Encyclopædia americana. A popular dictionary of arts, sciences, literature, history, politics and biography, a new ed.; including a copious collection of original articles in American biography; on the basis of the 7th ed. of the German Conversations-lexicon. Ed. by Francis Lieber, assisted by E. Wigglesworth ...

BLIGHT-BLIND. 133
culture. Palliatives are to be found in other persons. A young man, whom
topical applications. Cheselden couched for a cataract, at the
BLIND, the; such as are deprived of moment he received sight, imagined that
their sight. The loss of the noblest all the objects which he saw were in
sense, by means of which man receives contact with his eyes: he could not disan idea of the world that surrounds him, tinguish objects, although of very differclothed in light and color, is an event as ent forms. Those with which he was
melancholy as it is frequent. Blindnless already familiar by the touch, he examis diferent, 1. in its degrees, some per- ined with great attention, in order to
sons being partially blind, retaining a recognisethem anothertime; hbut, having
slight perception of light, with tile power too many things to notice at once, he
of distinguishing very orilliant colors, and soon forgot all that lie had observed. He
the general outlines of bodies; others be- wondered that those persons whom lihe
ing entirely deprived of the faculty of loved most were not handsomer than
seeing; 2. in its causes: some men are others. Before he received his sight, he
blind from their birth; others have be- had expressed a great desire to obtain
corle blind by local diseases of the eyes, this sense. The other senses of persons,
for instance, by inflammation, suppura- who have been blind for a long time, betion, cancer of the eye-ball, spots, films, come nmore exquisite, perhaps, because
tumors on the cornea (by which its trans- they are not subject to the distraction
parency is destroyed), also by closure of produced by the sight of so many objects.
the pupil, by a turbid state of the hu- The blind, therefore, are often distinmors, by a debility of the optic nerve, or guished for a remalnrkable mental activity,
by general diseases of the body, violent and a wonderfull developement of the infevers, nervous fevers, plethora and ten- tellectual powvers. Their touch anda l heardency of the blood to the head, erysipelas ing, particularly, become very acute.
in the face, small-pox, scarlet fever, &c., Thus it is related of a blind man, who
or by excessive exertion of the eyes, by lived at Puisaux, in France, and was a
which the optic nerve is enfeebled; for chemist and musician, that he could acwhich reason, some classes of mechanics curately estimate the proportions of oband artists, as blacksmiths, laborers inr jects, could judge of the distance of fire
glass and smelting-houses, watch-makers, by the degree of heat, determine the
&c. not unfrequently lose their sight, and, quantity of fluid in vessels by the sound
in northern countries, which are covered it produced while running from one veswith snow for a long time, and which sel into another, and the proximity of
dazzle the eyes by the reflection of the objects by the effect of the air upon his
sunbeams, as well as in the sandy deserts face. He determined very accurately the
of Africa, blindness is a frequent com- weights of bodies and the capacities of
plaint. Old age is sometimes accompa- vessels. The celebrated Saulnderlson, pronied with blindness, occasioned by the fessor of mnatlhematics at Cambridge, lost
drying up of the humors of the eye, or by his sight in his early youth. IHe invented
the opacity of the cornea, the crystalline several processes to facilitate his studies
lens, &c. There are several causes iln arithmnetic and geometry. His sense
which produce blindness from the birth. of touch was so acute, that he distinSometimes the eyelicls adhere to each guisbed spurious coins merely by letting
other or to the e e-ball itself, or a mem- them pass through his fingers, though
brane covers the eyes; sornetimes the they were so well executed, that even
pupil of the eye is closed, or adheres to skilful judges were deceived by them.
the cornea, or is not situated in the right BLIND, INSTITUTIONs FOR THE. In the
place, so that the rays of light do not fall case of persons destitute of sight, it is
in the middle of the eye; besides other necessary to have recourse to the other
defects. Those who are born blind have senses to supply the want of the eye. If,
no idea of vision, and are entirely desti- for instance, we wish to teach them the
tute of all the ideas derived from the arts of reading and writing, letters Must
sense of sight. They cannot, therefore, be prepared, which will be palpable to
be sensible of their misfortune in the the touch, and the hand guided until they
same degree as those who have lost their are able to copy them. If we wish to
sight at a later neriod. Experience has communicate to them a knowledge of the
showin, that those who acquire the power surface of the earth, globes and maps
of seeing aRfter being born blind, or having nmust be prepared with the divisions, &c,
lost their sight in their childhood, form in relief. Knowledge obtained in this
very different ideas of visible objects from way must, of course, be acquired much
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