This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Soldanella & convolvulus maritimus Ph. Paris. Soldanella maritima minor C. B. Convolvulus Soldanella Linn. Soldanella: a species of convolvulus, with roundish or kidney-shaped leaves set on long pedicles; and large reddish-purple flowers standing solitary in the bosoms of the leaves. It grows wild about the sea coasts in the north of England, and flowers in June.
The leaves of soldanella are said to be a strong and a rough cathartic, generally oc-casioning gripes and disordering the stomach. Their virtue resides in an acrid, bitterish, milky juice, which exudes upon wounding them. In drying, they lose much of their taste, but seem to retain their purgative virtue: a decoction of from half a dram to two or three drams of the dried leaves is directed for a dose. In some places, it is customary among the common people to prepare a strongly purgative liquor by boiling a small handful of the fresh leaves in broth. But as their degree of strength is very little known, and as we have many other medicines, for the same intention, whose qualities have been ascertained by general experience, the fol-danella, though retained in moil catalogues of the materia medica, stands excluded from practice,
(a) Hoffman, De remediis domesticis, § 14.
(b) Boerhaave, Hist. plant. hort. Lugd. Bat. p. 423.