Sunday, 10 March 2013

Going for gold




Ever wondered how the ancients refined precious metals? This is Pliny's explanation for the production of pure gold - "Gold is first heated with twice its weight of salt, three times its weight of copper pyrites, and then heated again with two parts salt and one of alum (most likely iron sulphate rather than potassium aluminium sulphate in this case). This process removes the impurities when the other substances have been burnt away in an earthenware crucible." For more Roman history check out 'Vagabond' - live on Amazon now or on YouTube