But idiosyncrasy will not account for all the cases of poisoning with muscles, oysters, and other fish. For, passing over other less unequivocal objections, it appears that, when the accident related above happened at Leith, every person who ate the muscles from a particular spot was more or less severely affected; and an important circumstance then observed for the first time was, that animals suffered as severely as man, a cat and a dog having been killed by the suspected article.
Another theory ascribes the poisonous quality to disease in the fish; but no one has hitherto pointed out what the disease is. The poisonous muscles at Leith were large and plump, and seemed to have been chosen on account of their size and good look. Dr. Coldstream, however, at the time a pupil of this University, and a zealous naturalist, thought the liver was larger, darker, and more brittle than in the wholesome fish, and certainly satisfied me that there was a difference of the kind. But whether this was really disease or merely a variety of natural structure, our knowledge of the natural history of the fish hardly entitles us to pronounce.
Considering the failure of all other attempts to account for the injurious properties acquired by muscles, it is extraordinary that no experiments have been hitherto made with the view of discovering in the poisonous fish a peculiar animal principle. It certainly seems probable, that the property resides in a particular part of the fish or in a particular principle. In 1827, I made some experiments on those which caused the fatal accident at Leith, but without success. My attention was turned particularly to the liver; but neither there nor in the other parts of the fish could I detect any principle which did not equally exist in the wholesome muscle. This result, however, should not deter others, any more than it would myself, from a fresh investigation; for the want of a sufficient supply prevented me from making a thorough analysis; and the reader will presently find an instance related, where another singular poison, sometimes contained in sausages and in cheese, was, after repeated failures, at length traced successfully to the real cause by the hand of the analytic chemist.
M. Lamouroux, in a letter to Professor Orfila, conjectures that the poison may be a particular species of Medusa, and enters into some ingenious explanations of his opinion. But it is not supported by any material fact, and seems to be surrounded by insuperable difficulties.[[1525]] It is not a new conjecture; for Möhring mentions in his paper formerly quoted, that several writers before him had conceived such a cause might afford an explanation of the phenomena.[[1526]]
Little or no light is thrown on this singular subject by the nature of the localities in which the poisonous muscle has been found. Even on this point we possess little information. Both in Dr. Burrows’s and Dr. Combe’s cases the fish was attached to wood. At Leith they were taken from some Memel fir logs, which formed the bar of one of the wet-docks, and had lain there at least fifteen years. From the stone-walls of the dock in the immediate vicinity of this bar muscles were taken which proved quite wholesome. It is impossible, however, to attach any importance to these facts; for Dr. Coldstream informs me, that he examined muscles which were attached to the fir piles of the Newhaven Chain-pier, about a mile from Leith, and found them wholesome. In the latter animals the liver was not large, as in the poisonous muscles of Leith. Lamouroux states, but I know not on what authority, that muscles never become poisonous unless they are exposed alternately to the air and the sea in their place of attachment, and unless the sea flows in gently over them without any surf,—these conditions being considered by him requisite for the introduction of the poisonous Medusæ into the shell.
Of Poisonous Oysters.
Oysters sometimes acquire deleterious properties analogous to those acquired by muscles. But fewer facts have been collected regarding them. M. Pasquier has mentioned some cases which occurred not long ago at Havre, in consequence apparently of an artificial oyster-bed having been established near the exit of the drain of a public necessary. But I have not been able to consult his work.[[1527]] Another instance of their deleterious operation occurred a few years ago at Dunkirk. At least an unusual prevalence of colic, diarrhœa, and cholera was believed to have been traced to an importation of unwholesome oysters from the Normandy coast. Dr. Zandyk, the physician who was appointed to investigate the matter, found that the suspected fish contained a slimy water, and that the membranes were retracted from the shell towards the body of the animal.[[1528]] Dr. Clarke believes that even wholesome oysters have a tendency to act deleteriously on women immediately after delivery. He asserts that he has repeatedly found them to induce apoplexy or convulsions; that the symptoms generally came on the day after the oysters were taken; and that two cases of the kind proved fatal.[[1529]] I am not aware that these statements have been since confirmed by any other observer.
Of Poisonous Eels.
Eels have also been at times found in temperate climates to acquire poisonous properties. Virey mentions an instance where several individuals were attacked with violent tormina and diarrhœa a few hours after eating a paté made of eels from a stagnant castle-ditch near Orleans; and in alluding to similar accidents having previously happened in various parts of France, he adds that domestic animals have been killed by eating the remains of the suspected dish.[[1530]]