_Native Ultramarine_, _Natural Ultramarine_, _Real Ultramarine_, _True Ultramarine_, _Ultramarine_, _Pure _Ultramarine_, _Azure_, _Outremer_, _Lazuline_, _Lazulite Blue_, and _Lazurstein_. This most costly, most permanent, and most celebrated of all pigments, is obtained by isolating the blue colouring matter of the _lapis lazuli_, a stone chiefly brought from China, Thibet, and the shores of Lake Baikal. About the antiquity of the stone, and its colour, much has been written, and many conflicting statements have been made; but there is little doubt that our lapis lazuli was the sapphire of the ancients; and that the first certain mention of ultramarine occurs in a passage of Arethas, who lived in the eleventh century, and who, in his exposition of a verse in the book of Revelation, says, the sapphire is that stone of which _lazurium_, as we are told, is made. It has been common to confound ultramarine with the _cyanus_ and _coeruleum_ of the ancients; but their cyanus, or Armenian blue, was a kind of mineral or mountain blue, tinged with copper; and their coeruleum, although it may sometimes have been real ultramarine, was properly and in general a copper ochre. That ultramarine was known to the ancients there seems every probability, for it is certain they were acquainted with the stone; and modern travellers describe the brilliant blue painting still remaining in the ruins of temples of Upper Egypt as having all the appearance of ultramarine. Whether it is so or not, however, could only be proved by analysis; for, be it recollected, although the colour had preserved its hue during so many centuries, it had been completely buried, and therefore most perfectly secluded from light and air. Mr. Layard, in his 'Nineveh,' referring to some painted plaster, remarks that "The colours, particularly the blues and reds, were as brilliant and vivid when the earth was removed from them as they could originally have been; but, on exposure to the air, they faded rapidly." In all likelihood, these were of organic, or semi-organic, origin, prepared in some such manner as that mentioned by Pliny, who speaks of an earth which, when boiled with plants, acquired their blue colour, and was in some measure inflammable. As a pigment, cobalt was unknown to the ancients; but to these vegetable and copper blues of theirs, a third blue may perhaps be added. Experiments made upon blue tiles, found in a Roman tesselated foot-pavement at Montbeillard, showed that the colour was due to iron. M. Gmelin has proved that a blue tint can be imparted to glass and enamel by means of iron; and it is probable that the ancients were first induced by the blue slag of their smelting-houses to study the colouring of glass with iron; that in this art they acquired a dexterity not possessed at present, and that they employed their iron-smalt as a pigment, as we do our smalt of cobalt. To sum up, there are grounds for believing that the ancients were acquainted with copper blues,