ferent shades, as the begonia discolor, a kind of mutual exchange of colors between the two surfaces has been noticed.
II.
The physiological phenomena just spoken of are usually confounded in books with the facts of electric medical treatment, and it seems better to distinguish the two classes. The true method consists in first explaining the phenomena displayed in the healthy organism, as the only way of understanding afterward those that are peculiar to disorders. Electric treatment forms a group of methods to be classed among the most efficacious in medicine, provided they are applied by a practitioner well trained in the theory of his art. Indeed, the most thorough physiological knowledge is essential for the physician who would make the electric current serviceable. Mere experimenting, even the most sagacious, must here be barren of good results—a fact of which it is well to remind those who impute to the method itself the failures it meets with in unskilful hands. It is true that, since the days of Galvani and Volta, physicians have used galvanism in the treatment of many diseases. Early in the century, galvanic medicine was much talked of, and supposed to be the universal panacea. Galvanic societies, journals, and treatises, undertook to spread its usefulness. The fashion lasted a certain time, and would perhaps have grown indifferent, when the discovery of induced electricity, due to Faraday, in 1832, called professional attention once more to the virtues of the electric fluid, and led to a new and interesting range of experiments. Yet it is likely that the true systems of electric medical treatment, after the extraordinary illusions of their earlier days had vanished, would at length have sunk into disuse, had they not escaped from the ruts of empiricism. With its usual boldness, it had at first gained them a high rank, which it had no power to maintain. It was experimental physiology, with its exact analysis of the mechanical effects of this fluid upon the springs of the organism, which made its application in the healing art sure, true, and solid, as it now is. In this, as in all things, blind art has been the impulse to scientific research, which in turn steadily enlightens and perfects art.
It is singular that induction-currents have met with much better fortune than galvanic ones. The latter, the use of which introduced electric treatment, have gained real importance in physiology and medicine only within a few years, and after the reputation of induction-currents was well established, thanks chiefly to the efforts of Duchenne. A German physiologist and anatomist, Remak, who died six years ago, was the first to urge the singular remedial virtues of the voltaic current. Remak, after devoting twenty years to the study of the most difficult questions in embryology and histology, undertook, in 1854, the systematic examination and ascertainment of the action of continuous currents on the vital economy. He soon
