VITMANNIA, in botany, so named in honour of Abbe F. Vitmann, professor at Milan, a genus of the Octandria Motion'. nia class and order. Essential character : calyx four-cleft; corolla four-petalled ; • nectary a scale at the base of each fila ment; nut semi-lunar, compressed, one seeded. There is but one species, vi:. V. ehiptica, a native of the East Indies. VITRIOL, natural, in mineralogy, a species of fossil salts, divided into three sub-species. 1. Iron vitriol. 2. Copper vitriol. 3. Zinc vitriol.
The iron vitriol is of an emerald and verdigris green, sometimes bordering on sky-blue ; sometimes on grass green. It occurs massive, tuberose, stalactitic, and crystallized. It occurs usually with iron pyrites, by the decomposition of which it is formed. It is found in many parts of Germany, Italy, Sweden, and in many of the English mines, in Teneriffe, and Greenland. It is employed to dye linen yellow, and wool and silk black ; it is also of use in the manufacture of ink, of Berlin blue, for the precipitation of gold from its solution ; and sulphuric acid can be obtained from it by distilla tion, and the residuum, called calcothar of iron, is used as a red paint, and when washed, for polishing steel, glass, &c.
Copper vitriol is of a dark sky-blue co lour, which sometimes approaches to ver digris green. It occurs massive, disse minated, stalactitic, dentiform, and crys tallized. If a plate of iron be inserted in a solution of copper vitriol, it soon be comes incrusted with metallic copper. With ammonia its solution acquires a blue colour. It is founFi in many parts of Ger many, Sweden, and Siberia, in the cop per mines of Ireland, and in Anglesea in Wales. It is used in cotton and linen printing, and the oxide is separated from it, and used as a pigment.
Zinc vitriol is of a greyish colour, and found also in Germany and Sweden.