, I truſt to bring it within your compaſs, and initiate jou into this infiniteſimal logic.
This celebrated blind man proves that touch, when improved by exerciſe, may become more preciſe than ſight; for, in 1 handling rs nes +» Ra * 1 & "1 & > —— — N 2 2 i INES — — ” mm --S 4 2 o 2 * R OS _ — — — - — EE TETTEL ON handling a ſeries of medals, he could dif. tinguiſh the genuine from the ſpurious *, though the imitation was ſuch as might have deceived a clear-ſighted connoiſſeur; and he judged of the exactneſs of a mathematical inſtrument, by drawing his fingers ends along its diviſions. Theſe are certainly things of another kind of difficulty, than forming a judgment by the touch of the likeneſs of a buſt to the per-ſon it repreſents. This ſhews that a blind people might have ſculptors, and put ſtatues to the ſame uſe as among us, to perpetuate the memory of glorious actions, and of perſons dear to them; and, in my opinion, feeling ſuch ſtatues would give them a more lively pleaſure than we have in ſeeing them. What a delight to a paſ-ſionate lover, in gently drawing his hand over beauties which he would know again, when illuſion, which would act more ſtrongly on the blind than in thoſe who The roughneſs of thoſe new caſt, is thought to have aſſiſted him in this diſtinction.
ſee, \ TREE 52 ſee, ſhould come to reanimate them; but likewiſe, the more pleaſure ſuch remembrance gave him, the leſs, perhaps, would his grief be for the loſs of the original.
Saunderſon, like the Puiſaux blind man, was affected on the leaſt alteration in the atmoſphere, and ſenſible, eſpecially in calm weather, of any objects being near him. It is related of him, that being preſent at the making ſome aſtronomical obſervations in a garden, the clouds, which now and then intercepted the ſun's dyſk, at the ſame time occaſioned ſuch a change in the action of the rays, on his face, as ſignified to him the intervals which tavoured or impeded the obſervations. You may, perhaps, think, that there was ſome agitation in his eyes, which apprized him of the preſence of light, but not of that of objects. So I ſhould have thought too, were it not certain that Saunderſon was not only blind, but without the very organ of ſight.
BD. 3 Thus BD. 3 Thus 54 LEST & K Q N Thus Saunderſon ſaw, by means of a pellicle; and of ſuch an exquiſite ſenſibility was this tegument, that a little practice | would have brought him to have known an acquaintance, by having his portrait de- g lineated on his hand, and that, by } the ſucceſſion of the ſenſations excited 7 by the pencil, he would have confidently ſaid, © Oh! this is Mr. ſuch a-* one.” Thus the blind have likewiſe a painting, in which their own ſkin ſerves for the canvas. Theſe ideas are ſo far from the chimera, that I make no queſtion, were ſomebody to draw on your hand Mr. — 's little mouth, you would immediately know it; yet, you muſt allow, that this would be much eaſier to one born blind, than to you, though ſo accuſtomed to fee it and to think it fo wonderful pretty. For, your decifion implies two or three circumſtances; the compart ſon of the delineation made on your hand, with the picture of it on the ground of your eye; the remembrance of the manner in which we are affected by things felt, and „ — — — — DOR mos a P - 2 — r — — * — — — . —— . . "4 * ' ; - — — * and of that with which we are affected by things which we have only ſeen and admired; laſtly, the application of theſe data to the deſigner's queſtion, who aſks you, with the point of his pencil on the ſkin of your hand, Whoſe mouth is this which « I am drawing?“ Whereas the ſum of the ſenſations excited by a mouth on the hand of a blind man, is the ſame as the ſum of the ſucceſſive ſenſations excited by a deſigner's pencil.
To this account of the Puiſaux blind man and Saunderſon, may be added Didymus of Alexandria, Euſebius the Aſiatic, and Nicaiſe of Mechlin, with ſome others, who appeared ſo ſuperior to other men, 1 might, without exaggeration, have feigned the gods to have deprived: them of it from ies I Jealouſy leſt mortals ſhould equal them. ar: or Tireſius, who had ſeen into the ſecrets nd, Nef the gods, and had the gift of predicton, what was he but a blind philoſoby fable? But we will keep to the won-4 derful THE BEIND 3s though with one ſenſe leſs, that the poets : pher, whoſe memory has been preſerved _ As —— — — —— — — —— — o — oy — & ——...06 BETTER ON derful Saunderſon, and follow this extraordinary perſon to his grave. |