Kish
When rich gray iron in a state of fusion is permitted to cool very slowly, a graphitic substance, resembling plumbago, gradually separates itself from the molten mass. This substance is called kish, and is composed of carbon, sulphur, and manganese in varying proportions. This phenomenon evidences the inability of the metal to hold as much carbon, etc., in solution at a low temperature as at a greater heat. The same metal, if run into moulds at a greater heat, and allowed to solidify rapidly, would retain the most of this carbon either in the graphitic or combined state, or both. See GRAPHITE IN PIG-IRON; CAST IRON.
Krupp's Crucibles for Steel.--See CRUCIBLES.