DECOLOR A′TION

The blanching or removal of the natural colour of any substance. Syrups and many animal, vegetable, and saline solutions are decoloured or whitened by agitation with animal charcoal, and subsequent subsidence or filtration. Many fluids rapidly lose their natural colour by exposure to light, especially to the direct rays of the sun. In this way castor, nut, poppy, and several other oils are whitened. Fish oils are partially deodorised and decoloured by filtration through animal charcoal. Cottons and linens are still commonly bleached by the joint action of light, air, and moisture. The peculiar way in which light produces this effect has never been satisfactorily explained. The decoloration of textile fabrics and solid bodies generally is called bleaching. See Blanching , Bleaching , Oils , Tallow , Syrups , Sugar , .