95 FIRST DIVISION. IMITATION OF COLOURED OBJECTS, WITH COLOURED MATERIALS IN A STATE OF INFINITE DIVISION. INTRODUCTION. (255.) COLOURED materials (pigments), such as Prussian Blue, Chrome-Yellow, Vermilion, &c., are infinitely divided, so to speak, when ground, either pure, or mixed with a white material, in a gummy or oily liquid. The reproduction of the images of coloured objects with these pigments is called THE ART OF PAINTING. (256.) There are two systems of Painting, the one consists in representing as accurately as possible, upon the flat surface of canvas, wood, metal, walls, &c., an object in relief, in such manner that the image makes an impression upon the eye of the spectator similar to that produced by the object itself. (257.) From this we learn that we must manage the light, the vivacity of colour for every part of the image which in the model receives direct light, and which reflects it to the eye of one who regards the object from the point where the painter placed himself to imitate it; while the parts of the image corresponding to those which, in the same object, do not reflect to the spectator as much light as the first,-either because they reflect it in another direction, or because the salient points protect them more or less from the daylight, -must appear in colours more or less dimmed with black, or, what is the same thing, by shade. It is, then, by the vivacity of White or coloured light, by the enfeebling of light by means of Black, that the painter manages, with the aid of a plane image, to attain all the illusion of an object in relief. The art of producing this effect by the distribution of light and shade constitutes essentially what is termed the art of Chiar'oscuro. (258.) There exists a means of imitating coloured objects much simpler by the facility of its execution than the preceding. It consists in tracing the outline of the different parts of the model, and in colouring them uniformly with their peculiar colours. There is no relief, no projections; it is the plane image of the object, since all the parts receive a uniform tint: this system of imitation is painting in flat tints. FIRST SECTION. PAINTING IN CHIAR'OSCURO. CHAPTER I.-ON THE COLOURS OF THE MODEL (259.)-(298.) CHAPTER II.-ON THE DIFFERENCE EXISTING BETWEEN A COLOURED WHEN THE SPECTATOR OBSERVES IT FROM A DIFFERENT SECTION I. PAINTING ON THE SYSTEM OF CHIAR'OSCURO. CHAPTER I. ON THE COLOURS OF THE MODEL. (259.) ARE the modifications which we perceive in a single coloured object-for example, in a blue or red stuff, &c.indeterminable when these stuffs are seen as the drapery of a vestment or as furniture, presenting folds more or less prominent, or are they determinable under given circumstances? This is a question which I shall undertake to resolve. First, let us distinguish three cases where these modifications of colours may be observed. 1st CASE. Modifications produced by coloured lights falling upon the model. 2nd CASE. Modifications produced by two different lights -as, for example, the light of the sun, and diffused daylight-each lighting distinct parts of the same object. 3rd CASE. Modifications produced by diffused daylight. (260.) To render these matters easier of comprehension, we will suppose that in the two first cases the lighted surfaces are plane, and that all their superficial parts are homogeneous, and in the same conditions, except that of lighting in the second case. In the third case we shall consider the position of the spectator viewing an object lighted by diffused daylight, the surface of which is so disposed as not to act equally in all its parts upon the light which it reflects to the eye of the spectator. |