Metal fillets removed from a Boulle clock were found to be badly corroded. Analysis showed that the fillets were made of a tin amalgam, formula HgSn7, containing 20 ± 1wt percent mercury. The fillets were covered with a thick, uneven layer of corrosion made of a mixture of tin (II) oxide (SnO, romarchite) and tin (IV) oxide (SnO2, cassiterite). The corrosion of tin amalgams is discussed and documentary references to the use of tin amalgams to imitate silver inlay in cabinet making are reported.
