THE TIMBERS OF COMMERCE 



Type specimen. Authenticated by the Forest Officer to the 

 Government of Ceylon. This description differs from that of 

 Gamble in respect to the rays, which are stated by him to be 

 prominent. 



No. 1 6. LIGNUM- VIT7E. Guaiacum officinale. 



Linn. 



Plate II. Fig. 14. 



Natural Order. Zygophyllacese. 



Synonym. G. bijugum. Stokes. 



Alternative Names. Guaiacum-wood. Bois Saint, Gaillard 

 Franc, Guayacan in Barbadoes (52). 



Sources of Supply. Tropical America. West Indies. 



Physical Characters, etc. Dry-weight 72^-83 lb. per cu. ft. 

 Even the bark will sink like stone in water. Splits with very 

 great difficulty and rough fracture. Hardness Grade 1, exces- 

 sively hard. Smell and taste none. Burns extremely well with 

 a quiet and rather smoky flame, heat expels a red gum, embers 

 glow in still air and consume very slowly to the ash. Solution 

 with water bright yellow ; with alcohol brownish-yellow. Com- 

 mercial form, small logs with sap-wood and bark about 6-12 

 long if under 22 ins. diam., if larger from 5-6 ft long. 



Grain. Very fine, close and even. Twisted (see the surface of 

 the log under the bark). Surface dull, smooth, cold to the touch 

 when freshly cut, rapidly becoming sticky with green gum, 

 when it feels like steatite. 



Bark f-W inch thick, smooth, leathery in appearance, hard, 

 heavy : the outermost layer brown, brittle, readily flaking off, 

 thus exposing the dark green second layer : beneath this a third 

 brown or white layer : no fissures : light brown or yellow in 

 section. 



Uses, etc. Pulley-blocks, rollers, handles, policemen's batons ; 

 also employed in medicine. 



Authorities. Nordlinger (2), vol. vi, p. 25. Schomburgk 

 (52). 



Anatomical Characters. Transverse section : — 



Colour. Dark-brown streaked with black, usually soon obscured 

 by sticky, green resin. Sap-wood not more than about £ inch 

 wide : yellow, sharply defined from the dark heart-wood. 



Pores. Just visible, size 3 : variable and a few smaller in the 

 later wood : chiefly in the pore-zone, scarce elsewhere : 16 -43 

 per sq. mm. : single or in groups of two to three pores : scattered : 

 slightly oval : green in the inner rings of the sap-wood, near the 

 heart : shining. 



Rays. Require lens : very fine, size 6, uniform and equidistant: 



18 



