674 PALM^. 



Dragon's blood is abundantly soluble in the usual solvents of resins, 

 namely, the alcohols (even in dilute spirit of wine), benzol, chloroform, 

 bisulphide of carbon, and the oxygenated essential oils, as that of 

 cloves. The residue left after the evaporation of these liquids is amor- 

 phous and of the original fine red colour. The drug is likewise dis- 

 solved by glacial acetic acid as well as by caustic soda; the latter 

 solution on addition of an excess of acid yields a dingy brown, jelly- 

 like precipitate, which on drying turns dark red like the original drug. 

 In ether dragon's blood is sparingly soluble, and still less so in oil of 

 turpentine ; but in the most volatile portions of petroleum, the so-called 

 petroleum, ether we find it to be entirely insoluble. It has a slightly 

 sweetish and somewhat acrid taste ; melts at about 120° C, evolving 

 the aromatic but irritating fumes of benzoic acid; boiled with water the 

 resin becomes soft and partially liquid. 



Chemical Composition — Dragon's blood is a peculiar resin, which 

 according to Johnston ^ answers to the formula C^"H'"0'. By heating 

 it and condensing the vapour an aqueous acid liquid is obtained, 

 together with a heavy oily portion of a pungent burning taste and 

 crystals of benzoic acid. The composition of these products has not 

 yet been thoroughly ascertained, but the presence of acetone, Toluol, 

 (THXCH^), Dracyl of Gle'nard and Boudault (1844), and Styrol, C^ff 

 (Bmconyl), has been pointed out,^ the latter perhaps due to the 

 existence in the drug of metastyrol (p. 274), as suggested by Kovalew- 

 sky.3 Both these hydrocarbons are lighter than water; yet we find 

 that the above oily portion yielded by dry distillation sinks in water, 

 a circumstance possibly occasioned by the presence of benzoic alcohol, 

 C6H5(CH20H). ■" •" J F 



As benzoic acid is freely soluble in petroleum ether it ought to he 

 removed from the drug by that solvent: on making the experiment we 

 got traces of an amorphous red matter, a little of an oily liq^ucl ^"^ 

 nothmg crystalline. Cinnamic acid, on the other hand, is always 

 present, according to Hirschsohn (1877). As to the watery liquid, it 

 a.ssumes a blue colour on addition of perchloride of iron, whence it 

 would appear to contain phenol or pyrogallol rather than pyrocatechin 

 (p. lOG). ^ ^-^ '^ 



By boiling dragon's blood with nitric acid, benzoic, nitro-benzoic, 

 and oxalic acids are chiefly obtained, and only very little picric acul. 

 Miasiwetz and Barth melted the drug with caustic potash, and toumi 

 among the products thus formed phloroglucin (p. 243), para-oxybenzoic, 

 protocatechuic, and oxalic acids, as well as several acids of the tatt} 

 series. Benzoin yields similar products. 



ommerce— Dragon's blood is shipped from Singapore and Batavia. 



Borneo 



J^arge quantities are annually exported from Baniarinasin in 

 these places and to China." 



Uses.— In medicine, only as the colouring agent of plasters 

 tooth powders ; in the arts, for varnish. 



Adulteration— Dragon's blood varies exceedingly in quality: 



and 



5 of 



2 Vm;^\^''of ^■^^^- ^^ ' 1S40. 384. 4 ^^ Sarawak, Us inhahUants an 



, ^""^i?"' B^^istri,, xvii. ( 1 8C6) 387. .h,rt!nJ 1 848. 43. . . 



clpro 



(18C6) 387. ductiom, 1848. 43. .,, „„rcwt., 



3 Om pirn >»/.., :z"i" ^:."- iouo oo/. auctions, ia4». 4.J. .,, „„- 



l^n S cSi^i '''^AoX"- 3S8; also^m,^. » The present price, £3 to £U P«r 



U.n aer Chemie, cxx. (1861) 68. sufficientlv indicates this. 



