In the Sherlock Holmes story, The Case of the Illustrious Client, a former paramour seeks revenge on the dastardly Baron Adelbert Gruner by splashing the Baron’s face with sulphuric acid, which at the time was commonly known as vitriol.  The effect was accurately described by Conan Doyle, which is not surprising, given that the author of the Sherlock Holmes stories was a physician: “The vitriol was eating into it everywhere and dripping from the ears and the chin. One eye was already white and glazed. The other was red and inflamed. The features which I had admired a few minutes before were now like some beautiful painting over which the artist has passed a wet and foul sponge. They were blurred, discoloured, inhuman, terrible.”  Such vitriolic attacks are terrible indeed.
Credit for the discovery of sulphuric acid is usually attributed to Jabir ibn Hayyan, an Arabian alchemist of the eight century.  Our term “gibberish” supposedly derives from his English name Geber, in reference to the alchemists’ use of secret codes that to others were incomprehensible, or “gibberish.”  But it seems Jabir’s experiments with hydrated sulfate salts of iron and copper were recorded well enough for him to be credited with the discovery of vitriol.  The term “hydrated” refers to the inclusion of water in the crystal structure of these substances.  Hydrated iron sulphate or copper sulphate decompose on heating to yield sulphur trioxide and water, which then combine to yield sulphuric acid, or vitriol.  Vitreus is the Latin word for glass, and since crystals of sulphate salts have a glass-like appearance, “oil of vitriol” became a reasonable name for the acid that was derived from the heat treatment of these salts.  Indeed, copper sulphate still has the common name blue vitriol, iron sulphate is green vitriol and cobalt sulphate is red vitriol.
Sulphuric acid is an extremely corrosive substance and can cause permanent disfigurement when splashed on the skin.  Unfortunately such vitriolic attacks are not limited to fictional detective stories, they happen in real life.  An attack by extremists on girls on their way to school in Afghanistan is a recent horrific example.  Believing that girls would be polluted by education, they carried out an attack leaving some of the students scarred for life, both figuratively and literally.  Used in this way, sulphuric acid is a terrible chemical weapon.  But it is also the most important industrial chemical in the world, without which the steel, fertilizer and plastics industries would be crippled.  There are no safe or dangerous chemicals, there are only safe and dangerous ways to use chemicals.
