The Collaborative International Dictionary
Sulphoarsenic
Sulphoarsenic \Sul`pho*ar*sen"ic\, a. (Chem.) Of, pertaining to, or containing, sulphur and arsenic; -- said of an acid which is the same as arsenic acid with the substitution of sulphur for oxygen.
Wiktionary
sulphoarsenic
a. (context chemistry obsolete English) Of, relating to, or containing, sulphur and arsenic; said of an acid which is the same as arsenic acid with the substitution of sulphur for oxygen.