(die) Kupellation, (die) Treibarbeit, (das) Abtreiben A process for the production of silver, by enrichment of argentiferous (silver-bearing) lead (Pb). Oxygen is blown onto a molten silver-bearing lead "alloy". The base metal lead is oxidized, the noble metal Silver stays as rest = regulus in the cupelle. The lead oxide (Litharge) is absorbed by the cupelle. The chemical process can be described as follows: Pb and metals + O2 → PbO and base metal oxides + Pb and noble metals The process is discountinued, when all lead is oxidized.