DIGITALIS 



389 



Synopsis of Drugs from the Scrophulariacea 



Leaves. 



DIGITALIS, 518. 



Euphrasia, 519. 

 *Verbascum, 520. 

 Rhizome. 



* Leptandra, 52 1 . 



C. Herbs. 



Veronica Officinalis, 522. 

 Scrophularia, 523. 

 Chelone, 524. 



518. DIGITALIS. DIGITALIS 



FOXGLOVE 



The carefully dried leaves of Digita'lis purpurea Linne', without admixture of more 

 than 2 per cent, of stems, flowers, or other foreign matter. 



BOTANICAL CHARACTERISTICS. Biennial, hoary-pubescent. Leaves alternate, 

 ovate-lanceolate, crenate, rugose. Racemes terminal, loose; flowers pur- 

 ple, sometimes white, hairy, and spotted within. 



SOURCE. The plant is indigenous to Southern and Central Europe, par- 

 ticularly in the western section, and grows wild as far north as Nor- 

 way, also in Madeira and the Azores, and is cultivated in the United 

 States. It is found on the edges of woody land and prefers sandy 

 soil. 



It is claimed by some investigators that Digitalis leaves of the 

 first and second year's growth have proved identical in their activity, 

 and the cultivated leaves are at least as active as those wild grown. 



DESCRIPTION OF DRUG. The margin of this leaf is rather irregularly 

 double crenate. In the market it comes in- wrinkled, velvety frag- 

 ments, the lower surface paler green than the upper, softly pubes- 

 cent, especially along the midrib and veins; the midrib is prominent, 

 but not so much so as in hyoscyamus; the venation forms prominent 

 meshes on the under surface of the leaf, the principal veins joining 

 the midrib at a very acute angle; odor slight and characteristic; taste 

 strongly bitter. 



ADULTERATIONS. Other dried leaves are sometimes mixed with digitalis; 

 the commonest of these are: Inula conyza (Conyza squarrosa), spike- 

 nard, and Inula helenium, both having entire, instead of crenate or 

 serrate, margins, and the latter having its veins branching off at 

 about right angles to the midrib; accidental impurities, such as 

 comfrey leaves, Symphytum qfficinale, have been found. These are 

 lanceolate and bear isolated stiff hairs. 

 Powder. Characteristic elements: See Part iv, Chap. I, B. 



CONSTITUENTS. The exact chemical composition of digitalis is a vexed 

 question, but the latest analysis shows it to be composed of at least 

 five principles: digitalin, CsHgOa (soluble in alcohol, insoluble in 

 water), digitalein (soluble in water and alcohol), digitonin, 

 C2yH44Oi3 (readily soluble in water, insoluble in alcohol, the diuretic 

 principle), digitin (inert), and digitoxin, CaiHsoOio, the most active 



