Blue

the color of the clear sky. The student of physics would say that it is the color produced by light having waves of a certain length. In the rainbow blue lies between green and indigo. Blue dyes are obtained from several sources. The Alexandria blue used by the ancient Egyptians was made from copper and lime. Cobalt blue is a dye of particular beauty. Prussian blue is a compound of iron. Saxony blue is prepared from indigo. Ultramarine blue is obtained from the mineral, lapis lazuli. Blue is a favorite with the dyer. Commercial blues are obtained chiefly from indigo and aniline preparations. Blue vitriol is sulphate of copper. Pottery blues are obtained from cobalt. The sapphire and the turquoise are blue gems. The Covenanters of Scotland carried a blue banner. They were called true blue Presbyterians. A bluestocking is a woman noted for intellectuality, possibly to the exclusion of womanly graces. Navy blue is the color of the British naval uniform. Blue is also the color of the American uniform; hence, our soldiers are called, not infrequently, "boys in blue." See Color