More particularly when rubbed the herb of Psoralea bitu-minosa, L. (family Leguminosae) gives off a strong asphalt-like odor. The leaves were formerly officinal as Herba trifolii bitu-minosi and were used as a remedy for a variety of ailments.
Upon distillation of 20,5 kg. of dry herb, Schimmel & Co.1), obtained 10 g. = 0,048 p. c. of an oil which was semisolid at ordinary temperature but which revealed no trace of the original bituminous odor. From it fatty acids could be isolated which melted between 38 and 40° (lauric acid?). The sp. gr. of the oil was 0,8988 at 25°; A. V. 57,18; E. V. 12,25.