258 BARKS 



Constituents. The most important constituents of pomegranate 

 bark are the alkaloids it contains. Four of these have been isolated 

 (Tanret, 1878-1880); three, viz. pelletierine, isopelletierine, and 

 methylpelletierine, are liquid, but pseudo-pelletierine is crystalline. 

 These alkaloids exist to the extent of about 0*5 per cent, in the stem- 

 bark, and 0-6 to 0-7 per cent, in the root-bark (Ewers, 1899). The 

 average of commercial bark appears to be about 0-35 per cent. Carr 

 and Reynolds (1908) found only 0-12 to 0-29 per cent. ; other 

 authorities give 0-5 to 0-7 per cent. The freshly dried bark has been 

 found (in Java) to yield as much as 3-0 per cent., and indications are 

 not wanting that the percentage of alkaloid diminishes on keeping. 



Pomegranate bark contains further about 22 per cent, of gallotannic 

 acid. 



Pelletierine (C 8 H 15 NO) (Tanret, 1878) or punicine (Bender, 1885) is a colour- 

 less liquid boiling at 195, but rapidly assuming a brown colour. Isopelletierine 

 closely resembles it; methylpelletierine boils at 215. Pseudopelletierine has 

 also been called ra-methylgranatonine (Cimician and Silber, 1893). 



Uses. Pomegranate bark has an anthelmintic and slightly irritant 

 action, but is somewhat astringent unless taken freely. It is used 

 in the treatment of tapeworm, which is expelled (not actually killed) 

 by the decoction, or by the sulphate of pelletierine. 



BLACK HAW BARK 



(Cortex Viburni Prunifolii) 



Source, &C. Black haw bark is the root-bark of Viburnum pruni- 

 folium, Linne (N.O. Caprifoliacece) , a shrub indigenous to the eastern 

 and central United States. 



Description. The drug occurs in short, quilled, channelled or curved 

 pieces from 1 to 4 mm. (usually about 2 or 3 mm.) in thickness, and 

 of a dull brown or reddish brown colour. In the youngest pieces 

 the outer surface is slightly longitudinally wrinkled, older pieces 

 exhibit small, rounded, or oval lenticels, while in old bark the surface 

 is irregularly wrinkled, fissured, and scaly. Inner surface longi- 

 tudinally striated, rough and reddish brown. Fracture short and 

 granular, the fractured surface exhibiting a dark brown cork and a 

 whitish or reddish cortex and bast, in which numerous pale yellowish 

 groups of sclerenchymatous cells are distinguishable. The odour is 

 slight, the taste bitter and astringent. Portions of the smaller roots 

 often occur in the drug. 



The student should observe 



(a) The dull outer surface, 



(b) The granular fracture, 



(c) The bitter taste ; 



