copple dust

English

Noun

copple dust (uncountable)

1. (obsolete) Cupel-dust; powder used in refining metals, or the gross parts separated by the coppel.
   • a. 1626, Francis Bacon, Inquisitions touching the compounding of metals:

     It may be also tried , by incorporating powder of steel , or copple-dust , by pouncing into the quick - silver , and so to proceed to the stupifying UPON glass