Note 36 — BOOK XI. (continued 2)

This operation would bring down a button of antimony under an iron matte, by de-sulphurizing the antimony. It would seem scarcely necessary to add lead before cupellation. This process is given in an assay method, in the Probierbüchlein (folio 31) 50 years before De Re Metallica: "How to separate silver from iron: Take that silver which is in iron plechen (plachmal), pulverize it finely, take the same iron or plec one part, spiesglasz (antimony sulphide) one part, leave them to melt in a crucible placed in a closed windtofen. When it is melted, let it cool, break the crucible, chip off the button that is in the bottom, and melt it in a crucible with as much lead. Then break the crucible, and seek from the button in the cupel, and you will find what silver it contains."