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Adulteration of Cochineal

Genuine cochineal has a specific gravity of 1.25; it is commonly increased in weight by slightly moistening it with gum water, and then rouncing it in a bag, first with sulphate of baryta, and then with finely powdered bone-black. In this way its specific gravity is raised to 1.35, by introducing about 12 per cent. of useless matter.