CARMINE, a rich crimson-red pigment prepared from coch ineal (q.v.), the dried bodies of the Coccus cacti insects indige nous to Mexico and Central America. The powdered cochineal is digested with a dilute solution of carbonate of soda through which live steam is passed ; after boiling for two hours the solu tion is filtered and the colouring matter precipitated by the addi tion of a requisite amount of alum and cream of tartar. The "crimson lake" thus formed is brought to the required shade by the addition of freshly prepared hydrate of alumina and the lake is washed, filtered and dried at a low temperature. Scarlet shades are obtained by the addition of genuine vermilion along with the hydrate of alumina, whilst the addition of lime produces lakes possessing a deep purple tone. The use of carmine in water colours is giving way to the aniline dyes.
Chemically, carmine may be said to be an aluminum-calcium compound of carminic acid. As a lake it is used in water colours, in cosmetics and in the preparation of fine coach-body colours, though in this it is being gradually superseded by the more per manent lakes obtained from aniline dyestuffs. (See PAINTS, CHEMISTRY OF.) (R. S. M.; W. E. W.)