DIGITALIS 



621 



Constituents. Several crystalline glucosides, including digitoxin 

 (0.2 to 0.3 per cent), digitalin and digitonin, the former two being the 

 more important. The drug also contains a volatile oil containing a 

 stearoptene digitalosmin, which has the odor of digitalis and a nau- 



FIG. 273. Transverse section of digitalis leaf, through one of the veins: UE, 

 upper epidermis; P, chlorenchyma (mesophyll), containing chloroplastids; 

 LE, lower epidermis; G, glandular hairs; N, non-glandular hairs; C, collen- 

 chyma; T, trachea? or vessels; S, leptome or sieve. 



seous, acrid taste; a volatile principle, antirrhinic acid> somewhat 

 resembling valerianic acid; digitalic acid, separating in white needles; 

 two coloring principles, one red and the other yellow, resembling 

 chrysophan, a glucoside found in rhubarb ; an oxydase ferment which 

 occurs in the recently dried leaves; a small quantity of tannic acid; 



