cupel

Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition

  • noun A porous cup, often made of bone ash, used in assaying to separate precious metals from base elements such as lead.
  • noun The bottom or receptacle in a silver-refining furnace.
  • transitive verb To assay or separate from base metals in a cupel.

from The Century Dictionary and Cyclopedia

  • noun In metallurgy, a small vessel made of pulverized bone-earth, in the form of a frustum of a cone, with a cavity in the larger end, in which lead containing gold and silver is cupeled.

Examples

  • Then a little lead (also weighed) is rolled up with the flake of silver and the two are melted at a great heat in a small vessel called a cupel, made by compressing bone ashes into a cup-shape in a steel mold.

    Roughing It

  • Ordinary lead is calcined in a cupel made of cinders or powdered bones; the lead is changed to a cinder which disappears into the cupel, and a button of silver remains.

    The Story of Alchemy and the Beginnings of Chemistry

  • His words had a passion in them not usual in the calm, pure flow most natural to his uttered thoughts; white-hot iron we are familiar with, but white-hot silver is what we do not often look upon, and his inspiring address glowed like silver fresh from the cupel.

    Ralph Waldo Emerson

  • Molten gold, with little or no silver, has a peculiar colour which is easy to recognise; it is more globular than a button of silver of the same size would be, and it shows less adhesion to the cupel.

    A Text-book of Assaying: For the Use of Those Connected with Mines.

Note

The word 'cupel' comes from a Latin word meaning 'little cup'.