. Animal physiology. Physiology, Comparative; Physiology, Comparative. ELECTRIC FISHES. 321. Fis. 165.—Gymnotus. charges of the larger individuals sometimes prove sufficient to deprive even men, of sense and mo- tion. This power is employed by the fish to defend itself against its enemies ; and even, it is said, to destroy its prey (which consists of other fishes) at some distance • the shock being conveyed by water, as a lightning-conductor conveys to the earth the effects of the electric discharge of the clouds. The first shocks are usually fee- ble ; but as the animal becomes more irritated
. Animal physiology. Physiology, Comparative; Physiology, Comparative. ELECTRIC FISHES. 321. Fis. 165.—Gymnotus. charges of the larger individuals sometimes prove sufficient to deprive even men, of sense and mo- tion. This power is employed by the fish to defend itself against its enemies ; and even, it is said, to destroy its prey (which consists of other fishes) at some distance • the shock being conveyed by water, as a lightning-conductor conveys to the earth the effects of the electric discharge of the clouds. The first shocks are usually fee- ble ; but as the animal becomes more irritated, their power increases. After a considerable num- ber of powerful discharges, the energy is exhausted, and is not recovered for some time; and this circumstance is taken advan- tage of in South America, both to obtain the fishes (which afford excellent food), and to make the rivers they infest passable to travellers. A number of wild horses are collected in the neigh- bourhood and driven into the water; the Gymnoti attack these, and speedily stun them, or even destroy their lives by repeated shocks; but their own powers of defence and injury are ex- hausted in the same degree, and they then become an easy prey to their captors. 421. The shock of the Torpedo is less power- ful ; but it is sufficient to benumb the hand that touches it. From its proximity to European shores, this fish has been made the subject of observation and experiment, more completely than the other; and some curious results have been attained. It seems essential to the proper reception of the shock, that two parts of the body should be touched at the same time ; and that these two should be in different electrical states. The most energetic discharge is procured from the Torpedo, by touching its back and belly simultaneously; the electricity of the back being positive, and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colora
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