potassium

[1963] The Discovery of Potassium and Sodium, and the Problem of the Chemical Elements ; Robert Siegfried ; ISIS 54 (1963) p. 247 [lien]
[2000] Devitalising the Elements: Johann Friedrich John (1782–1847) and the Liberation of Phosphorus and Potassium from a Vital Force ; Theodore L. Sourkes ; Ambix 47 (2000) p. 37 [lien]