unadorned, white-washed walls, and justify their want of taste by a reference to nature, whose light and atmosphere, they will tell you, they are admitting. And like this is the argument of many an artist, when he would cover the poverty of his invention under the plea of his imitation of nature--a plea, too, urged in ignorance of nature, for nature does actually endeavour--if such a word as endeavour maybe used where all is done without effort--to subdue the rawness of every colour, and even to stain the white-wash we put upon her works, and covers the lightest rocks with lichen. But as the mind _colours_, and absolute naturalness is not necessary, it results that there must be a science by which the mind can effect its purpose. For the cultivation of a sense arises from a want which the mind alone at first feels, and to the mind in that state of desire things speak suggestively that were before mute; discoveries are made into the deeper and previously hidden secrets of nature, and new means are invented of gratifying the awakened senses. Hence all art which is above the merely common and uncultivated sense. All we see and all we hear takes a vitality not its own from our thoughts, mixes itself (as aliment does, and becomes our substance) with our intellectual texture, and is anew created. Winds might have blown, and wild animals have uttered their cries, but it was the heightened imagination that heard them _howl_ and _roar_. And it was from a further cultivation of the sense, giving forth, at every step, new wants, that the nature of all sounds was investigated and music invented--science but discovering wonderful mysteries, secrets, and gifted faculties drawing them out of their deep hiding-places, making them palpable, and combining and converting them into humanities whereby mankind may be delighted and improved. If, then, the ear has its science, so has the eye. There is the mystery of colours as well as of sounds. Nor can it be justly said that we are out of nature because we pursue that mystery beyond its commonly perceptible and outward signs to its more intricate truths; nay, on the contrary, as we have thereby _more_ of those truths, we have _more_ of nature; and we know them to be truths by their power and by their adoption. This science of colour has been, perhaps, too much neglected. In conversing with artists, one is surprised how little attention they have paid to it; and even where it has been studied, it is only upon its surface, and by those well known diagrams which show the oppositions.