Colomba radix Ph. Lond. & Edinb. Ca-lumba Redi Exper. nat. A root brought from Columbo, a town in the island of Ceylon, to which it was originally transplanted from the continent of India. It is called by the Portu-gueze Raijs de Mosambique. We are as yet unacquainted with the vegetable of which it is a part.

Columbo root comes to us in circular pieces, which are from half an inch to three inches in diameter, and from two inches to one quarter of an inch in length. The sides are covered with a thick wrinkled bark, of a dark brown colour externally, but of a light yellow within, The surfaces of the transverse sections appear very unequal, highest at the edges, with a concavity towards the center. On paring off this rough surface, the root is seen to consist of three lamina, the cortical, ligneous, and medullary. This last is much the softest, and when chewed seems very mucilaginous. A number of small fibres run longitudinally through it, and appear on the surface. The cortical and ligneous parts are divided by a circular black line. All the thicker pieces have small holes drilled through them, for the convenience of drying.

This root has an aromatic smell, but is dis-agreeably bitter and pungent to the taste, some-what resembling mustard-seed long kept.

From a number of pharmaceutical experiments on the. columbo root, it appears to give out its virtues more completely to spirituous, than to watery menstrua. The watery infusion is more perishable than that of other bitters. A copious precipitation takes place in it in. twenty-four hours; and in two days it becomes ropy and musty. By the united action of water and rectified spirits, an extract weighing eight ounces and two drams was obtained from twelve ounces of the root. This extract is found to retain the entire flavour of the columbo, and to be equal, if not superiour, in virtue to the powder of the root. The antiseptic power of an infusion of columbo, upon animal flesh, was found to be less than that of Peruvian bark; but its efficacy in correcting and preventing the putridity of the bile, appeared to be superiour to that of bark or camomile flowers. Columbo considerably checks the progress of fermentation in alimentary mixtures; and neutralizes a large proportion of acid. It has little or no astringency.

The columbo root has long been a medicine in repute among the natives of the countries which produce it, in disorders of the stomach and bowels. They carry it about with them, and take it, sliced or scraped, in Madeira wine. Our practitioners in the East Indies adopted the the use of it from them; and frequently found it of great service in the cholera morbus, so common and fatal in those hot climates. It was observed to flop the violent vomiting in this complaint, more speedily and effectually than any other remedy; an effect attributed to its property of correcting the putrid disposition of the bile. It was, however, little known or regarded in this country, till Dr. Percival, in his Essays Medical and Experimental, Vol. II. published observations and experiments on this root, (from which the substance of this article is taken) with cases of its efficacy in various diseases depending on the state of the bile; as the bilious colic, bilious fevers, diarrhoeas, habitual vomitings, etc. The experience of other practitioners has confirmed its utility in these cases. The dose of the powder usually employed has been from one to two scruples. A tincture of columbo, in the proportion of two ounces and a half of the root to a quart of proof spirit, is directed by the London college.