Water retention, formally known as edema, is a symptom of a number of conditions including dehydration, constipation, hormonal changes, excess sodium in the diet, heart conditions and kidney problems.
dross. n. 1. Waste or impure matter: discarded the dross after recycling the wood pulp. 2. The scum that forms on the surface of molten metal as a result of oxidation. 3. Worthless, commonplace, or trivial matter: He was wide-awake and his mind worked clearly, purged of all dross (Vladimir Nabokov).
Dross is removed from the surface of the liquid bath with a skimmer. The liquid metal entrained mechanically with the dross drains into the bath. Dross is highly complex with respect to its chemical and phase composition; the refined metal constitutes its base.