Popular Science Monthly/Volume 29/June 1886/The Poisons in Spoiling Food
IT is a well-known fact that food undergoing decomposition—spoiling, as it is termed—is unwholesome. Cases of poisoning that have occurred on the partaking of meat, fish, sausage, and cheese, that is, food of animal origin, will be readily recalled, for on such occasions the daily press has rarely failed to sound notes of warning. Until quite recently, however, the nature of these poisons was veiled obscurity, and it is chiefly owing to the excellent investigations of Professor L. Brieger, at Berlin, that some light has been thrown on this subject.
As the study of the poisons of putrefaction is not only of great interest from the scientific point of view, but of the utmost importance in everyday life (for these poisons may be generated and produced daily in pantry and cellar), it seems desirable, in the interest of hygiene, to relate the new discoveries that have been made in this field, and review the earlier work done in it.
Schlossberger, who for some time past has been compiling statistics of cases of poisoning caused by food that had spoiled, records for Swabia alone, from the year 1793 to 1853, four hundred cases of sickness caused by sausage-poison; of this number, one hundred and fifty terminated fatally. Cases where cheese was the cause of poisoning are also on record; the symptoms in these instances were those of typhus fever. The plague-like epidemic which occurred some time ago in the Volga district, and spread terror throughout Europe, was traced and ascribed to the diet of the population in those regions, which consisted almost exclusively of fish. Illness resulting from the eating of food that has spoiled is of so common occurrence that many will be able to recall instances of it from among the circle of their own friends and acquaintances.
Animal food that has entered into decomposition may generally be distinguished from fresh food by its presence proving unpleasant to the eye and nose. In fact, the nose may be considered as a sort of guardian of safety, for, generally speaking, whatever proves disagreeable to the sense of smell is injurious to the system. However, an ill-advised economy often causes these warnings to be not heeded; and among the lower classes we sometimes meet with so great an indifference, the result of habit, as to such indications, that frequently no distinction is made between food in a state of good preservation and that having a bad odor. To this circumstance must be ascribed the fact that diseases resulting from the poisons of putrefaction are of relatively much more frequent occurrence among the poorer ranks.
Cases of poisoning by food have, however, also been noted where no warning was given by the sense of smell. The explanation of this must be sought in the fact that the pure poisons of putrefaction are odorless compounds, and may probably occur without necessitating—at least, in any perceptible degree—the formation of products of decomposition which possess a strong odor.
The Danish scientist, Panum, had already ascertained that the poison of putrefaction is not destroyed by boiling. G. O. Weber, Hammer, and Schwenninger, further inferred from their investigations that it is of a chemical nature. Brieger, however, was the first clearly to establish this; he has succeeded in preparing the poisons of putrefaction in a pure state, and has given an explanation of their chemistry. He mixed pure white of egg with the juice from the stomach of a pig freshly killed, and allowed the mixture to stand twenty-four hours at a temperature of blood-heat. By means of a rather complex chemical process he succeeded in obtaining pure a small quantity of a substance, a few drops of an aqueous solution of which were sufficient to kill frogs in fifteen minutes. Rabbits died in the same time after inoculation with a larger quantity. From this it must be inferred that a poisonous principle was formed from the white of egg when it was subjected to artificial digestion.
From putrid meat Brieger succeeded in preparing a substance, neuridine, which acted as a poison as long as it was contaminated with other products of putrefaction; but when obtained in a state of purity it was perfectly harmless. It is closely related to two substances which occur in the human system in its normal condition, namely, neurine, one of the constituents of the brain, and choline, which is present in the bile. By putrefaction, neuridine and the rather harmless choline are transformed into neurine, which is highly poisonous. It is a remarkable fact that neurine, which is identical with muscarine, the poisonous principle of a toad-stool (Agaricus muscarius), and which is a normal constituent of the human system, should prove so destructive when introduced into the body from an outside source.
The proof that the poisons of putrefaction are of a chemical nature is of the utmost importance. The fact affords an explanation of the presence of poisons which have been found in corpses, subjected to examination in cases where murder was suspected; for the poisons formed by putrefaction bear a certain resemblance to the alkaloids of the hemlock, strychnine, veratrine, etc. Thus, there was found in the corpse of General Gibbone, in Rome—whose sudden death excited a suspicion that he had been murdered by his servant—a virulent poison, which occurs in the larkspur. However, the rare occurrence of this poison led to a more careful examination of the substance found, which indeed bore a great resemblance to the vegetable poison referred to, but was ultimately recognized as having been formed in the corpse, for Professor Selmi, of Bologna, obtained the same substance from the corpse of another person, where every suspicion of poisoning was excluded.
Brieger was eminently successful in the preparation of the poisons found in corpses, and which are termed "ptomaines" by chemists. According to his investigations, they are created by the putrefaction of white of eggy meat, fish, cheese, gelatine, and yeast, all of them substances used as articles of food. The presence of moisture is an essential condition, whence it follows that the moist mixture of sausage-filling is especially well adapted to the formation of ptomaines. In accordance with this is also the observation that a great many cases of poisoning have occurred after the consumption of sausage or of fish that had been kept damp. A careful supervision of the markets and a destruction of all spoiled food of animal origin should be strictly insisted upon—especially so, as it is known that the poisons of putrefaction, when once formed, are not to be destroyed by boiling or by roasting. The action of the ptomaines is more virulent when they are introduced into the circulation through wounds than when they are brought into the stomach. Cuts and other wounds received while dissecting corpses have often been the cause of blood-poisoning ending in death. The savages of the New Hebrides are not only acquainted with the properties of poison of this kind, but make use of it in their wars. They plunge the points of their arrows, which are made of human bones and provided with grooves, into a corpse, about a week old, and then coat them with the sap of a certain creeping plant. Before discharging the arrow they dip it into water. A serious wound caused by such an arrow is inevitably followed by death in from three to five days. Report as to a similar practice comes from the Narrinjeris, inhabitants of South Australia. They are said to wound their enemies by splinters of bone previously plunged into corpses undergoing putrefaction.
Jacob Doepler, in his "Theatrum Pœnarum," mentions a method of poisoning wells, the account of which was formerly discredited, but has become plausible in the light of modern researches. He states that people suffering from leprosy took of their blood, mixed it with herbs and toad-spawn, formed little pellets of the mixture, and threw the pellets weighted with stones into the wells. Many people who drank from these wells were taken with the same disease, and some of them died. This happened in the reign of Philip V of France, who caused all lepers cognizant of the outrage to be burned, and the Jews, who were accused of being the instigators of the crime, to be persecuted.
That many who drank of such water should become leprous seems very likely, inasmuch as the partaking of spoiled food causes eruption of the skin, nettle-rash, etc., in many persons; chiefly are these symptoms to be noticed after eating spoiled fish. Of course the effects are more serious with some persons than with others. Some people are so sensitive that partaking of fish, seemingly fresh, will cause them inconvenience; others are liable to suffer from a peculiar eruption of the skin after eating crabs or lobsters. Possibly the meat of these animals, even when in the normal condition, contains neurine sufficient to exert its influence on persons susceptible to it, while it may not affect others at all. In the maize-porridge which is called "polenta," and which is the chief food of a certain class of Italian working-men, there is formed, by putrefaction, during the hot months, a poison which causes "pellagra." This is an eruption of the skin, resembling erysipelas, which grows worse in time and finally induces death.
In connection with this subject, the investigations of Pouchet must be referred to. Pouchet isolated a ptomaine from the excreta of cholera-patients, which seemed to possess highly poisonous properties, for, when he tried to crystallize the salt he had obtained, he inhaled the fumes, and eighteen hours later was seized with chills and cramps in the limbs, while he also experienced an irregular pulse and nausea without vomiting. His assistant, who was not so much exposed to the fumes, was taken ill with the same symptoms, but not to the same extent.
The development of cholera and the processes of putrefaction are ascribed to the agency of minute living organisms, the bacilli, a great variety of which have been found in cases of putrefaction and infectious diseases. Professor Brieger has discovered in both fresh meat and meat undergoing putrefaction, also in the white of eggs, the non-poisonous neuridine from which is formed the poisonous neurine. The bacilli decompose the neuridine and form neurine from it. Spread on fish they generate muscarine, the virulent poison also found in certain toad-stools. These bacilli hence produce a peculiar ptomaine, according to the soil in which they happen to be growing. We have as an instance the poison of the pellagra and of cholera, which, when formed in the human system, will exercise a most deadly effect upon it.
In every-day life, too, the ptomaines very often give proof of their presence. Heretofore, however, such cases have not always been well understood. The frequent inflammations of the fingers of persons engaged in washing dishes, etc., are due to this cause. The poisons of putrefaction, so easily formed, need only enter into a scratch or abrasion of the skin, and they will cause a slight poisoning. This is commonly termed having a "sore finger," and is rather unpleasant, but is generally soon cured. The best remedy for the evil is washing with soap, which acts like a mild disinfectant.
The investigation of these poisons of putrefaction is, however, by no means brought to an end by the results reached thus far. Much remains to be done in order to solve the new questions constantly arising. So far as practical life is concerned, it is evident that all food, be it of vegetable or of animal origin, must be regarded with suspicion as soon as the first signs of decomposition become noticeable. Especially should great care be taken in times of epidemics. Hygiene alone, in kitchen and cellar, is competent to guard against the evil!—Translated for the Popular Science Monthly from Daheim.