COCHINEAL, a natural dye-stuff used for the production of scarlet, crimson, orange and other tints, and for the prepara tion of lake and carmine. It consists of the females of Dacty lopius coccus, an insect of the family Coccidae of the order Hemiptera, which feeds upon various species of Cactaceae, especially nopal, Opuntia coccinelli f era, a native of Mexico and Peru. The dye was introduced into Europe from Mexico, where it had been used long before the entrance of the Spaniards. Cochineal has almost entirely been replaced by aniline dyes. The male of the cochineal insect is half the size of the female, and, unlike it, is devoid of nutritive apparatus ; it has long white wings, and a body of a deep red colour, terminated by two diverging setae. The female is wingless, and has a dark-brown plano-convex body; it is found in the proportion of 150-200 to one of the male insect. The dead body of the mother insect serves as a protection for the eggs until they are hatched. Cochineal is now furnished not only by Mexico and Peru, but also by Algiers and southern Spain. It is collected thrice in the seven months of the season. The insects are carefully brushed from the branches of the cactus into bags, and are then killed by immersion in hot water, or by ex posure to the sun, steam, or the heat of an oven—much of the variety of appearance in the commercial article being caused by the mode of treatment. The dried insect has the form of irregular, fluted and concave grains, of which about 70,000 go to a pound. The best crop is the first of the season, which consists of the un impregnated females ; the later crops include an admixture of young insects and skins, which contain proportionally little colour ing matter.
Cochineal owes its tinctorial power to the presence of a sub stance termed cochinealin or carminic acid, (the formula shown by Dimeoth in 192o), which may be prepared from the aqueous decoction of cochineal. Cochineal also contains a fat and wax; cochineal wax or coccerin, C30H60(C31H6103)2, may be extracted by using benzene; the fat is a glyceryl myristate C3H5