468 RESINS 



1*5 cm. thick, each carefully wrapped in a palm leaf. These varieties 

 are known as 'lump,' 'saucer,' 'reed,' &c., dragon's blood. 



Good samples of the drug usually have a dull, dark red colour, 

 and are more or less covered, where the pieces have rubbed against 

 one another, with a crimson powder. They are brittle and friable, 

 breaking with a glossy but irregular, uneven fracture, minute frag- 

 ments being translucent and of a deep garnet-red colour. 



The drug yields when crushed a bright crimson powder, has no 

 odour, and is practically tasteless, breaking up when chewed into a 

 fine gritty powder. Inferior qualities are duller in colour and tougher. 

 They yield a duller crimson or even brick-red powder, and exhibit 

 less powder on the surface of the lumps. Such specimens frequently 

 contain numerous fragments of the fruit scales, which are easily seen 

 when the drug is broken, or are left when it is exhausted with alcohol. 



Tears, in which form the drug is now seldom seen, give a glassy, 

 conchoidal fracture, thin flakes being of a clear garnet-red colour. 



Constituents. Dragon's blood consists principally of a red resin 

 (56'8 per cent.), a compound of dracoresinotannol with benzoic and 

 benzoylacetic acids. Other constituents are a white, amorphous 

 dracoalban (2*5 per cent.), a yellow resinous dracoresene (1.3'58 per 

 cent.), vegetable debris (18'4 per cent.), and ash (8'3 per cent.). 



It is frequently considerably adulterated both with earthy matter 

 and with fragments of the scales of the fruits, the amount of residue 

 insoluble in alcohol amounting sometimes to as much as 40 per 

 cent, of the drug. 



Uses. Dragon's blood is chiefly used for colouring varnishes, &c. 



Varieties. The term ' dragon's blood ' has also been applied to 

 several other resins resembling Sumatra dragon's blood in appear- 

 ance. They may be distinguished by their insolubility in benzene and 

 carbon disulphide. The only one of these that appears in commerce 

 is Socotrine dragon's blood which is occasionally imported from 

 Bombay and Zanzibar and is technically termed 'Zanzibar drop' 

 dragon's blood. It is obtained from Draccena Cinnabari, Balfour. 

 It occurs in small tears or fragments seldom exceeding 2 cm. in 

 length with a vitreous fracture, thin splinters being of a ruby red 

 colour. It does not when heated evolve an odour of benzoic acid, and 

 contains no scales similar to those found in Sumatra dragon's blood. 



MASTICH 



(Mastiche) 



Source, &C. Mastich is a resin obtained from a broad-leaved variety 

 of Pistacia Lentiscus, Linne (N.O. Anacardiacece) , a shrub or small 

 tree indigenous to the countries bordering on the Mediterranean. 



