腐黑酸; 腐黑物; 烏敏素
Humin \Hu"min\, n. [L. humus the earth, ground.] (Chem.) A bitter, brownish yellow, amorphous substance, extracted from vegetable mold, and also produced by the action of acids on certain sugars and carbohydrates; -- called also {humic acid}, {ulmin}, {gein}, {ulmic} or {geic acid}, etc.
humin n : a black humic substance that is not soluble in water