The plant was introduced into Mauritius a century ago in the time of the French governor Le Poivre, but seems to have been lost, for after many attempts it was again introduced in 1825 by living specimens procured from Ibo by Captain Owen.[106] It still thrives there in the Botanical Garden of Pamplemousses.
It was taken from Mozambique to India in 1805 and afterwards cultivated by Roxburgh in the Calcutta Garden, where however it has long ceased to exist.
History—The root is held in high esteem among the natives of Eastern Africa who call it Kalumb, and use it for the cure of dysentery and as a general remedy for almost any disorder.
It was brought to Europe by the Portuguese in the 17th century, and is first noticed briefly in 1671 by Francesco Redi, who speaks of it[107] as an antidote to poison deserving trial.
No further attention was paid to the drug for nearly a century, when Percival[108] in 1773 re-introduced it as “a medicine of considerable efficacy ... not so generally known in practice as it deserves to be.” From this period it began to come into general use. J. Gurney Bevan, a London druggist, writing to a correspondent in 1777 alludes to it as—“an article not yet much dealt in and subject to great fluctuation.” It was in fact at this period extremely dear, and in Mr. Bevan’s stock-books is valued in 1776 and 1777 at 30s. per lb., in 1780 at 28s., 1781 at 64s., 1782 at 15s., 1783 at 6s. Calumba was admitted to the London Pharmacopœia in 1788.
Collection—As to the collection and preparation of the drug for the market, the only account we possess is that obtained by Dr. Berry,[109] which states that the roots are dug up in the month of March, which is the dry season, cut into slices and dried in the shade.
Description—The calumba plant produces great fusiform fleshy roots growing several together from a short head. Some fresh specimens sent to one of us (H.) from the Botanic Garden, Mauritius, in 1866, and others from that of Trinidad in 1868, were portions of cylindrical roots, 3 to 4 inches in diameter, externally rough and brown and internally firm, fleshy, and of a brilliant yellow. When sliced transversely, and dried by a gentle heat, these roots exactly resemble imported calumba except for being much fresher and brighter.
The calumba of commerce consists of irregular flattish pieces of a circular or oval outline, 1 to 2 inches or more in diameter, and ⅛ to ½ an inch thick. In drying, the central portion contracts more than the exterior: hence the pieces are thinnest in the middle. The outer edge is invested with a brown wrinkled layer which covers a corky bark about ⅜ of an inch thick, surrounding a pithless internal substance, from which it is separated by a fine dark shaded line. The pieces are light and of a corky texture, easily breaking with a mealy fracture. Their colour is a dull greenish yellow, brighter when the outer surface is shaved off with a knife.[110] The drug has a weak musty odour and a rather nauseous bitter taste. It often arrives much perforated by insects, but seems not liable to such depredations here.
Microscopic Structure—On a transverse section the root exhibits a circle of radiate vascular bundles only in the layer immediately connected with the cambial zone; they project much less distinctly into the cortical part. The tissue of the whole root, except the cork and vascular bundles, is made up of large parenchymatous cells. In the outer part of the bark, some of them have their yellow walls thickened and are loaded with fine crystals of oxalate of calcium, whilst all the other cells contain very large starch granules, attaining as much as 90 mkm. The short fracture of the root is due to the absence of a proper ligneous or liber tissue.
Chemical Composition—The bitter taste of calumba, and probably likewise its medicinal properties, are due to three distinct substances, Columbin, Berberine, and Columbic Acid.