‖ thoria Chem.
(ˈθɔərɪə)
[f. as thorium + -a, after alumina, magnesia, silica, etc.]
An oxide of thorium, ThO2; a very heavy white substance discovered in the mineral thorite by Berzelius, 1828, and named by him in Swedish, Thorjord, Ger. Thorerde, lit. Thor-earth. Now important in the manufacture of incandescent gas mantles. Also attrib.
| 1847 in Webster. 1881 Watts Dict. Chem. VIII. 1967 Thorium Oxide, or Thoria,..is insoluble in dilute acids. 1899 Westm. Gaz. 10 June 6/3 The expiry of the master patent this year, and the thoria patent next spring. 1904 Ibid. 16 Apr. 7/1 About [1888] experiments on incandescent mantles gave to thoria considerable commercial value. A mantle of pure thoria gives a very little light; but, on the other hand, it gives a stability to the fragile mantle which no other body yet discovered is able to do. |