326 POWDERED VEGETABLE DRUGS 



81. DEXTRINUM. Dextrin. 

 A dry fine powder. 



British gum, E. Dextrin, G. Dextrin, Fr. 



Derived from starches. (See starch.) 



Rather light brown, quite mobile. Nearly white, yellowish brown 

 tinge, less mobile (white dextrin). 



Odorless. 



Sweetish. 



Outline of granules indistinct, quite irregular, hili and stratifica- 

 tion quite distinct. The histological characteristics are still sufficiently 

 marked to determine the kind of starch employed. (See starches.) 



In the United States corn starch is employed. White dextrin con- 

 sists largely of unmodified starch granules; no high temperature is 

 employed in its preparation. 



82. (Fig. 89.) DIGITALIS. Digitalis. U. S. 

 Fl. ex. 60. Tinct. 60. 



Foxglove, E. Fingerhut, G. Digitale pourpree, Grand digitale, Fr. 



The leaves (second years' growth) of Digitalis purpurea L., Scro- 

 phulariaceae. 



Dull green. 



Faintly fragrant when dry; heavy, nauseous, when moist. 



Bitter. 



Vertical walls of upper and lower epidermis wavy, those of the 

 lower more so than the upper; stomata on lower surface only; simple, 

 many celled, rather large trichomes with minute warty outer mark- 

 ings; some glandular trichomes with two secreting cells; no crystal 

 bearing cells. 



Ash 8.5 per cent. 



Adulterated with leaves of first year's growth; leaves of Verbas- 

 cum Thapsus, (large, branched trichomes); Conyza squarrosa; Sym- 

 phytum officinale; Inula Helenium; and common Comfrey. The his- 

 tology of first and second year leaves requires further careful compara- 

 tive study. The leaves of the first year plants contain fewer trichomes 

 than the second year leaves and it is probable that a careful compara- 

 tive trichome count will make it possible to detect admixtures. 



