This retort consists of a cylinder, A, made of silica or other non-conducting material, suitably embedded in a body, B, of powdered charcoal, mineral wool, or of some other material which is not a good conductor of heat. The rear end of the retort-cylinder is closed by means of a carbon plate, C, which plate forms the positive electrode, and with this plate the positive wire of the electric circuit is connected. The outer end of the retort is closed by means of an inverted graphite crucible, D, to which the negative wire of the electric circuit is attached. The graphite crucible serves as a plug for closing the end of the retort. It also forms a condensing chamber for the zinc fumes, and it also constitutes the negative electrode. The term "electrode" is used in this case as designating the terminals of the circuit proper, or that portion of it which acts simply as an electrical conductor, and not with the intention of indicating the ends of a line between which there is no circuit connection. The circuit between the "electrodes," so called, is continuous, being established by means of and through the body of broken carbon contained in the retort, A. There is no deposit made on either plate of the decomposed constituents of the material reduced. The mouth of the crucible is closed with a luting of clay, or otherwise, and the opening, _d_, made in the upper side of the crucible, near its extremity, comes entirely within the retort, and forms a passage for the zinc fumes from the retort chamber into the condensing chamber. The pipe, E, serves as a vent for the condensing chamber. The zinc ore is mixed with pulverized or granular carbon, and the retort charged nearly full through the front end with the mixture, the plug, D, being removed for this purpose. A small space is left at the top, as shown. After the plug has been inserted and the joint properly luted, the electric circuit is closed and the current allowed to pass through the retort, traversing its entire length through the body of mixed ore and carbon. The carbon constituents of the mass become incandescent, generating a very high degree of heat, and being in direct contact with the ore, the latter is rapidly and effectually reduced and distilled. The heat evolved reduces the ore and distills the zinc, and the zinc fumes are condensed in the condensing chamber, precisely as in the present method of zinc making, with this important exception that, aside from the reaction produced by heating carbon in the presence of zinc oxide, the electric current, in passing through the zinc oxide, has a decomposing and disintegrating action upon it, not unlike the effect produced by an electric current in a solution. This action accelerates the reduction, and promotes economy in the process.