ULTRAMARINE

(Lat. ultra, beyond, and mar in us, to the sea. i The blue colouring matter of the a-t + 4 «3 lapis li/.uli. This substance is much valued by painters, 4, 0, 4, 1, on account of the beauty and permanence of its colour, UNCIALES both fur oil and water painting. In its preparation the In Diplomatics, finest lapis lazuli is selected, heated to a dull red heat, and the capital quenched in water; it is thus rendered friable, and is ground of the letters down into an impalpable powder. This is then mixed with supposed B tenacious paste made of linseed oil, wax, resin, turpentine, the third and mastic; and the mixture being kneaded in warm water tenth. ■ it the blue particles, winch Me afterwards collected UNCIFORM by sab moists have long in vain endeavoured bone of the to imitate this colour, but till lately its nature even had not its hook-like been determined. It appears from the experiments of the hand, n that sulphuret of sodium is the principle to which down the the blue colour is owing, and he has succeeded in preparing UN< '< an artificial ultramarine by beating sulphuret of sodium chord of with a mixture of silica and alumina. (See the Annates de unusual el Physique, vol. xxxvii., p. 409..I chord, wherein ba . See ULTRAMONTANE, or [s. 1297]