Potassium tree leaves, adding water, heating, and evaporating the solution. When Humphry Davy first isolated the pure element using electrolysis in 1807, he named it "potassium", which he derived from the word potash. The symbol "K" stems from "kali", itself from the root word "alkali", which in turn comes from "" "al-qalyah" "plant ashes." In 1797, the German chemist Martin Klaproth discovered "potash" in the minerals leucite and lepidolite, and realized that "potash" was not a product of plant growth but actually contained a new element, which he proposed to call "kali". In 1807, Humphry Davy produced the element via electrolysis:
Potassium chloride vital in the human body, and potassium chloride by mouth is the common means to treat low blood potassium, although it can also be given intravenously. It can be used as a salt substitute for food, but due to its weak, bitter, unsalty flavor, it is usually mixed with ordinary table salt (sodium chloride) to improve the taste. The addition of 1 ppm of thaumatin considerably reduces this bitterness. Complaints of bitterness or a chemical or metallic taste are also reported with potassium chloride used in food. As a chemical feedstock, it is used for the manufacture of potassium hydroxide