Epsom Salt is a pure mineral compound (Magnesium Sulfate) in crystal form. Soaking in an Epsom Salt bath is one of the most effective means of making the magnesium your body needs readily available.Known for its premium quality and many therapeutic uses, Old Tree Epsom Salt dissolves easily in warm water to help soothe muscle pain, relieve aching feet, cleanse pores, and detoxify the skin. Old Tree is a naturally translucent/white salt in medium grain and is unscented.