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,