_Canella Bark_, _Canella Alba Bark_; F. _Canelle blanche_; G.
_Canella-Rinde_.
=Botanical Origin=—_Canella alba_ Murray,[310] a tree, 20 to 30 or
even 50 feet in height, found in the south of Florida, the Bahama
Islands (whence alone its bark is exported), Cuba, Jamaica, Ste. Broix,
Guadaloupe, Martinique, Barbadoes and Trinidad.
=History=—The drug was first mentioned in 1605 by Clusius,[311] who
remarks that it had been then newly brought to Europe and had received
the name of _Canella alba_ (White Cinnamon). It was afterwards known
as _Costus Corticosus_, _Costus dulcis_, _Cassia alba_, _Cassia lignea
Jamaicensis_ or _Jamaica Winter’s Bark_. Dale[312] writing in 1693
notices it as not unfrequently sold for Winter’s Bark. Pomet[313]
(1694) describes it as synonymous with Winter’s Bark, and observes that
it is common, yet but little employed.
The drug is mentioned by most subsequent writers, some of whom like
Pomet probably confounded it with the bark of _Cinnamodendron_ (p.
19). It is usually described as produced in Jamaica or Guadaloupe,
from which islands no Canella alba is now exported. On the other hand,
New Providence, one of the Bahamas whence the Canella alba of the
present day is shipped, is not named. Nor do we find any allusion to
the drug in the records of the Company (1630-50) which was formed for
the colonization of New Providence and the other islands of the group,
though their staple productions are frequently enumerated.[314]
_Canella alba_ Murr. was described and figured by Sloane (1707) and
still better by Patrick Brown in 1789, and Olaf Swartz in 1791.[315]
[310] Fig. in Bentley and Trimen, _Medic. Plants_, part 6 (1876).
[311] _Exotica_, 78.
[312] _Pharmacologia_, 432.
[313] _Hist. des Drog._ part i. 130.
[314] _Calendar of State Papers, Colonial Series_, 1584-1660, Lond.
1860.
[315] O. Swartz, Trans. of the Linnean Soc., i. 96. See also Bonnet,
_Monographie des Canellées_, 1876.
=Collection=—In the Bahamas, where the drug is known as _White-Wood
Bark_ or _Cinnamon Bark_, it is collected thus:—preparatory to being
stripped from the wood, the bark is gently beaten with a stick, which
removes the suberous layer. By a further beating, the remaining bark is
separated, and having been peeled off and dried, is exported without
further preparation.[316]
=Description=—Canella bark occurs in the form of quills, more or less
crooked and irregular, or in channelled pieces from 2 or 3 up to 6,
8, or more inches in length, ½ an inch to 1 or 2 inches in width, and
a line or two in thickness. The suberous layer which here and there
has escaped removal is silvery grey, and dotted with minute lichens.
Commonly, the external surface consists of inner cellular layers
(_mesophlœum_) of a bright buff, or light orange-brown tint, often a
little wrinkled transversely, and dotted (but not always) with round
scars. The inner surface is whitish or cinnamon-coloured, either smooth
or with slight longitudinal striæ. Some parcels of canella show the
bark much bruised and longitudinally fissured by the above-mentioned
process of beating. The bark breaks transversely with a short granular
fracture, which distinctly shows the three, or in uncoated specimens
the two, cortical layers, that of the liber being the largest, and
projecting by undulated rays or bundles into the middle layer, which
presents numerous large and unevenly scattered oil-cells of a yellow
colour.
Canella has an agreeable cinnamon-like odour, and a bitter, pungent
acrid taste.[317] Even the corky coat is somewhat aromatic.
=Microscopical Structure=—The spongy suberous coat consists of very
numerous layers of large cells with thin walls, showing an undulated
rather than rectangular outline. The next small zone is constituted
of sclerenchymatous cells in a single, double, or triple row, or
forming dense but not very extensive groups. This tissue is sometimes
(in unpeeled specimens) a continuous envelope, marking the boundary
between the corky layer and the middle portion of the cellular layer;
but an interruption in this thick-walled tissue often takes place when
portions of it are enveloped and separated by the suberous layer.
The proper cellular envelope shows a narrow tissue with numerous very
large cells filled with yellow essential oil. The liber forming the
chief portion of the whole bark, exhibits thin prosenchymatous cells,
which on traverse section form small bands of a peculiar horny or
cartilaginous appearance, on which account they have been distinguished
as _horny liber_ (_Hornbast_ of German writers).[318] The liber-fibres
show reticulated marks due to the peculiar character of the secondary
deposits on their cell-walls. The oil-cells in the liber are less
numerous and smaller; the medullary rays are not very obvious unless
on account of the crystalline tufts of oxalate of calcium deposited in
the latter. This crystalline oxalate retains air obstinately, and has a
striking dark appearance.
[316] Information communicated to me by the Hon. J. C. Lees,
Chief-Justice of the Bahamas. The second beating would seem to be not
always required.—D. H.
[317] A specimen in Sloane’s collection in the British Museum labelled
“_Cortex Winteranus of the Isles_,” but under the microscope seen to
be absolutely identical with canella alba, still retains its proper
fragrance after nearly two centuries.—F. A. F.
[318] First figured and described by Oudemaus, —_Aanteekeningen op het
... Gedeelte der Pharm. Neerlandica_, 1854-56. 467.
=Chemical Composition=—The most interesting body in canella is the
volatile oil, examined in 1843 under Wöhler’s direction by Meyer and
von Reiche, who obtained it in the proportion of 0·94 from 100 parts of
bark. They found it to consist of four different oils, the first being
identical with the _Eugenol_ or _Eugenic Acid_ of oil of cloves; the
second is closely allied to the chief constituent of cajuput oil. The
other oils require further examination.[319]
The bark, of which we distilled 20 lb., afforded 0·74 per cent. of
oil. This when distilled with caustic potash in excess was found to
be composed of 2 parts of the acid portion and 1 part of the neutral
hydrocarbon; the latter has an odour suggesting a mixture of peppermint
and cajuput.
Meyer and von Reiche evaporated the aqueous decoction of canella, and
removed from the bitter extract by alcohol 8 per cent. of mannite,
which they ascertained to be the so-called _Canellin_ described in 1822
by Petroz and Robinet.
The bark yielded the German chemists 6 per cent. of ash, chiefly
carbonate of calcium. The bitter principle has not yet been isolated.
An aqueous infusion is not blackened by a persalt of iron.
=Commerce=—Canella alba is collected in the Bahama Islands and shipped
to Europe from Nassau in New Providence, the chief seat of trade in the
group. In 1876 the export of the bark amounted to 125 cwt.
=Uses=—The bark is an aromatic stimulant, now but seldom employed. It
is used by the West Indian negroes as a condiment.