Cobalt-containing wastes from Harz Mountain smelters resemble in composition the manillas in circulation for many centuries in West Africa. Indications are that in the 15th and 16th centuries, similar wastes from north German smelters were converted into such materials and exported to West Africa, where they were preserved intact up until 1948. Such wastes and manillas were also used, both in Europe and Africa, as additives in the smelting of brass and bronze. The chemical composition of a number of such brass and bronze specimens is given. -- AATA