GUIDE TO TIMBERS OF NIGERIA 33 



often being twinned, especially on the bark side. General 

 arrangement of the vessels indefinite. Shape oval for the 

 most part, but the larger almost circular. Contents, a little 

 red deposit. 



Rays visible with lens with difficulty, extremely fine, of one 

 kind only ; very regular in size and spacing, at intervals of 

 about 3-4 times their own width apart, or about 14 per mm. 

 Proportion of the mass about one-sixth. 



Ground-tissue deep in colour and horny ; about one-half the 

 whole mass ; cells not visible with macroscope. 



Rings not indicated, unless the dense zones of nearly pore- 

 less wood, which occur at fairly regular intervals, mark the 

 boundaries. 



Radial section. -The rays appear as minute flakes (on 

 limit of vision with unaided eye), slightly darker than the 

 fibres. Vessels very coarse, nearly empty, shining grooves. 

 Parenchyma appears as extremely thin, hoary, vertical 

 lines. 



Tangential section as the radial, but the rays are extremely 

 minute lines in parallel, the rows being scarcely visible to 

 the naked eye, and about four to the mm., i.e. they are 

 about 0-1 mm. high, and at intervals of rather more than 

 their own height. 



SAPWOOD exceptionally well defined from the heartwood ; 

 dirty white in colour and about 2J-3 inches wide. The paren- 

 chyma becomes coloured a little in advance of the other ele- 

 ments. Pith ? Bark ? 



Density, No. 3623, 0-81, or about 51 Ib. per cu. ft. 

 (Cf. 1992 0-753 46| ) 



USES, ETC. Dyeing. The wood ought to sell on its merits 

 as an easily- worked wood of rich colour, quite apart from its 

 tinctorial properties. 



The N'Gula powder from the Gaboon from a sample from 

 the Musee Colonial de Marseille (No. 169, Gabon), when mixed 

 with water (hot or cold), makes a rather dirty 'purplish-brown 

 extract, but on the addition of soap, the wood in suspension 

 falls and leaves the solution nearly clear. With alcohol the 

 powder forms a rich orange tincture which on evaporation 

 leaves a purplish residue. Both of our specimens fail to yield 

 any coloration with distilled water and with potable water 



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