123 - To Extract the Spirit of Saturn, Which Serves Many Uses in Enamels and Glasses
Take well ground litharge, put it in a glazed earthen bowl, and as above [chapter 91] add distilled vinegar, covering it to a depth of four fingers. Let it stand this way, until you see the vinegar tint up in colour of milk, which will happen quickly, then decant this coloured vinegar, and put new distilled vinegar over the litharge, as above, so it too tints up a white colour, like milk.
Decant it, and repeat this work, with distilled vinegar, until it no Ionger tints, and then put these colored vinegars in a glazed earthen basin, let it rest so the milky substance of Saturn goes to the bottom. Distill off the clear vinegar; the milky substance left, the nobler part, is the spirit of Saturn. lt serves for many things in the enamels, and glasses. If this white material does not all go to the bottom throw fresh water over it, which will force it to the bottom. Recover what still does not precipitate by evaporating the vinegar and water, so in the bottom will be the finest part of the [milky] vinegar, good for many things in the art of glassmaking.