482 



GUM-RESINS 



These constituents have been further investigated, with the following 

 results (Halbey, 1898) : 



Soluble in alcohol, 

 72 per cent. 



Insoluble in alcohol, 

 28 per cent. 



Boswellic acid, free . . . 33'0 per cent. 



,, combined . . 1'5 

 Olibanoresene . . . 33*0 



Volatile oil . . .7-0 



Bitter principle . . . 0*5 

 Gum (arabio acid with Ca and Mg) 20*0 

 Bassorin .... 6*0 



[Vegetable Debris . . .2-0 



According to this analysis the resin consists principally of a resin 

 acid (boswellic acid) and an indifferent resin (olibano-resene) in about 

 equal proportions. The gum consists mainly of arabin, with which is 

 associated a little bassorin. The volatile oil is yellowish and fragrant ; 

 it contains pinene, dipentene, and phellandrene, but the aromatic 

 constituent is not yet known. 



Uses. Olibanum is used chiefly in the manufacture of incense and 

 as an ingredient in plasters and fumigating pastilles. 



AMMONIACUM 



(Ammoniacum) 



Source, &C. Ammoniacum is a gum-resin exuded from the flowering 

 and fruiting stem of Dorema Ammoniacum, D. Don (N.O. Umbelliferce), 

 and probably other species, distributed throughout Persia and extend- 

 ing into southern Siberia. 



The drug is collected chiefly in central Persia. 



The stems of the ammoniacum plants contain, especially in the 

 cortex, numerous, large, schizogenous ducts full of a milky secretion. 

 In the summer, when the plant is fruiting, it is visited by numbers of 

 beetles, which puncture the stem and cause an abundant exudation 

 of the secretion in the form of milky drops, some of which harden on 

 the stem, whilst others drop on to the ground. It is collected, sorted, 

 and exported from the Persian Gulf ports. 



Description. Ammoniacum occurs in commerce in two forms 

 viz. tear ammoniacum and lump ammoniacum, the former being alone 

 official. 



The tears are small, rounded or nodular masses varying usually from 

 0-5 to 3 cm. in diameter. When fresh they are of a pale dull yellow 

 colour, which, however, darkens by keeping. They are hard and brittle 

 when cold, but soften when warmed. Internally the tears are opaque, 

 and vary in colour from milky white to pale brownish yellow, the 

 freshly fractured surface having a waxy lustre. The drug has a 



