18:14 · An early chemistry sign for vitriol. The vitriols are compounds of sulphur and some metal. They are formed when a metal is dissolved in sulphuric acid and the liquid then is allowed to evaporate.
    In earlier times sulphuric acid (see in Group 53) was produced by roasting iron vitriol, i.e. . When talking about vitriol one usually referred to copper sulphate. Sulphuric acid was often referred to as vitriol oil.
    Vitriol could also be drawn and , and otherwise.