424 SCITAMINEJiJ. 



case It is called coated; or deprived of epidermis, and theu 

 termed scraped or uncoated. The pieces, wliicli are called by 

 the spice dealers 7rwes or hands, rarely exceed 4 inches in Icngtli 

 and have a somewhat palmate form, being made np of a series 

 of short, laterally compressed, lobe- like shoots or knobs. 

 TJncoated Cochin ginger, which is the best kind produced in 

 India, has a pale buff hue, and a striated, somewhat fibrous, 

 Surface. It breaks easily, exhibiting a short and farinaceous 

 fracture with numerous bristle-like fibres and closely resembles 

 Jamaica ginger in appearance and flavour. " Black " Cochin 

 ginger is that dried in the wet weather by means of hot ashes. 

 Bengal and Bombay gingers have a brownish or reddish 

 external surface, and the fractured surface is harder and darker, 

 the flavour is less delicate than that o£ the Cochin sort. Coated 

 gingers are now seldom met w^ith, but Indian commercial 

 samples usually contain a proportion of shrivelled and im- 

 perfectly scraped roots. 



Chemical composition. — Ginger has been very completely 

 examined by J. 0. Thresh. {Pharm. Journ. (3} xil., 721). 

 He found Cochin ginger to contain volatile oil r350 ; fat, wax 

 (?) and resin (in the petroleum other solution), 1*205; neutral 

 resin -950; a. and &. resins, '865; Gimjeroly -600 ; substance 

 precipitated by acids, 5'350 ; mucilage, 1'450; indifferent 

 substance pi^ecipitatod by tannin, organic acids, &c., C800; 

 extractive soluble in alcohol not in ether or water, '280 ; alkaloid 

 a trace; raetarabin, 8120 ; starch, 15-790 ; pararabin, 14*400 ; 

 oxalic acid (as CaC'O^), '427; cellulose, 3'750; albuminoids, 

 5-570; vasculose, &c., 14-763; moisture, 13'530 ; ash, 4-800. 

 The essential oil is pale-yeUow, loevogyre and not acrid. 

 Gingerol, the active principle, is a straw-coloured, viscid, 

 odourless fluid of extremely pungent taste* 



ginger 



cent, of oleo-resin, whereas Jamaica ginger only yields 5 per 

 cent.^ It may be best extracted by alcohol, ether or chloroform, 

 benzin wiU dissolve it, but it docs not exhaust the drug a a 

 eatisfactorily as the other solvents. 



