Potash

Potash /ˈpɒtæʃ/ is the common name for various mined and manufactured salts that contain potassium in water-soluble form. In some rare cases, potash can be formed with traces of organic materials such as plant remains, and this was the major historical source for it before the industrial era. The name derives from "pot ash", which refers to plant ashes soaked in water in a pot.