Note 38 — Chapter II

“The electric eel.” These animals are found in several of the rivers of South America. They are three or four feet in length, though a few have been found measuring six feet. The viscera lie close to the head, and all the rest of the body is taken up by the electrical apparatus, which consists of four batteries, two on each side. These batteries consist of horizontal membranous plates, intersected by delicate vertical plates; the spaces contain a glutinous matter. The batteries are supplied with two hundred and twenty-four pairs of nerves on each side. Humboldt gave much study to these eels, and wrote a graphic description of how the Indians captured them by driving horses into the water occupied by them. The powers of the fishes were exhausted in shocking the horses (some of which died from the effects), and the eels were caught. It is said, too, that the Indians sometimes caught wild horses by driving them into the water and capturing them while they were under the influence of the shock. Faraday calculated that the eel emitted a force as great as the highest charge of a Leyden battery of fifteen jars, having a coated surface of 3,500 square inches. The most powerful shocks are felt by touching the head of the eel with one hand, and the tail with the other.