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. CCXXIX. To prepare a mild and a strong Lixivium for the Lapis-Lazuli.

WE have promised to give this Preparation here, and the manner of making hereof, which we will shew, together with another stronger, to wash the Lapis withal, when 'tis mixt with the Ce∣ment, as hereafter directed.

To make these Lixiviums, take ten handfuls of Vine-stalk-Ashes well searced; put this into a large Vessel that will hold thirty Pound of Water, with a Faucet at bottom; press the Ashes very well, and put to them twenty Pound of warm Water; when 'tis sunk to the bottom, open the Faucet, so as it may only drop into an Earthen-Vessel; when 'tis all come out, stop the hole, and strain this Lixivium through a Felt Strainer, and so keep it in a Glass, or glazed Pot well covered: This is the strong Lixivium.

Again, pour in on the same Ashes, the like quan∣tity of warm Water, and do as before, so you'll have an indifferent strong Lixivium, which keep as the former.

Do this a third time, and you'll have the mild Lixivium mentioned in the preceding Chapter.

These three are very useful both for moistening, and to draw the Powder of Lapis-Lazuli from the Cement; wherewith it must be mixed, as we shall shew in the succeeding Chapters, which Separation being sometimes hard to perform, we are obliged to have recourse to these Varieties of Lixiviums stron∣ger,

or weaker, as we find them convenient for the purpose.

You may yet make another Lixivium to take away the greasiness of the Cement, thus: Boil Calx of Tar∣tar, as much as you please, in clean Water, for a∣bout a quarter of an Hour, and keep it for use as the former. This is excellent for washing the Lapis-Lazuli with; it strengthens and improves the colour thereof, is good for the Itch, Scurvey, &c. and to take away the Witherings in the Fair Sex.