GENERAL INDEX. 



419 



Page. 

 Ore bodies, likely to bo foiiud iu the bangiug wall, vun 



Kicbthofen on 19 



deposits, magnetic effects of 309,365 



deposition of 285 



distribution of 39IJ 



found ou the west laee of the diabase 282 



influence of tbe rocks on the 285 



minerals of the Comstock 270, 385 



near the surface on tbe Union abaft section 280 



occurrence of, on the Comstock 218 



precipitation of, from solution 226 



probabilities of finding at great depths 288 



probable cause of fluctuations in the tenor of tbe 273 



relation of tbe, to tbe rocks 218, 220 



small amount of, in sight during examination 266 



source of, relations of decomposition to 222 



source of, von Richthofen on 18 



tenor of 273 



Ores, analyses of 153 



earthy cliaracter of, at Eureka 364 



electrical properties of 3U, 366 



how dissolved 226 



of diflerent grades, time relations of 221 



of the Lode, von Richthofen on 17 



uniform character of, von Richthofen on 22 



yield of 6 



yield of, von Kicbthofen on 18 



Otsbiaton sbaft (D. 3), diabase in the 198 



Outer liquid 325 



Overman, assay of diabase from tbe 155 



assay of porpby ritic diorite from the 154 



earlier diabase in the 198 



later diabase in the 199 



partial cross-section through the 279 



quartz-porphyry of the 47, 110, 196 



Plagioclase with zonal structure in eruptive diorite 37 



zonal structure of. (^ee illustrations.) 



Popmlation of Virginia, Gold Hill, and Silver City 4 



Potential, continuity in variation of, with distance. . .354, 361 



difference of, between terminals 362 



Precipitation accelerated by evaporation 227 



conditions affecting 226, 396 



Product, bullion, from tailings 11 



of the Comstock Lode, by mines, table. 10 



of tbe Lode, Lord ou 7 



Propylite 81,375 



{See illustrations.) 



analysis of table following page 151 



and andesite, Zirkel on 27 



association with silver ores, von Kicbthofen on 13 



causes leading to its detemiination 88 



European 90 



from other districts tba.i Washoe 89 



from Utah, descriptions of slides of 143 



King on its relations to andesite 24 



typical localities of 86 



von Richthofen on 13 



von Richthofeu's, based largely on Washoe oc- 

 currences* 33 



Zirkel's diagnostic points based largely on 



Washoe occurrences 33 



Propylitesof theFortieth Parallel, description of slides of 135 



Prospecting, rules applicable to 186 



Pumpelly, R.,ou rock-weathering 371 



Py ri t e, formation of 75, 210 



heal of the Lode attributed to the oxidation of.. 231 



Page. 



Pyrite, relations of, to ore 222 



relations to the ferro-maguesian silicates 210 



Quarry 1,0U0 feet west of the Yellow Jackettid&t shaft 



(C. 4), earlier hornblende andesite of the 119 



500 feet N. of N. Twin Peak (C. 4), andesite of. ... 34 

 1,500 feet SW. of Justice (C. 5), assay of (piartz- 



porphyry from 155 



2,000 feet E. of Occidental Mill {E. 5), later born- 



blende-audesite of 34, 67, 69, 131, 407 



2,000 feet NE. of Sutro sbaft III., later born- 



blende-andesite from 34, 66, 69, 130, 151, 407 



2,000 feet NE. of Sutro sbaft HI. (E. 4), assay of 



later bornblende-andesite from 155 



near the Sierra Nevada (D. 2), younger horn- 



blendeandesile of 70 



near tbe Utah (D. 2), assay of later bornblende- 

 andesite from 155 



near the Utah, later hornblende-andeaite from. . . 34, 

 131, 407 



Quartz and ore, origin of 221 



crushed, von Richthofen on 16 



deposited in openings 273 



difference between east and west, von Richtboftm 



on IC 



gold, on Cedar Hill, von Richthofen on 16 



bow dissolved 22C 



in earlier bornblende-andesite 121 



occurrence of solid and of crushed 270 



precipitation of, from solution 226 



secondary, characteristics of 85 



sugar, Church on 30 



von Richthofen on - 17 



Quartz-porphyry 373 



(See illustrations.) 



analysis of table following page 151 



assays of 155 



•lecomposition of , 79 



description of slides of 108 



■ feldspars of 110,406 



ftlsitic variety of 47 



lithological description of 45 



occurrence aud age of 19G 



separation of, by Thoulet's method 110 



von Richthofen on the 13 



Quartz -prop y lite. King on 13 



Rath, G. vom, on propy lite 90 



Ravines produced by faulting 177 



Reade, F., computations by 245 



Red Jacket, assay of granite from the 154 



granite of the 33, 34, 91, 190, 405 



Reich, F., experiments on theelectricity of metalliferous 



veins 309,312,313,317,365 



Resistance of circuits 330, 334, 338. 345, 351 



of layers of rock between consecutive similar 



surfaces 359 



of rocks decreases with porosity and moist- 

 ure 341,348,351 



specific, of rock in place 359 



Results for earth-potential from different methods 355 



Reuleaus, F.. on friction 158 



Richmond mine chambers, Nos. 7, 10, 11, 12, 13, 14, 15, 16, 



etc.. 



332 



Nos. 14 and 15 connected elec- 

 trically 350 



disposition of points, 500-foot level 335 



disposition of points, 400-foot level 338 



