dragon's blood. 169 



The sassa, the tree which produces the opocalpasum, does not 

 grow in Arabia. Arabian myrrh is easily known from Abys- 

 sinian 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 *. 



iBruce. Phil. Trans. 1775. 



SECTION XI. 



Dragon's Blood. 

 Calamus Rotang. Woonv. 



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 neigh, 

 bouring trees to the distance of fifty or even one hundred feet : the 

 leaves are several feet long, and composed of numerous pinnae, 

 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, con- 

 cave, 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, 

 Editoti, 



