CARYOPHYLLUS 



319 



tube under the microscope shows a thin outer layer surrounding a 

 darker zone; this outer layer contains a double ring of oil cells; the 

 inner darker zone contains an outside circle of about thirty fibro- 

 vascular bundles, with a larger bundle running through the center. 

 Odor highly aromatic, especially when scratched; taste pungent and 

 aromatic, followed by slight numbness. 



Powder. Characteristic elements: See Part iv, Chap. I, B. 



FIG. 185. Eugenia, aromatica. 



CONSTITUENTS. About 18 per cent, of volatile oil, 17 per cent, of tannin, 

 a little fixed oil, gum, resin, etc. Two crystalline principles have 

 been separated, caryophyllin, CioHieO, white, odorless, and taste- 

 less, resinous, and eugenin, CioHi 2 02, isomeric with eugenol of the 

 volatile oil, soluble in boiling alcohol and ether, as is also caryophyllin, 

 but differing from the latter in turning red with nitric acid. Water 

 extracts the volatile oil with scarcely any of the pungency of taste. 

 Ash, not exceeding 8 per cent. 



