Vitriol

Alchemical diagram from Daniel Stolz von Stolzenberg, Theatrum Chymicum, 1614 representing VITRIOL as the alchemical motto Visita Interiora Terrae Rectificando Invenies Occultum Lapidem ('Visit the interior of the earth and rectifying (i.e. purifying) you will find the hidden/secret stone'), found in L'Azoth des Philosophes by the 15th Century alchemist Basilius Valentinus. This is a backronym, sometimes incorrectly said to be the origin of the word "vitriol".

In chemistry, vitriol is an archaic name for a sulfate. The name comes from the Latin word "vitriolum" for glassy, as crystals of several metallic sulfates resemble pieces of colored glass.

Vitriol with no further qualification often means sulfuric acid.

In particular:

• Black vitriol, a mixture of iron(II) sulfate and iron sulfide
• Blue vitriol, copper(II) sulfate pentahydrate
• Green vitriol, iron(II) sulfate heptahydrate
• Oil of vitriol, sulfuric acid
• Red vitriol, cobalt(II) sulfate heptahydrate
• Roman vitriol, copper(II) sulfate pentahydrate
• Spirit of vitriol', sulfuric acid
• Sweet oil of vitriol', diethyl ether (not a sulfate)
• Vitriol of argile, aluminium sulfate (alum)
• Vitriol of clay, aluminium sulfate (alum)
• Vitriol of Cyprus, copper(II) sulfate pentahydrate
• Vitriol of Mars or vitriol martial, iron(III) sulfate
• White vitriol, zinc sulfate heptahydrate

Many other names have the obvious meaning given that "vitriol" means "sulfate": for example, vitriol of lead is lead sulfate and so on.