A few observations may be here added on the effects of the salts of strontia on the animal frame. These compounds bear a close resemblance to the salts of baryta, and the two earths were consequently long confounded together till Dr. Hope pointed out their distinctions. One of the most striking differences is, that the salts of the strontia are very feebly poisonous. Some experiments of this purport were made by M. Pelletier of Paris,[[1399]] and by Blumenbach; but the most accurate researches are those of Professor Gmelin. He found that ten grains of the chloride in solution had no effect when injected into the jugular vein of a dog,—that two drachms had no effect when introduced into the stomach of a rabbit,—that half an ounce was required to cause death in that way,—that two drachms of the carbonate had no effect,—and that two drachms of the nitrate, dissolved in six parts of water and given to a rabbit, merely caused increase of the frequency and hardness of the pulse and a brisk diarrhœa.[[1400]] Mr. Blake also found that small doses of the salts of strontia have little effect when injected into the veins; but that forty grains arrest the action of the heart in fifteen seconds.[[1401]]
CHAPTER XX.
The fourth order of the irritant poisons contains a great number of genera derived from the vegetable kingdom, and at one time commonly arranged in a class by themselves under the title of Acrid Poisons. The order includes many plants of the natural families Ranunculaceæ, Cucurbitaceæ, and Euphorbiaceæ, and other plants scattered throughout the botanical system. It likewise comprehends a second group consisting of some acrid poisons from the animal kingdom, namely, cantharides, poisonous fishes, poisonous serpents, and animal matters become poisonous by disease or putrefaction.
OF POISONING WITH THE VEGETABLE ACRIDS.
The vegetable acrids are the most characteristic poisons of this order. They will not require many details, as they are seldom resorted to for criminal purposes, and their mode of action, their symptoms, and their morbid appearances are nearly the same in all.
We are chiefly indebted to Professor Orfila for our knowledge of their mode of action. He has subjected them to two sets of experiments. In the first place, he introduced the poison in various doses into the stomach, sometimes tying the gullet, sometimes not: and, secondly, he applied the poison to the subcutaneous cellular tissue by thrusting it into a recent wound.
In the former way he found that, unless the gullet was tied, the animal soon discharged the poison by vomiting, and generally recovered; but that, if the gullet was tied, death might be caused in no long time by moderate doses. The symptoms were seldom remarkable. Commonly efforts were made to vomit; frequently diarrhœa followed; then languor and listlessness; sometimes, though not always, expressions of pain; very rarely convulsions; and death generally took place during the first day, often within three, six, or eight hours. The appearances in the dead body were redness over the whole mucous coat of the stomach, at times remarkably vivid, often barely perceptible, and occasionally attended with ulcers; very often a similar state of the whole intestines, more especially of the rectum; and in some instances a slight increase of density, with diminished crepitation, in patches of the lungs.
When the poison, on the other hand, was applied to a recent wound of the leg, the animal commonly whined more or less; great languor soon followed; and death took place on the first or second day, without convulsions or any other symptom of note. It was seldom that any morbid appearance could then be discovered in the bowels. But in every instance active inflammation was found in the wound, extending to the limb above it and even upwards on the trunk. Every part affected was gorged with blood and serum; and an eschar was never formed. The appearances in short were precisely those of diffuse inflammation of the cellular tissue, when it proves fatal in its early stage.[[1402]]
Since these poisons do not appear to act more energetically through a wound than through the stomach, it has been generally inferred that they do not enter the blood, and consequently that the local impression they produce is conveyed to distant organs through the nerves. This inference is correct in regard to such species of the vegetable acrids as act in small doses. But the validity of the conclusion may be questioned when the poison acts only in large doses, as in the case with many of those now under consideration. For they cannot be applied to a wound over a surface equal to that of the stomach, and may therefore be more slowly absorbed in the former than in the latter situation. And, in point of fact, a few plants of the present order have been found to act through the medium of absorption, as soon as chemistry discovered their active principles, and thus enabled the physiologist to get rid of fallacy by using the poison in small quantity. This principle has been proved to be in some plants a peculiar resin, in others a peculiar extractive matter, in others an oil, in others an alkaloid, and in others a neutral crystalline matter. But in all there exists some principle or other in which are concentrated the poisonous properties of the plant. Some of these principles appear to act through the medium of the blood.
There is no doubt, however, but many plants of the present order, as well as their active principles, have a totally different and very peculiar action. They produce violent spreading inflammation of the subcutaneous cellular tissue, and acute inflammation of the stomach and intestines, without entering the blood; and death is the consequence of a sympathy of remote organs with the parts directly injured.