Niobium

Niobium (sym. Nb; equiv. 94) is a rare metal discovered by H. Rose in the mineral Tantalite. It may be obtained by passing the vapour of the chloride along with hydrogen through a red-hot tube. It is of a steel-gray colour, specific gravity 4.66, and takes fire when heated in the air or in chlorine gas. It is but little acted on by hydrochloric or nitric acid, but is soluble in strong sulphuric acid. It forms compounds with oxygen, chlorine, sulphur, &c., but these are of little practical importance.