206 LAVBINEM 



essential oil, large quantities' of wHicli are shipped from 



Canton. In a chemical point of view, no difference can 

 be pointed out between this oil and that of Ceylon cinnamon. 

 The flavour of cassia oil is somewhat less agreeable, and, as at 

 exists in the less valuable sorts of cassia, decidedly different m 

 aroma from that of cinnamon. We find the sp. gr, of a Chmese 



m 



long, only 01*^ to the right, differing consequently in this 

 respect from that of cinnamon oil. 



"If t^iii sections of cassia bark are moistened with a dilute 

 solution of perchloride of iron, the contents of the parenchy- 

 matous part of the whole tissue assume a dingy brown colour ; 

 in the outer layers the starch granules even are coloured. 

 Tannic matter is consequently one of the chief constituents of the 

 bark; the very cell- walls are also imbued with it. A decoction 

 of the bark is turned blackish-green by a per salt of iron. 



** If cassia bark (or Ceylon cinnamon) is exhausted by cold 

 water, the clear liquid becomes turbid on addition of iodine; tne 

 same occurs if a concentrated solution of iodide of potassium is 

 added. An abundant precipitate is produced by addition oi 

 iodine dissolved in the potassium salt. The colour of iodine 

 then disappears. There is consequently a substance present, 

 which unites with iodine; and, in fact, if to a decoction of 

 cassia or cinnamon, the said solution of iodine is added, itstriKCS 

 a bright blue coloration, due to starch. But the colour quickly 

 disappears, and becomes permanent only after much of the te» 

 has been added. "We have not ascertained the nature of the 

 substance that thus modifies the action of iodine ; it can hardly 

 be tannic matter, as we have found the reaction to be the satne 

 when we used the bark that had been tireviouslv repeatedly 



s 



etli 



spirit of wine and tlien several times witH 



er. 



The 



ai3 



of cassia is easily dissolved by cold water, and may be precipi- 

 tated together with taimln, by neutral acetate of lead, but notb)' 

 alcohol. In the thicker barks it appears less soluble, merel}' 

 swelling into a slimy jelly." 



