GINGER 377 



passing through the cortex to the leaves, and laid bare by the peeling 

 of the rhizome. It breaks with a short, mealy or sometimes resinous 

 fracture, short scattered fibres usually protruding from the fractured 

 surface ; these are the fibro- vascular bundles in the stele and cortex. 



The smoothed transverse section exhibits a large stele which is 

 sharply delimited by a fine yellow line from a narrow cortex, both 

 stele and cortex containing numerous yellow oil-cells. No cork layer 

 is to be discerned. Ginger has an agreeable aromatic odour and a 

 strong pungent taste. 



The student should observe 



(a) The fibrous surface, 



(b) The short fracture with protruding fibres and yellow oil- cells. 



Microscopical Characters. The transverse section exhibits a large stele and 

 a cortex free from cork. The parenchymatous cells, which are very abun- 



FIG. 201. Ginger. A, transverse section through the 

 rhizome, magnified 3 diam. B, longitudinal section 

 through a branch, natural size, o, cortex ; v, endo- 

 dermis ; b, stele. (Berg.) 



dant, have very thin walls ; some contain yellow oleo-resin, but most are filled 

 with starch. The fibro-vascular bundles in the stele contain a few reticulated 

 vessels supported by sclerenchymatous fibres, which have rather thin walls and 

 large cavities ; abutting on the vessels are small cells filled with a dark brown 

 secretion. The starch grains are typically Scitaminaceous ; they are simple, 

 12/x to 30/x long, ovoid or sack-shaped and fiat, the hilum being at the extreme, 

 pointed end. 



Powdered ginger is characterised by the abundant typical starch, by the very 

 thin walls of the parenchymatous cells, by the characteristic sclerenchymatous 

 fibres, and by the oleo-resin cells ; the latter are mostly broken, but the suberised 

 walls are always to be found. It should contain no cork, no isodiametric scleren- 

 chymatous cells, and no hairs. It should yield about 7 per cent, of extract to 

 90 per cent, alcohol, from 12 to 15 per cent, to cold water, not more than 6 per 

 cent, of ash, and not less than 1'5 per cent, of ash soluble in hot water. The 

 last two data are specially useful in detecting adulteration with exhausted ginger. 



Constituents. Ginger contains from 0'25 to 3 per cent, of a volatile 

 oil possessing the aronm but not the pungency of the drug. The latter 

 property is due to a yellowish oily body, gingerol, which is odourless, 



