CORTEX BIBIRU. 535 



CORTEX BIBIRU. 

 Cortex Fedandrce ; Greenheart Bark, Bibirit or Bcbeerii Bark. 



Botanical Origin — Nectandra Rodicvi Schomburgk — Tlie jUibiru 

 or Greeuheart is a large forest tree,^ growing on rocky soils in British 

 Guiana, twenty to fifty miles inland. It is found in abundance on the 

 hill sides which skirt the rivers Essequibo, Cuyuni, Denierara^ Ponieroon 

 and Berbice. The tree attains a height of 80 to 90 feet, witli an 

 undivided erect trunk, furnishing an excellent timber whicli is ranked 

 m England as one of the eight first-class woods for shipbuilding, and is 

 to be had in beams of from GO to 70 feet loni^. 



History — In 17G9 Bancroft, in his History of Guiana, called 

 attention to the excellent timber afforded by the Greenheart or Sipeira. 

 About the year 1835 it became known that Hugh Rodie, a navy 

 surgeon who had settled in Demerara some twenty years previously, had 

 discovered an alkaloid of considerable efficacy as a febrifuge, in the bark 

 of this tree.2 In 1843 this alkaloid, to which Rodie had given the name 

 Bebeerine, was examined by Dr. Douglas Maclagan ; and the following 

 year the tree Avas described by Schomburgk under the name of 

 Ncdandra Rodkei? 



Description— Greenheart bark occurs in long heavy flat pieces, not 

 unfrequently 4 inches broad and ^o of an inch thick, externally of a 

 light greyish brown, with the inner surface of a more uniform cinnamcm 

 hue and with strong longitudinal stri». It is hard and brittle; the 

 fracture coarse-grained, slightly foliaeeous, and only fibrous in the umer 

 layer. The grey suberous coat is always thin, often forming small wart., 

 and leaving when removed longitudinal depressions analogous to the 

 <ligital furrows of Flat Calisaya Bark (p. 353), but mostly longer. 

 Greenheart bark has a strong bitter taste, but is not aromatic. Its 

 watery infusion is of a very pale cinnamon brown. 



Microscopic Structure— The general features of this bark are 

 very uniform, almost the whole tissue having been changed into thick- 

 waUed cells. Even the cells of the corky layer show secondary deposits ; 

 tlie primary envelope has entirely disappeared, and no transition Horn 



the suberous coat to liber is obvious. . , , 



^. The prevalent forms of the tissue are the stone-cells and very short 

 iber-fibres, intersected by small medullary rays and crossed transversely 

 ^y parenchyme or small prosenchyme cells with walls a I'ttle i^ss 

 thickened, so as to appear in a transverse section as irregular sq aics 

 or groups. The only cells of a peculiar character are the «'.'arp-pointca 

 fibres of the inner liber, which are curiously saw-shaped, being piovide^i 

 ^vith numerous protuberances and sinuosities. , , 



^ The very small lumen of the thick-walled ceUs conta ns a dark 

 brown mass which is coloured greenish-black by sulphate o^jon^j^^^ 

 same coloration takes place throughout the less dense tissue suiiound- 



