CRUDE DRUGS. 537 



principle which on subHmation gives off an odor of coumarin ; 

 0.22 per cent, of an acrid resin; and 31 per cent, of a fixed oil 

 which absorbs oxygen on exposure to air and is in the nature of 

 a drying oil. 



The barks of a number of other plants of this family are used 

 like that of Mezereum, as DapJmopsis Schzvartzii of the West 

 Indies, LasiosipJion eriocephalus of India and Ceylon, and various 

 species of Stellera, Struthiola and Thymelaea. 



PRUNUS VIRGINIANA. WILD BLACK CHERRY 

 BARK. The bark of the stem and branches of Pruniis serotina 

 Ehrhart (Syn. Primus virginiana JMiller) (Fam. Rosacese), a 

 tree (Fig. 150) indigenous to the Eastern and Central United 

 States and Canada. The bark is collected in autumn, and should 

 be carefully dried and preserved in air-tight containers (p. 287). 



Description. Usually in transversely curved pieces 2.5 to 8 

 cm. long, I to 5 cm. in diameter, 0.5 to 4 mm. thick ; outer surface 

 light brown or greenish-brown, somewhat glabrous, with numer- 

 ous lenticels 3 to 4 mm. long ; inner surface light brown, longitud- 

 inally striate and occasionally fissured ; fracture short, granular ; 

 cork dark brown, thin, easily separable from the green phello- 

 derm, inner bark porous and granular ; odor of the drug distinct, 

 and on the addition of water developing an odor of benzaldehyde 

 and hydrocyanic acid; taste astringent, aromatic (Fig. 235). 



The bark of the trunk is dark brown and rough externally. 



Constituents. A cyanogenetic glucoside, identified by 

 Power and Moore as 1-mandelonitrile glucoside, a compound 

 which has been prepared by Fischer by the partial hydrolysis 

 of amygdalin and is isomeric with sambunigrin (d-mandelo- 

 nitrile glucoside) from the leaves of Samhucus nigra and prulau- 

 rasin (dl-mandelonitrile glucoside) from the leaves of Primus 

 lauroccrasus. It also contains a ferment resembling emulsin ; 

 )8-methyliesculetin (methyl ether of di-hydroxy-coumarin) which 

 probably occurs in combination as a crystalline glucoside. the 

 solutions giving a blue fluorescence ; a phytosterol ; l-mandelic 

 acid, oleic acid ; p-coumaric acid ; tri-methyl-gallic acid ; ipu- 

 ranol ; dextrose ; sugar ; tannin 2.5 to 4.5 per cent. ; starch and 

 calcium oxalate. The yield of hydrocyanic acid varies from 0.23 

 to 0.32 per cent, (inner bark) to 0.03 per cent, (trunk bark) and 



