362 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



acid; and a light yellow, rather thick ethereal oil (guaiac oil), which 

 cannot be obtained by distillation and possesses a characteristic 

 aromatic odor. Among the other constituents are vanillin and a 

 yellow gum. The yield of ash should not be more than 4 per cent. 

 Guaiac wood yields from 20 to 25 per cent of resin. 



Of particular interest are the decomposition products obtained 

 on heating guaiac resin. On dry distillation the following sub- 

 stances are obtained: Tiglic aldehyde, a colorless, aromatic liquid 

 with the odor of benzaldehyde; guaiac oil; and a crystalline sub- 

 stance, pyroguaiacin, which on distillation with zinc yields guaiacene 

 (an aldehyde of tiglic acid). 



RUTACE-E, OR RUE FAMILY 



Mostly trees and shrubs, with compound leaves, regular, 3- to 

 5-merous flowers and capsular fruits. With very few exceptions 

 they always possess schizogenous or schizo-lysigenous cavities in 

 the branches and leaves, giving rise to transparent dots in the latter. 

 They usually have isolated groups of bast fibers in the pericycle, in 

 Pilocarpus, however, there is a composite and continuous sclerenchy- 

 matous ring. The trachea and wood fibers usually possess simple 

 pores, except when the trachea are in contact with parenchyma cells, 

 when they are replaced by bordered pores. Calcium oxalate is 

 usually secreted in the form of rosette aggregates, but styloids, 

 raphides and membrane crystals are also present, the latter being 

 especially prominent in the genus Citrus. Both glandular and non- 

 glandular hairs are present, stellate hairs being quite common in 

 the family. 



ZANTHOXYLUM. Xanthoxylum, Prickly Ash Bark. The dried 

 bark of Zanthoxylum americanum and Zanthoxylum (Fagara) Clava- 

 Herculis (Fam. Rutacese). Z. americanum is a shrub or small tree 

 indigenous from Quebec to Virginia and west to South Dakota, 

 Nebraska and Kansas, and yields Northern Prickly Ash. Z. Clava- 

 Herculis is a shrub found south from Virginia to Texas, and furnishes 

 the Southern Prickly Ash. The latter, however, appears to be less 

 valuable medicinally. 



Northern Prickly Ash. In transversely curved pieces, occa- 

 sionally in single quills, 2 to 17 cm. in length, 1 to 2 cm. in diameter, 

 0.5 to 3 cm. in thickness; outer surface light brown to brownish- 

 black, with grayish patches of foliaceous lichens, numerous small 

 black apothecia and whitish lenticels; fracture short, uneven; inner 

 surface light brown, finely longitudinally striate, with numerous 



