Cream of tartar was known to the ancients under the name of Fæx Vini, which is the designation for it used by Dioscorides.
The tartar of wine was found to be only soluble in water with difficulty; but if boiled in water a turbid liquor was yielded which in the boiled condition continually threw up a sort of skin or scum. This was taken off with a skimmer and dried; it was naturally called Cream of Tartar.
Paracelsus and other chemists distilled this cream and got an oil from it which they called oil or spirit of tartar. It was chiefly a pyro-tartaric acid with some empyreumatic constituents. It was a thin, light yellow, bitter tasting but rather tart, and pleasant smelling oil, and was credited with remarkable penetrating powers. It was used in disorders of the ligaments, membranes, and tendons. Particularly surprising to them was the fact that the residue of a distinctly acid substance was a strong alkali. This “salt of tartar” was found to yield another oil called oleum tartari per deliquium, or lixivium tartari, which was the name by which it was called in the Pharmacopœia. Salt of tartar and cream of tartar together yielded the tartarum tartarisatus. It was when making this that Seignette produced by accident his double tartrate of potash and soda, now familiarly known as Rochelle salt.
Vitriol.
Visitando Interiora Terræ Rectificando Invenies Occultum Lapidem Veram Medicinam. (Visiting the interior of the earth you may find, by rectifying the occult stone, the true medicine.) This acrostic is first found in the works attributed to Basil Valentine.
The vitriols enjoyed an enormous reputation in medicine, at least until their chemical composition was definitely explained by Geoffrey in 1728. It was certainly known that the green vitriols contained iron, and they were sometimes named vitriol of Mars; that the blue vitriols contained copper, which obtained for them the designation of vitriol of Venus; and the white was understood to be associated with calamine, though by some it was supposed to be only green vitriol which had been calcined.
The name of vitriol cannot be traced further back than to Albertus Magnus in the thirteenth century. He expressly applies the term to atramentum viride, the Latin name for sulphate of iron. Presumably it was given to the salt on account of its glassy appearance. The alchemists, on distilling these vitriols found that they always yielded a spirit or oil, to which they naturally gave the name of spirit or oil of vitriol.
In Greek the vitriols were called chalcanthon, as they were extracted from brass; the common name in Latin was atramentum sutorium, because they were employed for making leather black. Dioscorides states that this substance is a valuable emetic, should be taken after eating poisonous fungi, and will expel worms. Pliny recommends it for the cure of ulcers, and Galen used it as a collyrium. There was a good deal of confusion between the vitriols and the alums, and the Greek stypteria and the Latin alumens were often an aluminous earth combined with some vitriol. Pliny gives a test for the purity of what he calls alum, which consists in dropping on it some pomegranate juice, when, he says, it should turn black if it is pure. Evidently his alum contained sulphate of iron.
Paracelsus declared that, with proper chemical management, vitriol was capable of furnishing the fourth part of all necessary medicine. It contained in itself the power of curing jaundice, gravel, stone, fevers, worms, and epilepsy.