CRUDE DRUGS. 527 



Constituents. A bitter, somewhat resinous principle, vibur- 

 nin ; valerianic (viburnic) acid and other organic acids; resin; 

 tannin; calcium oxalate; ash about 10 per cent. 



Adulterants. The barks of one or more allied species, espe- 

 cially Jlbitniiiiii dentatnin (page 383), are said sometimes to be 

 substituted for the official bark. 



HAMAMELIDIS CORTEX. WITCHHAZEL BARK. 

 The bark and twigs of Hamamclis virginiana (Earn. Hamameli- 

 dacese), a shrub (Fig. 264) indigenous to Canada and the United 

 States west to Minnesota and south to Texas (p. 286). 



Description. Bark in transversely curved pieces 5 to 20 

 cm. long, 5 to 15 mm. in diameter, bark 0.5 to i mm. thick; usu- 

 ally with the grayish-brown or reddish-brown periderm removed, 

 outer surface light browaiish-red, smooth ; inner surface light 

 reddish-brown, longitudinally striate; fracture short-fibrous; odor 

 slight ; taste astringent. 



Twigs 2 to 5 mm. in diameter; the outer surface varying in 

 color from yellowish-brown to blackish-brown, smooth or some- 

 what scurfy, longitudinally wrinkled, and with numerous small 

 lenticels ; small twigs somewhat zigzag from numerous leaf-scars ; 

 bark thin, easily separable from the whitish, hard, radiate wood ; 

 pith small (Eig. 230). 



Constituents. Gallotannic acid, a glucosidal tannin, and 

 gallic acid. The bark apparently also contains a volatile oil con- 

 sisting chiefly of a terpene which is obtained by distillation in the 

 preparation of hamamehs water or extract of witchhazel. 



GOSSYPII CORTEX. COTTON ROOT BARK. The 

 dried bark of the root of Gossypium hcrbaccmn, and of other 

 species of Gossypium (Fam. Malvaceae), biennial or triennial 

 herbs or shrubs indigenous to sub-tropical Asia and Africa, and 

 now cultivated in all tropical and sub-tropical countries (p. 329). 



Description. 'In flexible, transversely curved or slightly 

 quilled pieces, 6 to 30 cm. long, 5 to 15 mm. in diameter, bark 

 0.2 to I mm. thick ; outer surface light brown, longitudinally wrin- 

 kled, with small lenticels, periderm frequently exfoliated ; inner 

 surface light brown, longitudinally striate ; fracture tough, fibrous, 

 surface light brown, tangentially striate, readily separable into 

 fibrous layers ; odor faint ; taste slightly astringent and acrid. 



