The New International Encyclopædia/Indian Yellow
INDIAN YELLOW, or Purree. A coloring matter highly esteemed by artists. It is exported from the East Indies and China in spherical masses, which are of a dark brown color externally, but of a bright orange yellow in the interior. It is obtained in Bengal as a sediment from the urine of cows fed on decayed and yellow mango leaves. Its odor is peculiar, and resembles that of castoreum. It consists chiefly of the magnesium salt of an acid termed purreic or euxanthic acid (C19H16O10). Alkaline solutions dissolve this acid, and form a yellow liquid. A solution of euxanthate of potash, when mixed with the solutions of the salts of the earths, gives brilliant yellow, sparingly soluble precipitates, and with acetate of lead it forms an insoluble yellow. Purree is often found adulterated with chrome yellow.