Ethiops mineral has ceased to be officinal, and probably deservedly so. it is prepared by simply rubbing mercury and sulphur together. A chemical union takes place, and a black powder results. At one time this was thought to be the protosulphuret of mercury; but, on the authority of Mr. Brande, it is now generally admitted to be a mixture of cinnabar or the deutosulphuret with sulphur.

It is a heavy, black, inodorous, and tasteless powder, insoluble in water and alcohol, and having no reaction with the alkaline chlorides. it is completely dissipated by heat.

In its operation upon the system, it is nearly if not quite inert. it has, however, been supposed to have an alterative effect, and has, therefore, been prescribed in scrofulous swellings and cutaneous eruptions, particularly in the cases of children. The dose is stated at from five to thirty grains several times a day; but doses of several drachms have been taken, for a considerable time, with little or no effect.

The Cyanide of Mercury (Hydrargyri Cyanidum, U. S.), though recognized in our Pharmacopoeia, is so potent a poison, and possesses so little distinctive medical virtue, that it might well be discharged from the officinal catalogue. The dose of it is from the sixteenth to the eighth of a grain. (See U. S. Dispensatory.)