[O]n this idea, in naming the bases of potash and soda, it will be proper to adopt the termination which, by common consent, has been applied to other newly discovered metals... Potasium and sodium are the names...
1808, Humphry Davy, The Bakerian Lecture, on some new Phenomena of chemical Changes produced by Electricity, particularly the Decomposition of the fixed Alkalis, and on the Exhibition of the new substances which constitute their bases; and on the general Nature of alkaline Bodies, Philosophical Transactions of the Royal Society of London, Part 1, p. 32.