As with particular tones, so with colours generally. People habituated to conditions of nature where extremes of sun effects are uncommon, as in the northern latitudes, may be temporarily pleased with schemes of glowing colours on their walls, because these relieve the monotony of daily experience, but they must necessarily quickly tire, as with all exceptional conditions of life which are concerned with the senses only. How soon one is fatigued with bright colours generally is obvious to any visitor to a public gallery which is crowded with pictures. In an hour or less the fatigue of his eyes becomes so extreme that his whole nervous system is affected, and he loses energy of both mind and body. But brilliant colors used sparingly with good designs may be a perpetual source of pleasure. Place a fine work by Rubens or Paolo Veronese in a living-room and it will attract attention every time one enters, for the colouring will always be a change from the normal eye experience. One turns to the picture involuntarily, and then the design is observed, and so one passes from sensual to intellectual pleasure. This process is repeated day by day, and the work never tires. Of course it is a condition that the design is able to hold the attention, otherwise the bright colours would serve little better purpose than if they defined a geometrical pattern. Nowadays quite a number of paintings are produced in which unusual tones are given to signs or shadows, but these are not to be taken seriously by the earnest student. In the sunlight, amidst certain surroundings, the arm of a woman may appear for some moments to have a bluish tone, but the artist would be entirely wrong to paint a bluish arm. The picture is to be seen under all lights, and if the tones be contrary to general experience under any of these lights, then the work appears to be a falsity, for the artist does not, and cannot, reproduce the conditions which together bring about the exceptional colours. To the normal eye under ordinary circumstances, the arm of a woman is of flesh colour, and the artist is not at liberty to vary this tone. He has to represent what appears to be true in general opinion, whether it be really true or not under certain conditions. The dictum of Aristotle in regard to poetry--that what appears probable, though in reality is impossible, is better than what seems improbable but is really possible--is equally true in painting. In fact it is of more importance that this maxim should be remembered in painting than in poetry, because the signs of the painter are permanent. A poet or novelist may refer to a passing exceptional sun effect, for the impression on the mind of the reader would probably be as transient as, or more transient than, the effect itself, but with the painter the transient effect becomes fixed. The blue arm is always blue, and in a very short time becomes a disagreeable unreality. It may be claimed that the objectionable sun