GLASS PAINTING. In Painting, the method of staining glass in such a manner as to produce the effect of repre senting all the subjects whereof the art is susceptible. A French painter of Mar seilles is said to have been the first who instructed the Italians in this art, during the pontificate of Julius II. It was, how ever, practised to a considerable extent by Lucas of Leyden, and Albert Durer. The different colors are prepared as follows : Black is composed of two-thirds of iron scales or flakes, and the other third of small glass beads, or a substance called roecaglia by the Italians. White is fire pared from sand, or small white pebbles, calcined, pounded, and then ground finely ; one fourth part of saltpetre is ad ded, and the mixture is then again cal cined and pulverized : when dyed, a lit tle gypsum or plaster of Paris is added. Yellow is formed from leaf silver ground and mixed in a crucible with saltpetre or sulphur; then ground on a porphyry stone; and, lastly, ground over again with nine times the quantity of red ochre. Red, one of the most difficult of the colors to make, i is prepared of li tharge of silver and iron scales, gum Ara bic, ferretta, glass beads, and bloodstone, in nearly equal quantities. Experience
alone will command success in making this color. Green is formed from as ustum one ounce, the same quantity of black lead, and four ounces of white lead, incorporated by the action of fire. When calcined a fourth part of saltpetre is ad ded, and after a second calcination a sixth part more ; after which a third coction is made before using it. Azure, purple, and violet are prepared in a similar man ner to green, omitting the acs and in its stead using sulphur for azure, perigneux for purple, and both these drugs for violet. Carnation's are com pounded colors, are calcined, and mostly mixed with water, and must be finished part by part, and each with great dis patch, before the plaster dries, and there is little opportunity for blending. The lights cannot be heightened; but the shadows may, when they begin to dry, be a little strengthened. Promptitude and facility in execution are the great requisites for this method of painting.