• Webster's Revised Unabridged Dictionary
    • n Ulmin (Chem) A brown amorphous substance found in decaying vegetation. Cf. Humin.
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Century Dictionary and Cyclopedia
    • n ulmin A name given to various substances which are present in vegetable mold, peat, etc. The name has also been applied to a dark-brown substance which exudes from the elm, oak, and various other trees. It has also been called humus, humin, gein. See humus.
    • n ulmin A brown substance produced by the action of strong acids or alkalis on various organic bodies, especially by heating treacle or alcohol with strong sulphuric acid, thoroughly washing the residue with water, then triturating it with gum, and drying the mixture.
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Chambers's Twentieth Century Dictionary
    • ns Ulmin a dark-brown gummy substance exuded from excrescences in the elm, oak, &c., and present in peat, vegetable mould, &c
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Webster's Revised Unabridged Dictionary
L. ulmus, an elm: cf. F. ulmine,
Chambers's Twentieth Century Dictionary
L. ulmus, an elm.


In literature:

They are formed when the alkalies or their carbonates act on ulmin and humin, or upon ulmates or humates of lime, iron, etc.
"Peat and its Uses as Fertilizer and Fuel" by Samuel William Johnson