The art of glass shewing how to make all sorts of glass, crystal and enamel : likewise the making of pearls, precious stones, china and looking-glasses : to which is added, the method of painting on glass and enameling : also how to extract the colours from minerals, metals, herbs and flowers ... : illustrated with proper sculptures / written originally in French, by Mr. H. Blancourt, and now first translated into English ; with an appendix, containing exact instructions for making glass-eyes of all colours.

CHAP. LXII. To make a Gold-Yellow in Glass.

GOld-colour being one of the most noble and fi∣nest we can make, by reason of its imitating the most perfect Metal in Nature, as we have said in Chap. 8. must be made with the purest Materials, and great precaution.

Take two parts of Crystal Fritt, made with Tar∣so, and not with Sand, which is not so good; and one part of Fritt composed of two thirds of Tarso, and one third of fine Salt of Polverine, prepared as in Chap. 7, pound and mix them well, and to each hundred Pound of this Composition, add one Pound of Tartar purified, pounded and searced fine; and one Pound of Manganese of Piedmont, prepared as in Chap. 18, mixing well these Powders with the two Fritts, because you must not cast them on the melted Glass as in other Colours: Then put the whole little by little into a Pot, and put them into a Furnace,

wherein let them stand at an ordinary Fire four Days, for fear the Glass rising, should run over. When that Matter is well purified, you may use it for making Vessels, and what other Works you please, which will be of a fair colour. If you would have the Co∣lour yet clearer, you must add more Powder, and you will have a very fine Golden-colour. If you would have it yet finer, take fine Crystal Fritt made of Polverine of Rochetta, and the Golden-colour will be yet more fair.