ELECTROPHORUS, an instrument invented by Alessandro Volta in 1775, by which mechanical work is transformed into electrostatic charge by the aid of a small initial charge of electric ity. In one form it consists of a disk of non-conducting material, such as pitch or resin, placed between two metal sheets, one being provided with an insulating handle. For the pitch or resin may be substituted a sheet of glass, ebonite, indiarubber or any other good dielectric placed upon a metallic sheet, called the sole plate. The method of use of the electrophorus is described in the article