CORTEX CASSIA LTGNE.E. 531 



have a pale cinnamon hue, but most are of a deep rich brown. They 

 present all variations in thickness, from that of cardboard to more than 

 a quarter of an inch thick. The flavour is more or less that of cinna- 

 mon, often with some unpleasant addition suggestive of insects of the 

 genus Gimex. Many, besides being aromatic, are higlily mucilaginous, 

 the mucilage being freely imparted to cold water. Finsilly, we have 

 met with some thick cassia bark of good appearance that wns 



distinguished by astringency and the almost entire absence of 

 aroma. 



Microscopic Structure — A transverse section of such pieces of 

 CJdnese Cassia lignea as still bear the suberous envelope, exhibits the 

 following characters. The external surface is made up of several rows 

 of the usual cork-cells, loaded with brown colouring matter. In pieces 

 from which the cork-cells have been entirely scraped, the surface is 

 formed of the mesophloeum, yet by far the largest part of the bark 

 belongs to the liberorendophlceum. Isolated liber-fibres and thick-walled 

 cells (stone-cells) are scattered even through the outer layers of a trans- 

 verse section. In the middle zone they are numerous, but do not fonn 

 a coherent sclerenchymatous ring as in cinnamon (p. 52fi). The inner- 

 most part of the liber shares the structural character of cinnamon 

 with differences due to age, as for instance the greater development of 

 the medullary rays. Oil-cells and gum-ducts are likewise distributed 



m the parenchyme of the former. 



The « China Cinnamon " of 1870 (p. 530) comes still nearer to 

 Ceylon cinnamon, except that it is coated. A transverse section of a 

 quill, not thicker than one millimetre, exhibits the three layers de- 

 scribed as characterizing that bark. The sclerenchymatous ring is 

 covered by a parenchyme rich in oil-ducts, so that it is obvious that the 

 flavour of this drug could not be improved by scraping i he corky 

 layer is composed of the usual tabular cells. The liber of this drug in 

 fact agrees with that of Ceylon cinnamon. - 



In Cassia Barks of considerable thickness, the same arrangement oi 

 tissues is met with, but their strong development causes a certain ais- 

 similarity. Thus the thick-walled cells are more and more separates! 

 one from another, so as to form only small groups. The same appnes 

 also to the liber-fibres, which in thick barks are surrounded b^ a par n- 

 chyme, loaded with considerable crystals of oxalate ot ^alc mm. 

 gum-ducts are not larger, but are more numerous in these baiRs, wmc. 

 swell considerably in cold water. 



Chemical Composition-Cassia bark owes its aromatic^^^^^ 



to an essential oil, which, in a chemical point ^V.'^f^' ^°...],at le 

 that of Ceylon cinnamon. The flavour of cassia «;^y!^ ^j^^^J^Jedly 

 agreeable, and as it exists ia the less valuable sorts o cas^a, deci lea y 

 different in aroma from that of cinnamon ^^e find the sp. g 

 a Chinese cassia oil to be V0G6, and its rotatory P^^^^^fJ-^^t^',^ " ct 

 50 mm. long, only O"! to the right, differing consequently in this p 



from that of cinnamon oil (p. 526). , . , i^^^ purified 



^■•1 of cassia sometimes deposits a ^tearop ene J. hich when P 

 colourless, inodorous substance, crystallizing m shmm^ 



I 1 "\1T^ 1 . J- m'^*^i'V% 1 f. 



Oil 



is a c 



prisms.^ We have never met with it. 



^ RochleJer and Schwarz (1850) iu Gmeliu . Chemistry, xvii. 395. 



