DIGITALIS—FOXGLOVE
The dried leaves of Digitalis purpurea Linne (Fam. Scrophulariaceae), collected from plants of the second year’s growth, at the commencement of flowering.
Habitat.—Foxglove grows wild in the temperate parts of Europe, where it flowers in the middle of summer. In this country it is cultivated for ornamental and for medical use.
Properties.—Foxglove is without odor in the recent state, but acquires a faint narcotic odor when dried. The color of the dried leaf is a dull pale green, modified by the whitish down upon the under surface; that of the powder is a fine deep green.
Constituents.—Digitalein, Digitonin, Digitalin and Digitoxin, the latter is most poisonous and active. Said to be cumulative.
Dose.—Digitalis leaves, horses, 15 gr. to 1 dr.; cattle, 30 gr to 11⁄2 dr.; sheep and pigs, 5 to 15 gr.; dogs, 1⁄2 to 3 gr.
Active Principles.—Digitoxin—It occurs in crystals, soluble in alcohol and chloroform, slightly in ether, and insoluble in water; said to be cumulative.
Dose.—Horses and cattle, 1⁄8 to 1⁄4 gr.; dogs, 1⁄250 to 1⁄50 gr.
Digitalein, an amorphous, bitter substance, soluble in water and alcohol and non-cumulative.
Dose.—Same as digitoxin.
Digitalin, a very bitter, crystalline substance, soluble in alcohol, and slightly soluble in water and ether.
Dose.—Same as for digitoxin.
Digitonin, resembling or identical with saponin of senega. White, amorphous powder, soluble in water. It is a heart depressant, muscular paralyzant and powerful irritant, besides being antagonistic to digitalis. In addition to these principles there are: Digitin, an inactive substance. Digitalic and antirrhinic acids. Tannin coloring matter, starch, sugar, gum, a volatile oil, salts, etc., common to most vegetables.