Manufacture of soap: (above) men are using long implements to work at the contents of a vat; (below) instruments. Engraving by Benard after Radel.

Licence: Public Domain Mark

Credit: Manufacture of soap: (above) men are using long implements to work at the contents of a vat; (below) instruments. Engraving by Benard after Radel. Wellcome Collection. Source: Wellcome Collection.