Alum

al'um, n. a mineral salt, the double sul- phute of alumina and pot a>h. [L. a lumen.) Alumina, al-Qmin-a, Alumine, alf i-mm, n. one of the eanhs the characteristic ingredient of common clay. Alumina is a compound of aluminium and oxygen. [L. alutnen, alum Aluminous, al-u mm-tis, cuij containing alum, or alumina. Aluminum, al-Ct min-uiu, Aluminium, al-umin'i-um, u. the metallic base of alumina, a metal resembling silver, and remarkable for its lightne .