Sodium History

Sodium (English, soda) has long been recognized in compounds, but was not isolated until 1807 by Sir Humphry Davy through the electrolysis of caustic soda. In medieval Europe a compound of sodium with the Latin name of sodanum was used as a headache remedy. Sodium's symbol, Na, comes for the neo-Latin name for a common sodium compound named natrium, which comes from the Greek nítron, a kind of natural salt. As early as 1860 Kirchhoff and Bunsen noted the sensitivity that a flame test for sodium could have. Stating in Annalen der Physik und der Chemie in the paper "Chemical Analysis by Observation of Spectra": "In a corner of our 60 cu.m. room farthest away from the apparatus, we exploded 3 mg. of sodium chlorate with milk sugar while observing the nonluminous flame before the slit. After a few minutes, the flame gradually turned yellow and showed a strong sodium line that disappeared only after 10 minutes. From the weight of the sodium salt and the volume of air in the room, we easily calculate that one part by weight of air could not contain more than 1/20 millionth weight of sodium."