Vermilion is a sulphuret of mercury, which, previous to its being levigated, is called cinnabar. It is an antient pigment, the I Vermilion 9 of the Greeks, and is both found in a native state and produced artificially. Vermilion probably obtained its name from resemblance, or admixture with the beautiful, though fugitive, colours obtained from the vermes, or insects which yield carmines. [See Kermes Lake.} The Chinese possess a native cinnabar so pure as to require grinding only to become very perfect vermilion, not at all differing from that imported in large quantities from China: it is said also to be found in abundance in Ca-rinthia, in the Palatinate, Friuli, Bohemia, Al-maden in Spain, the principality of Deux-Ponts, and also in South America, particularly in Peru, etc. Chinese vermilion is of a cooler or more crimson tone than that generally manufactured from factitious cinnabar in England, Holland, and different parts of Europe. The artificial, which was antiently called minium, a term now confined to red lead, does not differ from the natural in any quality essential to its value as a pigment; it varies in tint from dark red to scarlet; and both sorts are perfectly durable and unexceptionable pigments, - the most so, perhaps, of any we possess, when pure. It is true, nevertheless, that vermilions have obtained the double disrepute of fading in a strong light and of becoming black or dark by time and impure air; but colours, like characters, suffer contamination and disrepute from bad association: it has happened, accordingly, that vermilion which has been rendered lakey or crimson by mixture with lake or carmine, has faded in the light, and that when it has been toned to the scarlet hue by red or orange lead it has afterwards become blackened in impure air, etc, both of which adulterations were formerly practised, and hence the ill fame of vermilion both with authors and artists. We therefore repeat, that neither light, time, nor foul air, effect sensible change in true vermilions, and that they may be used safely in either water, oil, or fresco, - being colours of great chemical permanence, unaffected by other pigments, and among the least soluble of chemical substances.

Good vermilion is a powerful vivid colour, of great body, weight, and opacity; - when pure, it will be entirely decomposed and dissipated by fire in a red heat, and is, therefore, in respect to the above mixtures, easily tested. This pigment, discovered, according to Theophrastus, by Callias, an Athenian, was so esteemed by the Romans, we are told by Pliny, as to have had its price fixed by an express law of the state.

The following brilliant pigment from iodine has been improperly called vermilion, and, if it should be used to dress or give unnatural vividness to true vermilion, may again bring it into disrepute. When red or orange lead has been substituted for or used in adulterating vermilion, muriatic acid applied to such pigments will turn them more or less white or grey; but pure vermilions will not be affected by the acid, nor will they by pure or caustic alkalis, which change the colour of the reds of iodine. By burning more or less, vermilion may be brought to the colour of most of the red ochres.