SPICES AND CONDIMENTS. 213 



and coated with gypsum or carbonate of lime to improve its appearance. 

 This method of treatment appears to be very common. 



Of the microscopic appearance of the rhizome Fliickiger and Han- 

 bury write as follows : 



A transverse section of coated ginger exhibits a brown, horny external layer, about 

 one millimetre broad, separated by a fine line from the whitish mealy interior por- 

 tion, through the tissue of which numerous vascular bundles and resin cells are 

 irregularly scattered. The external tissue consists of a loose outer layer, and an inner 

 composed of tabular cells; these are .followed by peculiar short prosenchymatous 

 cells the walls of which are sinuous on transverse section and partially thickened, 

 imparting a horny appearance. This delicate felted tissue forms the striated surface 

 of scraped ginger and is the principal seat of the resin and volatile oil, which here 

 fill large spaces. The large-celled parenchyme which succeeds is loaded with starch 

 and likewise contains numerous masses of resin and drops of oil. The starch gran- 

 ules are irregularly spherical, attaining at the utmost 40 mm . Certain varieties of 

 gingsr, owing to the starch having been rendered gelatinous by scalding, are through- 

 out horny and translucent. The circle of vascular bundles which separates the outer 

 layers and the central portion is narrow and has the structure of the corresponding 

 circle or nucleus sheath on turmeric. 



In the best ground ginger of the trade little is seen of this structure. 

 The appearance is one of predominating starch grains which are so 

 abundant in the parenchyma, and whicli are figured in Plate XXI, Fig. 

 41, and Plate XXVII, Fig. 58. They are so characteristic in shape and 

 in their appearance with polarized light, that they are readily dis- 

 tinguished from adulterations. 



Among them are seen scattered the fibre-vascular bundles, the tur- 

 meric-like resin bodies, and less prominently the oil globules, which are 

 few in number. 



When the source of the powder is the ordinary uuscraped ginger, 

 the outer horny layer is prominent, but not distinct in its character, 

 and at times when the rhizome has been scalded the starch grains are 

 swollen and the whole structure is more difficult to make out. It is 

 not, however, as a rule, difficult to detect foreign matter in the powder 

 of this spice. 



ADULTERANTS. 



The principal adulterants are said to be mineral matter, sago, tapioca, 

 flour of rice, wheat, and potato, cayenne, mustard hulls, turmeric, and 

 exhausted ginger. The foreign starches, cayenne, and mustard hulls, are 

 easily detected, but the turmeric cells, from their resemblance to the 

 resin globules of the ginger, are more confusing. The too frequent 

 occurrence of such cells is suspicious. For the detection of exhausted 

 ginger recourse must be had to proximate analysis. The recommenda- 

 tion also of Hassall, to wash away some of the starch, or the use of a 

 sieve, will be found of advantage, the remaining coarse particles being 

 then seen in greater numbers and with more ease. We have found in 

 the gingers of the trade rice flour, turmeric, and hulls of foreign seeds. 

 But two of the specimens were derived from coated root. 





