_Copaiba_; _Balsam of Copaiba or Copaiva_, _Balsam Capivi_; F. _Baume
ou Oléo-résine de Copahu_; G. _Copaivabalsam_.
=Botanical Origin=—The drug under notice is produced by trees belonging
to the genus _Copaifera_, natives of the warmer countries of South
America. Some are found in moist forests, others exclusively in dry
and elevated situations. They vary in height and size, some being
umbrageous forest trees, while others have only the dimension of
shrubs; it is from the former alone that the oleo-resin is obtained.
The following are reputed to furnish the drug, but to what extent each
contributes is not fully known.
1. _Copaifera officinalis_ L. (_C. Jacquini_ Desf.), a large tree
of the hot coast region of New Granada as far north as Panama, of
Venezuela and the island of Trinidad.
2. _C. guianensis_ Desf., a tree of 30 to 40 feet high, very closely
related to the preceding, native of Surinam, Cayenne, also of the Rio
Negro between Manaos and Barcellos (Spruce). According to Bentham it
seems to be the same species as the _C. bijuga_ of Hayne.[878]
3. _C. coriacea_ Mart. (_C. cordifolia_ Hayne), a large tree found in
the _caatingas_ or dry woods of the Brazilian provinces of Bahia and
Piauhy.
4. _C. Langsdorffii_ Desf.[879] (_C. nitida_ Hayne, _C. Sellowii_
Hayne,? _C. Jussieui_ Hayne), a polymorphous species, varying in the
form and size of leaflets, and also in dimensions, being either a
shrub, a small bushy tree, or a large tree of 60 feet high. Bentham
admits, besides the type, three varieties:—β. _glabra_ (_C. glabra_
Vogel), γ. _grandifolia_, δ. _laxa_ (_C. laxa_ Hayne). The tree grows
on dry _campos_, _caatingas_ and other places in the provinces of
S. Paulo, Minas Geraes, Goyaz, Mato Grosso, Bahia and Ceará; it is
therefore distributed over a vast area. According to Gardner,[880] the
Brazilian traveller, it yields an abundance of balsam.
In addition to these species, must be mentioned a tree described by
Hayne and commonly cited under the name of _Copaifera multijuga_, as a
special source of the drug shipped from Pará.[881] As its name implies,
it is remarkable for the number of leaflets (6 to 10 pairs) on each
leaf. But it is only known from some leaves in the herbarium of Martius
which Bentham, who has examined them, informs us are unlike those
of any _Copaifera_ known to him, though certainly the leaflets are
dotted with oil-vessels as in some species. In the absence of flowers
and fruits, there is no sufficient evidence to prove that it belongs
even to the genus _Copaifera_. It is not mentioned by Martius in his
_Systema Materiæ Medicæ Brasiliensis_ (1843) as a source of the drug.
=History=—Among the early notices of Brazil is a treatise by a
Portuguese friar who had resided in that country from 1570 to 1600.
The manuscript found its way to England, was translated, and was
published by Purchas[882] in 1625. Its author notices many of the
natural productions of the country, and among others _Cupayba_ which
he describes as a large tree from whose trunk, when wounded by a deep
incision, there flows in abundance a clear oil much esteemed as a
medicine.
Balsam. _Copæ. yvæ_ is already enumerated in the 6th edition of the
Pharmacopœa of Amsterdam, A.D. 1636.[883]
Father Cristoval d’Acuña,[884] who ascended the Amazon from Pará,
arriving at Quito in 1638, mentions that the country affords very
large Cassia fistula, excellent sarsaparilla, and the oils of Andirova
(_Carapa guianensis_ Aublet, _Meliaceæ_), and _Copaiba_, as good as
balsam for curing wounds.
Piso and Marcgraf,[885] who in 1636 accompanied the Count of Nassau
to the Dutch establishments in Brazil, each give an account of the
_Copaiba_ and the method of obtaining its oleo-resin. The former states
that the tree grows in Pernambuco and the island of Maranhon, whence
the balsam is conveyed in abundance to Europe.
[878] Hayne (1827) enumerated and figured 15 species, some of
them founded on very imperfect materials. Bentham in the _Flora
Brasiliensis_ of Martius and Endlicher (fasc. 50, _Leguminosæ_, ii.
1870. pp. 239-244) admits only 11, one of which is doubtful as to the
genus.
[879] Fig. in Bentley and Trimen, _Med. Plants_, part 32 (1878);
Langsdorffii, not Lansdorffi, is to be written; see _Pharm. Journ._ ix.
(1879) 773.
[880] MS. attached to specimens in the Kew Herbarium.
[881] “Alle Arten geben mehr oder weniger Balsam, und den meisten giebt
die in der Provinz Para vorkommende _Copaifera multijuga_.”—Hayne,
_Linnæa_, i. (1826) 429.
[882] _Pilgrimes and Pilgrimage_, Lond. iv. (1625) 1308.
[883] _Pharm. Journ._ vi. (1876) 1021.
[884] _Nuevo Descubrimiento del gran Rio de las Amazonas_, Madrid,
1641, No. 30.
[885] _Hist. Nat. Brasiliæ_:, 1648, Piso, 56, Marcgraf, 130.
The drug was formerly brought into European commerce by the Portuguese,
and used to be packed in earthen pots pointed at the lower end;
it often arrived in a very impure condition.[886] In the London
Pharmacopœia of 1677, it was called _Balsamum Capivi_, which is still
its most popular name.
=Secretion=—Karsten states that he observed resiniferous ducts,
frequently more than an inch in diameter, running through the whole
stem. He is of the opinion that the cell-walls of the neighbouring
parenchyme are liquefied and transformed into the oleo-resin.[887] We
are not able to offer any argument in favour of this opinion.
In the vessels already alluded to, the balsam sometimes collects in
so large a quantity, that the trunk is unable to sustain the inward
pressure, and _bursts_. This curious phenomenon is thus referred to
in a letter addressed to one of us by Mr. Spruce:—“I have three or
four times heard what the Indians assured me was the bursting of an
old capivi-tree, distended with oil. It is one of the strange sounds
that sometimes disturb the vast solitudes of a South American forest.
It resembles the boom of a distant cannon, and is quite distinct
from the crash of an old tree falling from decay which one hears not
unfrequently.”
A similar phenomenon is known in Borneo. The trunks of aged trees of
_Dryobalanops aromatica_ contain large quantities of oleo-resin or
Camphor Oil,[888] which appears to be sometimes secreted under such
pressure that the vast trunk gives way. “There is another sound,” says
Spenser St. John,[889] “only heard in the oldest forests, and that is
as if a mighty tree were rent in twain. I often asked the cause, and
was assured it was the camphor tree splitting asunder on account of the
accumulation of camphor in some particular portion.”
=Extraction=—Balsam Capivi is collected by the Indians on the banks
of the Orinoco and its upper affluents, and carried to Ciudad Bolivar
(Angostura); some of this balsam reaches Europe by way of Trinidad. But
it is obtained much more largely on the tributaries of the Caisquiari
and Rio Negro (the Siapa, Içanna, Uaupés, etc.) and is sent down to
Pará. Most of the northern tributaries of the Amazon, as the Trombetas
and Nhamundá, likewise furnish a supply. According to Spruce, in
the Amazon valley it is the tall virgin forest, _Caaguaçú_ of the
Brazilians, _Monte Alto_ of the Venezuelans, that yields most of the
oils and gum-resins, and not the low, dry _caatingas_, or the riparial
forests. The same observant traveller tells us that in Southern
Venezuela, capivi is known only as _el Aceite de palo_ (_wood-oil_),
the name _Balsamo_ being that of the so-called _Sassafras Oil_,
obtained from a species of _Nectandra_.
[886] Valmont de Bomare, _Dict. d’Hist. Nat._ i. (1775) 387.
[887] _Botanische Zeitung_, xv. (1857) 316.
[888] Motley in Hooker’s _Journ. of Botany_, iv. (1852) 201.
[889] _Life in the Forests of the Far East_, ii. (1862) 152.
Balsam Copaiba is also largely exported from Maracaibo where, according
to Engel,[890] it is produced by _C. officinalis_, the Canime of the
natives.
The finest sort, called by the collectors white copaiba, is met with in
the province of Pará, where Cross[891] saw a tree of a circumference
of more than 7 feet at 3 feet from the ground. Its trunk was clear of
branches to a height of at least 90 feet. The collector commenced the
work by hewing out with his axe a hole or chamber in the trunk about
a foot square, at a height of two feet from the ground. The base or
floor of the chamber should be carefully and neatly cut with a gentle
upward slope, and it should also decline to one side, so that the
balsam on issuing may run in a body until it reaches the outer edge.
Below the chamber a pointed piece of bark is cut and raised, which,
enveloped with a leaf, serves as a spout for conveying the balsam from
the tree to the tin.[892] The balsam, continues Cross, came flowing in
a moderate sized cool current, full of air bubbles. At times the flow
stopped for several minutes, when a singular gurgling noise was heard,
after which followed a rush of balsam. When coming most abundantly a
pint jug would have been filled in the space of one minute. The whole
of the wood cut through by the axeman was bedewed with drops of balsam;
the bark is apparently devoid of it. Trees of the largest size in
good condition will sometimes yield four “potos,” equal to 84 English
imperial pints.
=Description=—Copaiba is more or less viscid fluid, varying in tint
from a pale yellow to a light golden brown, of a peculiar aromatic,
not unpleasant odour, and a persistent, acrid, bitterish taste. Pará
copaiba newly imported is sometimes nearly colourless and almost as
fluid as water.[893] The balsam is usually quite transparent, but
there are varieties which remain always opalescent. Its sp. gr. varies
from 0·940 to 0·993, according as the drug contains a greater or less
proportion of volatile oil. Copaiba becomes more fluid by heat; if
heated in a test tube to 200° C. for some time, it does not lose its
fluidity on cooling. It is sometimes slightly fluorescent, it dissolves
in several times its weight of alcohol 0·830 sp. gr., and generally in
all proportions in absolute alcohol,[894] acetone, or bisulphide of
carbon, and is perfectly soluble in an equal volume of benzol. Glacial
acetic acid readily dissolves the resin but not the essential oil.
Copaiba that is rich in resin of an acid character, unites with the
oxides of baryum, calcium, or magnesium, to form a gradually hardening
mass, provided a small proportion of water is present. Thus 8 to 16
parts of balsam will combine as a stiff compound when gently warmed
with 1 part of moistened magnesia; and still more easily with lime or
baryta.
[890] _Zeitschrift der Gesellschaft für Erdkunde zu Berlin_, v. (1870)
435.
[891] Report to the Under Secretary of State for India, on the
investigation and collecting of plants and seeds of the india-rubber
trees of Pará and Ceara, and Balsam of Copaiba. March 1877,—8.
[892] See figure in the above Report.
[893] We saw such as this which had been imported into London in 1873;
though regarded by the dealers with suspicion, we are not of opinion
that it was sophisticated.
[894] Such is the case with some very authentic specimens collected
for one of us in Central America by De Warszewicz, but other samples
which we had up reason to suppose adulterated, left a certain amount of
white residue when treated with _twice their weight_ of alcohol sp. gr.
0·796.
Buignet has first shown (1861) that copaiba varies in its optical
power. A sample from Trinidad examined by one of us was strongly
dextrogyre, and also several samples imported in 1877 from Maturin
(near Aragua, Venezuela), and Maracaibo into Hamburg, whereas we found
Pará balsam to be levogyre.[895]
The Pará and Maranham balsams are regarded in wholesale trade as
distinct sorts, and experienced druggists are able to distinguish
them apart by odour and appearance, and especially by the greater
consistence of the Maranham drug. Maracaibo balsam is reckoned as
another variety, but is now rarely seen in the English market. West
Indian copaiba is usually said to be of inferior quality, but except
that it is generally opalescent, we know not on what precise grounds.
=Chemical Composition=—The balsam is a solution of resin in volatile
oil; the latter constitutes about 40 to 60 per cent. of the
balsam,[896] according to the age of the latter and its botanical
origin. The oil has the composition C₁₅H₂₄; its boiling point is 245°
C. or even higher. It smells and tastes like the balsam, and dissolves
in from 8 to 30 parts of alcohol 0·830 sp. gr. The oil exhibits several
modifications differing in optical as well as in other physical
properties, but numerous samples of the drug, either _dextrogyre_ or
levogyre, invariably afforded us essential oils deviating to the left;
their sp. gr. varies from about 0·88 to 0·91.
After the oil of copaiba has been removed by distillation, there
remains a brittle amorphous resin of an acid character soluble both in
benzol and amylic alcohol, and yielding only amorphous salts. Sometimes
copaiba contains a small amount of crystallizable resin-acid, as
first pointed out in 1829 by Schweitzer. By exposing a mixture of 9
parts of copaiba and two parts of aqueous ammonia (sp. gr. 0·95) to a
temperature of-10° C., Schweitzer obtained crystals of the acid resin
termed _Copaivic Acid_. They were analysed in 1834 by H. Rose, and
exactly measured and figured by G. Rose. Hess (1839) showed that Rose’s
and his own analyses assign to copaivic acid the formula C₂₀H₃₂O₂. It
agrees with Maly’s abietic acid from colophony in composition, but not
in any other way. Copaivic acid is readily soluble in alcohol, and
especially in warmed copaiba itself; much less in ether. We have before
us crystals, no doubt of copaivic acid, which have been spontaneously
deposited in an authentic specimen of the oleo-resin of _Copaifera
officinalis_ from Trinidad, which we have kept for many years. The
crystals may be easily dissolved by warming the balsam; on cooling the
liquid, they again make their appearance after the lapse of some weeks.
After recrystallization from alcohol they fuse at 116-117 C°., forming
an amorphous transparent mass which quickly crystallizes if touched
with alcohol.
An analogous substance, _Oxycopaivic Acid_, C₂₀H₂₈O₃, was examined in
1841 by H. von Fehling, who met with it as a deposit in Pará Copaiba.
And lastly Strauss (1865) extracted _Metacopaivic Acid_, C₂₂H₃₄O₄, from
the balsam imported from Maracaibo. He boiled the latter with soda-lye,
which separated the oil; the heavier adjacent liquid was then mixed
with chloride of ammonium, which threw down the salts of the amorphous
resin-acid, leaving in solution those of the metacopaivic acid. The
latter acid was separated by hydrochloric acid and recrystallization
from alcohol. We succeeded in obtaining metacopaivic acid by washing
the balsam with a dilute solution of carbonate of ammonium, and
precipitating by hydrochloric acid. The precipitate dissolved in dilute
alcohol yields the acid in small crystals, but to the amount of only
about one per cent.
[895] Flückiger in Wiggers and Husemann’s _Jahresbericht_ for 1867.
162, and for 1868. 140.
[896] Or 18 to 65 per cent., sp. gr. 0·915 to 0·995, according to
Siebold (1877).
These resin-acids have a bitterish taste and an acid reaction; their
salts of lead and silver are crystalline but insoluble; metacopaivate
of sodium may be crystallized from its watery solution.
=Commerce=—The balsam is imported in barrels direct from Pará and
Maranham, sometimes from Rio de Janeiro, and less often from Demerara,
Angostura, Trinidad, Maracaibo, Savanilla, and Cartagena. It often
reaches England by way of Havre and New York. In 1875 there were
exported 10,150 kilogrammes from Savanilla, 99,800 lb. from Ciudad
Bolivar (Angostura), and 65,243 kilos. from Pará.
=Uses=—Copaiba is employed in medicine on account of its stimulant
action on the mucous membranes, more especially those of the
urino-genital organs.
=Adulteration=—Copaiba is not unfrequently fraudulently tampered
with before it reaches the pharmaceutist; and owing to its naturally
variable composition, arising in part from its diverse botanical
origin, its purity is not always easily ascertained.
The oleo-resin usually dissolves in a small proportion of absolute
alcohol: should it refuse to do so, the presence of some fatty oil
other than castor oil may be surmised. To detect an admixture of this
latter, one part of the balsam should be heated with four of spirit
of wine (sp. gr. 0·838). On cooling, the mixture separates into two
portions, the upper of which will contain any castor oil present,
dissolved in alcohol and the essential oil. On evaporation of this
upper layer, castor oil may be recognized by its odour; but still more
positively by heating it with caustic soda and lime, when œnanthol will
be formed, the presence of which may be ascertained by its peculiar
smell. By the latter test an admixture of even one per cent. of castor
oil can be proved.
The presence of fatty oil in any considerable quantity is likewise made
evident by the greasiness of the residue, when the balsam is deprived
of its essential oil by prolonged boiling with water.
The admixture of some volatile oil with copaiba can mostly be detected
by the odour, especially when the balsam is dropped on a piece of
warmed metal. Spirit of wine may also be advantageously tried for
the same purpose. It dissolves but very sparingly the volatile oil
of copaiba: the resins of the latter are also not abundantly soluble
in it. Hence, if shaken with the balsam, it would remove at once the
larger portion of any essential oil that might have been added. For the
recognition of Wood Oil if mixed with copaiba, see page 233, note 1.
=Substitutes=—Under this head two drugs deserve mention, namely
_Gurjun Balsam_ or _Wood Oil_, described at p. 88, and _Oleo-resin of
Hardwickia pinnata_ Roxb.—The tree, which is of a large size, belongs
to the order _Leguminosæ_ and is nearly related to _Copaifera_.
According to Beddome,[897] it is very common in the dense moist forests
of the South Travancore Ghats, and has also been found in South Canara.
The natives extract the oleo-resin in exactly the same method as that
followed by the aborigines of Brazil in the case of copaiba,—that is to
say, they make a deep notch reaching to the heart of the trunk, from
which after a time it flows out.
[897] _Flora Sylvatica for Southern India_, Madras, part 24 (1872),
255.
This oleo-resin, which has the smell and taste of copaiba, but a
much darker colour, was first examined by one of us in 1865, having
been sent from the India Museum as a sample of Wood Oil; it was
subsequently forwarded to us in more ample quantity by Dr. Bidie of
Madras. It is a thick, viscid fluid, which, owing to its intense
tint, looks black when seen in bulk by reflected light; yet it is
perfectly transparent. Viewed in a thin layer by transmitted light, it
is light _yellowish-green_, in a thick layer _vinous-red_,—hence is
dichromic. It is not fluorescent, nor is it gelatinized or rendered
turbid by being heated to 130° C., thus differing from Wood Oil.[898]
Broughton[899] obtained by prolonged distillation with water an
essential oil to the extent of 25 per cent. from an old specimen,
and of more than 40 per cent. from one recently collected. The oil
was found to have the same composition as that of copaiba, to boil
at 225° C., and to rotate the plane of polarization to the left. The
resin[900] is probably of two kinds, of which one at least possesses
acid properties. Broughton made many attempts, but without success, to
obtain from the resin crystals of copaivic acid.
The balsam of _Hardwickia_ has been used in India for gonorrhœa, and
with as much success as copaiba.