120 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 







FIG. 51. Powdered ginger containing foreign tissues. The following are the 

 typical elements of ginger: F, sclerenchymatous fibers which vary from 0.3 to 

 1.3 mm. long and from 0.020 to 0.030 mm. in diameter, the walls being some- 

 what undulate, about 0.003 mm. thick, slightly yellowish, non-lignified and 

 having slender, oblique, simple pores; T, reticulate tracheae varying from 

 0.030 to 0.060 mm. in diameter, the walls consisting mostly of cellulose, and 

 with phloroglucin giving but a faint reaction for lignin; SC, secretion cells, the 

 walls of which are suberized and the contents of which in the fresh rhizome 

 are oily and of a light yellow color, changing to golden yellow with sulphuric 

 acid, whereas in the older commercial specimens the contents are yellowish, 

 or reddish-brown, balsam-like or resinous, becoming of a deep brownish- 

 black on treatment with sulphuric acid; K, cork cells which on an average 

 are about 0.060 in length and 0.025 mm. in width; S, starch grains which vary 

 from 0.020 to 0.060 mm. in length, the largest being found in Jamaica ginger, 

 have indistinct lamellae, and so do not polarize well unless mounted in a fixed 

 oil, as almond or olive; W, swollen starch grains; L, small, swollen, altered 



