an electrolytic cell and chamber for converting electric power into heat . the cell includes a non - conductive housing and a conductive end member sealingly positioned in and extending from each open end of the housing . the end members have spaced apart proximal end surfaces to define , in cooperation with said housing , a chamber . catalytic particles comprising an admixture of palladium or palladium black particles , inert non - conductive particles and optionally boron particles are closely packed into said chamber and against each proximal end . a longitudinal gas passage extends through each end member in gas communication with the chamber . each gas passage is sealably closeable , one gas passage being connectable to a source of pressurized hydrogen or deuterium gas deliverable under pressure into the chamber . a distal end of each end member is connected to an electric power source whereby , when electric current flows through the end members and across the chamber which is filled with said catalytic particles and hydrogen or deuterium gas , heat is produced within the chamber for external use .