2WARTBAST 



practically uniformly : no pore-ring : variable in size, especially 

 within the groups, some groups contain very small pores : few 

 4-50 per mm., according to the subdivision of the groups, which 

 are radial and sometimes two-rowed, and of 2-1 1 pores : clear 

 only in the sap-wood, where there is sometimes resin. 



Rays. Need lens, size 5-7 : uniform : equidistant, rather 

 more than a pore-group apart : scarcely avoiding the pores, in- 

 terrupted or running round them : very numerous, 8-23 per 

 mm. : straight or gently waved : in the sap-wood much lighter 

 than the ground and coarser-celled : obscure in the Ebony. 



Rings. Not traceable, all indications quite absent, unless 

 the clearer lines of soft-tissue occurring at intervals indicate 

 them. 



Soft-tissue. Needs lens, abundant in concentric lines or bars, 

 size equals that of the rays (5-6 ray-scale) : the perfect lines 

 chiefly in the Spring (?) zones, only bars in the later (?) wood : 

 numerous, 6-8 per mm. : contour much serrated or jagged : 

 equidistant. 



Pith.? 



Radial Section. Pores readily visible but scarcely prominent : 

 usually 'filled. Rays inconspicuous yet readily visible, shining 

 flakes of the colour of the ground. Rings not traceable : in the 

 sap-wood the soft-tissue appears as excessively fine, continuous 

 pink lines. 



Tangential Section. As the Radial, but the rays in the sap- 

 wood are on the limit of vision with lens, but clearer when 

 moistened : about o - 5 mm. high : and the soft-tissue is not 

 traceable. 



Type specimens from commercial sources not authenticated, 

 but checked by Nordlinger's description and section, and 

 Gamble's description. 



No. 135. ZWARTBAST. Royena lucida. Linn. 

 Plate X. Fig. 85. 



Natural Order. Ebenaceae. 



Alternative Name. Black-wood (57). 



Sources of Supply. South Africa. 



Physical Characters, etc. Recorded dry-weight 39 lbs. per 

 cu. ft. My specimen has only a small proportion of the Ebony, 

 hence the weight appears unduly low. Hardness of the Ebony 

 Grade 2, compare Boxwood : of the lighter wood. Grade 7, 

 compare Beech. Smell or taste none. The lighter part of the 

 wood burns well, heat expels a copious brown juice, embers glow 

 dully in still air. Solution pale, the colour of the lighter wood : 

 a brown ppt. upon the addition of potash. 



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