Group 12 element have zinc in its active site. In 1817, cadmium was discovered in Germany as an impurity in zinc carbonate minerals (calamine) by Friedrich Stromeyer and Karl Samuel Leberecht Hermann. It was named after the Latin "cadmia" for "calamine", a cadmium-bearing mixture of minerals, which was in turn named after the Greek mythological character, Κάδμος Cadmus, the founder of Thebes. Stromeyer eventually isolated cadmium metal by roasting and reduction of the sulfide. In 1927, the International Conference on Weights and Measures redefined the meter in terms of a red cadmium spectral line (1 m = 1,553,164.13 wavelengths). This definition has since
Breinigerberg its calamine flora. The hill of "Schlangenberg" is 276 metres above sea level and originates in the former ore mine of Breinigerberg. Names like "Bleiweg", which means "Way of lead", even today, give hints to the history of the village. The calamine from the ore mine Breinigerberg was used exclusively in Stolberg for the production of brass. The history of Breinigerberg can be traced back to the Romans. Twenty five coins dated between 100 BC and the year 92/93 AD as well as remains of a Roman craftsmen settlement had been found in the village. The buildings show that the