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

Context paragraphs:
Dorobanțu, Tulcea: Dorobanțu is a commune in Tulcea County, Romania.  It is composed of five villages: Ardealu (depopulated as of 2002, historical name: "Asînlar"), Cârjelari, Dorobanțu, Fântâna Oilor (historical name: "Coiumbunar" or "Coiumpunar") and Meșteru (historical name:"Canat Calfa").

Iodic acid: Iodic acid, HIO, can be obtained as a white or off-white solid.  It dissolves in water very well, but it also exists in the pure state, as opposed to chloric acid or bromic acid.  Iodic acid contains iodine in the oxidation state +5 and it is one of the most stable oxo-acids of the halogens in its pure state.  When iodic acid is carefully heated, it dehydrates to iodine pentoxide.  On subsequent heating, the iodine pentoxide further decomposes, giving a mix of iodine, oxygen and lower oxides of iodine.

Yulin, Guangxi: Yulin (), formerly romanized as Watlam, is one of the fourteen prefecture-level cities of the Guangxi Zhuang Autonomous Region, People's Republic of China.  Its Chinese name was changed in 1956 from the historical name 鬱林 (), which only sounds the same in Mandarin as the current one, but very different in the local dialect of Yue Chinese; 鬱 is uat˥ while 玉 is ȵok˨.  The former romanization follows the pronunciation of the historical name in Yue Chinese.

Casimcea: Casimcea is a commune in Tulcea County, Romania.  It is composed of seven villages: Casimcea, Cișmeaua Nouă (historical name: "Ramazanchioi"), Corugea, Haidar, Rahman and Războieni (historical name: "Alifacâ").

Sulfuric acid: 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.

Phenazine: 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.

Ascorbic acid (molecular aspects): Ascorbic acid is a naturally occurring organic compound with antioxidant properties.  It is a white solid, but impure samples can appear yellowish.  It dissolves well in water to give mildly acidic solutions.  Ascorbic acid is one form ("vitamer") of vitamin C.  It was originally called -hexuronic acid, but, when it was found to have vitamin C activity in animals ("vitamin C" being defined as a vitamin activity, not then a specific substance), the suggestion was made to rename it.  The new name, ascorbic acid, is derived from "a-" (meaning "no") and "scorbutus" (scurvy), the disease caused by a deficiency of vitamin C. Because it is derived from glucose, many animals are able to produce it, but humans require it as part of their nutrition.  Other vertebrates which lack the ability to produce ascorbic acid include some primates, guinea pigs, teleost fishes, bats, and some birds, all of which require it as a dietary micronutrient (that is, in vitamin form).

Acid strength: The strength of an acid refers to its ability or tendency to lose a proton (H).  A strong acid is one that completely ionizes (dissociates) in a solution (provided there is sufficient solvent).  In water, one mole of a strong acid HA dissolves yielding one mole of H (as hydronium ion HO) and one mole of the conjugate base, A. Essentially, none of the non-ionized acid HA remains.  Examples of strong acids are hydrochloric acid (HCl), hydroiodic acid (HI), hydrobromic acid (HBr), perchloric acid (HClO), nitric acid (HNO) and sulfuric acid (HSO).  In aqueous solution, each of these essentially ionizes 100%.

Bouin solution: Bouin solution is a compound fixative used in histology.  It is composed of picric acid, acetic acid and formaldehyde in an aqueous solution.  It is especially good for gastrointestinal tract biopsies because this fixative allows crisper and better nuclear staining than 10% neutral-buffered formalin.  It is not a good fixative when tissue ultrastructure must be preserved for electron microscopy.  However, it is a good fixative when tissue structure with a soft and delicate texture must be preserved.  Formalin-fixed tissue is normally mordanted with Bouin solution for better staining results in the trichrome stains.  The acetic acid in this fixative lyses red blood cells and dissolves small iron and calcium deposits in tissue.  A variant in which the acetic acid is replaced with formic acid can be used for both fixation of tissue and decalcification.

Boric acid: Boric acid, also called hydrogen borate, boracic acid, orthoboric acid and acidum boricum , is a weak, monobasic Lewis acid of boron, which is often used as an antiseptic, insecticide, flame retardant, neutron absorber, or precursor to other chemical compounds.  It has the chemical formula HBO (sometimes written B(OH)), and exists in the form of colorless crystals or a white powder that dissolves in water.  When occurring as a mineral, it is called sassolite.

Supporting paragraphs: Phenazine Sulfuric acid
Answer: oil of vitriol