Di·thi·on·ic a.  Chem. Containing two equivalents of sulphur; as, dithionic acid.
  Dithionic acid Chem., an unstable substance, H2S2O6, known only in its solutions, and in certain well-defined salts.
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  Hy·po·sul·phur·ic a.  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.
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