Aconitic Acid, C₁₆H₆O₆, discovered by Peschier in 1820 in somewhat considerable quantity in the leaves of aconite, occurs also in those of larkspur, and is identical with the Equisetic Acid of Braconnot and the Citridic Acid of Baup.[45] It has been stated to be present likewise in Adonis vernalis L. (Linderos, 1876,—10 per cent. of dried leaves!) and in the sugar cane (Behr, 1877).
Schoonbroodt[46] (1867) on treating the extract with a mixture of alcohol and ether, obtained acicular crystals, which he thought were the so-called Aconella of Smith. He further found that the distillate of the plant was devoid of odour, but was acid, and had a burning taste. By saturation with an alkali he obtained from it a crystalline substance, soluble in water, and having a very acrid taste. Experiments made about the same time by Groves,[47] a careful observer, led to opposite results. He distilled on different occasions both fresh herb and fresh roots, and obtained a neutral distillate, smelling and tasting strongly of the plant, but entirely devoid of acridity. Hence he concluded that A. Napellus contains no volatile acrid principle.
In an extract of aconite that has been long kept, the microscope reveals crystals of aconitate of calcium, as well as of sal-ammoniac.
The leaves contain a small proportion of sugar, and a tannin striking green with iron. When dried they yield on incineration 16·6 per cent. of ash.
Uses—In Britain the leaves and small shoots are only used in the fresh state, the flowering herb being purchased by the druggist in order to prepare an inspissated juice,—Extractum Aconiti. This preparation, which is considered rather uncertain in its action, is occasionally prescribed for the relief of rheumatism, inflammatory and febrile affections, neuralgia, and heart diseases.
RADIX ACONITI INDICA.
Bish, Bis or Bikh, Indian Aconite Root, Nepal Aconite.
Botanical Origin—The poisonous root known in India as Bish, Bis, or Bikh[48] is chiefly derived from Aconitum ferox Wallich, a plant growing 3 to 6 feet high and bearing large, dull-blue flowers, native of the temperate and sub-alpine regions of the Himalaya at an elevation of 10,000 to 14,000 feet in Garhwal, Kumaon, Nepal and Sikkim.[49] In the greater part of these districts, other closely allied and equally poisonous species occur, viz. A. uncinatum L., A. luridum, H. f. et Th., A. palmatum Don, and also abundantly A. Napellus L., which last, as already mentioned, grows throughout Europe as well as in Northern Asia and America. The roots of these plants are collected indiscriminately according to Hooker and Thomson[50] under the name of Bish or Bikh.
History—The Sanskrit name of this potent drug, Visha, signifies simply poison, and Ativisha, a name which it also bears, is equivalent to “summum venenum.” Bish is mentioned by the Persian physician Alhervi[51] in the 10th century as well as by Avicenna[52] and many other Arabian writers on medicine,—one of whom, Isa Ben Ali, calls it the most rapid of deadly poisons, and describes the symptoms it produces with tolerable correctness.[53]
Upon the extinction of the Arabian school of medicine this virulent drug seems to have fallen into oblivion. It is just named by Acosta (1578) as one of the ingredients of a pill which the Brahmin physicians give in fever and dysentery.[54] There is also a very strange reference to it as “Bisch” in the Persian Pharmacopœia of Father Ange, where it is stated[55] that the root, though most poisonous when fresh, is perfectly innocuous when dried, and that it is imported into Persia from India, and mixed with food and condiments as a restorative! Ange was aware that it was the root of an aconite.