History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c37.56

c37.56

In general 10 parts of lead and 3 parts of tin are oxidized by continued heat and exposure to air. To the mixed oxide are added 10 parts of powdered quartz and 10 parts of common salt. The mixture is melted in crucibles. A white enamel is thereby obtained, which forms the basis of coloured enamels A soda-lead glass with tin oxide in suspension is thereby produced. The metallic oxides are added to this for colouring. The oxides of lead or of antimony produce a yellow enamel. Red enamels are obtained by a mixture of the oxides of gold and iron. The oxides of copper, cobalt and iron give green, blue and violet respectively, and a variety of intermediate colours by mixtures.