Wax representations made from white lead and cerussite are not made to be burned and melted in a mold where you want to cast silver and gold; this would make it brittle. Moreover if you use such a mold, the wax would be stripped thanks to the violence of the fire which makes it boil, and the mixture made of cerrusite or any other metal would attack the mold. That’s why if you want to sketch things
at left bottom margin of folio 131r
+White wax is more delicate than the other, and it doesn’t leave any filth when you want to mold it as a core, or to mold hollow.
to be cast with gold and silver. Do not add to your wax all the drugs you are preparing, but only melted sulphur, as the candle melts, and also candle smoke. Melted sulphur falls down to the bottom of your mold, but lets the wax keeps some of its quality, melting it but leaving it a little firm. You can thus melt your wax representation on fire. If your wax is composed of cerussite or something similar, you need to put your mold into boiling water.
at left top margin of folio 131v
You don’t need all this to mold flat representations made of wax, because the wax can be removed completely from the mold, and won’t remain inside it.