pyrosulphuric

Century Dictionary and Cyclopedia

1. Obtained from sulphuric acid by the action of heat.

Wiktionary

1. adj. UK alternative spelling of pyrosulfuric.

GNU Webster's 1913

1. adj. (Chem.) 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.