1-156-428 - Ann Ronan Picture Library/Heritage-Images

Refining copper using the 'Hungarian' process, 1683. Copperplate engraving showing cupellation cakes being roasted, releasing lead. The lead obtained is smelted at top left. Illustration from the 1683 English edition of Beschreibung Allerfurnemisten Mineralischen Ertzt (Treatise on Ores and Asssaying), by Lazarus Ercker, published in 1580. This edition has new plates with numbers rather than letters, but the process is faithfully copied.