Acid measures, 49

Acidimetry, 323

Acidity of ores, 168

Acids, 54
strength of, 54, 75, 436

Air of mines, carbonic acid in, 428

Alkalies, 330
determination of, 331
Lawrence Smith's method for, 333, 412
separation of, 332

Alkalimetry, 323

Alkaline earths, 320

Alumina, 314
determination of, 315
in mineral phosphates, 316
separation of, 314, 316

Amalgamation, 126

Ammonia, detection of, 341
determination of, 342
in natural waters, 353

Antimony, 225
detection of, 227
dry assay for, 226
gravimetric assay, 228
separation of, 228
volumetric assay, 229

Arsenic, 381
detection of, 381
dry assay for, 382
gravimetric assay, 383
in brimstone, 393
in crude arsenic, 388, 393
in mispickel, 125, 392
iodine, assay for, 386
separation by distilling, 384
uranium acetate, assay for, 389
Volhard's method  applied to, 124

Assay book, 11
note, 12
results, 7
tons, 13, 131

Assaying, 1
methods, 15

Assays, check, 154
preliminary, 147

Atomic weights, 69
table of, 433


Barium, 326

Baryta, 326

Barytes, sulphur in, 378

Base bullion, sampling of, 157

Basic acetate separation, 233

Baumé's hydrometer, 77

Beryllia, 319

Bismuth, 220
colorimetric assay, 223
detection of, 221
gravimetric determination of, 222
in commercial copper, 208
separation of, 222

Black tin, 271
an analysis of, 287
assay of, 276
copper in, 204
examination of, 285
separation by vanning, 272

Blank assays, 34

Blende, sulphur in, 375
zinc in, 266

Book, assay, 11
laboratory, 10
sample, 9

Boracic acid. See Boron

Borax, examination of, 431

Boron, 429
direct determination of, 431

Brass, copper in, 194
zinc in, 265

Bromine and bromides, 361

Bronze, copper in, 194
tin in, 281

Burettes, 51

Burnt ore, silver in, 116, 118
sulphur in, 377


Cadmium, 269
gravimetric determination, 269
separation of, 269

Caesium, 339

Calcination, 22, 92, 139, 345

Calcium, 320
detection of, 321
gravimetric determination, 321
separation of, 321
titration with normal acid, 322
titration with permanganate, 322

Calculation of results, 7

Calculations from formulæ, 70

Calorific effect of coal, 419

Calorimeter, 419

Calx, 345

Carbon, 414
gravimetric determination, 416
in iron or steel, 423

Carbonates, 424

Carbonic acid in the air of mines, 428

Caustic potash = potassium hydroxide, 65

Caustic soda = sodium hydroxide, 66

Cerium, 318

Chalybite, iron in, 243

Charcoal, 21, 94

Check assays for gold, 154
for silver, 104, 113

Chlorine and chlorides, 359

Chromium, 307
gravimetric assay, 309
in chrome iron ore, 308
volumetric assay, 309

Clays, examination of, 316

Coals, 418

Cobalt, 259
detection of, 259
dry assay for, 251
gravimetric determination, 260
in hardhead, 288
separation from nickel, 442, 254, 258

Coke, 25

Common salt, examination of, 336

Concentrates, assay for gold of, 140

Colorimetric assays, 44

Copper, 175

Copper, bismuth in, 208
colorimetric assay for, 190, 203
commercial, arsenic in, 208, 388
commercial, copper in, 193
commercial, examination of, 205
cyanide assay for, 194
dry assay of, 176
dry assay, loss of, in, 176
electrolytic assay for, 190, 203
gold in, 206
iodide assay for, 199
iron in, 209, 249
lead in, 206
separation of, 183
silver in, 205
sulphur in, 207

Copper ores, solution of, 183
valuation of, 181

Copper pyrites, copper in, 179, 188, 198, 202
sulphur in, 376

Culm, 22

Cupel, 23, 142

Cupellation, loss, corrections for, 103
loss in gold, 145
loss in silver, 101
of gold lead alloys, 182
of silver lead alloys, 98, 110
temperature of, 143

Cyanicides, 169

Cyanide assay for copper, 194
for nickel, 255
for tin, 278

Cyanides, alkalinity of, 167
assay of, 167
commercial, 160
double, 161
gold-dissolving power, 162
prussic acid, 162
volumetric determination of, 163, 165

Cyanide liquors, alkalinity of, 167
assay of, 164, 165
assay of, for gold, 140
assay of, for zinc, &c., 169


Daniell cells, 185

Didymium, 319

Dollars to the ton, 9

Dry assays, 16

Drying, 5, 33


Earths, 314
the alkaline, 320

Electrodes, 187

Electrolysis for copper, 184
for nickel, 254

Equations, 69

Erbia, 319


Ferrous and ferric salts, 231

Filtration, 31

Finishing point, 42

Flasks, graduated, 49

Flatting, 149

Fluorine and fluorides, 363

Fluxes, 16, 93, 136, 138, 140

Formulæ, 68

Furnaces, 25


Galena, lead in, 217, 218

Gangue, 405
iron in the, 244

Gas-measuring apparatus, 52

Gases, measurement of, 44

Gay-Lussac's assay for silver, 119
assay for silver modified, 123

German silver, copper in, 194
nickel in, 255, 259

Gold, 126
amalgamation of, 126
in cyanide liquor, 140
loss of, in cupellation, 145
loss of, in parting, 154
preparation of, 63
silver in, 157
silver in, after parting, 154
test for, 126

Gold-lead alloys, cupellation of, 142
sampling of, 158

Gold ores assay with cyanide solutions, 141
calcination of, 139
concentrates, 140
fluxing, 136, 138, 140
sampling of, 127
size of assay charges, 127
tailings, 140

Gold-parting, 150
platinum in, 145, 154, 170, 171

Gold-zinc slimes, 142

Graduated vessels, 49

Gravimetric methods, 15, 27


Halogens, 358

Hardhead, 287
an analysis of, 289

Hot plate, 30

Hydrogen, preparation of, 62
reduction by, 280

Hydrometer, 77


Ignition, 32
in hydrogen, 280

Indicators, 42

Inquartation, 146

Iodine and iodides, 362

Iridium, 171

Iron, 231
bichromate assay for, 237, 243,
carbon in, 423
colorimetric assay for, 247
ferrous and ferric, 231
gravimetric determination, 233
permanganate assay for, 236, 238
phosphorus in, 399
reduction of ferric solutions, 235, 241
separation of, 232
stannous chloride assay for, 244
volumetric assays for, 234

Iron ores, iron in, 244, 247
phosphates in, 399


Laboratory books, 9

Lanthanum, 319

Lawrence Smith's method for alkalies, 333, 412

Lead, 211
colorimetric assay for, 218
detection of, 211
dry assay for, 211
gravimetric determination  of, 213
in commercial copper, 206
in commercial zinc, 214
in galena, 217, 218
separation of, 211, 213
volumetric  determination of, 214

Litharge, use of, in dry assays, 20, 93

Lithium, 338

Lime, 320
milk of, 321
volumetric assays for, 322

Limestone, examination of, 329
lime in, 324

Limewater, 321

Loths, 9


Magnesia, magnesium, 328
mixture, preparation of, 64

Manganese, 298
colorimetric assay, 306
detection of, 299
gravimetric  determination  of, 300
separation of, 299
volumetric determination of, 300

Manganese peroxide, ferrous sulphate assay for, 301
iodine assay for, 302
= manganese dioxide, 298

Manganese ore, copper in, 204
manganese in, 300
peroxide in, 302

Matte, 18

Measuring, 49
flasks, 49
gases, 44, 52
gold buttons, 133, 440,
liquids, 49
silver buttons, 106

Mechanical methods, 16

Mercury, 171
dry assay, 172
wet assay, 173

Metallic particles in ores, gold, 129
particles in ores, silver, 108
particles, tin, 278, 287

Micrometer, 133

Microscope, measuring with the, 440, 133

Mispickel, arsenic in, 125, 392
sulphur in, 376

Moisture, 7, 350

Molybdate separation for phosphates, 395
solution, preparation of, 60

Molybdenum, 311

Muffle, 25


Nessler's solution, 342

Nickel, 251
dry assay for, 251
electrolytic assay, 254
gravimetric determination of, 254
in German silver, 255, 259
separation from cobalt, 254, 258, 442
separation from iron, 258
separation from manganese, 258
separation of, 253
volumetric assay, 255

Niobium, 297

Nitre, 22
use of, in dry assays, 95

Nitrogen and nitrates, 400

Nitrometer, 403

Normal acid, normal solutions, 323


Ores, determining water in, 5, 351
drying, 5
powdering, 4, 109, 130, 448
quantities of, for an assay, 11, 27, 127
sampling, 1, 127, 444
with metallic particles, 3, 108, 129

Osmiridium, 171

Osmium, 171

Ounces to the ton, long, 107
to the ton, short, 132

Oxidation, 345

Oxides, 345
determination of oxygen in, 346

Oxidising agents, 22, 95, 345
effect of nitre, 95
effect of nitric acid, 56

Oxygen, 344
equivalent, 358
in natural waters, 344, 356
in ores, 348


Palladium, 171

Parting, 150
acids, 150
in flasks, 151
in glazed crucibles, 153
in special apparatus, 156
in test tubes, 152

Phosphate, assay of apatite for, 399
assay of iron ore for, 399

Phosphates, gravimetric assay, 396
volumetric assay, 397

Phosphorus and phosphates, 394
in iron, 399

Pipette, 50, 120

Platinum, 170