Strontium was first detected by Crawford in Edinburgh, in 1790, although some authors credit the discovery of the element to William Cruikshank, also Scottish, in 1787. Both used the ore strontianite (SrCO3), extracted from a lead mine located in Strontian, Scotland. According to other versions, Kirwan and Klaproth are the discoverers of the element, in 1793. These chemists analyzed strontianite, and found a carbonate of a new earth, which would be called strontia. The metal was only isolated by Sir Humphrey Davy, in 1808, through the electrolysis of a mixture of strontium hydroxide with mercury oxide.