260 ECONOMIC BOTANY. 



upon incisions being made into the trunts, which are seven 

 or eight inches in diameter. Incisions are usually made 

 three or four times a year ; after ten or twelve years the 

 product is not so good — it is dark in color, and not very 

 odorous. The resin occurs in the wood, in the Medullary 

 Eays, and in the cortex. It has an aromatic, sweetish, but 

 biting, taste. The color may be whitish, yellowish, reddish, 

 or brownish. Several distinct resinous bodies enter into its 

 composition. It is used in perfumery, very largely for 

 purifying animal fat which is to receive odors of flowers, 

 also in the manufacture of essences, pomatums, etc. 



231. The resinous substance Dragon's-blood is pro- 

 duced principally by Calamus Draco, of the Palm family 

 (Palmacea). It grows in India, Sumatra, the Moluccas, 

 etc. The ripe fruits are heated over a fire, when a slimy 

 mass exudes between the scales, which is collected in 

 hollow canes or on Monocotyledonons leaves. In some 

 regions that which exudes spontaneously, and is found in 

 the shape of small grains, is collected and kneaded into 

 balls. This is considered the best. Another mode of 

 obtaining it is by subjecting the fruits to hot steam ; some- 

 times the fruits are shaken in a sack, and the brittle resin 

 is separated from the shells by a sieve, and heated in the sun 

 or in hot steam. The best sorts of Dragon's-blood are of a 

 deep red or blackish color ; the poorer, brick-red. The 

 streak is blood-red ; it has a sweetish taste ; its specific 

 gravity is about 1.2. It is soluble in alcohol, alkalies, and 

 acetic acid. In it are found a red resin called Dracin 

 (ninety per cent.), benzoic acid, calcic oxalate, calcic sul- 

 phate, and cellulose. It is mostly adulterated with Damar 

 and gum. It finds extensive use as a coloring for alcoholic 

 varnishes, for staining marble and horn, preparing gold 



