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.1 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,* according to the age of the latter and its botanical origin. The oil has the composition CH; 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 CHO. 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 Co., forming an amorphous transparent mass which quickly crystallizes if touched with alcohol. An analogous substance, Oxycopaivic Acid, C2H2O3, 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, C22H3404, from the balsam imported from Maracaibo. He boiled the latter with sodalye, 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 1 Flückiger in Wiggers and Husemann's Jahresbericht for 1867. 162, and for 1868.140. 2 Or 18 to 65 per cent., sp. gr. 0.915 to 0.995, according to Siebold (1877). 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. 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 urinogenital 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 oenanthol 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 Leguminosa and is nearly related to Copaifera. According to Beddome,' it is very common in the dense moist forests of the South Travancore Ghats, and has also been found in 1 Flora Sylvatica for Southern India, Madras, part 24 (1872), 255. 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. 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 subquently 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. Broughton 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 resin3 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 gonorrhoea, and with as much success as copaiba. GUMMI ACACIÆ. Gummi Arabicum; Gum Arabic; F. Gomme Arabique; G. Botanical Origin-Among the plants abounding in mucilage, numerous Acacia of various countries are in the first line. The species particularly known for affording the largest quantities of the finest gum arabic is Acacia Senegal Willdenow (syn. Mimosa Senegal L., A. Verek Guillemin et Perrottet), a small tree not higher than 20 feet, growing abundantly on sandy soils in Western Africa, chiefly north of the river Senegal, where it constitutes extensive forests. It is called by the negroes Verek. The same tree is likewise found in Southern Nubia, Kordofan, and in the region of the Atbara in Eastern Africa, where it is known as Hashab. It has a greyish bark, the inner layers of which are strongly fibrous, small yellowish flowers densely arranged in spikes 2 to 3 inches long, and exceeding the bipinnate leaves, and a broad legume 3 to 4 inches in length containing 5 to 6 seeds. According to Schweinfurth,' it is this tree exclusively that yields the fine white gum of the countries bordering the Upper Nile, and especially of Kordofan. He states that only brownish or reddish sorts of gum are produced by the Talch, Talha or Kakul, Acacia stenocarpa Hochstetter, by the Ssoffar, A. fistula Schweinf. (A. Seyal Delile, var. Fistula), as well as by the Ssant or Sont, A. nilotica Desfont (A. arabica Willd.). These trees grow in north-eastern Africa; the lastnamed is, moreover, widely distributed all over tropical Africa as far as Senegambia, Mozambique and Natal, and also extends to Sindh, Gujarat and Central India. We find even the first sort, " Karami,” of gum exported from the Somali coast, to be inferior to good common Arabic gum. Hildebrandt (1875) mentions that gum is there largely collected from Acacia abyssinica Hochst. and A. glaucophylla Steudel. 3 History The history of this drug carries us back to a remote antiquity. The Egyptian fleets brought gum from the gulf of Aden as early as the 17th century B.C. Thus in the treasury of king Rhampsinit (Ramses III.) at Medinet Abu, there are representations of gum-trees, together with heaps of gum. The symbol used to signify gum, is read Kami-en-punt. i.e. gum from the country of Punt. This, in all probability, includes both the Somali coast as well as that of the opposite parts of Arabia (see article Olibanum, p. 136). Thus, gum is of frequent occurrence in Egyptian inscriptions; sometimes mention is made of gum from Canaan. The word kami is the original of the Greek Kóμm, whence through the Latin our own word gum. The Egyptians used gum largely in painting; an inscription exists which states that in one particular instance a solution of Kami (gum) was used to render adherent the mineral pigment called chesteb, the name applied to lapis lazuli or to a glass coloured blue by cobalt. Turning to the Greeks, we find that Theophrastus in the 3rd and 4th century B.C. mentioned Kóμμ as a product of the Egyptian "Akav@a, of which tree there was a forest in the Thebaïs of Upper Egypt. Strabo also, in describing the district of Arsinöe, the modern Fayûm, says that gum is got from the forest of the Thebaïc Akanthe. Celsus in the 1st century mentions Gummi acanthinum; Dioscorides and Pliny also describe Egyptian gum, which the latter values at 3 denarii [28.] per lb. In those times gum no doubt used to be shipped from north-eastern Africa to Arabia; there is no evidence showing that Arabia itself had ever furnished the chief bulk of the drug. The designation gum arabic 1 Aufzählung und Beschreibung der Acacien-Artendes Nilgebiets.-Linnæa, i. (1867) 308-376, with 21 plates. Schweinfurth's observations are strongly confirmed by an account of the commerce of Khartum in the Zeitschrift für Erdkunde, ii. (1867, Berlin) 474. 2 The A. Adansonii Guill. et Perr. is the same tree. 3 The "Kikar" of the Punjaub, or "Babul" or "Babur" of Central India. As presented to me by Capt. Hunter of Aden, July 1877.-F. A.F. 5 We have to thank Professor Dümichen for most of the information relating to Egypt, which may be partly found in his own works, and partly in those of Brugsch, Ebers, and Lepsius. Lepsius, Abhandl. der Akademie der Wissensch. zu Berlin for 1871, p. 77. 126. Metalle in den Aegyptischen Inschriften. occurs in Diodorus Siculus (2, 49) in the first century of our era, also in the list of goods of Alexandria mentioned in our article on Galbanum. Gum was employed by the Arabian physicians and by those of the school of Salerno, yet its utility in medicine and the arts was but little appreciated in Europe until a much later period. For the latter purpose at least the gummy exudations of indigenous trees were occasionally resorted to, as distinctly pointed out about the beginning of the 12th century, by Theophilus or Rogker: "gummi quot exit de arbore ceraso vel pruno." During the middle ages, the small supplies that reached Europe were procured through the Italian traders from Egypt and Turkey. Thus Pegolotti, who wrote a work on commerce about A.D. 1340, speaks of gum arabic as one of the drugs sold at Constantinople by the pound not by the quintal. Again, in a list of drugs liable to duty at Pisa in 1305, and in a similar list relating to Paris in 1349, we find mention of gum arabic. It is likewise named by Pasi, in 1521, as an export from Venice to London. Gum also reached Europe from Western Africa, with which region the Portuguese had a direct trade as early as 1449. Production-Respecting the origin of gum in the tribe Acacia, no observations have been made similar to those of H. von Moll on tragacanth.6 It appears that gum generally exudes from the trees spontaneously, in sufficient abundance to render wounding the bark superfluous. The Somali tribes of East Africa, however, are in the habit of promoting the outflow by making long incisions in the stem and branches of the tree." In Kordofan the lumps of gum are broken off with an axe, and collected in baskets. The most valued product, called Hashabi gum, from the province of Dejara in Kordofan, is sent northward from Bara and El Obeid to Dabbeh on the Nile, and thence down the river to Egypt; or it reaches the White Nile at Mandjara. A less valuable gum, known as Hashabi el Jesire, comes from Sennaar on the Blue Nile; and a still worse from the barren table-land of Takka, lying between the eastern tributaries of the Blue Nile and the Atbara and Mareb; and from the highlands of the Bisharrin Arabs between Khartum and the Red Sea. This gum is transported by way of Khartum or El Mekheir (Berber), or by Suakin on the Red Sea. Hence, the worst kind of gum is known in Egypt as Samagh Savakumi (Suakin Gum). According to Munzinger, a better sort of gum is produced along the Samhara coast towards Berbera, and is shipped at Massowa. Some of it reaches Egypt by way of Jidda, which town being in the district of 1 Schedula diversarum artium, Ilg's edition in Eitelberger's Quellenschriften für Kunstgeschichte, vii. (1874) 60. 2 Della Decima e di varie altre gravezze imposte dal commune di Firenze, iii. (1766) 18. 3 Bonaini, Statuti inediti della città di Pisa, Firenze, iii. (1857) 106. 114. 4 Ordonnances des Rois de France, ii. (1729) 310. 5 Tariffa de pesi e misure, Venet. 1521. 204. First edition, 1503. 6 See, however, Möller, Academy of Vienna, Sitzungsberichte, June 1875. 7 Vaughan (Drugs of Aden), Pharm. Journ. xii. (1853) 226. 8 Private information to F.A. F. |