who was executed there for poisoning her husband, was proved to have administered this substance [see p. 61]. The root of another species, the A. ferox, is well known to be in common use as a poison, under the name of Bikh, in Bengal, and Nabee, in the Madras Presidency. The toxicological history of the genus, and of this species in particular, has been rendered complex and obscure, by the extreme difficulty of distinguishing accurately the several species from one another. The whole genus, now a numerous one, is generally conceived to be eminently poisonous. But from some observations of my own, as well as an elaborate inquiry, not yet made public, by Dr. Alexander Fleming,[1] a recent graduate of this university, I am inclined to think that this is a mistake, that the poisonous species are not numerous, and that many aconites are inert, at least in this climate. The A. napellus, a doubtful native of Britain, and the most common species in our gardens, shoots up annually a leafy stem from a black, tapering, spindle-shaped root. The stem, which is from two to five feet high, ends in a long dense spike of fine blue flowers; and when the seeds ripen in autumn, it dies down, and the root also shrivels and perishes. But in the spring, while the stem is rising, one or more tubers form near the crown of the root; each tuber quickly assumes the spindle-shaped form of its parent, but has a light brown, instead of a brownish-black tegument; and when the plant is in flower, the new tuber, destined for the root of next year's plant, is as large as the parent one, firmer, more amylaceous, and not so apt to shrivel in drying. This mode of propagation has led some to describe the root erroneously as sometimes palmated. Dr. Fleming considers the young, full-grown tuber to be the most active part of the plant; but the root of the existing plant, the leaves, and also the seeds, are highly energetic; and every part is more or less so. Every part of the A. napellus, but especially the root, affects remarkably the organs of taste, producing a very singular sense of heat, numbness, and tingling of those parts of the mouth to which it is applied. Dr. Fleming has ascertained, that this peculiar taste, or rather sensation, is a property belonging to the narcotic principle of monkshood, and that in all probability it is a measure of the activity of the plant as a poison. It is most intense in the root, next in the seeds, and next in the leaves before the flowers blow. Geiger first ascertained, and I have since observed, that the sensation thus occasioned by the leaves diminishes in intensity as the flowers expand, and almost disappears when the seeds ripen. Contrary to what has been often stated, it is not diminished by drying the leaves, even with the heat of the vapour-bath. Nor is it materially lessened by time, if the dried leaves be preserved with care; for I have found it intense after six years. Geiger observed some years ago, that several species or varieties do not possess it. I have ascertained that A.
- ↑ Prize Thesis, on the Physiological and Medicinal Properties of the Aconitum napellus. Edinburgh, 1844.
