_Cortex Eleutheriæ_; _Cascarilla Bark_, _Sweet Wood Bark_,
_Eleuthera[2083] Bark_; F. _Ecorce de Cascarille_; G. _Cascarill-Rinde_.
=Botanical Origin=—_Croton Eluteria_ Bennett,[2084] a shrub or small
tree, exclusively native of the Bahama Islands.
=History=—It is not improbable that cascarilla bark was imported
into Europe in the first half of the 17th century, as there was much
intercourse subsequent to the year 1630 between England and the
Bahamas.[2085] These islands were occupied in 1641 by the Spaniards,
who became at that time acquainted with the Peruvian bark or Cascarilla
(see page 346), as we have shown at page 343. The external appearance
of the bark of Eluteria being somewhat similar to that of Cinchona
quills, the former began soon to be known under the name of _China
nova_. This drug occurs along with true Cinchona bark, _China de
China_, in the tariff of the year 1691 of the pharmaceutical shops of
the German town Minden, in Westphalia. There can be no doubt that the
cheaper kind of “China,” called China nova, was really the bark under
examination, for in many other tariffs a few years later distinct
mention is made of _Cortex Chinæ novæ seu Schacorillæ_; and Savary,
in his “Dictionnaire de Commerce” (1723, 1750), confirms the fact,
adding that it was first seen in the great fair of Brunswick.[2086]
Another early statement concerning Cascarilla bark likewise refers to
the duchy of Brunswick. Stisser, a professor of anatomy, chemistry,
and medicine in the University of Helmstedt in Brunswick, relates
that he received the drug under the name of _Cortex Eleuterii_ from a
person who had returned from England, in which country, he was assured,
it was customary to mix it with tobacco for the sake of correcting
the smell of the latter when smoked. He also mentions that it had
been confounded with Peruvian bark, from which however it was very
distinct in odour, etc.[2087] Eleutheria bark was then frequently
prescribed as a febrifuge in the place of Cinchona bark, then a more
expensive medicine. Hence the name _cascarilla_, signifying in Spanish
_little bark_, which was the customary designation of Peruvian bark,
was erroneously applied to the Bahama bark, until at last it quite
superseded the original and more correct appellation. That of _China
nova_ was subsequently applied to a quite different bark (see page
364). The drug under notice was first introduced into the London
Pharmacopœia in 1746 as _Eleutheriæ Cortex_, which was its common name
among druggists down to the end of the last century. In the Bahamas the
name _cascarilla_ is still hardly known, the bark being there called
either _Sweet Wood Bark_ or _Eleuthera Bark_.
[2083] From Eleuthera, one of the Bahama Islands, so named from the
Greek ἐλεύθερος, signifying _free_ or _independent_.
[2084] Bentley and Trimen’s _Med. Plants_, part i. (1875).
[2085] In that year a patent was granted by Charles I. for the
incorporation of a Company for colonizing the Bahama Islands, and
a complete record is extant of the proceedings of the Company for
the first eleven years of its existence. In some of the documents,
particular mention is made of the introduction, actual or attempted,
of useful plants, as cotton, tobacco, fig, pepper, pomegranate, palma
Christi, mulberry, flax, indigo, madder, and jalap; and there is also
frequent allusion to the importation of the produce of the islands, but
no mention of _Cascarilla_. See _Calendar of State Papers_, Colonial
Series, 1574-1660, edited by Sainsbury, Lond. 1860. pp. 146. 148. 149.
164. 168. 185. etc.
[2086] Flückiger, _Pharm. Journ._, vi. (1876) 1022, and “Documente”
quoted there, pp. 74-77, etc.
[2087] Stisser (J. A.) _Actorum Laboratorii Chemici specimen secundum_,
Helmestadi, 1693. c. ix. Stisser is said to have mentioned Cascarilla
bark in his pamphlet “De machinis fumiductoriis,” Hamburg, 1686, but
we found this to be incorrect. Nor have we seen the paper of Vincent
Garcia Salat, “Unica quæstiuncula, in qua examinatur pulvis de Burango,
vulgo _Cascarilla_, in curatione tertíanæ,” Valentiæ. 1692. It is
quoted by Haller, _Bibl. Bot._ ii. (1772) 688, and several later
authors, but appears to be extremely rare.
The plant affording cascarilla has been the subject of much discussion,
arising chiefly from the circumstance that several nearly allied West
Indian species of _Croton_ yield aromatic barks resembling more or less
the officinal drug. Catesby in 1754 figured a Bahama plant, _Croton
Cascarilla_ Bennett, from which the original _Eleuthera Bark_ was
probably derived, though it certainly affords none of the cascarilla
of modern commerce. Woodville in 1794, and Lindley in 1838, both
investigated the botany of the subject, the latter having the advantage
of authentic specimens communicated by the Hon. J. C. Lees of New
Providence, to whom one of us also is indebted for a similar favour.
The question was not however finally set at rest until 1859, when J. J.
Bennett by the aid of specimens collected in the Bahamas by Daniell in
1857-8, drew up lucid diagnoses of the several plants which had been
confounded, and disentangled their intricate synonymy.[2088]
[2088] _Journal of Proceedings of Linn. Soc._ iv. (1860) Bot. 29.
=Description=—Cascarilla occurs in the form of tubular or channelled
pieces of a dull brown colour, somewhat rough and irregular, rarely
exceeding 4 inches in length by ½ an inch in diameter. The chief bulk
of that at present imported is in very small thin quills and fragments,
often scarcely an inch in length, and evidently stripped from very
young wood. The younger bark has a thin suberous coat easily detached,
blotched or entirely covered with the silvery white growth of a minute
lichen (_Verrucaria albissima_ Ach.), the perithecium of which appears
as small black dots. The older bark is more rugose, irregularly
tessellated by longitudinal cracks and less numerous transverse
fissures. Beneath the corky envelope the bark is greyish-brown.
The bark breaks readily with a short fracture, the broken surface
displaying a resinous appearance. It has a very fragrant odour,
especially agreeable when several pounds of it are reduced to coarse
powder and placed in a jar; it has a nauseous bitter taste. When
burned it emits an aromatic smell, and hence is a common ingredient in
fumigating pastilles.
=Microscopic Characters=—The suberous coat is made up of numerous
rows of tabular cells, the outermost having their exterior walls much
thickened. The mesophlœum exhibits the usual tissue, containing starch,
chlorophyll, essential oil, crystals of oxalate of calcium, and a
brown colouring matter. The latter assumes a dark bluish coloration
on addition of a persalt of iron. In the inner portion of that layer
ramified laticiferous vessels are also present. The liber consists of
parenchyme and of fibrous bundles, intersected by small medullary rays.
On the transverse section, the fibrous bundles show a wedge-shaped
outline; they are for the most part built up, not of true liber-fibres,
but of cylindrical cells having their transverse walls perforated
sieve-like (_vasa cribriformia_). The contents of the parenchymatous
part of the liber are the same as in the mesophlœum; as to the oxalate
of calcium, the variety of its crystals is remarkable.[2089]
[2089] For more particulars see Pocklington, _Pharm. Journ._ iii.
(1873) 664.
=Chemical Composition=—Cascarilla contains a volatile oil, which it
yields to the extent of 1·1 per cent. According to Völckel (1840),
it is a mixture of at least two oils, the more volatile of which is
probably free from oxygen. Gladstone (1872) assigns to the hydrocarbon
of cascarilla oil the composition of oil of turpentine. By examining
the oil optically we found it to have a weak rotatory power—some
samples deviated to the right, some to the left. The resin, in which
cascarilla is rich, has not yet been examined more exactly.
The bitter principle was isolated in 1845 by Duval, and called
_Cascarillin_. C. and E. Mylius (1873) have obtained it from a deposit
in the officinal extract, in microscopic prisms readily soluble in
ether or hot alcohol, very sparingly in water, chloroform or spirit
of wine. It melts at 205° C., is not volatile, nor a glucoside. Its
composition answers to the formula C₁₂H₁₈O₄.
=Commerce=—The bark is shipped from Nassau, the chief town of New
Providence (Bahamas), and is usually packed in sacks. The quantity
imported into the United Kingdom in 1870 was 12,261 cwt., valued at
£16,482. The exports from the Bahamas were 676 cwt. in 1875, and 1,093
cwt. in 1876.
=Uses=—Cascarilla is prescribed as a tonic, usually in the form of a
tincture or infusion.
=Adulteration=—A spurious cascarilla bark has lately been noticed
in the London market; it was imported from the Bahamas mixed with
the genuine, to which it bears a close similarity. The quills of
it resemble the larger quills of cascarilla; though covered with a
lichen, the latter has not the silvery whiteness of the _Verrucaria_
of cascarilla. The spurious bark has a suberous coat that does
not split off; its inner surface is pinkish-brown, and distinctly
striated longitudinally. In microscopic structure the bark may be said
to resemble cascarilla and still more copalchi. But it is at once
distinguishable by its numerous _roundish groups_ of sclerenchymatous
cells, which become very evident when thin sections are moistened with
ammonia, and then with solution of iodine in iodide of potassium. The
bark has an astringent taste, without bitterness or aroma; its tincture
is not rendered milky by addition of water, but is darkened by ferric
chloride,—in these respects differing from a tincture of cascarilla.
Mr. Holmes[2090] suggests that this spurious cascarilla is probably the
bark of _Croton lucidus_ L.
Copalchi Bark; Quina blanca of the Mexicans.
This drug is derived from _Croton niveus_[2091] Jacquin (_C.
Pseudo-China_ Schlechtendal), a shrub growing 10 feet high, native
of the West Indian Islands, Mexico, Central America, New Granada and
Venezuela. It has occasionally been imported into Europe, in quills
a foot or two in length, much stouter and thicker than those of
cascarilla, to which in odour and taste it nearly approximates. The
bark has a thin, greyish, papery suberous layer, which when removed
shows the surface marked with minute transverse pits, like the lines
made by a file; it has a short fracture.[2092]
Copalchi bark was examined by J. Eliot Howard,[2093] and found to
contain a minute proportion of a bitter alkaloid soluble in ether,
which resembled quinine in yielding a deep green colour when treated
with chlorine and ammonia, though it did not afford any characteristic
compound with iodine. Mauch,[2094] who also analysed the bark, could
not obtain from it any organic base. He extracted by distillation
the essential oil, which he found to consist of a hydrocarbon and an
organic acid,—the latter not examined; he likewise got from the bark an
uncrystallizable bitter principle, which proved to be not a glucoside.
[2090] _Pharm. Journ._ iv. (1874) 810.
[2091] De Candolle’s _Prodromus_, xv. part 2. (1862) 518; beautifully
figured in Hayne, _Arzneigewächse_, xiv. (1843) plate 2.
[2092] For more particulars see Oberlin and Schlagdenhauffen, _Journ.
de Pharm. 28_ (1878) 248.
[2093] _Pharm. Journ._ xiv. (1855) 319.
[2094] Wittstein’s _Vierteljahresschrift für prakt. Pharm._ xviii.
(1869) 161.