Corrosion products on metal objects from the Thames river (England) waterfront sites are described. Analysis revealed sulphides, such as chalcopyrite, pyrrhotite, chalcocite and covellite, attributed to sulphate-reducing bacteria in wet, anaerobic conditions. The stability of these products is discussed: alteration products may be harmful to metal objects. Comparison is made with similar material in natural history collections. Some treatments for removal of sulphides on copper alloys are evaluated. Photographs, tables, references.