The charge sent to the cupellation furnace would contain between 3% and 5% copper, and between 3% and 5% sulphur.
The history of cupellation is specially dealt with in note on p. 465.
The test to be applied to the regulus by way of cupellation and parting of a sample with nitric acid, requires no explanation.
If this be the case, then cupellation was practised in 2500 B.C.
By cupellation with lead, gold may be deprived of any antimony united with it.
They both recommend preserving this precipitate and its cupellation after melting with lead—which Agricola apparently overlooked.
But in either case the cupellation is imperfect, and should be repeated with a larger proportion of lead.
The refining of silver in "tests" (Latin testa) is merely a second cupellation, with greater care and under stronger blast.
cupellation, in which the lead was converted into a vitreous oxide, which was floated off from the surface of the silver.
The coppery skimmings from the cupellation furnace are referred to again in Note 28, p. 539.