Question: What is the historical name of the acid that dissolves phenazine?

Related documents: [0]  [DOC] Sulfuric acid (alternative spelling sulphuric acid) is a highly corrosive strong mineral acid with the molecular formula HSO and molecular weight 98.079 g/mol. It is a pungent-ethereal, colorless to slightly yellow viscous liquid that is soluble in water at all concentrations. Sometimes, it is dyed dark brown during production to alert people to its hazards. The historical name of this acid is oil of vitriol. [END] 
[1]  [DOC] Phenazine is an organic compound with the formula (CH)N. It is a dibenzo annulated pyrazine, and the parent substance of many dyestuffs, such as the toluylene red, indulines, and safranines (and the closely related eurhodines). Phenazine crystallizes in yellow needles, which are only sparingly soluble in alcohol. Sulfuric acid dissolves it, forming a deep-red solution. [END]  
Answer: oil of vitriol
oil of vitriol