MICROSCOPICAL EXAMINATION 



SO? 



FIG. 280. Powdered Henbane Leaves (Hyoscyamus niger.) (X 210.) ccr. Crystal cells, cr, 

 Crystals of calcium oxalate. ei. Lower epidermis, es. Upper epidermis, ffv. Portion of fibrovas- 

 cular bundle of midrib, ip, Scar of fallen hair, m,* Spongy parenchyma, pa, p'a'. Palisade 

 cells, pg, Glandular hairs, pt. Simple hairs, st, Stomata. if. Cortical parenchyma of midrib. 

 tr, Tracheid and vessels. (After Greenish and Collin.) 



GENERAL DIRECTIONS 



As a general direction for the detection of adulteration or admixture 

 it cannot be too strongly emphasized, that authentic samples of the pure 

 drug, and of the suspected adulterant or admixture, should be carefully 

 studied, macroscopically, and microscopically, as a preliminary process. 

 This laboratory method supersedes all the aids in the form of representa- 

 tion by drawings and figures on paper. 



An examination of a drug powder should never be considered complete 

 until the sample has been compared with authentic specimens oj the same 

 drug or drugs oj the same degree of fineness. 



