Active Ingredients. - The toxic and medicinal properties of Aconite are mainly, if not wholly, represented by the alkaloid Aconitia, C30H47NO7, discovered by Pallas about the year 1770. (Besides Aconitia there is another body called Napelline, and in the Aconitum ferox, one differing somewhat from the others, to which the name of pseudo-aconitia has been given. For therapeutic purposes the most highly prized at present is Duquesnel's crystallized aconitia.)

Physiological Action. - The ancients, who were very imperfectly acquainted with mineral poisons, considered aconite to be the most deadly thing in nature, and their opinion is almost justified by modern experience. Every portion of the plant is more or less virulent; even the odor thrown out when the plant is in full bloom is said to operate injuriously upon susceptible constitutions. Sometimes it causes loss of sight for a day or two; in other instances it has been known to induce faintingfits. The juice of the stem or leaves, accidentally introduced into a wound in the hand, affects the whole system; pains are produced in the hand itself, and in the arm; to these succeed cardialgia, a sense of suffocation, with great mental anxiety, and not uncommonly syncope.

If a leaf or a small scraping of the root be chewed, a sensation of numbness is quickly produced upon the lips and tongue, and this effect is still perceived after the lapse of many hours. A quantity sufficient to cause death, if received into the stomach, produces pungent heat in the palate and fauces, accompanied by a sensation of burning in the stomach itself. To these sensations are soon added a condition of painful numbness, which pervades the limbs, to the fingers and toes, and a general tremor of the whole body. Severe vomiting, attended by pain in the ab-1 domen, quickly follows, and along with it an intermittent, weak, and ir regular action of the heart. There is then an approach to suffocation, with great anxiety, restlessness, and vertigo; the limbs become cold and clammy, the pulse is more and more irregular, and death soon puts an end to the patient's sufferings. Neither convulsions, spasms, stupor, nor delirium can be reckoned upon as certain, though it is true that in several recorded cases one or more of these phenomena have been manifested, and it frequently happens that after full and poisonous doses the mind remains unclouded to the last. Pereira states that a dog under the influence of aconite will recognize and follow his master, but is insensible to any pain or feeling produced by running needles into the skin or paws.

Dr. Thompson states that the first results of swallowing aconite are acrid and burning sensations, accompanied by profuse salivation. He further tells us that if the extract be administered without the greatest caution, it operates first upon the stomach, then upon the nervous system, producing vomiting, hypercatharsis, vertigo, cold sweats, delirium, and convulsions which terminate in death. The same authority states that aconite placed upon the eyelids causes a flow of tears, but no sensation of heat; also that if the powdered leaves be sprinkled upon an ulcer, neither heat nor pain ensues. (It causes in the whole region of the trigeminus a peculiar pain, which at first is vague, but at length becomes constant. (Ott.))

Hirtz, in a paper of great interest, considers that quasi-electric twitch-ings beneath the skin are a characteristic and necessary part of poisoning with a good specimen of aconite itself; and regards the fact of the alkaloid, aconitia, not producing this effect, to be strong evidence that that substance does not fully represent the plant in its powers.

The experimental researches of Achscharumow (Virchow's Archiv, 1866, p. 255) are the most complete that have been made upon the physiological effects of aconite. He experimented on both cold and warm blooded animals; and the general conclusions at which he arrived are the following. Fatal doses of the drug -

1. Produce death from asphyxia by cardiac paralysis.

2. They, in the first place, stimulate the medulla oblongata.

3. This stimulation affects the vagi, and is succeeded by paralysis of these nerves.

4. The cerebro-spinal motor nerves are paralyzed, and voluntary movements are abolished, the muscular substance remaining unaffected.

5. Finally, the reflex action of the spinal cord and the conductivity of the afferent nerves remain unaffected; while the conductivity of the sympathetic ones is stimulated.

These observations, however, are far from explaining the whole action of aconite; and, as bearing on its therapeutical use, the only points that they distinctly suggest are its power to diminish excessive action of the heart, and to relieve pain by partially and temporarily paralyzing the sensory nerves.

The general effects produced by taking aconite are remarkable for the great rapidity with which the symptoms follow each other. This may possibly be referable in part to a direct action of aconite through the medium of the nervous system, independent of the effects of actual absorption of the drug, which, however, itself takes place with great rapidity.

Therapeutic Action. - The poison invested with these formidable characters has been reduced to so manageable a condition as to become a powerful and valuable therapeutic agent in some of the most troublesome and dangerous diseases to which the human frame is subject.

Baron Storck was the first to draw public attention to its value in therapeutics. In the year 1762 he published a little volume upon three or four of the principal vegetable poisons, aconite included, and described it as narcotic, diuretic, and diaphoretic. Himself a physician, the Baron administered it in intermittent fever, also in chronic rheumatism, gout, exostosis, paralysis, and scirrhus; and relates many instances of the success which attended its exhibition in these disorders. Being well acquainted with the potency of the drug, he recommends small doses at first, the increase, if necessary, to be very gradual. Storck's observations soon led to the employment of aconite in various other diseases; in many of which it was found useful. In consequence, however, of the terrible energy of the medicine, and the uncertainty of its operation, alarming symptoms have occasionally been produced, and hence upon the part of some practitioners there has arisen a certain distrust of it.