PREFACE 



THIS brochure is the first of a series which will, it is hoped, 

 extend to the whole of the more useful woods of Africa. At 

 present, however, we confine ourselves to those species only 

 which have been sent to us by the Government of Nigeria for 

 the purpose. Many of the woods are very widely distributed, 

 in some cases ranging from Senegal to the Sudan and from the 

 Cape to the East African ^Protectorate, hence our descriptions 

 may be found useful by those interested in the timbers of the 

 adjacent regions. 



Our method of identification is based upon the examination 

 of the solid wood by means readily applicable to all, after 

 preparation (smoothing) with glass-paper, pumice-stone, the 

 sharp edge of broken glass, by the plane, or even by the use 

 of a hone. Each wood may demand a different method to 

 bring it into a condition in which the structure will be clearly 

 visible. Hence in comparing our descriptions it will be neces- 

 sary to treat the wood in the same way as stated in the schedules 

 in connection with each species under the paragraph " trans- 

 verse section." The various tissues are thrown into relief 

 by different processes, for example, the wood-parenchyma, 

 or soft-tissue, is made visible by the use of glass-paper, 

 whereas it is frequently obscured by the use of a plane. A 

 corner of the wood cleanly cut with a razor will serve as a 

 control. 



The means of magnification are : a hand-lens affording 

 about three diameters, and a hand-microscope (which we shall 

 refer to as a " macroscope ") giving about ten diameters. Our 

 figures are all enlarged by three diameters, to accord with the 

 image obtained by the hand-lens. The hand-microscope can 

 easily be made by detaching the tube of a student's microscope 

 together with its eye-piece and objective, and fitting it with 

 an external sliding tube (of sheet metal, cardboard, or even 



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