More than 300 objects from the Middle Ages of central Europe were analyzed by emission spectrography. It was found that copper was mined in the early periods in the Harz. First the secondary weathering products of the ores and later the primary coppersulfides were used. In the 14th century copper from the Mansfeld region predominated. Zinc ores came from the region of Aachen. Variation in compositions of the bronzes and brasses from different regions and periods can be understood by chemical analysis. -- AATA