The species of fish, from which deleterious effects have more commonly arisen in this country, are the _Mytilus Edulis_, or muscle. _Dr. Burrows_ has given us an account of two cases of death from eating these fish, which occurred at Gravesend, under the care of _Mr. Rogers_, surgeon of that place, upon whose authority the statement is drawn up.[489] The subjects of the history were two youths of the ages of nine and fourteen, who had each eaten about a dozen of small muscles, which they had picked from the side of a fishing smack, in a dead and tainted state. In the _Gazette de Santé_,[490] and in the works of _Fodéré_,[491] and _Behren_,[492] similar cases are recorded. _Vancouver_,[493] in his voyage to the coast of America, relates that several of his men were ill from eating some muscles which they had collected and roasted for breakfast; in an hour after which they complained of numbness of the face and extremities, sickness, and giddiness. Three were more affected than the others, and one of them died. _Origin of Fish-poison._ If we admit that the symptoms which are occasionally produced by the ingestion of certain fish, depend upon the presence of poison, we have next to inquire into its nature and origin. _Dr. Burrows_ considers that all the opinions which have been advanced upon this subject may, for the greater perspicuity and facility of discussion, be arranged under seven heads, viz. does the poison exist—1. _In the skin?_—2. _In the stomach and intestinal canal?_—3. _In the liver or gall bladder?_—4. _In the entire substance of the fish?_—5. _In the food of fishes?_—6. _Is it a morbid change in the system of the fish?_—7. _Is it a poison, sui generis?_ Upon these several questions _Dr. Burrows_ has offered some observations. There do not appear to be any facts which can induce us to consider that the poison resides only in the skin. Experience has shewn that the _virus_ is particularly energetic in the viscera, commonly called the _offals_; and yet there are no grounds for concluding that it exclusively belongs to these parts. _Captain Cook_, and _Messrs. Forster_ were poisoned by eating a piece of the liver only of a species of _tetrodon_; yet they who ate of its substance were also poisoned. An opinion has long prevailed that the poisonous principle is derived from the substances upon which the fish feeds; and that of muscles, in particular, from copper; this latter hypothesis has received the sanction of _Dr. Chisholm_. We however agree with _Dr. Burrows_ in considering that it has neither the support of observation or analogy. _Dr. Beune_ has supposed that the acrid principle is no other than the spawn of the _stella marina_, an insect which very commonly lodges in the muscle. It seems, however, more probable that it is a product of decomposition, but which requires the concurrence of certain circumstances for its developement.