warrant. 1  authorization, sanction, or justification. 2  something that serves to give reliable or formal assurance of something; guarantee, pledge, or security. 3  something considered as having the force of a guarantee or as being positive assurance of a thing: The cavalry and artillery were considered sure warrants of success.
Potassium metal was discovered in 1807 in England by Sir Humphry Davy, who derived it from caustic potash (KOH), by the use of electrolysis of the molten salt with the newly discovered voltaic pile. Before the 18th century, no distinction was made between potassium and sodium.
Its chemical symbol is Mn and atomic number is 25. It is found in nature and in minerals. It was discovered in 1774 by Johan Gottlieb Gahn, a Swedish chemist. He isolated and discovered this pure element by heating the pyrolusite (MnO 2) mineral in the presence of charcoal.