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. CCXLIV. To make Mercury-Water for giving Transparency and Splendour to the Pearls.

HAVING promised this Secret of making Mer∣cury-Water to compleat the Transparency, and Natural Lustre of your Pearls, which is a Mat∣ter so highly valuable, that a very considerable Sum has been offered in our Presence, for the Discovery thereof, to a certain Person; yet we are free, that Ex∣perience should have its due course of informing the Ignorant, and shall, for our part, generously acquit our Engagement.

You must take Plate Tin of Cornwall calcined, let the Calx be very fine and pure, amalgamate one Ounce thereof, with two Ounces of prepared Mer∣cury well purified; wash the Amalgama with Wa∣ter, until the Water remains clear and insipid; then drying the Amalgama throughly, put it into a Ma∣trass

over a Furnace, keeping such a degree of heat as is required for Sublimation; when the Matter is well Sublimated, take off the Matrass and let it cool, and so take out the Sublimate; to which add one Ounce of Venice Sublimate and grind them well to∣gether on a Marble, so put them into another Ma∣trass, close it very well, and set it topsy-turvy in a Pail of Water, and the whole Mass will resolve its self in a little time, all into Mercury-Water: This done, filter it into a Glass Receiver, and set it on a gentle Ash-Fire to coagulate, and it will be brought to a Crystalline Mass; take it 〈◊〉〈◊〉, and with a Glass Pestle and Mortar pound it very well to a very fine Powder, which searce through a fine Searce, and put it into a well stopt Matrass in B. Mariae, let∣ting it remain till it resolve again into Water; and this last shall be the Mercury-Water which you must preserve to employ on your Pearl.