546 BOTANY AND PHARMACOGNOSY. 



Allied Drugs. The barks of Picrasma excelsa and Quassia 

 ainara are used in medicine and probably contain similar principles 

 to the wood. The Surinam bark occurs in thinner, light-colored 

 pieces and is sometimes admixed with the powdered drug. It is 

 determined by the large stone cells. The wood of Picrcena quas- 

 sioidcs quite closely resembles Jamaica Quassia in general appear- 

 ance, microscopical structure and chemical constituents. Bitter 

 principles are also found in other species of Picrasma and 

 Quassia. An allied bitter principle and an alkaloid are found in 

 Cascara Amarga or Honduras Bark, which is derived from 

 Picrcena Vellozii, of Southern Brazil. 



SiMARUBA is the bark of the root of Simaruha aiuara and S. 

 officinalis, plants growing in Guiana. The bark comes in flat or 

 somewhat curved pieces about i AI. long. 7 cm. wide. 3 to 5 mm. 

 thick ; the outer corky surface is bluish-brown or dark brown, the 

 periderm, however, being frequently removed, when it is grayish- 

 or yellowish-brown ; the fracture is tough-fibrous, and the surface 

 shows the presence of light yellow stone cells. The taste is very 

 bitter. Simaruba contains a crystalline bitter principle, giving 

 a violet color with sulphuric acid ; a crystalline non-bitter sub- 

 stance ; a fluorescent principle ; a resin ; a volatile oil with an odor 

 of benzoin ; gallic acid, and calcium oxalate and malate. 



H^MATOXYLON. LOGWOOD. The heartwood of 

 Hcemafoxyloii caiiipccJiianiim (Fam. Leguminosge). a tree indig- 

 enous to Central America, and naturalized in tlie West Indies. 

 Much of the commercial logwood being used for dyeing is allowed 

 to ferment, and as a result the chips become dark red and have a 

 greenish, metallic lustre, but it is the unfermented wood that 

 should be used for medicinal purposes (p. 295). 



Description. Usually in small chips, externally reddish- 

 brown, freshly cut surface dark yellowish-red, in transverse sec- 

 tion slightly radiate and with numerous, alternate, yellowish and 

 reddish concentric rings, medullary rays four cells wide ; fracture 

 hard, fibrous ; odor slight ; taste sweet, astringent ; the wood 

 imparting to water a violet or wine color. 



Constituents. Haematoxylin. 10 to 12 per cent., occurs 

 in colorless or pale yellow needles or prisms (Fig. 154). tastes like 

 glycyrrhizin, becomes red on exposure to light and is soluble in 



