The great and innocent are insulted by the scum and refuse of the
people.
Addison.
Scum, v. t. [imp. & p. p. Scummed (?); p. pr. & vb. n. Scumming (?).]
1. To take the scum from; to clear off the impure matter from the
surface of; to skim.
You that scum the molten lead.
Dryden & Lee.