Natrium

1874 June 19, H. Beins, The Successor of Steam, The Chemical News and Journal of Physical Science, Volume XXIX.—1874, page 267, It occurred to us to make an experiment to see what degree the tension of the carbonic acid given off by natrium-bicarbonate would amount to, when heated in a closed space.

1991, S. O'Neill, M. Valdeolmillos, C. Lamont, P. Donoso, D. Eisner, The contribution of natrium-calcium exchange to relaxation in mammalian cardiac muscle, Annals of the New York Academy of Science, Volume 639, pages 444-452, cited in 2002, Christian J. F. Holubarsch, Mechanics and Energetics of the Myocardium, page 165,

The highest solute content (more then 1000 mg/L) and value of pH is found in the urban runoff from residential and transport zones, as well as the maximum concentrations of suspended solids, chlorides, natrium and nitrites.