CHAP. LXXXII. The Way to make Glass of Lead.
WE have told you the Beauty of this Glass, in Chap. 77, which may be tinged of several Colours, as Black, White, Green, and Red, which are natural to it, the degrees of the Fire only ma∣king it take those different Colours.
This Glass being well made, besides the Beauty it has, which it communicates to Glass, and to Tin∣ctures of precious Stones wherein it is employ'd, it has other great Virtues in Metallick Operations, which are not known to all the World, whereof we could largely treat, if it were not besides our Sub∣ject.
To make Vitrum Saturni: Take fifteen Pound of calcined Lead, as we have shewn in the preceding Chapter, and twelve Pound of Crystal or Rochetta Fritt, according to what colour you would have; mix them well together, and put them in a Pot in the Furnace, where ten Hours after it will be in good fusion; then cast the whole into Water, and take out speedily the remaining Lead at bottom of the Vessel, for fear it should break; then take it out of the Water and dry it, and put it into the same Pot to melt again: Take care not to put in the Grains of Lead (if there by any) which were in the Water, and which will be loosened from the Matter. After