l66 PLANT ORGANS OR PARTS OF PLANTS. 



Chemistry. — Ethereal oil between 2 and 3 per cent. ; tan- 

 nin, mannit, mucilage, sugar, and ash from 2 to 5 percent. 



Oil of Cinnamon consists of a hydrocarbon, cinnamyl 

 acetate, and 80 to 90 per cent, of cinnamic aldehyde, 

 CgHgOg, which takes up oxygen to form cinnamic acid. 



CORTEX GRANATI. POMEGRANATE. 



The bark of the stem and root of Punica granatum, 

 Linne (nat. ord. LythrariecB) , a plant of India and south- 

 western Asia; naturalized in subtropical countries. 



Description. — In thin quills or fragments, from 5 to 10 

 cm. long, and from i to 3 mm. thick ; outer surface yellow- 

 ish-gray, somewhat warty, or longitudinally and reticu- 

 lately ridged; the stem bark often partly covered with 

 blackish lichens ; the thicker pieces of the root bark more 

 or less scaly externally; inner surface smooth, finely 

 striate, grayish-yellow; inodorous; taste astringent, very 

 slightly bitter. 



Cross-sections of the. bark, made with a sharp knife, 

 are characteristic in that they appear almost completely 

 homogeneous. The color of the cut surface is yellowish 

 toward the outside, usually somewhat darker than the 

 inner side. On very careful examination the medullary 

 rays may be recognized as very fine dark radiating lines, 

 and the tangential rows or parenchyma cells, in the 

 fibres of the bark, as exceedingly fine cross-lines. In 

 consequence of the lack of long, sclerotic elements the 

 bark breaks short. 



Histology. — Only the thinnest pieces of the drug 

 are furnished with a cork layer, since in the first year a 

 cork cambium is produced deep within the primary 

 bark, and later breaks off. Of the primary bark there 

 remains, after the first production of periderm, only the 

 innermost cell deposit of the thin- walled parenchyma, 

 and the primary sieve tubes. Therefore, the cork cam- 

 bium of the wood bark produces an apparently abundant 



