Magnesium sulfate (or sulphate) is a chemical compound containing magnesium and sulfate, with the formula MgSO₄. It is often encountered as the heptahydrate, MgSO₄·7H₂O, commonly called Epsom salts. Anhydrous magnesium sulfate is used as a drying agent. Since the anhydrous form is deliquescent and therefore harder to weigh accurately, the hydrate is often preferred when preparing solutions, for example in medical preparations. Epsom salts have traditionally been used as a component of bath salts.

HISTORY
In 1618 a farmer at Epsom in England attempted to give his cows water, but they refused to drink it due to its sour/bitter taste. However the farmer noticed that the water seemed to heal scratches and rashes. The fame of Epsom salts then began to spread. Epsom salt was originally prepared by boiling down mineral waters at Epsom, England, and later prepared from sea water. In modern times, these salts are obtained from certain minerals such as epsomite.

GENERAL USES
Magnesium sulfate is used as in bath salts, particularly in flotation therapy where high concentrations raise the bath water's specific gravity, effectively making the body more buoyant. This property is also used to restore some Lava lamps damaged by being shaken by exchanging the water and adding drops of a concentrated solution until sustainable buoyancy is reached. Traditionally, it is also used to prepare foot baths, intended to soothe sore feet.