I Idaho copper output, 15. Improvements in roasting practice, 69–79. Impure anodes, 228–231, 235. Impurities and annealing temperature, 31. " and conductivity, 23, 24, 34. " and hardness, 32. " and specific gravity, 25. " elimination from mattes, 50, 217. " in anode copper, 219, 228–231, 233, 235. " in copper, 18, 20, 23, 24, 26, 28, 31, 40–42, 217, 218. " in electro-refining, 219, 228–231, 233, 236. " in furnace refining, 239, 241. Increase in blast-furnace size, 113. " reverberatories, 88–91. Incrustation in blast furnaces, 129. Industrial uses of copper, 18, 21. Influence of conditions on properties of copper, 30, 34. Ingot copper, 242. Intermittent working of roasters, 72. Internal settling, 123, 133, 134. Iron and copper silicates, 39. " in blast-furnace charges, 118, 147, 149–152. " in converting practice, 193, 200, 203, 205, 207, 212–217. " in copper, 20, 23, 31, 44. " in electro-refining, 229–232. " in furnace refining, 221, 241. " in pyritic smelting, 172–176, 179, 180, 181, 183, 188. " in slags, 149–153, 211. " pyrites (see _Pyrites_). " reduction in the blast furnace, 115, 116. " silicates, 148–150. " sulphide in matte, 37, 146, 147, 203. " " reactions on roasting, 64. Isabella Smelter (see _Ducktown_). Italy, Copper output of, 15. J Jacketing (see _Water-jacketing_). James (and Nicholl) process, 9, 35. Japan, Copper ores of, 46. " " output of, 15. " old smelting methods, 3. Johnson, F., 26, 34, 243. " T., 34. " on electrical conductivity, 23, 24. K Katanga, 46. Keith, 238. Keller, E., 50, 71, 193, 202, 215, 217, 243. Keswick Smelter, Cal., 119, 120. Kiddie blast heater, 144. Kilns, Roasting in, 67, 68. Kletko (and Evans) roaster, 74–79. Knudsen process, 194, 215.