34* PROPERTIES OF WOOD. 



there are closed vessels, which are visible as bright spots. 

 The medullary rays are scarcely visible. 



Radial Section. Vessels in the late wood show as bright 

 lines, those in the early wood as dark shining grooves cut 

 longitudinally. The annual rings form bright lines. The 

 medullary rays are brighter or darker, according to the angle 

 of incidence of light, than the slightly lustrous mass of 

 the wood. 



Tangential Section. Alternately dark and pale bands show 

 the season's growth ; the vessels are as in the radial section. 



No less frequent, but very characteristic features, are the 

 isolated larger vessels filled with a snow-white matter, that 

 appear in the transverse action as white points, and on the 

 longitudinal sections as white lines. Besides the scent, 

 resembling that of caoutchouc, the brownish-grey tint of 

 the heartwood is noteworthy. 



21. Boxwood (Buxus). 



(Chiefly from southern Europe, Asia and America, but also 

 indigenous in England and France.) 



Medullary rays and vessels invisible on all the sections. 

 The annual rings appear as darker lines in the otherwise 

 uniformly bright yellow-coloured hard and heavy wood. 



22. Oliveicood (Olea). 

 (Southern Europe, America and Asia.) 



Vessels and medullary rays invisible on all the sections, but 

 differs from boxwood by inferior hardness and specific gravity ; 

 its colour is also rather pale-brown than yellow, and the 

 annual rings are often obliterated by a brown colouring 

 matter, which permeates the wood. By rubbing the wood, a 

 characteristic scent resembling that of teakwood, occurring 

 also in boxwood, is noticeable. 



23. Lignum-Vitae or Pullcif-icood (Guaiacum) . 

 (Tropical America.) 



The annual rings are distinct on all the sections, owing to a 

 dark brown zone. Medullary rays invisible ; the vessels are 



