What is "oil of vitriol"

Sulphuric \Sul*phu"ric\, a. [Cf. F. sulfurique.]

1. Of or pertaining to sulphur; as, a sulphuric smell.

2. (Chem.) Derived from, or containing, sulphur; specifically, designating those compounds in which the element has a higher valence as contrasted with the sulphurous compounds; as, sulphuric acid. Sulphuric acid.

   1. Sulphur trioxide (see under Sulphur); -- formerly so called on the dualistic theory of salts. [Obs.]

   2. A heavy, corrosive, oily liquid, H2SO4, colorless when pure, but usually yellowish or brownish, produced by the combined action of sulphur dioxide, oxygen (from the air), steam, and nitric fumes. It attacks and dissolves many metals and other intractable substances, sets free most acids from their salts, and is used in the manufacture of hydrochloric and nitric acids, of soda, of bleaching powders, etc. It is also powerful dehydrating agent, having a strong affinity for water, and eating and corroding paper, wood, clothing, etc. It is thus used in the manufacture of ether, of imitation parchment, and of nitroglycerin. It is also used in etching iron, in removing iron scale from forgings, in petroleum refining, etc., and in general its manufacture is the most important and fundamental of all the chemical industries. Formerly called vitriolic acid, and now popularly vitriol, and oil of vitriol.

      Fuming sulphuric acid, or Nordhausen sulphuric acid. See Disulphuric acid, under Disulphuric.

      Sulphuric anhydride, sulphur trioxide. See under Sulphur.

      Sulphuric ether, common an[ae]sthetic ether; -- so called because made by the catalytic action of sulphuric acid on alcohol. See Ether, 3 (a) .

Vitriol \Vit"ri*ol\, n. [F. vitriol; cf. Pr. vitriol, vetriol, Sp. & Pg. vitriolo, It. vitriuolo; fr. L. vitreolus of glass, vitreus vitreous. See Vitreous.] (Chem.)

1. A sulphate of any one of certain metals, as copper, iron, zinc, cobalt. So called on account of the glassy appearance or luster.

2. Sulphuric acid; -- called also oil of vitriol. So called because first made by the distillation of green vitriol. See Sulphuric acid, under Sulphuric.

   Blue vitriol. See under Blue.

   Green vitriol, ferrous sulphate; copperas. See under Green.

   Oil of vitriol, sulphuric or vitriolic acid; -- popularly so called because it has the consistency of oil.

   Red vitriol, a native sulphate of cobalt.

   Vitriol of Mars, ferric sulphate, a white crystalline substance which dissolves in water, forming a red solution.

   White vitriol, zinc sulphate, a white crystalline substance used in medicine and in dyeing. It is usually obtained by dissolving zinc in sulphuric acid, or by roasting and oxidizing certain zinc ores. Formerly called also vitriol of zinc.

n. (context chemistry dated English) sulphuric acid.

n. (H2SO4) a highly corrosive acid made from sulfur dioxide; widely used in the chemical industry [syn: vitriol, sulfuric acid, sulphuric acid]