This, the germ of the most remarkable of the sciences, was noticed by Sulzar, fifty years before Galvani observed the convulsions in the limbs of frogs, when excited by the action of dissimilar metals; but the former paid little attention to the phenomenon, and the discovery led to no results. When Galvani’s observant mind was directed to the remarkable fact that the mere contact of two dissimilar metals with the moist surface of living muscles produced convulsions, there was an awakening in the soul of that philosopher to a great fundamental truth, which was nurtured by him, tried and tested, and preserved to work its marvels for future ages. Although the world of science looks back to Volta as the man who gave the first true interpretation of this discovery, yet the ordinary world will never disconnect this important branch of physical science from the name of Galvani, and chemical electricity in all its forms will for ever be known under the familiar name of Galvanism. And it must not be forgotten, that the phenomena of the manifestation of electricity, in connection with the conditions of vitality, are entirely due to Galvani. Let us examine the phenomena of Galvanism in its most simple phases:-- If we place a live flounder upon a plate of zinc, put a shilling on its back, and then touch both metals with the ends of a metallic wire, the fish will exhibit painful convulsions. The zinc becomes oxidized by the separation of oxygen from the fluid on the surface with which it is in contact, whilst hydrogen gas is liberated at that surface touched by the other metal. Here we have, in the first place, a chemical change effected, then a peculiar muscular disturbance. Each successive combination or decomposition, like a pulsation, is transmitted along the circuit from one extremity to the other. How the impulse which is derived from the zinc is transmitted through the body of the animal, or the tongue, to the silver or copper is the next consideration.