The sassa, the tree which produces the opocalpasum, does not grow in Arabia. Arabian myrrh is easily known from Abyssinian by the following method: take a handful of the smallest pieces, found at the bottom of the basket where the myrrh was packed, and throw them into a plate, and just cover them with water a little warm; the myrrh will remain for some time without visible alteration, for it dissolves slowly; but the gum will swell to five times its original size, and appear so many white spots among the myrrh. The pieces sent are, No. 1, Virgin Troglodyte myrrh. No. 2, the worst sort of Troglodyte myrrh, called cancabs. No. 3, Opocalpasum, from the myrrh country*. [Bruce. Phil. Trans. 1775. SECTION XI. Dragon's Blood. Calamus Rotang.-WOODV. THE calamus is a genus containing nine separate species; three of which supply us with useful and elegant canes; C. sispionum, which affords the common walking-cane; C. verus, which yields the elastic or pliable cane; and C. rotang, which produces the rattan, or rotang. This last is also the source of the resin, called dragon's blood. The tree may be considered as a scandent kind of palm: the lower part of the stem, to the extent of two or three fathoms, is strong, erect, hollow, jointed, and beset with numerous spines; afterwards it takes a horizontal direction, and overruns the neighbouring trees to the distance of fifty or even one hundred feet: the leaves are several feet long, and composed of numerous pinnæ, which are nearly a foot long, narrow, sword-shaped, and at the edges serrated with spinous teeth: the flowers are produced in spikes, which separate into long spreading branches: the calyx is divided into six persistent leafits, three exterior and three interior; the former are very short and pointed, the latter are oblong, concave, rigid, and unite closely, so as commonly to conceal the inner parts of the flower: it has no corolla: the filaments are six, capil· Some years after this paper was sent to the Royal Society, Mr. Bruce, in his Travels to discover the Source of the Nile, vol. v. gives a few other hints, which render it still more probable that the myrrh-tree is a species of mimosa.-EDITOR. lary, and furnished with round antheræ : the germen is roundish, placed above the insertion of the calyx, and the style is trifid, filiform, twisted in a spiral manner, and terminated by simple stigmata: the fruit is somewhat larger than that of a filbert, membraneous, round, one-celled, covered with regular inverted, obtuse scales, and contains a red resinous pulp, which soon becomes dry: the seed is round and fleshy. It is a native of the East Indies, where it commonly grows in woods near rivers, and has long supplied Europe with walking-canes, which have usually been imported by the Dutch. According to Linnæus there are several varieties of the calamus rotang, which he has founded upon the different figures of this tree given by Rumphius; but whether these are varieties only, or distinct species, it is not for us to determine. The specimens of the calamus in the herbariums of Sir Joseph Banks and Dr. Smith, differ considerably in their foliage; so that different species of this obscure genus will probably in future be systematically defined; our business however has only been to select for delineation that which accorded best with the description of it given by Rumphius and Kæmpfer, conformably to the synonyms to which we have referred. Several trees are known to abound with a red resinous juice, which is obtained by wounding the bark, and called dragon's blood, as the pterocarpus draco or pterocarpus officinalis of Jacquin, the dracaena draco, the dalbergia monetaria, and the pterocarpus sontolinus. Besides these, many of the Indian red-woods, while growing, pour forth through the fissures of the bark a blood-coloured juice, forming a resinous concretion, to which the name dragon's blood has been affixed *. This drug, however, is chiefly obtained from the fruit of the calamus rotang, and is procured at the Molucca Islands, Java, and other parts of the East Indies, according to Kæmpfer, by exposing this fruit to the steam of boiling-water, * As some of the crotons, (vide Linn. Supp. p. 319) and other trees noticed by Cranz, De duabus draconis arboribus, ad, p. 13. An exudation similar to the sanguis draconis produced from a tree at Botany Bay, was discovered by Sir Joseph Banks and Dr. Solander. Vide Hawkesworth's Collection of Voyages, vol. iii. p. 498 and 505. But the substance now known at New South Wales by the name of red gum, is perfectly soluble in water; the yellow gum of this place is, however, in its chemical and medicinal qualities, not very different from sanguis draconis, and has been successfully employed as an astringent by Dr. Blane. See Phillips's Voyage to New South Wales, p. 59. which softens the external shell, and forces out the resinous fluid, which is then inclosed in certain leaves, of the reed kind, and hung in the air to dry. Another way of obtaining the Sanguis Draconis is by simply boiling the fruit in water, inspissating the strained decoction, and drying it in the same manner as the former. In Palimbania the external surface of the ripe fruit is often observed covered with the resin, which is rubbed off by shaking the fruit together in a bag; when this is done, the drug is melted by the sun's heat, and formed into globules, which are folded in leaves: this is deemed the purest kind of dragon's-blood; and that which is next in goodness is procured by taking the fruit, which is found to be still distended with resin, out of the bag, and, after bruising it, exposing it to the sun, or boiling it gently in water; the drug then appears floating upon the surface, and is skimmed off and shaped into small cakes. The inferior sort of dragon's blood is that which rises from the crude fruit after being long boiled, and is usually formed into very large cakes or masses, in which the membraneous parts of the fruit, and other impurities, are intermixed. It is also brought to us adulterated, or artificially composed, in various ways. Both the small globules and the large masses, which we have noticed, are imported here, and found to vary widely in goodness and purity. The best kind of this gummy resinous substance breaks smooth, is of a dark red colour, and when powdered changes to crimson; it readily melts, and catches flame. It is not acted upon by watery liquors, but it totally dissolves in pure spirit, and is soluble likewise in expressed oils. It has no smell, but to the taste discovers some degree of warmth and pungency. The cinnabris and sanguis draconis appear to have signified the same thing with the ancient Greeks*, who were well acquainted with the astringent power of this medicine; and in this character it has since been much employed in hæmorrhages and alvine fluxes. At present, however, it is rarely used internally, being superseded by more certain and effectual remedies of this numerous class; and it enters no officinal composition but that of emplastrum thuris of the London pharmacopoeia. [Linn. Kampfer. Jacquin. * Κινναβαρί. αιμα δρακοντος. SECTION XII. Turpentine, Rosin, Pitch, Burgundy-pitch, Frankincense. Pinus. LINN. THERE are three varieties of pine-tree turpentine commonly known under this name in Europe. 1. The common turpentine, obtained chiefly from the pinus sylvestris (Scotch fir). 2. The Strasburg turpentine, extracted from the pinus picea, (silver fir); and, 3. The Venice turpentine, procured from the pinus laryx, (larch). To these may be added two liquid turpentines: as, 4. The Carpathian or Hungary balsam, which exudes from the pinus lembra (Siberian stone-pine). 5. The Canada balsam, or resinous juice of the pinus balsamea (balm of Gilead fir). The fine fragrant Chio turpentine is not procured from a pine, but from a low shrub, the pistacea lentiscus. Of the three first-mentioned turpentines, the Venice is the thinnest and most aromatic; the Strasburg the next in these qualities; and the common is the firmest and coarsest. The two former are often adulterated by a mixture of the common turpentine and oil of turpentine; and it is to be observed that the terms Venice and Strasburgh turpentine are not now appropriate, as they are procured from various countries. Common turpentine is obtained largely in the pine-forests in the south of France, in Switzerland, in the Pyrenees, in Germany, and in many of the southern states of North America; and it has also been occasionally obtained, though in a small quantity, in our own country. The greater part of what is consumed in England is, or at least has been till of late, imported from North America. The method of obtaining it is by making a series of incisions through the bark of the tree, from which the turpentine exudes, and falls into holes or other receptacles at the foot. The age of the fir, when first operated upon, is from thirty to forty years old. The coarse bark is first stripped off from the tree, a little above the hole into which the turpentine is designed to run, down to the smooth inner bark after which a portion of the inner bark, together with a little of the wood, is cut out with a sharp tool, so that there may be a wound in the tree about three inches square and an inch deep. The working commences about April, and continues throughout the summer. "The cutting the trees," says an intelligent writer in the Transactions of the Society of Arts and Manufactures, "for the purpose of collecting, is called boxing them, and it is reckoned a good day's work to box sixty in a day; the trees will not run longer than four years, and it is necessary to take off a thin piece of the wood about once a week, and also as often as it rains, as that stops the trees running. While in North Carolina, I was particular in my enquiries respecting the making of tar and pitch, and I saw several tar-kilns ; they have two sorts of wood that they make it from, both of which are the pitch pine: the sort from which most of it is made are old trees, which have fallen down in the woods, and whose sap is rotted off, and is what they call light wood, not from the weight of it, as it is very heavy, but from its combustible nature, as it will light with a candle, and a piece of it thrown into the fire will give light enough to read and write by. All the pitch-pine will not become lightwood; the people concerned in making tar know it from the appearance of the turpentine in the grain of the wood. The other sort of wood which is used, after the trees which have been boxed for turpentine have done running, they split off the faces over which the turpentine has run; and of this wood is made what is called green tar, being made from green wood instead of dry. "When a sufficient quantity of wood is got together, the first step is to fix a stake in the ground, to which they fasten a string, and from the stake, as a centre, they describe a circle on the ground according to the size they wish to have the kiln. They consider that one, twenty feet in diameter, and fourteen feet high, should produce them two hundred barrels of tar. They then dig out all the earth a spit deep, shelving inwards within the circle, and sloping to the centre; the earth taken out is thrown up in a bank about one foot and a half high round the edge of the circle; they next get a pine that will split straight, of a sufficient length to reach from the centre of the circle some way beyond the bank; this pine is split through the middle, and both parts are then hollowed out, after which they are put together, and sunk in such a way, that one end comes without the bank, where a hole is dug in the ground for the tar to run into, and whence the tar is taken up and barrelled |