cause of its ill effect on the paffions evident enough at the first impreffion; in ordinary cases, it is indeed frequently loft; but this is, because the original association was made very early, and the consequent impreffion repeated often. In our inftance, there was no time for fuch an habit; and there is no reason to think that the ill effects of black on his imagination were more owing to its connexion with any difagreeable ideas, than that the good effects of more cheerful colours were derived from their connexion with pleafing ones. both probably their effects natural operation. They had from their SECT. XVI. Why DARKNESS is terrible. T may be worth while to examine, how darkness can operate in fuch a manner as to caufe pain. It is obfervable, that ftill as we recede from the light, nature has fo contrived it, that the pupil is enlarged by the retiring of the iris, in proportion to our recefs. Now instead of declining from it but a little, fuppofe that we withdraw entirely from the light; it is reasonable to think, that the contraction of the radial fibres of the iris is proportionably greater: and that this part may by great darkness come to be fo contracted, as to ftrain the nerves that compofe it beyond their natural tone; and by this means to produce a painful fenfation. Such a tenfion it seems there certainly is, whilft we are involved in darkness; for in such a state whilst the eye remains open, there is a continual nifus to receive light; this is manifeft from the flashes, and luminous appearances which often feem in these circumstances to play before it; and which can be nothing but the effect of spasms, produced by its own efforts in pursuit of its object; feveral other strong impulfes will produce the idea of light in the eye, befides the substance of light itfelf, as we experience on many occafions. Some who allow darkness to be a cause of the fublime, would infer from the dilatation of the pupil, that a relaxation may be productive of the subtime as well as a convulfion; but they do not, I believe, confider, that although the circular ring of the iris be in fome fense a fpincter, which may poffibly be dilated by a fimple relaxation, yet in one refpect it differs from most of the other sphincters of the body, that it is furnished with antagonist muscles, which are the radial fibres of the iris; no fooner does the circular muscle begin to relax, than these fibres wanting their counterpoife, are forcibly drawn back, and open the pupil to a confiderable widenefs. But though we were not apprized of this, I believe any one will find if he opens his eyes and makes an effort to see in a dark place, that a very perceivable pain enfues. And I have heard fome ladies remark, that after having worked a long time upon a ground of black, their eyes were so pained and weakened they could hardly fee. It may perhaps be objected to this theory of the mechanical effect of darkness, that the ill effects of darkness or blackness seem rather mental than corporeal; and I own it is true, that they do fo; and fo do all thofe that depend on the affections of the finer parts of our syftem. The ill effects of bad weather appear often no otherwife, than in a melan melancholy and dejection of fpirits, though without doubt, in this case, the bodily organs fuffer first, and the mind through these organs. SECT. XVII. The effects of BLACKNESS. Lackness is but a partial darkness; Blackness is but a and therefore it derives fome of its powers from being mixed and furrounded with coloured bodies. In its own. nature, it cannot be confidered as a colour. Black bodies, reflecting none, or but a few rays, with regard to fight, are but as so many vacant spaces dispersed among the objects we view. When the eye lights on one of these vacuities, after having been kept in fome degree of tenfion by the play of the adjacent colours upon it, it suddenly falls into a relaxation; out of which it as fuddenly recovers by a convulfive fpring. To il Juftrate |