(Mn. Eq.=27.5). Black Oxide of Manganese. Binoxide of Manganese.

Prop. & Comp. Binoxide of manganese, called also black oxide of manganese, is found native, sometimes crystallized, sometimes amorphous; as met with in commerce it is a black heavy powder, devoid of odour and taste; yielding, when heated with hydrochloric acid, or with sulphuric acid and salt, chlorine gas. It consists of the metal manganese (which has some resemblance to iron) and oxygen. Formula (Mn O2).

Use. In the preparation of Liquor Sodae Chloratae, and Liquor Chlori. It may be employed also as a source of oxygen by heating it alone, or with sulphuric acid.

Therapeutics. Manganese preparations have been occasionally employed in medicine: the sulphate of the protoxide, in large doses, as from sixty grains to one hundred and twenty grains, produces purgative effects, and by some is considered to increase the excretion of bile; in small doses this salt, as well as the carbonate, have been given, with the idea of improving the condition of the blood, in cases of anaemia; but its value has not as yet been satisfactorily established. The binoxide is not used in medicine.