CHAPTER XXII.

OF THE DELETERIOUS EFFECTS OF POISONOUS FISH. The species of fish which act deleteriously, either always or in particular circumstances, have also been commonly arranged in the present order of poisons. The subject of fish-poison is one of the most singular in the whole range of toxicology, and none is at present veiled in so great obscurity. It is well ascertained that some species of fish, particularly in hot climates, are always poisonous,—that some, though generally salubrious and nutritive, such as the oyster and still more the muscle, will at times acquire properties which render them hurtful to all who eat them,—and that others, such as the shell-fish now mentioned, and even the richer sorts of vertebrated fishes, though actually eaten with perfect safety by mankind in general, are nevertheless poisonous, either at all times or only occasionally to particular individuals. But hitherto the chemist and the physiologist have in vain attempted to discover the cause of their deleterious operation. A good account of the poisonous fishes of the tropics has been given by Dr. Chisholm[1510] and by Dr. Thomas;[1511] and some farther observations on the same subject have been published by Dr. Fergusson.[1512] These essays may be consulted with advantage. On the effects of poisonous muscles several interesting notices and essays have been written, among which may be particularized one by Dr. Burrows[1513] of London, another by Dr. Combe of Leith,[1514] and the observations of Professor Orfila, including some cases from the Gazette de Santé, and from the private practice of Dr. Edwards.[1515] Of all the sources of information now mentioned, that which appears to me the most comprehensive and precise, is the essay of Dr. Combe, who has collected many facts previously known, added others equal in number and importance to all the rest put together, and weighed with impartiality the various inferences which have been or may be drawn from them. The succeeding remarks will be confined to a succinct statement of what appears well established. In this work, however, the poisonous fishes of the West Indies and other tropical countries may be laid aside, because we are still too little acquainted with the phenomena of their action to be entitled to investigate its cause, and they are objects of much less interest to the British medical jurist than the fish-poison of his own coast. There is little doubt that some of the inhabitants of the sea on the coast of Britain are always poisonous. Thus it is well known that some of the molluscous species irritate and inflame the skin wherever they touch it,—a fact which is familiar to every experienced swimmer. The fishermen of the English coast are also aware that a small fish known by the name of Weever (_Trachinus vipera_, Cuv.) possesses the power of stinging with its dorsal fin so violently as to produce immediate numbness of the arm or leg, succeeded rapidly by considerable swelling and redness; and indeed an instance of this accident, which happened at Portobello on the Firth of Forth, has been mentioned to me by Mr. Stark, author of the Elements of Natural History, who witnessed the effects of the poison. But our knowledge of the poisons of that class is too imperfect to require more particular notice. Of fishes which are commonly nutritive, but sometimes acquire poisonous properties, by far the most remarkable is the common _Muscle_. Opportunities have often occurred for observing its effects,—so often, indeed, that its occasional poisonous qualities have become an important topic of medical police, and in some parts, as in the neighbourhood of Edinburgh and Leith, it has of late been abandoned by many people as an article of food, although generally relished, and in most circumstances undoubtedly safe. This result originated in an accident at Leith in 1827, by which no fewer than thirty people were severely affected and two killed. _Of the Symptoms and Morbid Appearances caused by Poisonous Muscles._ The effects of poisonous muscles differ in different cases. Sometimes they have produced symptoms of local irritation only. Thus Foderé mentions the case of a sailor in Marseilles, who, in consequence of eating a large dish of them, died in two days, after suffering from vomiting, nausea, pain in the stomach, tenesmus, and quick contracted pulse. The stomach and intestines were found after death red and lined with an abundant tough mucus.[1516] One of the cases described by Dr. Combe, which, however, terminated favourably, is of the same nature. The patient had severe stomach symptoms from the commencement, attended with cramps and ending in peritonitis, which required the frequent use of the lancet. But much more commonly the local effects have been trifling, and the prominent symptoms have been almost entirely indirect and chiefly nervous. Two affections of this kind have been noticed. One is an eruptive disease resembling nettle-rash, and accompanied with violent asthma; the other a comatose or paralytic disorder of a peculiar description. Of the former affection several good examples have been recorded in different numbers of the Gazette de Santé.[1517] In these the number of muscles eaten was generally small; in one instance ten, in another only six. Nay, in a case related with several others by Möhring in the German Ephemerides, the patient only chewed one muscle and swallowed the fluid part, having spit out the muscle itself.[1518] The symptoms have usually commenced between one and two hours after eating, and rapidly attained their greatest intensity. In the patient who was affected by ten muscles the first symptoms were like those of violent coryza; swelling and itching of the eyelids, and general nettle-rash followed; and the eruption afterwards gave place to symptoms of urgent asthma, which were removed by ether. In other cases the symptoms of asthma preceded the eruption. In one instance the eruption did not appear at all. The swelling has not been always confined to the eyelids, but, on the contrary, has usually extended over the whole face. All the patients were quickly relieved by ether. The eruption, though generally called nettle-rash, is sometimes papular, sometimes vesicular, but always attended with tormenting heat and itchiness. Several cases of this kind have been related by Möhring. The eruption was preceded by dyspnœa, lividity of the face, insensibility, and convulsive movements of the extremities. All recovered under the use of emetics.[1519] This affection, however, may prove fatal. In the cases of two children related by Dr. Burrows, the symptoms began, as in Möhring’s cases, with dyspnœa, nettle-rash, and swelling of the face, combined with vomiting and colic; but afterwards the leading symptoms were delirium, convulsions, and coma; and death took place in three days. In these children it is worthy of remark, that none of the symptoms began till twenty-four hours after eating. In Möhring’s cases, on the contrary, the symptoms began in a few minutes. The other affection is well exemplified in the correct delineations of Dr. Combe. The following is his general summary of the cases, which, with the exception of the instance of peritonitis already alluded to, were all singularly alike in their leading features.—“None, so far as I know, complained of anything peculiar in the smell or taste of the animals, and none suffered immediately after taking them. In general, an hour or two elapsed, sometimes more; and then the bad effects consisted rather in uneasy feelings and debility, than in any distress referable to the stomach. Some children suffered from eating only two or three; and it will be remembered that Robertson, a young and healthy man, only took five or six. In two or three hours they complained of a slight tension at the stomach. One or two had cardialgia, nausea, and vomiting; but these were not general or lasting symptoms. They then complained of a prickly feeling in their hands; heat and constriction of the mouth and throat; difficulty of swallowing and speaking freely; numbness about the mouth, gradually extending to the arms, with great debility of the limbs. The degree of muscular debility varied a good deal, but was an invariable symptom. In some it merely prevented them from walking firmly, but in most of them it amounted to perfect inability to stand. While in bed they could move their limbs with tolerable freedom; but on being raised to the perpendicular posture, they felt their limbs sink under them. Some complained of a bad coppery taste in the mouth, but in general this was an answer to what lawyers call a leading question. There was slight pain of the abdomen, increased on pressure, particularly in the region of the bladder, which suffered variously in its functions. In some the secretion of urine was suspended, in others it was free, but passed with pain and great effort. The action of the heart was feeble; the breathing unaffected; the face pale, expressive of much anxiety; the surface rather cold; the mental faculties unimpaired. Unluckily the two fatal cases were not seen by any medical person; and we are therefore unable to state minutely the train of symptoms. We ascertained that the woman, in whose house were five sufferers, went away as in a gentle sleep; and that a few minutes before death, she had spoken and swallowed.”[1520] She died in three hours. The other fatal case was that of a dock-yard watchman, who was found dead in his box six or seven hours after he ate the muscles. The inspection of the bodies threw no light on the nature of these singular effects. No appearance was found which could be called decidedly morbid. The stomach contained a considerable quantity of the fish half digested. Dr. Combe’s narrative agrees with that of Vancouver, four of whose sailors were violently affected, and one killed in five hours and a half, after eating muscles which they had gathered on shore in the course of his voyage of discovery.[1521] In closing this account, allusion may be briefly made to a case related by Dr. Edwards, which differs from all the preceding. The symptoms were uneasiness at stomach, followed by epileptic convulsions, which did not entirely cease for a fortnight. Dr. Edwards imputed the illness to muscles; but it must be observed that this is a solitary instance of simple convulsions arising from such a cause.[1522] The case deserves particular attention, because a suspicion of intentional poison might have been excited by the circumstances in which it occurred. The individual, a young man, was attacked soon after eating in company with another, who was about to marry his mother, and with whom on that account he lived on bad terms. _Of the Source of Poison of Muscles._ Various opinions have been formed as to the cause or causes of the poisonous qualities of some muscles. The vulgar idea that the poisonous principle is copper, with which the fish becomes impregnated from the copper bottoms of vessels, is quite untenable. Copper does not cause the symptoms described above. I analyzed some of the muscles taken from the stomach of one of Dr. Combe’s patients, without being able to detect a trace of copper. Others have arrived at the same result in former cases. The only instance indeed to the contrary is a late analysis by M. Bouchardat; who does not mention the quantity of copper he detected, or what was the source of the poisonous fish.[1523] The theory which ascribes their effects to changes induced by decay is equally untenable. In Dr. Burrows’s two cases the muscles appear to have been decayed; yet he very properly refuses to admit this fact as explanatory of their operation. And, indeed, it rather complicates than facilitates the explanation; as it shows that the poison differs from animal poison generally, in not being destroyed by putrefaction. Dr. Combe’s inquiries must satisfy every one, that in the Leith cases decay was out of the question, and I may add my testimony to the statement: the muscles taken from the stomach of one of his fatal cases, and likewise others obtained in the shell, and brought to me for analysis, were perfectly fresh. By some physicians, and especially by Dr. Edwards, their poisonous effects have been referred to idiosyncrasy on the part of the persons who suffer. It can hardly be doubted that this is the cause in some instances. It was formerly mentioned that muscles, oysters, crabs, and even the richer sorts of vertebrated fishes, such as trout, salmon, turbot, holibut, herring, mackerel, are not only injurious to some people, while salutary to mankind generally, but likewise that this singular idiosyncrasy may be acquired. A relation of mine for many years could not take a few mouthfuls of salmon, trout, herring, turbot, holibut, crab, or lobster, without being attacked in a few minutes or hours with violent vomiting; yet at an early period of life, he could eat them all with impunity; and at all times he has eaten without injury cod, ling, haddock, whiting, flounder, oysters, and muscles. Among the cases which have come under Dr. Edwards’s notice in Paris, there is one evidently of the same nature. In two others, the idiosyncrasy existed in regard to the muscle, and although in both of these the affection induced was slight, there is no doubt but idiosyncrasy will also account even for some instances of the severe disorders specified above. In particular, it appears sometimes to operate in the production of nettle-rash and asthma; for in the instance quoted from the Gazette de Santé, as arising from ten muscles, it happened that the father of the patient partook very freely of the same dish without sustaining any harm whatever; and in each of three distinct accidents mentioned by Möhring, it appeared that other individuals had eaten of the same dish with equal impunity.[1524] 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]