clouded with the mucus from which he thus relieves the surface of his body. When this species of fish was first discovered, marvellous accounts respecting them were transmitted to the Royal Society: it was even said that in the River Surinam, in the western province of Guiana, some existed twenty feet long. The present specimen is forty inches in length; and measures eighteen inches round the body; and his physiognomy justifies the description given by one of the early narrators, who remarked, that the Gymnotus “resembles one of our common eels, except that its head is flat, and its mouth wide, like that of a cat-fish, without teeth.” It is certainly ugly enough. On its first arrival in England, the proprietors offered Professor Faraday (to whom this country may possibly discover, within the next five hundred years, that it owes something) the privilege of experimenting upon him for scientific purposes, and the result of a great number of experiments, ingeniously devised, and executed with great nicety, clearly proved the identity between the electricity of the fish and the common electricity. The shock, the circuit, the spark, were distinctly obtained; the galvanometer was sensibly affected; chemical decompositions were obtained; an annealed steel needle became magnetic, and the direction of its polarity indicated a current from the anterior to the posterior parts of the fish, through the conductors used. The force with which the electric discharge is made is also very considerable, for this philosopher tells us we may conclude that a single medium discharge of the fish is at least equal to the electricity of a Leyden Battery of fifteen jars, containing three thousand five hundred square inches of glass, coated upon both sides, charged to its highest degree. But great as is the force of a single discharge, the Gymnotus will sometimes give a double, and even a triple shock, with scarcely any interval. Nor is this all. The instinctive action it has recourse to in order to augment the force of the shock, is very remarkable.