In the second picture the thing to be chiefly admired, is the resemblance that the youth bears to the old man his father, allowing, of course, for the difference in age; above them soars an eagle, which grasps a dragon in its talons. Philochares[1857] attests that he is the author of this work, an instance, if we only consider it, of the mighty power wielded by the pictorial art; for here, thanks to Philochares, the senate of the Roman people, age after age, has before its eyes Glaucion and his son Aristippus, persons who would otherwise have been altogether unknown. The Emperor Tiberius, too, a prince who was by no means very gracious, has exhibited in the temple dedicated by him, in his turn, to Augustus, several pictures which we shall describe hereafter.[1858] CHAP. 11. (5.)—THE ART OF PAINTING. Thus much then with reference to the dignity of this now expiring art. We have already[1859] stated with what single colours the earlier artists painted, when speaking of these pigments under the head of metals. The new modes of painting which were afterwards discovered, and are known as “neogrammatea,”[1860] the names of the artists, their different inventions, and the periods at which these inventions were adopted, will all be described when we come to enumerate the painters: for the present, however, the proposed plan of this work requires, that I should enlarge upon the nature of the several colours that are employed. The art of painting at last became developed, in the invention of light and shade, the alternating contrast of the colours serving to heighten the effect of each. At a later period, again, lustre[1861] was added, a thing altogether different from light. The gradation between lustre and light on the one hand and shade on the other, was called “tonos;” while the blending of the various tints, and their passing into one another, was known as “harmoge.”[1862] CHAP. 12. (6.)—PIGMENTS OTHER THAN THOSE OF A METALLIC ORIGIN. ARTIFICIAL COLOURS. Colours are either[1863] sombre or florid, these qualities arising either from the nature, of the substances or their mode of combination. The florid colours are those which the employer supplies[1864] to the painter at his own expense; minium,[1865] namely, armenium, cinnabaris,[1866] chrysocolla,[1867] indicum, and purpurissum. The others are the sombre colours. Taking both kinds together, some are native colours, and others are artificial. Sinopis, rubrica, parætonium, melinum, eretria and orpiment, are native colours. The others are artificial, more particularly those described by us when speaking of metals; in addition to which there are, among the more common colours, ochra, usta or burnt ceruse, sandarach, sandyx, syricum, and atramentum. CHAP. 13.—SINOPIS: ELEVEN REMEDIES.