Color enhanced woodcut showing workers purifying silver. For coins--the use to which most silver was put--the metal obtained by the cupellation of lead was not the best,because it contained too much undesirable material. It was necessary to purify it still further,by smelting it in a porous mould prepared in a pot full of ashes,which absorbed the undesirable constituents of the alloy. This woodcut from Lazarus Ercker's 16th century book shows the far more efficient method of purification in a muffle furnace. Ercker was an important German writer on metallurgy,as well as an assayer and control tester | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / New York Public Library |
Bildgröße: | 2784 px × 3926 px |
Modell-Rechte: | nicht erforderlich |
Restrictions: |
|