2-490-612 - Historisk Bildbyrå/Mustang media/Heritage Images

Carl Wilhelm Scheele, 18th century Swedish chemist. Scheele (1742-1786) played an important role in discrediting the theory of phlogiston in chemistry. He is widely believed to have discovered oxygen before Joseph Priestley or Antoine Lavoisier but did not publish his work before them. He discovered chlorine in 1774 but mistakenly believed it to be 'dephlogisticated muriatic acid', a gas containing oxygen. It was not until 1810 that Humphry Davy correctly proved that it was a separate element. Scheele's early death is thought to have been caused by the cumulative effects of exposure to the dangerous chemicals, notably heavy metals, that he used in his experiments.