318 



INDEX 



Selenium, extraction of, 284 



geographical distribution, 284 



geological horizon, 284 



ores of, 283 



origin of ores, 283 



production of, 308 



properties of, 283 



uses of, 284 

 Selen-sulphur, 283 

 Selen-tellurium, 283 

 Selvage, 12 

 Semmons, W., 178 

 Senarmontite, 171 

 Shaler, N. S., 194 

 Siderite, 189, 196 

 Siebenthal, C. E., 296 

 Sierra region, 72 

 Silver, 89 



character of ore bodies, 91 



cyanide process, 101 



electrolytic process, 101 



extraction of, 98 



geographical distribution, 97 



geological horizon, 98 



lixiviation process, 100 



native, 89 



ores of, 90 



origin of ores, 91 



primary ores, 35 



production of, 290 



properties of, 89 



smelting process, 99 



uses of, 102 



Silverton district, Colorado, 69 

 Singewald, J. T., 210 

 Sippylite, 281 

 Skutterudite, 235 

 Smaltite, 164, 235 

 Smith, G. O., 268 

 Smith, W. S. T., 262 

 Smithsonite, 257 

 Smyth, C. H., 183, 201 

 Smyth, H. L., 207, 209 

 Solder, 185 

 Solfataras, 7 

 Solutions, ascending, 2 



descending, 2 



lateral secreting, 2 



trend of, 2 



South Lorrain, Ontario, 97 

 Spencer, A. C., 79, 259, 260 

 Sperrylite, 102 

 Sphalerite, 257 

 Spiegeleisen, 255 

 Spurr, J. E., 54, 70, 120 

 Stannite, 177 

 Steel, Bessemer, 216 

 Stephanite, 90 

 Stibnite, 170 

 Strike, 9 



Stolzite, 110, 269 

 Sudbury, Ontario, 239 

 Swinburne. See Ashcroft and Swin- 

 burne, 265 



Tantalum, 282 



character of ore bodies, 282 



extraction of, 282 



geographical distribution, 282 



geological horizon, 282 



ores of, 282 



origin of ores, 282 



production of, 308 



properties of, 282 



uses of, 282 

 Tellurium, 285 



character of ore bodies, 286 



extraction of, 286 



geographical distribution, 286 



geological horizon, 286 



ores of, 285 



origin of ores, 285 



production of, 308 



properties of, 285 



uses of, 286 



Telluride district, Colorado, 69 

 Tellurite, 286 

 Tennantite, 135 

 Tenorite, 135 

 Tetradymite, 131, 286 

 Tetrahedrite, 135 

 Thames district, 95 

 Thermit, 227 



Thomas and MacAlister, 30, 32, 39, 

 112, 137, 140, 167, 172, 

 178, 181, 214, 225, 232, 

 264 



