Ulmin \Ul"min\, n. [L. ulmus an elm: cf. F. ulmine.]

(Chem.) A brown amorphous substance found in decaying vegetation. Cf. Humin. [Formerly written ulmine.]

Source: Webster's Revised Unabridged Dictionary (1913)
 

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.

Source: Webster's Revised Unabridged Dictionary (1913)