CRUDE DRUGS. 671 



uine article, and also by the formation of a turbid mixture on the 

 addition of two parts by weight of glacial acetic acid. 



Allied Plants. — Canada (or Hemlock) Pitch is the oleo- 

 resin of the common Hemlock [Tsuga (Abies) canadensis] 

 which is obtained by making incisions in the trunk and collect- 

 ing the exudate, or by boiling' pieces of the wood and bark and 

 skimming off the melted oleo-resin. It occurs in dark, reddish- 

 brown, opaque or translucent pieces resembling Burgundy Pitch, 

 and probably contains similar constituents. 



ASAFETIDA. — A gum-resin obtained from the root of 

 Ferula fceiida and other species of Ferula (Fam. Umbelliferse), 

 perennial herbs (p. 352) indigenous to Eastern Persia and West- 

 ern Afghanistan. Asafetida is obtained by incising the crown 

 of the root, when the gum-resin exudes, hardens and is then 

 scraped from the root. It is exported by way of Bombay. 



Description. — In irregular masses composed of tears, from 

 I to 2.5 cm. in diameter, which when fresh are tough, yellow- 

 ish-white and translucent or milky white and opaque, changing 

 gradually to pinkish and finally reddish-brown, and becoming, on 

 drying, hard and brittle ; internally yellowish and translucent or 

 milky white and opaque ; odor persistent, alliaceous ; taste bitter, 

 alliaceous and acrid. 



Asafetida yields a milk-white emulsion when triturated with 

 water, which becomes yellowish on the addition of solutions of 

 the alkalies. Treated with strong hydrochloric acid, the filtrate 

 gives a blue fluorescence on making it alkaline with ammonia 

 water (distinguishing it from ammoniac). The freshly fractured 

 surface gives a greenish color on the application of a few drops 

 of 40 per cent, nitric acid solution (distinguishing 'it from gal- 

 banum). Not less than 40 to 50 per cent, should dissolve in 

 alcohol. 



Constituents. — About 60 per cent, of a reddish-brown amor- 

 phous RESIN (consisting of the ferulaic ester of asa-resinotannol), 

 yielding on dry distillation umbelliferone ; on treatment with sul- 

 phuric acid, resorcin, and on fusion with potassium hydrate, pro- 

 tocatechuic acid ; from 3 to 6.7 per cent, of a volatile oil, con- 

 sisting in part of hexenyl sulphide, hexenyl disulphide, pinene and 

 cadinerie, and to which the odor of the drug is due; about 1.28 



