377 LECTURE IX. ON CHIARO-OSCURO. THE GENTLEMEN, HE principle of the art of painting to which I would now direct your attention, is CHIARO-OSCuro. It comprehends not only light and shade, without which the forms of no object can be perfectly represented; but also, all arrangements of light and dark colours, in every degree: in short, in accordance with the words composing its name, which we have adopted from the Italian, the light and dark of a picture. Though the laws of nature, as illustrated by the science of optics, must be the guiding principles of the painter in the representation of natural objects, it is in his own power to command the course, and the degree, and the colour of the light which illumines them. He can likewise, so direct the illumination he employs, in accordance with the arrangement of his figures and the forms produced by their combinations, that he may cause them to take any order, or variety of effect, most agreeable to his taste. By the introduction of extraneous objects, or the supposition of them, he may produce shadows upon his figures; and by such artificial means, aiding the natural effects of light and shade, he may create masses of light and dark composing agreeable forms throughout the surface of his pictures. The result of these combinations, which are now become essential to good painting, is understood by the compound word, CHIARO-OSCURO; and also by the simple one, EFFECT. As it is by light and dark hues of colour, producing light and shade, that the appearance of projection is given to the forms of objects exhibited by design upon a flat surface; it is by Chiaro-oscuro in its most extended sense, that all those objects which are represented in a picture are made to operate to one end. It is therefore the most efficient means in possession of a painter for directing the attention of an observer to whatever portion of his picture he thinks proper. Chiaro-oscuro thus becomes the governing principle of effect in painting; or that control over design, composition, and colouring, which most agreeably unites and displays the perfections of each, or of them all; or which (so powerful is its influence), can disguise their defects, and render pleasing, works deficient in those important requisites of fine art. It is producible by light and shade only, or by light and dark colours; but is generally the most effective when they are combined: that is, when order and arrangement are given to masses of light or of shade, by uniting them with light or dark colours. Thus, without falsifying the nature of the illumination employed, painters obtain breadth and arrangement of light and dark throughout the surfaces of their pictures; or, in the technical phrase of the art, Chiaro-oscuro. Before I treat of this artificial management of light and dark, it is necessary that I should more distinctly dwell upon the properties of light itself. I do not mean in its natural qualities as sought by the philosopher, but by the painter, in the effects it produces on our sense of vision by its reflection from the surfaces of objects, and from the atmosphere around us; and of its privation also, which we call shadow. The varied influence of that great element of nature, light, seen throughout the progress of the day, the twilight, and the moon-illumined night; in the rays of fire, or of the torch, or the lightning, has been from time immemorial, the theme of the poet; far more is it a medium of effect fitted for the employment of the painter. |