Richard Liebreich

“ It is more difficult to demonstrate whether a person sees colors correctly or not. Such glaring mistakes as those produced by color-blindness can be easily recognized, but faults produced by a diminished sensation of small differences in the shades of color can only be recognized as such by the fact that the majority of persons with normal vision declare them to be faults. Such, for instance, are deviations produced by an incorrect perception of pigments, which in painting makes itself felt by a constantly-recurring plus or minus of a single color in the whole picture. ”

“ Thus it seems to me perfectly natural that the peculiar poetical haze which is produced by the diffusion of light in Turner's pictures after 1831 should have a particular attraction for many of Turner's admirers. On the other hand, passing over the faults, we discover in these pictures peculiar merits, and we recognize that the great artist continued in many ways to improve, even at a time of his life when his failing sight began to deprive his works of general favor. ”

“ In this way art-critics will often obtain an explanation of the development of the artist, while artists will avoid the inward struggles and disappointments which often arise through the difference between their own perceptions and those of the majority of the public. Never will science be an impediment to the creations of genius.—Macmillan's Magazine. ”

“ The short-sighted eye has, in consequence of an extension of its axis, a stronger refraction, and unites, therefore, in front of the retina the rays of light which proceed from infinite distance. In order to be united upon the retina itself, the rays of light must be divergent; that is to say, they must come from a nearer point. The more short-sighted the eye is, the stronger must be the divergence; such an eye, in order to see distinctly distant objects, must make the rays from a distant object more divergent, by aid of a concave glass. ”

“ It can, of course, only produce optical delusions, never a real optical identity; that is to say, the image which is traced in our eye by real, objects is not identical with the image produced in our eye by the picture. ”

“ The capacity of the eye to accommodate itself to different consecutive distances, so as to receive on the retina distinct images of objects, is called accommodation. This faculty depends upon the power of the crystalline lens to change its form. The accommodation is at its greatest tension if we adapt our eye to the nearest point. It is, on the contrary, in complete repose if we adapt it to the farthest point. The optical state of the eye during its adaptation for the farthest point, when every effort of accommodation is completely suspended, is called its refraction. ”

“ If science aims at proving that certain works of art offend against physiological laws, artists and art-critics ought not to think that, by being subjected to the material analysis of physiological investigation, that which is noble, beautiful, and purely intellectual, will be dragged into the dust. ”

“ In the picture, on the contrary, there is found in many places only as much blue as is perfectly absorbed by the yellow glass, and this, therefore, can never be perceived, however long we continue the experiment. Even for those parts of the picture which have been painted with the most intense blue the painter could produce, the quantity of blue excluded by the yellow glass will make itself felt, because its power is not so small with regard to pigments as with regard to the blue in Nature. ”

“ But it is extremely difficult and in many cases impossible to convince those of their defect who suffer from incorrect vision as to form and color. They never become conscious of it themselves, even if it is not congenital, and the most enlightened and intelligent among them remain incredulous, or become even angry and offended, when told of it. Incorrect perception of form may, however, easily be demonstrated. If in consequence of astigmatism a square appears oblong to any one, he can measure the sides with a compass ”

“ But we meet with slighter degrees of color-blindness, where the perception of red is not entirely wanting, but only considerably diminished; so that, for instance, an intense or strongly illuminated red can be perceived as such, while a less intense red appears green. This moderate degree of color-blindness does not always deter people from painting. A proof of this I saw at the last year's Exhibition, in a picture which represented a cattle-market. ”

“ To be physiologically normal is not at all a fundamental condition in art; and we cannot deny the legitimacy of the taste which regards that which is entirely sound and healthy as commonplace, trivial, and uninteresting, and which on the contrary is fascinated by that which approaches the border of disease and even, goes beyond it. ”

“ The disturbing light had been diffused by the refracting media of the eye, and had fallen on the same part of the retina on which the picture was formed. If we examine the eye by an illumination resembling that by means of which Prof. Tyndall, in his brilliant experiments, demonstrated to you the imperfect transparency of water, we find that even the clearest and most beautiful eye is not so perfectly transparent as we would suppose. The older we get the more the transparency decreases, especially of the lens. ”

“ He will see in Nature almost every thing correctly; but in his picture every thing will appear to him yellowish, and consequently he will paint it too blue. Does he not perceive this himself? Does he not believe it if told of it? Were this the case, it would be easy for him to correct the fault, since an artist can paint in a yellower or bluer tone, as he chooses. ”

“ Even less illuminated objects, like houses or figures, form considerably elongated streaks of light. In this manner, therefore, houses that stand near the water, or people in a boat, blend so entirely with the reflection in the water, that the horizontal line of demarcation between house and water or boat and water entirely disappears, and all becomes a conglomeration of vertical lines. ”

“ The slighter degrees of this anomaly, in the form of an insufficient perception of colors, have probably been the real cause why several great artists, who have become famous on account of the beauty of their drawing and the richness of their compositions, have failed to attain an equal degree of perfection in coloring. ”

“ The fact is, it is impossible to change the sky-blue of the first picture so as to form a color that looks like it when seen through a yellow glass. If more white is added, the sky becomes too pale; if a deeper blue is used, it becomes too dark. Mulready was thus forced to content himself by giving to the sky in his later pictures the same color as in the earlier ones. ”

“ The portrait-painter, in whom a slight degree of astigmatism manifested itself at first only by the indistinctness of the horizontal lines, has now become far-sighted for vertical lines, and therefore sees a distant person elongated in a vertical direction ”

“ It happens that Mulready has painted the same subject twice—first in 1836, when he was 50 years of age and his lens was in a normal state, and again in 1857, when he was 71, and the yellow discoloration had considerably advanced. The first picture was called "Brother and Sister; or Pinching the Ear;" the second was called "The Young Brother." In both pictures a girl, whose back only is visible, is carrying a little child. A young peasant, in a blue smock-frock, stands to the right and seizes the ear of the child. ”

“ Many of the best musicians, for instance, and some of the greatest admirers of Beethoven, prefer his latest works, and consider them the most interesting, although the influence of his deafness upon them is apparent to others. ”

“ Such glasses produce an optical effect only in one direction. If instead of white lines I make the experiment with colored lines, it will show the mixing of colors produced by astigmatism; and if I now turn the axis of the lens, you will observe the effect of different forms of astigmatism. I show you a square (Fig. 3) : if I add a cylindrical concave glass, with its axis placed horizontally, the square becomes an oblong. ”

“ Small differences of this kind are found in almost every eye, but are not perceived. Higher degrees of astigmatism, which decidedly disturb vision, are, however, not uncommon, and are, therefore, also found among painters. ”

“ They resemble the porter of a certain dealer in works of art, who one day, when he had to deliver the torso of a Venus at a gentleman's house, answered the servant, who had expressed his astonishment that his master should have bought a thing without head, arms, or legs, "You don't understand ”