The mussel, mytilus edulis Lin. Syst. Naturae, musculus. A sea shell fish of a luscious flavour, found on many parts of our coast, of a moderate size, larger between the tropics, and smaller in the arctic sea. As from mushrooms, so from this shell fish very alarming symptoms are often produced, ascribed to a quality in the mussels, either proper to them, or accidentally acquired from their situation or nourishment. The pea crab, often found in them, has been accused; but as similar effects are observed to arise from various other causes besides mushrooms and mussels, the peculiarity of the person's constitution is generally supposed to occasion them. Similar complaints have sometimes been produced by eating salmon, taking the Peruvian bark, by washing the hands in water after fish hath been boiled in it, bathing in the sea, cantharides applied to the skin, and the internal use of wild valerian root.

"The signs which announce the noxious effects of boiled mussels," observes an author in the second volume of the Memoirs of the Academy at Brussels,"are an universal uneasiness, or numbness, that commonly takes place three or four hours after they have been eaten. These symptoms are succeeded by a tightness of the throat, a sense of heat about the head and eyes, immoderate thirst, nausea, and sometimes vomiting. If the patient hath the good fortune to vomit up the whole of the offensive matter, this evacuation is generally sufficient to stop the progress of the complaint; but if he does not bring up any or only part of the noxious substance, the disorder becomes more or less alarming, according to the quantity of the deleterious matter in the first passages, and the particular constitution of the patient. The want of a sufficient evacuation, by vomit, increases the tightness of the throat, and the swelling of the face, eyes, and tongue: all the parts within the mouth appear inflamed, and, as it were, excoriated; and the redness soon spreads to the outer surface, appearing first in the face, and extending from thence to the neck, breast, and abdomen, and by degrees over the whole body. This particular eruption is the symptom the most distinguishing and characteristic of the malignancy of mussels; it is constantly accompanied with a kind of delirium, with singular uneasiness, and an insupportable itching. It has no affinity with the eruption produced by the erysipelatous fever, with the scarlatina, measles, purpura urticaria, or any other known species of red eruption; but has these particularities, viz. that it never appears unless mussels have been eaten; is not preceded by fever, or accompanied by symptoms which appear united in any other disease; and lastly, that the whole surface of the body, though redder than in any other eruptive disease, appears as it were spotted with an infinite number of points of a deeper red than the rest of the skin. These points are infinitely smaller than a millet seed; if we examine them through a lens, we see distinctly that they are the opening or pores of the cuticle, while the redness which is seen only through the epidermis appears of a paler hue."

The proper treatment of these complaints is the same with that directed when mushrooms are the offending cause. (See Amanita.) The itching is considerably allayed by washing the whole surface of the body with vinegar and water for about half an hour.

It is advised as a preventive of their injuries to wash them with water, and afterwards with vinegar, to boil them for use in an earthen pot with vinegar and water, and a few grains of Jamaica pepper.

The dangerous consequences supposed to arise from eating mussels are, however, greatly exaggerated. They very rarely occur, and scarcely with the violence just described; and, though such effects are occasionally heard of, yet years elapse without such an occurrence, on coasts where mussels are a common article of food. These deleterious consequences are sometimes attributed to one particular part of the fish; at others, to their lying on beds of cupreous pyrites; sometimes to their richness, at others to a peculiarity of constitution. No part of the fish, however, seems to have been pointed out, the absence of which would secure the person from the peculiar effects: the symptoms are not those which follow the swallowing of copper, and the fish is not peculiarly rich. It is certainly more deleterious to some constitutions than others. M. Debeunie thinks that the cause is the spawn of the star fish (the asteria), and has added some experiments in a late volume of the Jour-, nal de Physique to support his opinion. This is by no means improbable; but the little crabs often found in mussels are far from being unwholesome.