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.
According to his Nobel Committee biography, Ramsay went on to discover Helium in 1895; and in 1898 he found Neon, Krypton and Xenon. In mid-1894, Sir William Ramsay worked in conjunction with John William Strutt, Lord Rayleigh, on research which led to the discovery of Argon. They announced the discovery at the meeting of the British Association in August 1894, and in 1904 were awarded Nobel Prizes for the discovery.