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. CXXXII. To make a fair Jacynth.

IT is scarce possible to make Iacynth, without Lead in its composition, wherefore you must put upon an Ounce of our Powder of Crystal, two Ounces and an half of Minium, with twenty four Grains of Ver∣digrease, two Drams of Sublimate, and five or six Leaves of Silver; the whole reduc'd to fine Powder in a Brass Mortar, and searced through a fine Sieve, mix them well together, and put them in a Crucible covered with another, and well luted, then bake and purifie it in a Glass-house Furnace for twelve Hours. Then take it off the Fire, then pound it again in a Brass Mortar to a fine Powder, sifting it through a fine Sieve. Then put it in a new Crucible, which cover and lute well, which set again in the Glass-house Furnace for twenty four Hours, and twelve

more in the Annealing Furnace. The Crucible being cold, take out the Matter which will be of a fine Ia∣cynth-colour, which cut and polish.