SIMPLICITY (which I am last to speak of) in the disposition of a great variety, is best accomplished by following nature's constant rule, of dividing composition into three or five parts, or parcels, see Chapter IV on simplicity: the painters accordingly divide theirs into fore-ground, middle-ground, and distance or back-ground; which simple and distinct quantities _mass_ together that variety which entertains the eye; as the different parts of base, tenor, and treble, in a composition in music, entertain the ear. Let these principles be reversed, or neglected, the the light and shade will appear as disagreeable as fig. [91 T p. II], whereas, was this to be a composition of lights and shades only, properly disposed, tho' ranged under no particular figures, it might still have the pleasing effect of a picture. And here, as it would be endless to enter upon the different effects of lights and shades on lucid and transparent bodies, we shall leave them to the reader's observation, and so conclude this chapter. [Illustration: Fig. 91] CHAPTER XIV. _Of COLOURING_. By the beauty of colouring, the painters mean that disposition of colours on objects, together with their proper shades, which appear at the same time both distinctly varied and artfully united, in compositions of any kind; but, by way of pre-eminence, it is generally understood of flesh-colour, when no other composition is named. To avoid confusion, and having already said enough of retiring shades, I shall now only describe the nature and effect of the prime tint of flesh; for the composition of this, when rightly understood, comprehends every thing that can be said of the colouring of all other objects whatever. And herein (as has been shewn in Chapter VIII, of the manner of composing pleasing forms) the whole process will depend upon the art of varying; i. e. upon an artful manner of varying every colour belonging to flesh, under the direction of the six fundamental principles there spoken of. But before we proceed to shew in what manner these principles conduce to this design, we shall take a view of nature's curious ways of producing all sorts of complexions, which may help to further our conception of the principles of varying colours, so as to see why they cause the effect of beauty.