Iodine

A nonmetallic element, of the halogen group, occurring always in combination, as in the iodides. When isolated it is in the form of dark gray metallic scales, resembling plumbago, soft but brittle, and emitting a chlorinelike odor. Symbol I. Atomic weight 126.5. If heated, iodine volatilizes in beautiful violet vapors.

a tincture consisting of a solution of iodine in ethyl alcohol; applied topically to wounds as an antiseptic