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
Calamine (mineral) century demand for latten (brass) in England came from the needs of wool-carding, for which brass-wire combs were preferred, and battery pieces (brassware formed by hammering sheet brass in a battery mill.) The only known method for producing the alloy was by heating copper and calamine together in the cementation process and in 1568 a royal charter was granted to the Society of the Mineral and Battery Works to search for the mineral and produce brass, to reduce dependence on imported metal from Germany. Factories to exploit the process were established at Isleworth and Rotherhithe. By the late 17th century