_Tuber Aconiti_; _Aconite Root_[33]; F. _Racine d’Aconit_; G.
_Eisenhutknollen_, _Sturmhutknollen_.
=Botanical Origin=—_Aconitum Napellus_ L.—This widely diffused and most
variable species grows chiefly in the mountainous districts of the
temperate parts of the northern hemisphere.
It is of frequent occurrence throughout the chain of the Alps up
to more than 6500 feet, the Pyrenees, the mountains of Germany and
Austria, and is also found in Denmark and Sweden. It has become
naturalized in a few spots in the west of England and in South Wales.
Eastward it grows throughout the whole of Siberia, extending to the
mountain ranges of the Pacific coast of North America. It occurs in
company with other species on the Himalaya at 10,000 to 16,000 feet
above the sea-level.
The plant is cultivated for medicinal use, and also for ornament.
The Abbé Armand David[34] saw in northern Sz-chuen (Setchuan) fields
planted with Aconite (A. Napellus?).
=History=—The Ἀκόνιτον of the Greeks and the _Aconitum_ of the Romans
are held to refer to the genus under notice, if not precisely to _A.
Napellus_. The ancients were well aware of the poisonous properties of
the aconites, though the plants were not more exactly distinguished
until the close of the middle ages. The Greek name is supposed to refer
to the same source as that of Conium. (See article on Fructus Conii.)
Aconite has been widely employed as an arrow-poison. It was used by
the ancient Chinese,[35] and is still in requisition among the less
civilized of the hill tribes of India. Something of the same kind was
in vogue among the aborigines of ancient Gaul.[36] Aconite was pointed
out in the thirteenth century, in “_The Physicians of Myddvai_,”[37] as
one of the plants which every physician is to grow.
Störck of Vienna introduced aconite into regular practice about the
year 1762[38]; the root and the herb occur in the German pharmaceutical
tariff of the seventeenth century.
[33] We use the word _root_ as most in accordance with the teaching of
English botanists.
[34] _Journal de mon troisième voyage en Chine_, i. (Paris 1875) 367.
[35] F. Porter Smith, _Mat. Med. and Nat. Hist. of China_, Shanghai,
1871. 2, 3.
[36] Pliny, lib. xxvii. c. 76, also xxv. 25.
[37] _The Physicians of Myddvai_; _Meddygon Myddfai_. Published for the
Welsh MSS. Society. Llandovery, 1861. 282, 457.
[38] _De Stramonio, Hyoscyamo et Aconito_, Vindob. 1762.
=Description=—The herbaceous annual stem of aconite starts from an
elongated conical tuberous root 2 to 4 inches long and sometimes as
much as an inch in thickness. This root tapers off in a long tail,
while numerous branching rootlets spring from its sides. If dug
up in the summer it will be found that a second and younger root
(occasionally a third) is attached to it near its summit by a very
short branch and is growing out of it on one side. This second root
has a bud at the top which is destined to produce the stem of the next
season. It attains its maximum development at the latter part of the
year, the parent root meanwhile becoming shrivelled and decayed. This
form of growth is therefore analogous to that of an orchis.
The dried root is more or less conical or tapering, enlarged and
knotty at the summit which is crowned with the base of the stem.
It is from 2 to 3 or 4 inches long and at the top from ½ to 1 inch
thick. The tuber-like portion of the root is more slender, much
shrivelled longitudinally, and beset with the prominent bases of
rootlets. The drug is of a dark brown; when dry it breaks with a
short fracture exhibiting a white and farinaceous, or brownish, or
grey inner substance sometimes hollow in the centre. A transverse
section of a sound root shows a pure white central portion (pith)
which is many-sided and has at each of its projecting angles a thin
fibro-vascular bundle.
In the fresh state the root of aconite has a sharp odour of radish
which disappears on drying. Its taste which is at first sweetish soon
becomes alarmingly acrid, accompanied with sensations of tingling and
numbness.
=Microscopic Structure=—The tuberous root as seen in a transverse
section, consists of a central part enclosed by a delicate cambial
zone. The outer part of this central portion exhibits a thin brownish
layer made up of a single row of cells (_Kernscheide_ of the Germans).
This is more distinctly obvious in the rootlets, which also show
numerous, scattered, thick-walled cells of a yellow colour.
The fibro-vascular bundles of aconite root are devoid of true ligneous
cells; its tissue is for the largest part built up of uniform
parenchymatous cells loaded with starch granules.
=Chemical Composition=—Aconite contains chemical principles which are
of great interest on account of their virulent effects on the animal
economy.
The first to be mentioned is _Aconitine_, a highly active
crystallizable alkaloid, furnishing readily crystallizable salts. It
is accompanied by another active alkaloid, _Pseudaconitine_, which
is crystallizable, but yields mostly amorphous salts. According to
the admirable researches of Wright and Luff,[39] aconitine may be
decomposed according to the following equation:—
C₃₃H₄₃NO₁₂. OH₂ = C₇H₆O₂. C₂₆H₃₉NO₁₁,
Aconitine. Benzoic acid. Aconine.
and pseudaconitine breaks up in accordance with the equation:
C₃₆H₄₉NO₁₁. OH₂ = C₉H₁₀O₄. C₂₇H₄₁NO₈
Pseudaconitine. Dimethyl- Pseudaconine.
protocatechnic acid.
[39] _Pharm. Journ._ 1875 to 1878, also _Yearbook of Pharmacy_, the
results being summarized in the _Yearbook_ for 1877, 466.—Comparative
qualitative reactions of Aconitine, Aconine, Pseudaconitine, and
Pseudaconine, see _Yearbook_ (1877) 459.
The decomposition of aconitine, as well as of pseudaconitine, may
be performed by means of mineral acids, alkaline solutions, or also
by heating the bases with water in sealed tubes. The two alkaloids,
_Aconine_ and _Pseudaconine_, appear to be present already in the
roots of Aconitum; they, moreover, contain two other alkaloids of less
physiological potency. One of them, _Picraconitine_, C₃₁H₄₅NO₁₀, is
merely bitter, producing no lip-tingling; it gives well crystallized
salts, although it is itself amorphous. Commercial aconitine is a
mixture of the above alkaloids. The total yield of basic substances
afforded by aconite root is not more than about 0·07 per cent.
The other constituents of aconite root are but imperfectly known. In
the preparation of the alkaloids, a dark green mixture of resin and
fat is obtained; it is much more abundant in European than in Nepal
aconite (Groves). The root contains _Mannite_, as proved by T. and H.
Smith (1850), together with cane-sugar, and another sugar which reduces
cupric oxide even in the cold. Tannin is absent, or is limited to the
corky coat. The absence of a volatile alkaloid in the root was proved
by Groves in 1866.
=Uses=—Prescribed in the form of tincture as an anodyne liniment;
occasionally given internally in rheumatism.
=Adulteration and Substitution=—Aconite root, though offered in
abundance in the market, is by no means always obtained of good
quality. Collected in the mountainous parts of Europe by peasants
occupied in the pasturing of sheep and cattle, it is often dug
up without due regard to the proper season or even to the proper
species,—a carelessness not surprising when regard is had to the
miserable price which the drug realizes in the market.[40]
One of the species not unfrequent in the Alps, of which the roots
are doubtless sometimes collected, is _A. Störckeanum_ Reichenb. In
this plant the tuberous roots are developed to the number of three or
four, and have an anatomical structure slightly different from that
of _A. Napellus_.[41] _A. variegatum_ L., _A. Cammarum Jacq._, and
_A. paniculatum_ Lam. are blue-flowered species having tuberous roots
resembling those of _A. Napellus_, but according to Schroff somewhat
less active.
The yellow-flowered _A. Anthora_ L. and _A. Lycoctonum_ L. produce
roots which cannot be confounded with those of _A. Napellus_ L.
The root of _A. japonicum_ Thunb. has been noticed in Europe by
Christison as early as 1859[42]; it is now imported occasionally from
the East. It forms grey or almost blackish tubers from ⁶/₁₀ of an
inch to upwards of 1 inch in length, and from ²/₁₀ to ⁴/₁₀ of an inch
in diameter, oblong or ovoid, either tapering or rounded at their
extremities. They are of plump, scarcely shrivelled appearance.[43]
_Japanese aconite_ afforded to Wright and Luff a crystallized active
alkaloid different from both aconitine and pseudaconitine.
Holmes[44] states that the _aromatic_ roots of _Imperatoria Ostruthium_
L. have been found mixed with aconite.
[40] Thus the continental druggists are able to offer it in quantity as
low as 4_d._ to 5_d._ per lb., and a pound, we find, contains fully 150
roots!
[41] See figure in Berg’s _Atlas zur pharm. Waarenkunde_ (1865) fig. 24.
[42] Hanbury, _Science Papers_ (1876) 258, with figure. See also
_Pharm. Journ._ ix. (1879) 615, where the drug is derived from Aconitum
Fischeri.
[43] Their microscopic structure is figured in the paper of Dr. Dunin
(quoted farther on, in our article on Aconitum heterophyllum at p. 14)
217-225.
[44] _Pharm. Journ._ vii. (1877) 749.