DISULPHURIC

Di`sul*phu"ric, a. Etym: [Pref. di- + sulphuric.] (Chem.)

Definition: Applied to an acid having in each molecule two atoms of sulphur in the higher state of oxidation. Disulphuric acid, a thick oily liquid, H2S2O7, called also Nordhausen acid (from Nordhausen in the Harts, where it was originally manufactured), fuming sulphuric acid, and especially pyrosulphuric acid. See under Pyrosulphuric.

Source: Webster’s Unabridged Dictionary 1913 Edition