Experiments on the Nervous System with Opium and Metalline Substances / Made Chiefly with the View of Determining the Nature and Effects of Animal Electricity

The author reports a series of physiological experiments, primarily on frogs, investigating how opium and various metallic substances influence nerve and circulatory activity. He describes anatomical observations, systematic tests that stimulate limbs and record contractions after cardiac removal, and comparative trials with metals to probe a movable fluid associated with nerve responses. Results are analyzed to contrast this agent with known electrical phenomena and the nervous energy, leading to corollaries and general conclusions about the nature and effects of what he terms animal electricity.