156 MELIACE^. 



CORTEX SOYMIDA. 



Cortex SwietenioB ; Rohun Bark. 



Botanical Origin — Soymida^ febrifuga Juss. (Smietenia febnfuga 

 Willd.), a tree of considerable size not uncommon in the forests of 

 Central and Southern India. The timber called by Europeans 

 Bastard Cedar is very durable and strong, and much valued for 

 building purposes. 



History — The introduction of Rohun Bark into the medical practice 

 of Europeans is due to Roxburgh" who recommended the drug as a 

 substitute for Cinchona, after numerous trials made in India about the 

 year 1791. At the same time he sent supplies to Edinburgh, where 

 Duncan made it the subject of a thesis^ which probably led to it being 

 introduced into the materia medica of the Edinburgh Pharmacopoeia 

 of 1803, and of the Dublin Pharmacopceia of 1807. 



Though thus officially recognized, it does not appear that the bark 

 came much into use or by any other means fulfilled the expectations 

 raised in its favour. At present it is regarded simply as a useful 

 astringent tonic, and as such it has a place in the Pharmacopceia of 

 India (1868). 



Description — Our specimen of Rohun bark* which is from a young 

 tree, is in straight or somewhat curved, half-tubular quills, an inch or 

 more in diameter and about i of an inch in thickness. Externally it is 

 of a rusty grey or brown, with a smoothish surface exhibiting no con- 

 siderable furrows or cracks, but numerous small corky warts. These 

 form little elliptic scars or rings, brown in the centre and but slightly 

 raised from the surface. The inner side and edges of the quilLs are of 

 a bright reddish colour. 



A transverse section exhibits a thin outer layer coloured by chloro- 

 phyll, and a middle layer of a bright rusty hue, traversed by large 

 medullary rays and darker wedge-shaped rays of liber. The latter has 

 a fibrous fracture, that of the outer part of the bark being rather corky 

 or foliaceous. The whole bark when comminuted is of a rusty colour, 

 becoming reddish by exposure to air and moisture. It has a bitter 

 astringent taste with no distinctive odour. The older bark frequently 

 half an inch thick and fibrous, has a thick ragged corky layer of a 

 rusty blackish-brown colour, deeply fissured longitudinally, and 

 minutely cracked transversely. Old bark, according to Dymock (1877), 

 is generally in half quills of a rich red-brown colour. 



Microscopic Structure —The bark presents but few structural 

 peculiarities. The ring of liber is made up of alternating prosenchyma- 

 tous and parenchymatous tissue. In the latter the larger cells are filled 

 with mucilage, the others with starch. The prosenchymatous groups of 

 the liber exhibit that peculiar form we have already described as 



1 From Sdmida, the Teluga name of the - Medical Facts and Observations, Lond. 



tree ; Bdhan is its name in Hindustani.— vi. (1795) 127. 



Fig. in Bentley and Trimen, Afed. Plants, ' Tentamen inaugurale de Stoietenid Soy- 



part 18 (1877). — See also C. De CandoUe, midd, Edinb. 1794. 



in Monogr. Pkanerogamar. i. (1878) 722. * Kindly sent us by Mr. Broughton of 



Ootacamund. 



