Magnesium the water's bitter taste, but the farmer noticed that the water seemed to heal scratches and rashes. The substance became known as Epsom salts and its fame spread. It was eventually recognized as hydrated magnesium sulfate, ·7. The metal itself was first isolated by Sir Humphry Davy in England in 1808. He used electrolysis on a mixture of magnesia and mercuric oxide. Antoine Bussy prepared it in coherent form in 1831. Davy's first suggestion for a name was magnium, but the name magnesium is now used. Magnesium is the third-most-commonly-used structural metal, following iron and aluminium. The main applications of
Magnesium oxychloride at about 23 °C, the completely liquid region has vertices at the following triple equilibrium points (as mass fractions, not molar fractions): The other vertices are pure water, magnesium chloride hexahydrate, and the saturated solution (0.0044 MgO + 0.9956 by mass). The anhydrous forms decompose when heated above 450-500 °C by decomposition of the hydroxide and chloride anions, releasing water and hydrogen chloride and leaving a magnesium oxide residue, by the reactions: Extended exposure of magnesium oxychlorides to water leaches out the soluble , leaving hydrated brucite . On exposure to the atmosphere, the oxychlorides will slowly react with carbon