Adulteration—The dried leaves of some other plants have occasionally been supplied for those of foxglove. Such are the leaves of Verbascum, which are easily recognized by their thick coat of branched stellate hairs; of Inula Conyza DC. and I. Helenium L., which have the margin almost entire, and in the latter plant the veins diverging nearly at a right angle from the midrib; in both plants the under side of the leaf is less strongly reticulated than in foxglove. But to avoid all chance of mistake, it is desirable that druggists should purchase the fresh flowering plant, which cannot be confounded with any other, and strip and dry the leaves for themselves.
ACANTHACEÆ.
HERBA ANDROGRAPHIDIS.
Kariyát or Creyat.
Botanical Origin—Andrographis[1727] paniculata Nees ab E. (Justicia Burm.), an annual herb, 1 to 2 feet high, common throughout India, growing under the shade of trees. It is found likewise in Ceylon and Java, and has been introduced into the West Indies. In some districts of India it is cultivated.
History—It is probable that in ancient Hindu medicine this plant was administered indiscriminately with chiretta, which, with several other species of Ophelia, is known in India by nearly the same vernacular names. Ainslie asserts that it was a component of a famous bitter tincture called by the Portuguese of India Droga amara; but on consulting the authority he quotes[1728] we find that the bitter employed in that medicine was Calumba. Andrographis is known in Bengal as Mahā-tīta, literally king of bitters, from the Sanskrit tikta, “bitter,” a title of which it has been thought so far deserving that it has been admitted to a place in the Pharmacopœia of India.
Description—The straight, knotty branch stems are obtusely quadrangular, about ¼ of an inch thick at the base, of a dark green colour and longitudinally furrowed. The leaves are opposite, petiolate, lanceolate, entire, the largest ½ an inch or more wide and 3 inches long. Their upper surface is dark green, the under somewhat lighter, and as seen under a lens finely granular. The leaves are very thin, brittle, and, like the stems, entirely glabrous.
In the well-dried specimen before us, for which we are indebted to Dr. G. Bidie of Madras, flowers are wanting and only a few roots are present. The latter are tapering and simple, emitting numerous thin rootlets, greyish externally, woody and whitish within. The plant is inodorous and has a persistent pure bitter taste.
Chemical Composition—The aqueous infusion of the herb exhibits a slight acid reaction, and has an intensely bitter taste, which appears due to an indifferent, non-basic principle, for the usual reagents do not indicate the presence of an alkaloid. Tannic acid on the other hand produces an abundant precipitate, a compound of itself with the bitter principle. The infusion is but little altered by the salts of iron; it contains a considerable quantity of chloride of sodium.
Uses—Employed as a pure bitter tonic like quassia, gentian, or chiretta, with the last of which it is sometimes confounded.