He [the artist] ought to have 'these powerful organs of expression' - colour and chiaroscuro - entirely at his command, that he may use them in every possible form, as well as that he may do with the most perfect freedom; therefore, whether he wishes to make the subject of a joyous, solemn, or meditative character, by flinging over it the cheerful aspect which the sun bestows, by a proper disposition of shade, or by the appearances that beautify its arising or its setting, a true "General Effect" should never be lost sight of.