LOGWOOD 



329 



H^MATOXYLON. Logwood. The heartwood of Haematoxylon 

 campecheanum (Fam. Leguminosse, sub-fam. Csesalpinaceae), a 

 tree indigenous to Central America, and naturalized in the 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 luster, but it is the unfermented wood that 

 should be used for medicinal purposes. 



Description. Usually in small chips, externally reddish-brown, 

 the freshly cut surface dark yellowish-red, in transverse section 

 slightly radiate and with numerous, alternate, yellowish and reddish 



FIG. 149. Haematoxylin : Monoclinic tabular crystals from aqueous solution. 



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. 



Powder. Dark brown; tracheae with simple pores; sclerenchy- 

 matous fibers long, thin-walled; crystal fibers with monoclinic crys- 

 tals of calcium oxalate. 



Constituents. Hsematoxylin, 10 to 12 per cent, occurs* in colorless 

 or pale yellow prisms (Fig. 149), having a taste like glycyrrhizin, 

 becomes red on exposure to light and is soluble in water and alcohol. 

 The solutions are colored with solutions of the alkalies, purplish-red, 



