Epsom salts is magnesium sulfate or magnesium sulfate heptahydrate, also known as sulfur bitter, bitter salt, diarrhea Li salt, Epsom salts, is a magnesium compound. Heptahydrate magnesium sulfate in the air (drying), the easily weathered as powder, crystal water when heated gradually off into anhydrous magnesium sulfate, molecular formula MgSO4 (or MgSO4 · 7H2O), magnesium sulfate is a chemical raw material. Anhydrous magnesium sulfate is a commonly used chemical reagent and dry reagents. However, most often interpreted as magnesium sulfate heptahydrate magnesium sulfate, because it is not easy to dissolve, weighing more easily than anhydrous magnesium sulfate, easy in the industry, a quantitative control.