Definition of "ulmin" []

• A brown amorphous substance found in decaying vegetation. (noun)

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• "Mulder, it is composed of a number of organic bodies, and he has identified the following substances -- ulmin, humin, ulmic, humic, geic acids, &c."
• "-- After extracting the peat with solution of carbonate of soda, it still contains ulmin or humin."
• "They are formed when the alkalies or their carbonates act on ulmin and humin, or upon ulmates or humates of lime, iron, etc. Their dilute solutions are yellow, or brown."