a. Chem. [f. TETRA- + Gr. θεῖον sulphur + -IC: see -THIONIC.] In tetrathionic acid, H2S4O6, a colorless, inodorous, very acid liquid, containing four atoms of sulphur in the molecule. Hence Tetrathionate, a salt of tetrathionic acid.
1848. Chem. Gaz., 1 Jan., 13. A double salt of the pentathionate and tetrathionate of potash. Ibid., 15 Sept., 369. Under the name of polythionic acids the author [F. Kessner] comprises the trithionic, tetrathionic and pentathionic acids.
1852. Fownes’ Chem. (ed. 4), 140. Tetrathionic Acid … was discovered by … Fordos and Gélis [1843].
1854. J. Scoffern in Orr’s Circ. Sc., Chem., 285. Bisulphuretted hyposulphuric acid (Tetrathionic acid).
1868. Watts, Dict. Chem., V. 641. Tetrathionic Compounds. Ibid., Tetrathionate of Barium, Ba″S4O6 2 H2O,… is obtained in large tabular crystals.
