AL'UMIN,

ALU'MINA, noun An earth or earthy substance, which has been considered to be elementary, and called pure clay; but recently, chimical experiments have given reason to believe it to be a metallic oxyd, to the base of which has been given the name aluminum. This metallic base however has not been obtained in such a state as to make its properties susceptible of examination. Alumina is destitute of taste and smell. When moistened with water, it forms a cohesive and ductile mass, susceptible of being kneaded into regular forms.