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.