This is the colour nearest the light. It appears on the slightest mitigation of light, whether by semi-transparent mediums or faint reflection from white surfaces. In prismatic experiments it extends itself alone and widely in the light space, and while the two poles remain separated from each other, before it mixes with blue to produce green it is to be seen in its utmost purity and beauty. How the chemical yellow developes itself in and upon the white, has been circumstantially described in its proper place. 766. In its highest purity it always carries with it the nature of brightness, and has a serene, gay, softly exciting character. 767. In this state, applied to dress, hangings, carpeting, &c., it is agreeable. Gold in its perfectly unmixed state, especially when the effect of polish is superadded, gives us a new and high idea of this colour; in like manner, a strong yellow, as it appears on satin, has a magnificent and noble effect. 768. We find from experience, again, that yellow excites a warm and agreeable impression. Hence in painting it belongs to the illumined and emphatic side. 769. This impression of warmth may be experienced in a very lively manner if we look at a landscape through a yellow glass, particularly on a grey winter's day. The eye is gladdened, the heart expanded and cheered, a glow seems at once to breathe towards us. 770. If, however, this colour in its pure and bright state is agreeable and gladdening, and in its utmost power is serene and noble, it is, on the other hand, extremely liable to contamination, and produces a very disagreeable effect if it is sullied, or in some degree tends to the _minus_ side. Thus, the colour of sulphur, which inclines to green, has a something unpleasant in it. 771. When a yellow colour is communicated to dull and coarse surfaces, such as common cloth, felt, or the like, on which it does not appear with full energy, the disagreeable effect alluded to is apparent. By a slight and scarcely perceptible change, the beautiful impression of fire and gold is transformed into one not undeserving the epithet foul; and the colour of honour and joy reversed to that of ignominy and aversion. To this impression the yellow hats of bankrupts and the yellow circles on the mantles of Jews, may have owed their origin. RED-YELLOW. 772. As no colour can be considered as stationary, so we can very easily augment yellow into reddish by condensing or darkening it. The colour increases in energy, and appears in red-yellow more powerful and splendid. 773.