QUALITIES. The leaves, when properly dried, have a strong and narcotic
odour, and a slightly bitter and nauseous taste: the fresh leaves
contain not only the narcotic, but also the acrid principle: by
exsiccation, the latter is nearly lost, but the former undergoes no
change; the medicinal properties of the leaves are therefore improved by
the operation of drying. CHEMICAL COMPOSITION. The medicinal activity of
the plant resides in a resinous element, which may be obtained in an
insulated form, by evaporating an ethereal tincture made with the
leaves, on the surface of water; it has a rich dark green colour, and
contains the peculiar odour and taste of hemlock in perfection; a dose
of half a grain will produce vertigo and head-ache. It may be
distinguished by the name of _Conein_. The watery extract of this plant
can therefore possess but little power, a fact which Orfila has fully
established by experiment. No part of the plant is entirely destitute of
efficacy, though the leaves possess the most activity. SOLUBILITY.
Alcohol and æther extract its virtues. INCOMPATIBLE SUBSTANCES. Its
energies are greatly diminished by vegetable acids; hence vinegar is its
best antidote. MEDICINAL USES. It is a powerful sedative, and has been
deservedly commended for its powers in allaying morbid irritability:
according to my own experience, it is, in well directed doses, by far
the most efficacious of all palliatives, for quieting pulmonary
irritation. It has been extolled also in the cure of schirrus and
cancer, and it will without doubt prove in such cases a valuable
resource, from its sedative influence. Externally, it will afford
considerable relief in irritable ulcers, when applied in the form of
fomentation or cataplasm, see _Form. 17, 18_. FORMS OF EXHIBITION. The
dried leaves, powdered, and made into pills, (_Form. 2, 17, 18_.) The
powder ought to have a fine lively green colour. DOSE, gr. iij,
gradually increased, until some effect is produced. Several different
plants have been mistaken for, and employed in the place of hemlock,
such as _Cicuta Virosa_, (the water hemlock,) _Æthusa Cynapium_,
_Caucalis anthriscus_, and several species of _Chærophyllum_. OFFICINAL
PREPARATIONS. _Extract._ _Conii._ L.E.D.