SUBJECT INDEX 311

tion of, 217; secondary concen
trations, 216-7 ; supplies of, 217 ;
value in agriculture, 214.
Propylitization, 26, 36-7, 45.
Prospecting, 4-7; tin-dish, 3
Varieties of, 8-10. :
Pyritic masses, 86-90, 134.
Pyrobitumen, 204.

RAKE Vein, 8.
Rand Banket, 57-63.
Reef, definition of; 12-13.
Replacements, 16, 33, 37, 45-8 82,
85-90, 92-4, 102-5, 126-7, 134-44.
Road metals, 182-4; adherence tc
bitumen, 183; macadam, 182;
tests of, 183-4.
Ruby, 165 ; Cape ruby, 167.

SADDLE lodes, 9, 10-11, 29, 37, 44.
Salt deposits, 206-17; bar theory,
210; Caspian water, analyses,
211; composition of Jordan and
Dead Sea water, 207 ; composi:
tion of sea-water, 206; concen:
tration in salt lakes, 207; Ger:
man salt fields, 208-9, 215-7:
great thickness of, 210-1; intrusive
 salt deposits, 210, 214;
potash salts, 214-7. Salt domes,
210, 212-3, 282, 287.
Sand, 191, 194.
Sapphire, 163.
Scheelite, 79.
Secondary enrichments, 31, 37, 51.
82, 84, 90-3. .
Segregation, chief mineral deposits
due to, 33.
Selenite, 30.
Shoots of ore, 30, 43, 81.
Silt, 191.
Silver, 110-2; chief producing
countries, 110; Cobalt field.
110-2; price of. 110; qualities.
110.
Slickensides, 8.
Soil, the, 190-6; clay, 191-2, 194;
colour of, 195; composition of,
192; constitution of, 191; crop
requirements, 193 ; definition and
function, 190 ; dry farming, 194 ;
lime, effect of, 191 ; mulch. effect

of, 195 ; nitrogen in, 193; nitrogen
 essential to most plants, 197 ;
phosphorus in, 192; potash in,
192; sand, 191, 104; sedentery
soil, 190; silt, 191; sodium carbonate
 in, 192-5; soil surveys,
195-6. Texture of, 194 ; transported,
 190; water capacity, 194.
Sperrylite, 65.
Staffelite, 203.
Step lodes, 8.
Stockwork, 28

TELLURIDES, 47, 48, 49.
Tin lodes, 21.
Tin, ores of, 71-8 ; alluvial deposits,
71; associated minerals, 73 ;
fissure-lodes and brecciated ores
of Bolivia, 76; historic importance,
 71; pneumatolytic origin,
71, 73, 76, 77; pseudo-bedded
ores, 74, 75; residual ores, 75 ;
variations in price of, 78 ; world
distribution of, ¥2.
Titaniferous magnetites, 132.
Topaz, 166.
Torsion balance, application of, 51.
Tungsten, ores of, 78-9; distribution
 of, 78-9; price of, 79; use
of, 78.

VARIOLITE in gold ores, 48, 52.
Veins, varieties of, 8.
Veinstones, 12.
Verticals in gold ores, 40.
Volcanic rocks with ores, 42-3, 48,
52, 56, 84, 86, 94, 102, 143.
Vugg, 11.

WATERS, 22; depth of, 22-3;
juvenile, 22; magmatic, 22;
plutonic, 22, 52, 95; sea-water,
gold in, 35.
Water Supply, 219-37; ‘‘ Artesian ”’
wells, 231; Australian flowing
wells, 234-5; connate water, 220 ;
dew-ponds, 219; dumb-wells,
229; exhaustion, cone of, 227;
evaporation, 223; gas-pressure,
233; hot springs, 221-2; imbibition,
 228; impurity in cities,
220: juvenile, 220-2: London