Thiosulphate
Pronunciation : Thi`o*sul"phate
Part of Speech : n.
Definition : Defn: A salt of thiosulphuric acid; -- formerly called hyposulphite.
Note: The sodium salt called in photography by the name sodium hyposulphite, being used as a solvent for the excess of unchanged silver chloride, bromide, and iodide on the sensitive plate.
(Chem.)
Source : Webster's Unabridged Dictionary, 1913