DIGITALIS 445 



SECTION "VI.— DEUGS ACTING ON THE HEAET. 



Class 1.— Increasing the Force and Decreasing the 

 Frequency of the Heart. 



Digitalis. Digitalis. 



Synonym. — Digitalis folia, B. P. ; foxglove, digitalis 

 leaves, E.; digitale, feuilles de digitale pourpree (de grande 

 digitals), Fr.; finger hutkraut, G. 



The leaves of Digitalis purpurea Linne (nat. ord. scro- 

 phularinese), collected from plants of the second year's 

 growth. 



Description. — From 10 to 50 cm. long ; ovate or ovate- 

 oblong, narrowed into a petiole, crenate, dull green, densely 

 and finely pubescent, wrinkled above, paler and reticulate 

 beneath, midrib near the base broad; odor slight, some- 

 what tea-like ; taste bitter, nauseous. 



Gonstituents. — The active principles of digitalis are four 

 glucosides; the three first represent its stimulant action. 

 1. Digi toxin, the most poisonous and active. Said to be 

 cumulative. It occurs in crystals, soluble in. alcohol and 

 chloroform, slightly in ether, and insoluble in water. 2. 

 Digitalein, an amorphous, bitter substance, soluble in water 

 and alcohol and non-cumulative. Dose. — H., gr.^-j (.008- 

 .015); D., gv.^ (.0006). 



3. Digitaliu, a bitter, crystalline body, soluble in alcohol, 

 and sparingly soluble in water and ether. 4. Digitonin* 

 (Cj, Hm O13), resembling, or identical with, saponin of senega. 

 Soluble in water. It is a heart depressant, muscular para- 

 lyzant and powerful irritant, besides being antagonistic to 

 digitalis. In addition to these principles, there are : 

 5. Digitin, an inert body. 6. Digitalic and antirrhinic 

 acids. 7. Tannin, coloring matters, starch, sugar, gum, a 

 volatile oil, salts, etc., common to most vegetables. 



Two substances Are found in commerce : I. Nativelle's 

 digitalin (C25H<,„Oi5), occurring in white crystslline tufts com- 

 posed of needles. It is bitter, and soluble in alcohol and 



* There exists anotHer gluooside in digitalis— digitophyllin— which has been 

 insuffloiently studied. 



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