_Stramonium Seeds_; F. _Semences de Stramoine_; G. _Stechapfelsamen_.
=Botanical Origin=—_Datura Stramonium_ L., see preceding article.
=Description=—The spiny, ovoid capsule of stramonium opens at the
summit in four regular valves. It is bilocular, with each cell
incompletely divided into two, and contains a large number (about 400)
of flattened, kidney-shaped seeds. The seeds are blackish or dark
brown, about 2 lines long and ½ a line thick, thinning off towards
the hilum which is on the straighter side. The surface of the seed is
finely pitted and also marked with a much coarser series of shallow
reticulations or rugosities. A section parallel to the faces of the
seed exhibits the long, contorted embryo, following the outline of the
testa, and bedded in the oily white albumen. The cylindrical form of
the embryo is seen in a transverse section of the seed.
The seeds have a bitterish taste, and when bruised a disagreeable
odour. When the entire seeds are immersed in dilute alcohol, they
afford a tincture displaying a beautiful green fluorescence, turning
yellow on addition of ammonia.
=Microscopic Structure=—The testa is formed of a row of radially
extended, thick-walled cells. They are not of a simply cylindrical
form, but their walls are sinuously bent in and out in the direction
of their length. Viewed in a direction tangential to the surface, the
cells appear as if indented one into the other. Towards the surface of
the seed the cell-walls are elevated as dark brown tubercles and folds,
giving to the seed its reticulated and pitted surface. The albumen and
embryo exhibit the usual contents, namely fatty oil and albuminoid
substances.[1686]
=Chemical Composition=—The active constituent of stramonium seeds is
the highly poisonous alkaloid _Daturine_, of which they afford only
about ⅒ per cent., while the leaves and roots contain it in still
smaller proportion.[1687] Daturine was discovered in 1833 by Geiger
and Hesse, and regarded as identical with atropine by A. von Planta
(1850), who found it to have the same composition as that alkaloid.
The two bodies exhibit the same relations as to solubility and fusing
point (88-90° C.); and they also agree in crystallizing easily. The
experiments of Schroff (1852), tending to show that although daturine
and atropine act in the same manner, the latter has twice the poisonous
energy of the former, raised a further question as to the identity of
the two alkaloids. Poehl (1876) also stated solutions of daturine to
be levogyrate, those of atropine being devoid of rotatory power. From
the observations of Erhard (1866), it would appear that the crystalline
form of some of the salts of atropine and daturine is different. In
stramonium seeds daturine appears to be combined with malic acid. The
seeds yielded to Cloëz (1865) 2·9 per cent. of ash and 25 per cent. of
fixed oil.
=Uses=—Stramonium seeds are prescribed in the form of extract or
tincture as a sedative or narcotic.
[1686] We have not seen W. G. Mann, _Onderzoek van het zaad van Datura
Stramonium_, Enschede, 1875.
[1687] Günther in Wiggers and Husemann’s _Jahresbericht_ for 1869. 54.