_Belladonna Root_; F. _Racine de Belladone_; G. _Belladonnawurzel_.
=Botanical Origin=—_Atropa Belladonna_ L., a tall, glabrous or slightly
downy herb, with a perennial stock, native of central and Southern
Europe, where it grows in the clearings of woods. The plant extends
eastward to the Crimea, Caucasia and Northern Asia Minor. In Britain it
is chiefly found in the southern counties, but even of these it is a
doubtful native.
[1665] _Jahresbericht_ of Wiggers and Husemann, 1873. 567; also
_Yearbook of Pharm._ 1876. 251.
[1666] _Blue Book_ of the Colony of Sierra Leone for 1871.
[1667] Do. of Natal for 1871.
[1668] Do. of the Straits Settlements for 1871.
[1669] _Statement of the Trade and Navigation of Bombay for 1872-73_,
pt. ii. 58. 91.
In a few localities in England and France, as well as in North America,
the plant is cultivated for medicinal use.
=History=—Although a plant so striking as belladonna can hardly have
been unknown to the classical authors, it cannot with certainty be
identified in their writings.
Saladinus of Ascoli,[1670] who wrote an enumeration of medicinal plants
about A.D. 1450, names the leaves of both _Solatrum furiale_ and
_Solatrum minus_, the former of which is probably _Belladonna_. However
this may be, the first indubitable notice of it that we have met with,
is in the _Grand Herbier_ printed at Paris, probably about 1504.[1671]
The plant is also mentioned about this period as _Solatrum mortale_ or
_Dolwurtz_, in the writings of Hieronymus Brunschwyg.[1672]
In 1542 belladonna was well figured as _Solanum somniferum_ or
_Dollkraut_ by the German botanist Leonhard Fuchs, who fully recognized
its poisonous properties.[1673] Yet it was confounded by other writers
of this period as Tragus,[1674] who reproduced Fuchs’ figure as
“_Solanum hortense_!” _Strygium_ and _Strychnon_ were other names not
unfrequently applied to Atropa during the 16th and 17th centuries.
Matthiolus, who terms the plant _Solatrum majus_, states[1675] that
it is commonly called by the Venetians _Herba Bella donna_, from the
circumstance of the Italian ladies using a distilled water of the plant
as a cosmetic. Gesner[1676] was also familiar with the name Belladonna.
The introduction of the root of belladonna into British medicine is of
recent date, and is due to Mr. Peter Squire of London, who recommended
it as the basis of a useful anodyne liniment, about the year 1860.
=Description=—Belladonna has a large, fleshy, tapering root, 1 to 2
inches thick, and a foot or more in length, from which diverge stout
branches. Externally the fresh roots are of an earthy brown, rough with
cracks and transverse ridges. The bark is thick and juicy, and as well
as the more fibrous central portion, is internally of a dull creamy
white. A transverse section of the main root shows a distinct radiate
structure. The root has an earthy smell with but very little taste at
first, but a powerfully acrid after-taste is soon developed.
_Dried root of Belladonna_ is sold in rough irregular pieces of a
dirty greyish colour, whitish internally, breaking easily with a short
fracture, and having an earthy smell not unlike that of liquorice root.
The bark being probably the chief seat of the alkaloid, roots not
exceeding the thickness of the finger should be preferred. The drug
is for the most part imported from Germany, and is often of doubtful
quality. English-grown root purchased in a fresh state (the large and
old being rejected), then washed, cut into transverse segments and
dried by a gentle heat, furnishes a more reliable and satisfactory
article.
[1670] _Compendium Aromatariorum_, 1488.
[1671] _Le Grant Herbier en francoys, contenāt les qualitez, vertus
et proprietez des herbes_ etc., Paris (no date) 4°. cap. _De Solastro
rustico._
[1672] _Das destillier Buch_ (sub voce _Nachtschet Wasser_).
Strassburg, 1521, fol. 93 _b_. The figure probably refers to Atropa,
but that given in the edition of the same work of the year 1500 shows
_Solanum nigrum_.
[1673] _Historia Stirpium_, Basil. 1542. 689.
[1674] _De Stirpium ... historia_, Argentorati, 1552. 301.
[1675] _Comment. in lib. vi. Dioscoridis_, Venetiis, 1558. 533.
[1676] _De hortis Germaniæ_, Argentorat. 1561, fol. 282.
=Microscopic Structure=—There is a considerable structural difference
between the main root and its branches, the former alone containing
a distinct pith. This pith is included in a woody circle, traversed
by narrow medullary rays. In the outer part of the woody circle,
parenchymatous tissue is more prevalent than vascular bundles. The
transverse section of the branches of the root exhibits a central
vascular bundle instead of a medullary column. The outer vascular
bundles show no regular arrangement; and medullary rays are not clearly
obvious in the transverse section.
The woody parts, both of the main root and its branches, contain very
large dotted vessels accompanied by a prosenchymatous tissue. The cells
of the latter, however, are always thin-walled; the absence of proper
so-called ligneous tissue explains the easy fracture of the root.
Sometimes the prosenchyme in which the vessels are imbedded assumes
a brownish hue and a waxy appearance, and such parts exhibit a very
irregular structure.
In the cortical portion of belladonna root, many of the cells of the
middle layer, and likewise some of the central parts of the root, are
loaded with extremely small octahedric crystals of calcium oxalate.
But most of the parenchymatous cells are filled up with small starch
granules.
=Chemical Composition=—In 1833 Mein prepared from the root, and Geiger
and Hesse from the herb, the crystallizable alkaloid _Atropine_. The
researches of Lefort (1872) have proved that the roots contain it in
very variable proportions, the young being much richer in alkaloid than
the old.[1677] The maximum proportion obtained was 0·6 per cent.; this
was from root of the thickness of the finger. Large old roots, 7 or 8
years of age, afford from 0·25 to 0·31 per cent. They have besides a
smaller proportion of bark than young roots, and it is chiefly in the
bark that the alkaloid appears to reside. Manufacturers of atropine
employ exclusively the root.
Ludwig and Pfeiffer (1861), by decomposing atropine with potassium
chromate and sulphuric acid, obtained benzoic acid and propylamine.
Other products are formed when atropine is treated with strong
hydrochloric acid, baryta water or caustic soda, thus—_Atropine_,
C₁₇H₂₃NO₂ + H₂O = _Tropic Acid_, C₉H₁₀O₃ + _Tropine_, C₈H₁₅NO.
Tropic acid, C₆H₅C(OH) {CH₃
{COOH,
being further boiled with the same agents is converted into
atropic acid, C₆H₅C {CH₂
{COOH,
which, especially by using hydrochloric acid, is gradually transformed
into isotropic acid. Both these acids are isomeric to cinnamic acid,
C₉H₈O₂, but otherwise remarkably dissimilar.
Tropine is a strongly alkaline body, readily soluble both in water and
alcohol, and furnishing tabular crystals by the evaporation of its
solution in ether. Neither tropine nor tropic acid, it is stated by
Kraut (1863), is present in the leaves and root of belladonna.
Hübschmann (1858) detected in belladonna root a second but
uncrystallizable alkaloid, called _Belladonnine_; it has a resinous
aspect, is distinctly alkaline, and when heated emits, like atropine, a
peculiar odour.
[1677] For Lefort’s process for estimating atropine, see p. 458.
The root further contains, according to Richter (1837) and Hübschmann,
a fluorescent substance, as well as a red colouring matter called
_Atrosin_.[1678] The latter occurs in greatest abundance in the fruit,
and would probably repay further investigation.
=Uses=—Belladonna root is chiefly used for the preparation of atropine,
which is employed for dilating the pupil of the eye. A liniment made
with belladonna root is used for the relief of neuralgic pains.
=Adulteration=—We may point out that the roots of _Mandragora
microcarpa_, _M. officinarum_, and _M. vernalis_ Bertoloni are very
nearly allied to the root under notice, both in external appearance
and in their structure. They are not likely to be confounded with
Belladonna root, their mother plants being indigenous in the South of
Europe.