Fraud and forgery are described in detail; in particular coin counterfeiting by mixing copper with silver, or even admixture with iron. Tests had been developed for counterfeit coins and proved very popular with the victims, mostly ordinary people. He deals with the liquid metal mercury, also found in silver mines. He records that it is toxic, and amalgamates with gold, so is used for refining and extracting that metal. He says mercury is used for gilding copper, while antimony is found in silver mines and is used as an eyebrow cosmetic.