This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Bdellium: a gummy-resinous juice; the produce of an oriental tree, of which we have no particular description; brought from Arabia and the East Indies, in pieces of different magnitudes and figures, externally of a dark reddish brown colour not unlike myrrh, internally clear and somewhat resembling glue.
This gummy-resin has a moderately agreeable smell, and a bitterish slightly pungent taste. It grows soft and tenacious in the mouth, and flicks to the teeth. Laid on a red-hot iron, it readily catches flame, and burns with a crackling noise; during which, little streams of liquid matter ooze out at the surface. Both water and rectified spirit dissolve, each, near one half of the bdellium: the spirituous tincture, of a transparent reddish yellow or orange colour, tastes stronger and smells more agreeably of the bdellium, than the watery infusion, which is turbid and brownish. Geoffroy relates, that its whole substance is dissolved by wine, vinegar, tartarized spirit of wine, and alkaline liquors; the active matter of the bdellium is indeed extracted by all these menstrua, but the three first were found upon trial to leave a considerable part of its substance undissolved: proof spirit took up nearly the whole. In distillation with water, it impregnates the aqueous fluid weakly with its flavour; nor is there any appearance of essential oil, at least when only small quantities, as three or four ounces, are submitted to the operation. The distilled spi-rit has very little flavour of the bdellium; nevertheless, the spirituous extract proves weaker, both in smell and taste, than the juice in substance, its active parts being probably enveloped, in this preparation, by the tenacious resin.
(a) Boerhaave, Hist. plant, hort. Lugd. Bat. p. 205.
This gummy-resin stands recommended, as a corroborant and attenuant, in disorders of the breast, for promoting urine and the menses; and externally for resolving or maturating hard tumours. It appears to be one of the weakest of the deobstruent gums, and is at present rarely made use of.