35. Venetian Red Or Scarlet Ocher

Venetian Red Or Scarlet Ocher. True Venetian red is believed to be a native ocher, but the various pigments sold under this name are prepared from sulphate of iron. It is frequently, during manufacture, adulterated with sulphate of lime, but this process increases its bulk and improves its mixing qualities at the expense of depth of color.

30. Indian red is a ground ore hematite or peroxide of iron, brought, as its name indicates, from Bengal, India, but may, by calcining sulphate of iron, be artificially prepared. Its tints vary greatly, but the best are those of a rosy hue. This pigment, an anomalous red of a purple-russet hue, has good body and is valued, when fine, for the pure lake-like tone of its tint. In its crude state, it is a coarse powder full of hard and brilliant particles, of dark appearance, somewhat magnetic, and, on account of a chemical tendency to deepen under this treatment, is greatly improved by grinding and washing. It is, besides, very permanent, unaffected either by light, impure air, or mixture with other pigments. Defying the effects of time or fire, it remains an opaque color, covering its surface satisfactorily. Indian red is, sometimes, called Persian red.

37. Lakes

Lakes. The name lake, given to a series of red and other colored pigments, is derived from the East Indian term lac or lacca, the material from which lakes were originally made. They are now usually prepared by precipitating colored tinctures of dyes upon alumine and other earths, etc. The lakes are, therefore, a class of pigments, numerous both with respect to variety of appellation and diversity of substance entering into their preparation. The coloring matter of common lake, also known as drop lake, is brazil wood, affording a very fugitive and unreliable color. Superior red lakes are prepared from lac, cochineal, and kermes, but the best from the root of rubia tinctorum, or madder plant.

38. Scarlet lake is one of a numerous lot of lakes made from cochineal, others being Florentine lake, Hamburg lake, Chinese lake, Roman lake, and carminated lake.

Cochineal consists of the bodies of female cochineal insects {coccus cacti) killed and dried by heat. This insect feeds on plants of the cactus family, particularly on one known in Mexico as the napal, nearly allied to the prickly pear. This insect is a small creature, a pound of cochineal containing, it is said, 70,000 dried bodies of cochineals. The male is of a deep red color, with white wings. The female, of a deep brown color, is wingless, covered with a white powder, the body being flat beneath and convex above.

Cochineal is of a deep red color which, treated with acids, becomes more or less of an orange tint, but if subjected to the influence of an alkali, turns to a violet color. Cochineal is the base of many red pigments, noted strictly for their glazing qualities.

39. Glazing is a term given to the method of spreading lakes and other transparent colors over a body color, previously applied. The effect is to add richness and depth to the under color, the transparent outer tint then receiving the name of glazing color.

40. Carmine is from kermes, the coccus ilicis, found on certain oaks in the Mediterranean. Although not generally used in house painting, this splendid color calls for notice. The name originally given to the finer tinctures of kermes and cochineal now generally denotes any pigment resembling these in beauty, richness of color, and fineness of texture. Carmines produced from cochineal, by the agency of tin, are of fine powdery texture, velvety richness, and beautiful brightness of color. Carmine was first discovered by a Franciscan monk while preparing medicine containing cochineal. It began, in 1656, to be manufactured, and is undoubtedly the finest red known. One process for its preparation is to digest 1 pound of cochineal in 3 gallons of water for 15 minutes. Add 1 ounce of cream of tartar, heat gently for 10 minutes, and, after allowing impurities to settle, the clear liquid is placed in a glass pan, when the carmine is slowly deposited. After a time the liquid is drained off, and the carmine dried in the shade on a bright, warm day.