Legumin is an albuminoid substance which occurs largely in the seeds of leguminous plants as lentils, peas, haricot beans, etc., in sweet and bitter almond's and other sources. Its exact.composition is unknown, and but little of its properties certainly determined. It appears to be almost identical with Casein (q.v.), and is also known by the name of vegetable casein. It is best obtained from an extract of peas and by precipitation by acids appears as a flocculent powder soluble in cold water, precipitated by acids, but redissolved by excess and coagulable by heat.