The chemical effects produced by electricity have, Mr. Davy says, long been objects of attention; but the novelty of the phenomena, their want of analogy to known facts, and the apparent discordance of some of the results, involved the inquiry in obscurity. It was very early observed, that acid and alkaline matter appeared in water acted upon by a current of electricity; but Mr. Davy soon found that the muriatic acid came from the animal or vegetable matters employed to connect the two portions of water; for when the same cotton was repeatedly used, it ceased to be evolved. The soda, in like manner, was found to proceed from the corrosion of the glass tube, as it did not appear in water electrified in an agate cup.