§ 437. The symptoms of poisoning by the tincture, extract, or other preparation, do not differ from those detailed. As unusual effects, occasionally seen, may be noted profound unconsciousness lasting for two hours (Topham’s case), violent twitching of the muscles of the face, opisthotonos, and violent convulsions. It is important to distinguish the symptoms which are not constant from those which are constant, or nearly so. The tingling and creeping sensations about the tongue, throat, lips, &c., are not constant; they certainly were not present in the remarkable German case cited at [p. 363]. Speaking generally, they seem more likely to occur after taking the root or the ordinary medicinal preparations. A dilated state of the pupil is by no means constant, and not to be relied upon. Diarrhœa is seen after taking the root or tincture by the stomach, but is often absent. In short, the only constant symptoms are difficulty of breathing, progressive muscular weakness, generally vomiting, and a weak intermittent pulse.
§ 438. Physiological Action.—Aconitine, according to Dr. S. Ringer, is a protoplasmic poison, destroying the functions of all nitrogenous tissue—first of the central nervous system, next of the nerves, and last of the muscles. Aconitine without doubt acts powerfully on the heart, ultimately paralysing it; there is first a slowing of the pulse, ascribed to a central excitation of the vagus; then a quickening, due to paralysis of the peripheral termination of the vagus in the heart; lastly, the heart’s action becomes slow, irregular, and weak, and the blood-pressure sinks. The dyspnœa and convulsions are the usual result, seen among all warm-blooded animals, of the heart affection. Plugge found that the motor nerves, and more especially their intra-muscular terminations, were always paralysed; but if the dose was small the paralysis might be incomplete. Bœhm and Wartmann, on the other hand, considered that the motor paralysis had a central origin, a view not supported by recent research. The action of aconitine in this way resembles curare. The muscles themselves preserve their irritability, even after doses of aconitine which are five to ten times larger than those by which the nerve terminations are paralysed.
§ 439. Post-mortem Appearances.—Among animals (mammals) the appearances most constantly observed have been hyperæmia of the cerebral membranes and brain, a fulness of the large veins, the blood generally fluid—sometimes hyperæmia of the liver, sometimes not. When aconitine has been administered subcutaneously, there have been no inflammatory appearances in the stomach and bowels.
In the case of Dr. Carl Meyer, who died in five hours from swallowing 4 mgrms. of aconitine nitrate, the corpse was of a marble paleness, the pupils moderately dilated. The colour of the large intestine was pale; the duodenum was much congested, the congestion being most intense the nearer to the stomach; the mucous membrane of the stomach itself was strongly hyperæmic, being of an intense red colour; the spleen was enlarged, filled with much dark blood. The liver and kidneys were deeply congested, the lungs also congested; the right ventricle of the heart was distended with blood; in the pericardium there was a quantity of bloody serum. The brain was generally blood-red; in the cerebral hemispheres there were several large circumscribed subarachnoid extravasations. The substance of the brain on section showed many red bloody points.
In a case recorded by Taylor, in which a man died in three hours from eating a small quantity of aconitine root, the only morbid appearance found was a slight reddish-brown patch on the cardiac end of the stomach, of the size of half a crown; all the other organs being healthy.
§ 440. Separation of Aconitine from the Contents of the Stomach or the Organs.—It would appear certain that in all operations for the separation of aconite alkaloids (whether from the organic matters which make up the plant, or from those constituting animal tissues), mineral acids and a high heat should be avoided. A 1 per cent. sulphuric acid does not, however, hydrolyse, if acting in the cold, so that the process already given, [p. 352], may be followed.
The chemical examination in the Lamson case was entrusted to Dr. Stevenson, assisted by Dr. Dupré, and was conducted on the principles detailed. The contents of the stomach were treated with alcohol, and digested at the ordinary temperature of the atmosphere; the contents were already acid, so no acid in this first operation was added. The mixture stood for two days and was then filtered. The insoluble portion was now exhausted by alcohol, faintly acidulated by tartaric acid, and warmed to 60°; cooled and filtered, the insoluble part being washed again with alcohol. The two portions—that is, the spirituous extract acid from acids pre-existing in the contents of the stomach, and the alcohol acidified by tartaric acid—were evaporated down separately, exhausted by absolute alcohol, the solutions filtered, evaporated, and the residue dissolved in water. The two aqueous solutions were now mixed, and shaken up with ether, which, as the solution was acid, would not remove any alkaloid, but might remove various impurities; the residue, after being thus partially purified by ether, was alkalised by sodic carbonate, and the alkaloid extracted by a mixture of chloroform and ether. On evaporation of the chloroform and ether, the resulting extract was tested physiologically by tasting, and also by injections into mice. By means analogous to those detailed, the experts isolated aconitine from the vomit, the stomach, liver, spleen, and urine, and also a minute quantity of morphine, which had been administered to the patient to subdue the pain during his fatal attack. When tasted, the peculiar numbing, tingling sensation lasted many hours. These extracts were relied upon as evidence, for their physiological effect was identical with that produced by aconitine. For example, the extract obtained from the urine caused symptoms to commence in a mouse in two minutes, and death in thirty minutes, and the symptoms observed by injecting a mouse with known aconitine coincided in every particular with the symptoms produced by the extraction from the urine.
With regard to the manner of using “life tests,” since in most cases extremely small quantities of the active principle will have to be identified, the choice is limited to small animals, and it is better to use mice or birds, rather than reptiles. In the Lamson case, subcutaneous injections were employed, but it is a question whether there is not less error in administering it by the mouth. If two healthy mice are taken, and the one fed with a little meal, to which a weighed quantity of the extract under experiment has been added, while to the other some meal mixed with a supposed equal dose of aconitine is given, then the symptoms may be compared; and several objections to any operative proceeding on such small animals are obviated. It is certain that any extract which causes distinct numbness of the lips will contain enough of the poison to kill a small bird or a mouse, if administered in the ordinary way.[482]
[482] Dr. A. Langaard has described a species of aconite root, named by the Japanese Kŭsa-ūsū. From his experiments on frogs and rabbits, its physiological action seems not to differ from that of aconitine generally.—Ueber eine Art Japanische Akonit-knollen, Kŭsa-ūsū genannt, u. über das in denselben vorkommende Akonitin. Virchow’s Archiv, B. 79, 1880, p. 229.