ZINGIBER. GINGER. 131 



are sieve tubes, cork cells, tracheids, and wood paren- 

 chyma. 



The starch is fairly typical. In the fresh condition it 

 is seen to consist of compound grains made up of from 

 five to twenty granules. In dry specimens of the market, 

 the grain is found to be broken up, and is apparently 

 much simpler in structure. The average diameter of the 

 grains is from -8 to 14 microns. The larger granules 

 measure from 4 to 6 microns. The hilum is inconspicu- 

 ous and concentric markings are few. 



The crystals are not very numerous, yet are large, well- 

 marked rosettes. They average from 40 to 80 microns, in 

 several specimens examined. 



Reticulated and pitted vessels are the most character- 

 istic in the powder. Fragments measure about 40 to 100 

 microns. The parenchyma, starch-filled, is thick- walled 

 and pitted, and the cells average from 40 to 100 microns. 

 The fibres in old dried specimens colored yellow are not as 

 frequent and typical ; tracheids average about 25 microns 

 across. Here and there in a field in the powder of the dry 

 drug, masses of resin-like material may be encountered. 



Chemistry. — Water will precipitate a resinous body 

 called podophyllin from the alcoholic extract. This 

 podophyllin contains fatty oil, extractives, a yellow 

 pigment called podophylloquercetin, an acid, podophil- 

 linic acid, and picro-podophyllin and podophyllotoxin, 

 which latter can be split up into the former and picro- 

 podophyllinic acid. 



ZINGIBER. GINGER. 



The rhizome of Zingiber officinale, Resave. The year- 

 old roots are those in commercial use. Ginger is cul- 

 tivated in the West Indies and in the tropics generally. 



Description.— Practically the cultivated rhizome alone 

 comes into the market at present. It is a large flattish- 

 branched rhizome, about 7 cm. long and 2 cm. thick. 



