53. Calamus Draco, Willd.—The Dragon's Blood Calamus.
Sex. Syst. Dioecia, Hexandria.
(Resina; Sanguis Draconis.)
Palma Juncus Draco, Rumph., Herb. Amb. pars v. p. 114, t. lviii. Fig. 1.
—A native of the islands of the Indian Archipelago. The berry, which is round, pointed, and about the size of a cherry, yields a resinous substance called in commerce dragon's blood (sanguis draconis)—a term which is also applied to a product of the Dracaena Draco (vide Liliaceae), and likewise to a substance obtained from the Pterocarpus Draco (vide Leguminosae). Lieut. Wellstead says that, in Socotra, Dragon's blood exudes spontaneously from the stem of a tree. [Athenaeum, May 10, 1835; also, Journal of Royal Geographical Society.] The following are the kinds of it which I have met with:—
1. Dragon's blood in the reed; Dragon's blood in sticks; Sanguis Draconis in baculis.—This occurs in dark reddish-brown sticks of from twelve to eighteen inches long, and from a quarter to half an inch in diameter, enveloped with the leaf of the Talipat palm (Corypha umbraculifera), and bound round with slender slips of cane (probably the stem of Calamus petraeus). It is supposed to be obtained from a species of Calamus, perhaps C. Draco.
2. Dragon's blood in oval masses; Dragon's blood in drops; Sanguis Draconis in lachrymis, Martius.—This occurs in reddish-brown lumps of the size and shape of an olive, enveloped with the leaf of Corypha umbraculifera or Corypha Licuala, which thus connects them together in a row, like the beads of a necklace. This kind is rare in English commerce. It is obtained, according to Rumphius, by rubbing or shaking the fruit of Calamus Draco in a bag. A resinous exudation is by this means separated, and is afterwards softened by heat, and made up in these masses.
3. Dragon's blood in powder.—This is a reddish powder, of very fine quality, imported from the East Indies. It is probably the dust obtained from the fruit of the C. Draco, in the way just described.
4. Dragon's blood in the tear; Sanguis Draconis in granis, Martius.—It occurs in irregular pieces, some as large as the fist. T. W. C. Martius [Pharmacognosie] says pieces of the fruit of the Calamus Rotang are frequently found intermixed.
5. Lump Dragon's blood; Sanguit Draconit in massis.—This is of inferior quality. It occurs in large masses, which, when broken, present a heterogeneous appearance.
Other varieties of Dragon's blood ore described, but I have never met with them. Guibourt mentions a dragon's blood in cakes, and a false dragon's blood in oval masses.
Dragon's blood is composed of red resin (called draconin) 90.7, fixed oil 2.0, benzoic acid 3.0, oxalate of lime 1.6, phosphate of lime 3.7. [Herberger, Journ. de Pharm, xvii. 225.] According to Johnstone, [Phil. Trans, for 1840, p. 384.] the resin of lump dragon's blood has the formula C40H21O8; that of reed dragon's blood C40H20O9.
It is inert, or nearly so, but was formerly reputed an astringent. It is a constituent of some tooth-powders and tinctures, but is never prescribed by medical practitioners. Its principal consumption is for colouring spirit and turpentine varnishes.