in sea-language, denotes the interval between the flux and reflux of the tide, or between the half of the ebb and the first of the flood, during which the current is interrupted, and the water apparently remains in a state of rest.

SLACKEN, in Metallurgy, a term used by miners to express a spongy and semifluid substance which is mixed with the ores of metals, to prevent their fusion. It is the scoria or scum separated from the surface of the former fusions of metals. To this is frequently added limestone, and sometimes a kind of coarse iron-ore, in the running of the poorer gold ores.