Hy`po*sul*phur"ic (?), a. [Pref.
hypo- + sulphuric.] (Chem.) Pertaining to,
or containing, sulphur in a lower state of oxidation than in the
sulphuric compounds; as, hyposulphuric acid.
Hyposulphuric acid, an acid,
H2S2O6, obtained by the action of
manganese dioxide on sulphur dioxide, and known only in a watery
solution and in its salts; -- called also dithionic acid. See
Dithionic.