Red Lead.—A common name for minium, see [p. 148].
Rouge.—One of the names for a particular shade of the oxide reds, [see p. 150.]
Venetian Red.—A fancy name for a special shade of oxide red, see [p. 150].
Vermilion.—This old pigment is gradually going out of use; the newer reds, which are more brilliant in colour and cheaper, are gradually displacing it, although it is doubtful whether it will ever go completely out of use. It is the mercuric sulphide HgS. When pure, it is not attacked by acids or alkalies; only aqua regia, a mixture of hydrochloric and nitric acids, is capable of dissolving it, when it forms a clear solution. Heated in the flame of a Bunsen burner, it is completely volatile, a property possessed by no other pigment in common use, therefore any adulteration can be readily detected by simply heating a little vermilion in a crucible; if a known weight is taken and the residue is weighed, the amount of adulteration can be ascertained. Vermilion is chiefly adulterated with oxide of iron and orange lead. From the character of the residue left on heating in a crucible, the kind of adulteration can be readily ascertained.
(1) The following notes are taken from Christy’s translation of a brochure on the Imperial Quicksilver Works at Idria, Krain:—
In the oldest times of the existence of the present works, vermilion was manufactured. In the beginning it was merely pure pulverised cinnabar ore, then later it was a product made by sublimation from this substance; and there were formerly other works for vermilion manufacture than those for quicksilver production. When the Venetians and Dutch began to produce better wares, the production here sank steadily.
The researches of Christofoletti, 1681, and of Baron Richtenfels, 1726, for the improvement of Idrian vermilion, met with as little success as those of some Venetian women—1740-1741—who had lost their husbands in the Venetian works and had offered themselves to manufacture vermilion according to the Venetian method.
After Hacquet had strongly urged the manufacture of vermilion, Oberhüttenmeister Ignaz v. Passetzky succeeded, with the Dutchman Gussig assisting him, in making beautiful cake cinnabar in 1782, and in 1785 vermilion also, in the newly-built works on the right bank of the Idriza.
In 1796 Oberhüttenverwalter (manager of the works) Leopold v. Passetzky introduced the sublimate and precipitate manufacture, but it was abandoned as unprofitable in 1824.
The many foreign attempts to manufacture vermilion in the wet way caused similar ones here, as those of Fabriks-Controlor Rabitsch in 1838, and later of Hüttenverwalter M. Glowacki, which brought large amounts of the vermilion so manufactured into the market. Still this manufacture came to no full development, and became forgotten, until, finally, in the years 1877 and 1878, experiments led to its being discontinued on account of the costliness and uncertainty of the method. A new set of experiments in 1878 and 1879, by Assayer E. Teuber and Director of Works (Hüttenverwalter) H. Langer, under the direction of the Imperial Agricultural Ministry, led to favourable results. A new manufactory, set in operation in 1880, furnishes three sorts of vermilion manufactured in the wet way.