Of Animal Matter rendered Poisonous by Modified Putrefaction.
The third way in which animal matters naturally wholesome may become irritant poisons, is by their undergoing a modified putrefaction.
It is probable that many common articles of food occasionally become poisonous in this way; but none are so liable to acquire injurious properties as certain articles much used in Germany, namely, a particular kind of sausage, a particular kind of cheese, and bacon. The last two species of poison have been occasionally observed in France, and probably occur in Britain also. But the first has been hitherto met with only in some districts of Germany.
The best account yet given of the sausage-poison is contained in two essays published by Dr. Kerner,[[1565]] in a Thesis by Dr. Dann,[[1566]] and in a prize-essay by Dr. W. Horn.[[1567]] It has at various times committed great ravages in Germany, especially in the Würtemberg territories, where 234 cases of poisoning with it occurred between the years 1793 and 1827; and of that number no less than 110 proved fatal.[[1568]]
The symptoms of poisoning seldom begin till twenty-four, or even forty-eight hours, after the noxious meal, and rather later than earlier. The tardiness of their approach seems owing to the great indigestibility of the fatty matter with which the active principle is mixed. The first symptoms are pain in the stomach, vomiting, purging, and dryness of the mouth and nose. The eyes, eyelids, and pupils then become fixed and motionless; the voice is rendered hoarse, or is lost altogether; the power of swallowing is much impaired; the pulse gradually fails, frequent swoonings ensue, and the skin becomes cold and insensible. The secretions and excretions, with the exception of the urine, are then commonly suspended; but sometimes profuse diarrhœa continues throughout. The appetite is not impaired; fever is rarely present; and the mind continues to the last unclouded. Fatal cases end with convulsions and oppressed breathing between the third and eighth day. In cases of recovery the period of convalescence may be protracted to several years. The chief appearances in the dead body are signs of inflammation in the mucous membrane of the alimentary canal,—such as whiteness and dryness of the throat, thickening of the gullet, redness of the stomach and intestines; also croupy deposition in the windpipe; great flaccidity of the heart; and a tendency in the whole body to resist putrefaction. In a set of cases which occurred so lately as 1841, there was found after death abscesses in the tonsils, dark bluish redness of the membrane of the pharynx, windpipe and bronchial ramifications, gorging of the pulmonary air-tubes and condensation of the pulmonary tissue itself, dark redness of the fundus of the stomach, with circumscribed softening, a dark gray, red, or black appearance of the mucous coat of the intestines, accumulation of greenish-yellow fæces in the colon, brittleness of the liver, and enlargement of the spleen.[[1569]]
The article which is apt to occasion these baneful effects is of two sorts, the white and the bloody sausage (leberwürste, blut-würste). Both are of large size, the material being put into swine’s stomachs; and they are cured by drying and smoking them in a chimney with wood-smoke. Those which have been found to act as poisons possess an acid reaction, are soft in consistence, have a nauseous, putrid taste, and an unpleasant sweetish-sour smell, like that of purulent matter. They are met with principally about the beginning of spring, when they are liable to be often alternately frozen and thawed in the curing. Those sausages only become poisonous which have been boiled before being salted and hung up. They are poisonous only at a particular stage of decay, and cease to be so when putrefaction has advanced so far that sulphuretted-hydrogen is evolved. The central part is often poisonous when the surface is wholesome.
Various opinions have been entertained of the cause of the deleterious qualities thus contracted. In recent times the principle has been supposed to be pyroligneous acetic acid, hydrocyanic acid, or cocculus indicus. Dr. Kerner, however, has shown that none of these notions will account for the phenomena; and at first conceived he had proved the poisonous principle to be a fatty acid analogous to the sebacic acid of Thenard, and originating in a modified process of putrefaction. From the poisonous sausage he procured by double decomposition an acid similar in chemical properties to that obtained from fat by destructive distillation; and by experiments on animals he thought he observed, that the acid procured in either way produced symptoms analogous to those of poisoning with the deleterious sausage. Subsequently, however, he changed his views in some measure; and he now considers that the poison is a compound one, consisting of a fatty acid analogous to the sebacic, and of a volatile principle.[[1570]] The results obtained by Dr. Dann coincide with the last opinion. Dann infers from his researches that the poisonous principle does not necessarily reside in an acid, but is an acrid empyreumatic oil, which when pure is not active, but is rendered so by uniting with various fatty acids.[[1571]]
The results lately obtained by Buchner after an elaborate and careful analysis are somewhat different and probably nearer the truth. He first ascertained that the product of the distillation of fat has no analogy with the sausage-poison. He found it to consist of animalized acetic acid, and a fetid empyreumatic oil, the former of which has no injurious effect on animals, while the latter, though an active poison, is purely narcotic in its operation. On next examining a sausage sent to him from Würtemberg, which had violently affected four individuals and killed one of them in six days, he remarked that the poisonous principle is not soluble in water, or capable of being distilled over with it; and that cold alcohol removes a granular fatty matter, which, when purified by distilled water, has a yellowish colour, a peculiar nauseous smell, and a disagreeable oleaginous taste, followed by extraordinary dryness of the throat for several hours. Although it does not possess an acid reaction on litmus, it forms a soap with alkalis, and is separated again by acids unchanged; and consequently it may be considered a fatty acid, to which Buchner proposes to give the name of Botulinic acid [Würst-fett-saüre]. It concentrates in itself the poisonous properties of the crude sausage. Thirty grains of it, which formed three-fourths of the whole product of a single sausage, were given in two doses to a puppy with an interval of a day between them. For some hours after the second dose no apparent effect was produced. But gradually the animal became dull, lay in the same spot, wasted rapidly away notwithstanding a vigorous appetite, and died of exhaustion on the thirteenth day. Half a grain causes insupportable dryness in the throat, which does not go off for several hours.[[1572]] With these results the contemporaneous and unconnected researches of Dr. Schumann accord very remarkably. Alcohol boiled on the poison-sausage deposited on cooling a fatty matter, which, when washed with distilled water, possessed all the properties specified by Buchner, as characterizing his fatty acid, and acted on animals in the same way as the sausage-poison.[[1573]]
The poison of cheese has been for some time more generally known. Dr. Henneman has published an interesting essay on several cases which happened at Schwerin in 1823.[[1574]] Another account of a similar accident which happened at Minden in 1825 has been published in Rust’s Magazin.[[1575]] But by far the best information on the subject is to be obtained from two papers in Horn’s Archiv,—the one by Professor Hünefeld of Greifswald, describing the phenomena as he witnessed them in that city in 1827, and containing an elaborate chemical analysis and physiological experiments, by means of which he conceives he has discovered the deleterious principles contained in the cheese,[[1576]]—the other by Dr. Westrumb of Hameln, who investigated the particulars of seven cases which came under his notice in 1826, and with the aid of Sertürner, the chemist, traced the properties of the poison to almost the same principles with those indicated by the researches of Hünefeld.[[1577]] Besides the cases which have given origin to these papers, others have occurred throughout Germany in the same period; and during the third quarter of last century this kind of poisoning was so common, that several of the German states investigated the subject, and legislative enactments were passed in consequence.
For a long time the prevalent belief was that the cheese acquired an impregnation from copper vessels used in the dairies; and accordingly the Austrian, Wirtemberg and Ratesberg States prohibited the use of copper for such purposes. This opinion, however, was proved by chemical analysis to be untenable; and the inquiries of Hünefeld and Sertürner, have now rendered it probable that the poisonous property of the cheese resides in two animal acids, analogous, if not identical, with the caseïc and sebacic acids.