カリウム

1807 also anchors potassium: Humphry Davy isolated it from caustic potash, KOH, and later element tables kept the symbol K. German Kalium names the element behind that symbol, and Duden defines Kalium as an alkali metal with sign K. PubChem traces K to Latin kalium, with an Arabic qali background for alkali. Japanese カリウム follows Kalium, not English potassium. Japanese chemical writing used カリウム before the Meiji state; Kotobank's Seisenban Nihon Kokugo Daijiten gives 舎密開宗, published 1837-47, as an early source. Meiji schools and medical texts then regularized names such as ナトリウム, カルシウム, and マグネシウム. The semantic range stayed near the element, but it expanded into salts and physiology, including 塩化カリウム and 血清カリウム. Modern Japanese uses カリウム in nutrition, medicine, agriculture, and chemistry, especially for intracellular fluid and fertilizer discussions. English speakers usually say potassium for K, so the Japanese form is not obviously related to the English name. The actual mismatch is between English and the symbol: カリウム keeps the Kalium side of K. Example: バナナはカリウムを含む.