lanthanum Chem.
(ˈlænθənəm)
Also 9 lant(h)anium.
[f. Gr. λανθάν-ειν to escape notice (see quot. 1841).]
A rare element belonging to the group of earth metals, found in certain rare minerals, e.g. cerite; it was discovered by Mosander 1839–41. Symbol Ln. Also attrib.
| 1841 Brande Man. Chem. (ed. 5) 877 Another metallic oxide, which, as it has hitherto lain concealed in oxide of cerium, he [Mosander] designates Lantanum (λανθανειν, to lurk). 1842 Parnell Chem. Anal. (1845) 338 Oxide of lantanium. 1849 D. Campbell Inorg. Chem. 167 Lanthanum. 1863 Fownes' Chem. (ed. 9) 320 Metallic lanthanium is prepared like cerium. Ibid., A tolerably pure lanthanium salt may be obtained by [etc.]. 1873 Ibid. (ed. 11) 381 Lanthanum Sulphate forms small prismatic crystals. |