pyrosulphuric

Pyr`o*sul*phu"ric, a. Etym: [Pyro- + -sulphuric.] (Chem.) Defn: Pertaining to, or designating, an acid called also disulphuric acid) obtained by distillation of certain sulphates, as a colorless, thick, oily liquid, H2S2O7 resembling sulphuric acid. It is used in the solution of indigo, in the manufacture of alizarin, and in dehydration.

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