DISEASE FROM POISONOUS FISH.
In tropical climates the perch, the gurnard, the goby, the sar dine, and the two varieties of globe fishes, the diadon or two toothed and the tetradon or four-toothed, are all, at particular seasons, causes of disease when they are taken as food. The poisonous substance is developed in their digestive organs, in the spawn, and in the liver of the fishes; it is most potent in those fishes which have arrived at maturity of growth.
The Spanish colonists give the name of Siguatera to the symp toms of acute disease which result from the eating of poisonous fishes in hot climates. The phenomena of disease that are pre sented are of two kinds—gastro-enteric and nervous. The gastro enteric form of disease begins with a severe attack of indigestion, followed by great pain in the stomach, and by all the indications of gastro-enteric irritation, viz.: nausea, vomiting, first of food then of mucous fluid, diarrhcea, coldness of the body, depression of the pulse, and cramps. The nervous type of the disease is marked by sudden muscular prostration : the face of the sufferer becomes flushed and then pale; the pupils are contracted; the lips are swollen and blue; the pulse is weak, quick, and intermit tent; 'and, very soon, there is general convulsion with inability to exert any volitional power. Death quickly occurs unless skilled help be at hand.
Both these forms of the ciguatera are dangerous to life. Re covery from the gastro-enteric form is rapid when it commences, but the nervous type of the malady causes, for several days, ex treme debility and irregular action of the heart. The poison, whatever may be its nature and composition, excites, it is clear, a most effective irritation of the pneumo-gastric nerves, an irritation as truly energetic as that which might be excited by submitting the nerves to the influence of a series of electrical discharges.
Some very serious forms of disease have been produced by taking mussels as food. There are certain persons who seem specially liable to irritation of the stomach even from taking a small quantity of mussels. There are others who suffer from nettlerash from the same cause. These facts are so general that the inference has been drawn that at certain seasons the mussel produces an irritant poison. In exceptional cases poisoning from mussels has been extremely severe and even fatal, the symptoms resembling those which have been described above as constituting the disease signatera, with other peculiar nervous symptoms. The indications are those of nausea and vomiting, followed by con striction of the mouth and throat, difficulty of speech, numbness of the limbs, muscular exhaustion, coldness of the body, and death with faintness and torpor. Notwithstanding the violence of the symptoms, the appearances after death have been rarely of sufficient importance to explain any fatal phenomena. The real nature of the poison remains up to this day unknown. At one time it was supposed to be a salt of copper with which the mus sels themselves were charged, but analysis, in fatal cases, has failed to establish this view. The probabilities are that the poison is of an organic kind, and is produced by the mussel itself at particular seasons.
The oyster has been accredited with producing disease under some circumstances, and I have myself known one example of oyster poisoning; but the occurrence is extremely rare. The symptoms are those of nausea and irritation of the stomach.
In the books of a recent past day treating on disease from foods, references are made to poisonous effects produced by the taking of sausages, pork, milk, and other animal substances. The symptoms cited refer, in nearly every case, to irritation affecting the alimentary canal, and various speculations are offered to ac count for the phenomena that have been observed. In these days much light has been thrown on that part of the subject which re lates to disease from sausages, pork, and bacon, owing to the dis covery in such foods of tricliinte and other parasitic forms of life. It is probable that in nearly all the instances of the kind recorded by the older writers the irritations described were due to para sitic introductions. We know now also that milk may be the bearer of various organic poisons, such as the poisons of typhoid fever, cholera, and probably diphtheria.