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. CXL. Another Way of making the Diamond of Alanson.

HERE follows a way of making Diamonds of Alanson, which is not quite so fine as the prece∣dent, but has, notwithstanding, several Advantages which attend it; besides it is more easie, since there only needs an ordinary Fire to succeed in it.

Take an Earthen glazed Pot, set it on a little Fur∣nace, put in it Filings of Steel, with some Vine∣Ashes at discretion, wherein place by one another Crystals cut and polished; then pour common Wa∣ter gently on it, which warm and boil during the space of twelve Hours, taking care to add boiling Water fresh into the Vessel, as the Water in it con∣sumes by boiling, and take care it boil continually. Then see if your Crystals have acquired the colour and hardness you expected: If not, continue the Fire some Hours longer, and they will be like the true Diamonds of Alanson; taking care to repolish them again at the Wheel, to give them colour and bright∣ness.