in natural history, a fossil substance usually found in copper-mines, composed of thin flakes, like the talc; which easily split, and are flexible, and not elastic, soluble in oil, fusible in a moderate fire, and yielding in burning an offensive smell like garlic.

Of this genus of fossils, there are, only three known species: 1. A broad-flaked, gold-coloured kind, much esteemed at present by our painters. This is found in several places, as in the islands of the Archipelago, in the mines of Gosselaer in Saxony, in some parts of Turkey, and in the East-Indies, and in its utmost purity about Smyrna; this makes the finest of all yellows in painting. 2. The small-flaked yellow kind, which is the common orpiment of the shops, and is a fine colour, though greatly inferior to the former. This is found in many parts of the Turkish dominions, and in Germany. And, 3. Red-orpiment, which is of a fine bright red: this is a very beautiful substance of a fine bright red, very glossy, and a little transparent, and is found in the Turkish dominions, in the islands of the Archipelago, and even in Cornwall, where it is known under the name of red mastic.

Geoffroy declares it a corrosive and poisonous mineral; on the other hand, Boerhaave declares orpiment an innocent and harmless medicine; and Hoffman, who has been at more pains than any body to examine into its nature, declares the same, and even gives instances of its being given to dogs without any harm.

It is an excellent depilatory, mixed with lime, and made into a paste with water. The painters are fond of it as a golden colour; and a lixivium of it, with quick-lime, makes sympathetic ink.