Group 12 element people in the 17th century. German chemist Andreas Marggraf is usually given credit for discovering pure metallic zinc in a 1746 experiment by heating a mixture of calamine and charcoal in a closed vessel without copper to obtain a metal. Experiments on frogs by the Italian doctor Luigi Galvani in 1780 with brass paved the way for the discovery of electrical batteries, galvanization and cathodic protection. In 1880, Galvani's friend, Alessandro Volta, invented the Voltaic pile. The biological importance of zinc was not discovered until 1940 when carbonic anhydrase, an enzyme that scrubs carbon dioxide from blood, was shown to
Ore Mountains last silver mines closed and the company was disbanded. Mining in the Ore Mountains was given new life during the First and Second World Wars in order to supply raw materials. The Third Reich also saw the resumption of silver mining. Afterwards the people returned to the manufacture of wooden products and toys, especially in the Eastern Ore Mountains. The clock industry is centred on Glashütte. In the Western Ore Mountains, economic alternatives were offered by the engineering and textile industries. In 1789 the chemical element uranium was discovered in St. Joachimsthal; then in pitchblende from the same area, radium