alumen

ălūmen, ĭnis, n. [Doed., Syn. VI. p. 16, compares ἄλοιμα ἄλειμμα = unguent],

alum , Cels. 5, 5; 5, 6; Plin. 35, 15, 52, § 183 sqq.; Col. 6, 13, 1; Vitr. 2, 6; 8, 3; cf. Gell. 15, 1.