_Radix Columba_; _Calumba or Colombo Root_; F. _Racine de Colombo_; G.
_Kalumbawurzel_, _Columbowurzel_.
=Botanical Origin=—_Jateorhiza palmata_ Miers[104] a diœcious perennial
plant, with large fleshy roots and herbaceous annual stems, climbing
over bushes and to the tops of lofty trees. The leaves are of large
size and on long stalks, palmate-lobed and membranous. The male flowers
are in racemose panicles a foot or more in length, setose-hispid at
least in their lower part, or nearly glabrous. The whole part is more
or less hispid with spreading setæ and glandular hairs.
It is indigenous to the forests of Eastern Africa between Ibo or Oibo,
the most northerly of the Portuguese settlements (lat. 12° 28′ S.), and
the banks of the Zambesi, a strip of coast which includes the towns
of Mozambique and Quilimane. Kirk found it (1860) in abundance at
Shupanga, among the hills near Morambala, at Kebrabasa and near Senna,
localities all in the region of the Zambesi. Peters[105] states that on
the islands of Ibo and Mozambique the plant is cultivated. In the Kew
Herbarium is a specimen from the interior of Madagascar.
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.
[104] Synonyms—_Menispermum palmatum_ Lamarck, _Cocculus palmatus_ DC,
_Menispermum Columba_ Roxb., _Jateorhiza Calumba_ Miers, _J. Miersii_
Oliv., _Chasmanthera Columba_ Baillon. As we thus suppress a species
admitted in recent works, it is necessary to give the following
explanation. _Menispermum palmatum_ of Lamarck, first described in
the _Encyclopédie méthodique_ in 1797 (iv. 99), was divided by Miers
into two species, _Jateorhiza palmata_ and _J. Calumba_. Oliver in his
_Flora of Tropical Africa_, i. (1868) 42, accepted the view taken by
Miers, but to avoid confusion abolished the specific name _palmata_,
substituting for it that of _Miersii_. At the same time he noticed
the close relationship of the two species, and suggested that further
investigation might warrant their union. The characters supposed to
distinguish them _inter se_ are briefly these:—In _J. palmata_, the
lobes at the base of the leaf _overlap_, and the male inflorescence is
nearly glabrous; while in _J. Calumba_, the basal lobes are rounded,
but _do not overlap_, and the male inflorescence is setose-hispid
(“_sparsely pilose_” Miers). On careful examination of a large number
of specimens, including those of Berry from Calcutta, and others from
Mauritius, Madagascar, and the Zambesi, together with the drawings of
Telfair and Roxburgh, and the published figures and descriptions, I
am convinced that the characters in question are unimportant and do
not warrant the establishment of two species. In this view I have the
support of Mr. Horne of Mauritius, who at my request has made careful
observations on the living plant and found that both forms of leaf
occur on the same stem.—D. H.
[105] _Reise nach Mossambique_, Botanik i. (1862) 172.
[106] Hooker, _Bot. Mag._ lvii. (1830) tabb. 2970-71.
=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 30_s._ per lb., in 1780 at
28_s._, 1781 at 64_s._, 1782 at 15_s._, 1783 at 6_s._ 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.
[107] “Sono ancora da farsi nuove esperienze intorno alla _radice di
Calumbe_, creduta un grandissimo alessifarmaco.”—_Esperienze_, p. 125.
(See Appendix, R.)
[108] _Essays Medical and Experimental_, Lond. ii. (1773) 3.
[109] _Asiatick Researches_, x. (1808) 385; Ainslie, _Mat. Med. of
Hindoostan_, 298.
[110] Wholesale druggists sometimes _wash_ the drug to improve its
colour.
=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_.
_Columbin_, or _Columba-Bitter_ was discovered by Wittstock in 1830.
It is a neutral bitter principle, crystallizing in colourless rhombic
prisms, slightly soluble in cold alcohol or ether, but dissolving more
freely in those liquids when boiling. It is soluble in aqueous alkalis
and in acetic acid.
The presence of _Berberine_ in calumba was ascertained in 1848 by
Bödeker, who showed that the yellow cell-walls of the root owe their
colour to it and (as we may add) to _Columbic Acid_, another substance
discovered by the same chemist in the following year. Columbic Acid is
yellow, amorphous, nearly insoluble in cold water, but dissolving in
alcohol and in alkaline solutions. It tastes somewhat less bitter than
columbin. Bödeker surmises that it may exist in combination with the
berberine.
Bödeker has pointed out a connection between the three bitter
principles of calumba. If we suppose a molecule of ammonia, NH₃, to be
added to columbin C₄₂H₄₄O₁₄, the complex molecule thence resulting will
contain the elements of berberine C₂₀H₁₇NO₄, columbic acid C₂₂H₂₄O₇,
and water 3H₂O.
Among the more usual constituents of plants, calumba contains (in
addition to starch) pectin, gum, and nitrate of potassium, but no
tannic acid. It yields when incinerated 6 per cent. of ash.
=Commerce=—Calumba root is shipped to Europe and India from Mozambique
and Zanzibar, and exported from Bombay and other Indian ports.
=Uses=—It is much employed as a mild tonic, chiefly in the form of
tincture or of aqueous infusion.