Magnesium sulfate is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen, with the formula MgSO4. It is strongly hygroscopic and often encountered as the heptahydrate sulfate mineral epsomite (MgSO4•7H2O), commonly called Epsom salt. And the monohydrate, MgSO4•H2O, is found as the mineral kieserite. In gardening and other agriculture, magnesium sulfate is used to correct a magnesium or sulfur deficiency in soil. In food preparation, magnesium sulfate is used as a brewing salt in beer production or used as a coagulant for making tofu. In chemistry, anhydrous magnesium sulfate is commonly used as a desiccant in organic synthesis due to its affinity for water. For Marine use, magnesium sulfate heptahydrate is used to maintain the magnesium concentration in marine aquaria which contain large amounts of stony corals. For medicine use, it is used in pregnant women to control seizures due to certain complications of pregnancy (eg, severe toxemia) and to control high blood pressure, severe brain function problems (encephalopathy), and seizures in children who have sudden, severe inflammation of the kidneys (acute nephritis). Besides, magnesium sulfate is also used as a laxative to relieve occasional constipation.
