The above catalogue of poisonous fishes is extracted from Dr. Dancer’s “Jamaica Practice of Physic,” and its correctness fell under my own observation in the Wrest Indies. The different systems and classifications of ichthyologists have produced much confusion, and may lead to fatal errors; I think it therefore advisable to submit to travellers, who may have to visit these unhealthy regions, the names of the toxicophorous fishes according to the French momenclature.

Le poisson armé, Diodon orbicularis.
La lune, Tetraodon mola.—Linn.
Le tétraodon ocellé, T. ocellatus.
Le t. scélérat, T. scelreatus.
La vieille, Balistes vetula.
La petite vieille, B. monoceros.—Linn.
Alutus monoceros.—Cuvier.
Le coffre triangulaire, Ostracion trigonus.—Bloch.
La grande orphie, Esox Brasiliensis.—Linn.
La petite orphie, E. marginatus.—Lacepede.
Le congre, Muræna conger.—Minn.
Le perroquet, Sparus psittacus.—Lacepede.
Le capitaine, S. erythrinus.—Bloch.
La bécune, Sphyræna becuna.
Le thon, Scomber thynnus.—Linn.
La carangue, Caranx carangus.

A work, in which a synonymous catalogue of all the fishes supposed to be poisonous might be found, would be highly desirable, as they generally bear different popular and scientific names, thus producing a dangerous confusion even amongst naturalists; how much more dangerous amongst seafaring people and voyagers!

I cannot conclude this article without noticing the singular properties of those electric fishes denominated the torpedo-ray and the gymnote. They had been long known to naturalists, and the ancients attributed their destructive faculties to a magic power that Oppian had recorded in his Alieuticon, where he describes a fisherman palsied through the hook, the line, and the rod. This influence being voluntary on the part of the animal, seemed to warrant the belief in its mischievous nature, since it allows itself sometimes to be touched with impunity, while at others it burrows itself under the sand of the beach, when the tide has receded, and maliciously benumbs the astonished passenger who walks over it. This singular fish, which is common in the Mediterranean Sea, has been described both by the Greek and Roman writers; amongst others, by Aristotle and Athenæus: and Socrates, in his Dialogues, compares a powerful objection, to the influence of the torpedo.

This voluntary faculty has been observed by Lacépède and Cloquet in the Mediterranean, and at La Rochelle. In torpedos kept in water for experimental purposes, Réaumur found that he handled them without experiencing any shock for some time, until they at last appeared to become impatient: he then experienced a stunning sensation along the arm, not easily to be described, but resembling that which is felt when a limb has been struck with a sudden blow. One of the experiments of this naturalist proved the extensive power of this faculty. He placed a torpedo and a duck in a vessel containing sea-water, covered with linen to prevent the duck from escaping, without impeding the bird’s respiration. At the expiration of a few minutes the animal was found dead, having been killed by the electric shocks of its enemy.

Redi was the first who demonstrated this faculty. Having laid hold of a torpedo recently caught, he had scarcely touched it, when he felt a creeping sensation shooting up to the shoulder, followed by an unpleasant tremor, with a lancinating pain in the elbow. These sensations he experienced as often as he touched the animal; but this faculty gradually decreased in strength as the animal became exhausted and dying. These experiments he related in a work entitled “Esperienze intorno à diverse cose naturali.” Florence, 1671.

In 1774, Walsh made some very interesting experiments at the Isle of Ré and La Rochelle, and clearly demonstrated this electric faculty in a paper On the electric property of the torpedo. In one of them he found that this fish could produce from forty to fifty shocks in the course of ninety minutes. The electrified individuals were isolated; and at each shock the animal gave, it appeared to labour under a sense of contraction, when its eyes sunk deep in their sockets.

The trichiurus electricus of Linnæus, the rhinobatus electricus of Schneider, and the gymnonotus electricus of Surinam, are the species of this singular fish with which experiments have chiefly been made. The gymnonotus is a kind of eel, five or six feet in length, and its electric properties are so powerful that it can throw down men and horses. This animal is rendered more terrific from the velocity of his powers of natation, thus being able to discharge its thunder far and near. When touched with one hand the shock is slight; but when grasped with both, it is so violent that, according to the accounts of Collins Flag, the electric fluid can paralyze the arms of the imprudent experimentalist for several years. This electric action is analogous to that which is obtained by means of the fulminating plate, which is made of glass with metallic plates. Twenty-seven persons holding each other by the hands, and forming a chain, the extremities of which corresponded with the points of the fish’s body, experienced a smart shock. These shocks are produced in quick succession, but become gradually weaker as the fluid appears to be exhausted. Humboldt informs us, that, to catch this fish, wild horses are driven into the water, and after having expended the fury and the vigour of the gymnonotus, fishermen step in and catch them either with nets or harpoons. Here we find that the irritable or sensorial power is exhausted through the medium of electricity. These phenomena may be attributed to an electric or Voltaic aura; and the organ of the animal that secretes the fluid resembles in its wonderful structure the Voltaic apparatus. Both the gymnote and the torpedo obey the laws of electricity, and their action is limited to the same conducting and non-conducting mediums. The electric sparks proceeding from the gymnote have been plainly seen in a dark chamber by Walsh, Pringle, Williamson, and others. The fish has four electric organs, two large and two small ones, extending on each side of the body from the abdomen to the end of the tail. These organs are of such a size that they constitute one third of the fish’s bulk. Each of them is composed of a series of aponeurotic membranes, longitudinal, parallel, horizontal, and at about one line’s distance from each other. Hunter counted thirty-four of these fasciculi in one of the largest. Other membranes or plates traverse these vertically, and nearly at a right angle; thus forming a plexus or net-work of numerous rhomboidal cells. Hunter found no less than two hundred and forty of these vertical plates in the space of eleven inches.

This apparatus, analogous to the Voltaic pile, is brought into action by a system of nerves rising from the spinal marrow, each vertebra giving out a branch; other branches, rising from a large nerve, running from the basis of the cranium to the extremity of the tail. All these ramifications are spread and developed in the cells of the electric organs, to transmit its powerful fluid, and strike with stupor or with death every animal that comes within its reach. Lacépède has justly compared this wonderful mechanism to a battery formed of a multitude of folio-electric pieces.

The electric organ of the malapterus electricus is of a different formation. This fish, found in the Nile and in other rivers of Africa, is called by the Arabs raash or thunder. In this animal the electric fluid extends all round the body, immediately under the integuments, and consists of a tissue of cellular fibres so dense, that it might be compared to a layer of bacon; but, when carefully examined, it consists of a series of fibres forming a complex net-work. These cells, like those in the gymnote, are lubricated with a mucous secretion. The nervous system of this intricate machinery is formed by the two long branches of the pneumo-gastric nerves, which in fishes usually run under each lateral line. Here, however, they approach each other on leaving the cranium, traversing the first vertebra.