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.