There are many persons who break out with irritative eruptions after eating certain descriptions of shell-fish, though they injure no other idiosyncrasies—others again are subject to diarrhœa from fish-diet, though the same food be harmless to other persons.
Almost all fishes are unwholesome at certain seasons, and hence the regulations laid down for the vend of oysters, lobsters, salmon, &c., only in prescribed periods. Science, in searching to determine the reason why this is the case, encounters certain wholesale occurrences which are due to some general, but at the same time, very specific causes. Mackerel sold in the New York market occasionally produce poisonous effects; and London is sometimes supplied with unwholesome salmon in large quantities.
Dr. Burroughs, in a paper on Poisonous Fishes, published last year in a Jamaica journal, remarks:
‘There are five obvious circumstances to be taken into consideration in the incidents of fish-poison.
‘1st. The existence of a sanies, from some disorder indicated in the living tissues of the animal.
‘2ndly. A natural deleteriousness in the flesh, without reference to a state of disease.
‘3rdly. The adventitious presence of something deleterious in the fish, from the food recently eaten.
‘4thly. The injury resulting from cooking fish with such large organs as the liver unextracted,—the liver being at all times dangerous as food in some particular fishes.
‘5thly. The poisonous putrefaction known to prevail in some fishes after 24 hours keeping. Morbid action set up in the healthy animal body that receives the putrefactive poison being indicated by oppression, nausea, giddiness, and general prostration.’
We might add a 6th,—the known existence of an irritating fluid,—issuing from the surface of some fishes of peculiar structure.