and Lesher, C. E., 371, 373, 373, 375

Smyrna, Turkey, emery, 268

Soapstone, 299-300

Societies, professional, standards of admission, 421-422, 428

Soils, classification, 97
composition, 96-97, 99
origin, 94-96
use of fertilizer minerals on, 99-101
use of geology in study of, 95-98

Sound waves, possible use in exploration, 319

South Africa, asbestos, 271, 272
cement, 87
coal, 116
cobalt, 255
copper, 197-198, 205
corundum, 268
diamond dust, 268
diamonds, 289, 291-292, 316
gold, 222-226, 228
iron, 154,164
mica, 286
tin, 260
vanadium, 187

South Africa, laws relating to ownership of mineral resources, 343, 345

South America, cement, 87-88
coal, 116
lead, 210, 211
mercury, 258
zinc, 214
_See also_ under individual countries.

South America, laws relating to ownership of mineral resources,
343-344, 345

South Carolina, coal, 117
monazite, 288, 289
phosphates, 105, 107

South Dakota, gold, 222, 228, 229
quartzite, 84
tin, 262
tungsten, 183

Southern Graphite Association, 405

Southern Pacific Railway, litigation in regard to oil lands, 348

Spain, arsenic, 250
barite, 272
cement, 87
copper, 197-198, 204
garnet, 268, 270
iron, 154, 156, 160-161, 162, 163
lead, 210, 211-212
manganese, 174
mercury, 256-257, 259
phosphates, 104, 106
platinum, 238
potash, 111-113
pyrite, 107-108
salt, 294
silver, 232
sulphur, 109-110
zinc, 214-215

Spain, commercial and political control of various minerals, 64

Spiegeleisen, 173-174

Springs, 72

Spurr, J. E., 43, 64, 403

Stassfurt, Germany, borax, 277
bromine, 278
potash, 111-112, 113, 296-297
salt, common, 296-297

Steel. _See_ Iron and steel

Stone. _See_ Building stone, Common rocks.

Storage of coal, 376

Stratigraphy, relation to economic geology, 4

Structural geology, relation to economic geology, 5
use of principles of in exploration for mineral deposits, 319-320

Structures of rocks, relation to earth stresses, 5
relation to topography, 7

Subsidence of ground over mining operations, geologic study of, 357, 417

Sudbury, Ontario, cobalt, 255
nickel ores, 34-35, 180-182, 308, 312, 318
platinum, 238, 239

Sulphide enrichment. _See_ Secondary enrichment.