378 



SUBTERRANEAN ORGANS 



but has an intensely pungent taste. The drug contains in addition 

 resin and abundance of starch. It yields from 3 to 5 per cent, of ash. 



Gingerol is a mixture of homologous phenolic substances of the formulae 

 C 17 H 26 O 4 , CjgHagOg, &c. Fixed alkalies, especially when heated, destroy its 

 pungency but baryta water splits it up into fatty aldehydes, especially 

 w-heptaldehyde and zingerone. Zingerone, CjjH^Oj, is crystalline and pungent ; 



FIG. 202. Ginger. A, Jamaica ; B, African ; C, Cochin. All slightly reduced. 



it has a sweet odour and is allied to vanillin from which it has been synthe- 

 sised; it is 4-hydroxy-3-methoxyphenylethylmethylketone. The pungency 

 of gingerol is destroyed by boiling with 2 per cent, solution of potassium hydr- 

 oxide, while that of capsaicin or paradol is scarcely affected. 



Uses. Ginger is largely used as a condiment, and medicinally as a 

 carminative and aromatic stimulant. 



Varieties. The chief commercial varieties of ginger are Jamaica, 

 Cochin, African, Japanese, and Bengal ; an inferior grade of Jamaica 

 ginger, obtained by allowing a part of the ' hand ' to remain in the 



