1266 



INDEX. 



Page. 

 Lafar, Franz, on action of bacteria in metamor- 



phism ... 467,472,826 



Lake Superior region , changes in rocks of 35 



copper deposits of 1032, 1103-1104, 1204-1205, 1231 



iron ore depositsof . 560-561, 608, 1193-1193, 1218-1219, 1231 

 Lake vein, San Juan district, Colorado, influence of 



wall rock on 1230 



Lakes, concentration of soluble materials in 551-554 



tufa deposits in 793 



Lancaster Gap, Pa., diminution of richness of sul- 

 phurets with depth in nickel mines 



of 1186 



Landolt, Hans, and Bornstein, Richard, on viscosity 



of water at different temperatures.. 141 

 Last Dollar mine, Cripple Creek mining district, 

 ore shoots near intersecting frac- 

 tures in 1227 



Lateral secretion, importance of, in first concentra- 

 tion of ore deposits 1078 



Latitudes, high, disintegration of rocks in 498-499 



low, decomposition of rocks in _ 502 



Laumontite, alterations and alteration products 



of 334,373,386,396,400,401 



chemical and physical constants of 198,331 



occurrence of 331-333 



sources and modes of formation of 262, 376, 397 



Launay, L. de, on contact metamorphic origin of 



ores 1050 



on genesis of ore deposits 1190 



on Witwatersrand banket 1041-1042 



Lavas, openings or pore spaces in... 127, 134 



Lawson, A. C. , on contact metamorphism 652 



on Franciscan cherts _ 852 



on fusion of sedimentary rocks 734 



on peripheral structure 716 



Lead and zinc deposits of Mississippi Valley, forma- 

 tion of, conditions of.... 1083-1084, 1208-1209 



secondary enrichment of _ 1186 



topography as affecting 1220 



Lead and zinc district of Mississippi Valley, caves in. 565 



ground-water level, changes in 429 



silicate of zinc formed in 480 



Lead carbonate, production of, equation showing 



reaction for 1147 



Lead ores, associated minerals of 1144-1145 



Lead sulphates, reactions involving 1149-1150 



solubility of __ 1075 



Lead sulphide, occurrence and genesis of 1148-1151, 



1154-1158 

 Leadville, Colo., secondary enrichment of ores at- - 1186 



silver ores at 1168-1169 



Lead, zinc, and iron compounds, association of. 1144-1158 



Le Chatelier, Henri, on chemical reactions 89 



on relation of pressure to solidification 102 



Le Conte, Joseph, on boric acid at Sulphur Bank, 



Cal 1107 



on formation of magnetite by oxidation of iron 



sulphide 846 



on ore deposition at Sulphur Bank, Cal 1110, 1176 



on ore deposits, genesis of 1031, 1118, 1128, 1190 



on silication of carbonates 667 



Lecoq, Henri, on carbon dioxide exhaled by mineral 



springs of Auvergne 678,971 



Lehmann, Johannes, on pegmatites.. 722,723 



Leith, C. K., acknowledgments to 29 



figures cited from 704, 810, 836, 888, 902 



on cleavage 756,757,760,778,903 



Page. 



Leith, C. K., on greenalite 1 284,827 



on hydration, temperature of, as determined by 



on igneous intrusions as an agency in produc- 

 ing iron-silicate rocks 840 



on iron-ore depositsof Lake Superior region 1219 



on quartzite-schists, diameters of particles of .. 869 



on water content of hematite 843 



Leith, C. K-, and Van Hise, C. R., on agency of 

 igneous intrusions in producing iron- 

 silicate rocks. 840 



Lemberg, J., dissolution of zeolites in water by 112 



on artificial transformation of leucite to analcite . 267 

 Lenher, Victor, on gold, salts, and soluble fluorides, 



reactions between _. 1123 



on insolubility of gold in hydrofluoric acid 1122 



on precipitation of silver by tellurous salts 1125 



on solubility of gold 1090 



Lenher, Victor, and Hall, R. D., on precipitation 



of gold .... 1091-1092, 1096-1097, 1098 



on telluride of silver, artificial production of . . . 1124 



on tellurides, formation of 1120-1121, 1124 



Lepidomelane, source of 370,378 



Lepsius, C. G. R., on Attic marbles, structureof ... 815 



on oxygen contained in ground waters 605 



on recrystallization _. 706-707 



Lesley, J. P., and d'Invilliers, E. V., on Cornwall 



iron-ore mines _ 1198 



Letts, E. A., and Blake, R. F., on bicarbonates in 



zone of weathering _ 536 



on carbon dioxide in atmosphere 962 



on carbon dioxide in soils 475 



on oxygen in soils 470 



Leucite, alterations and alteration products of .. 266-267, 

 373,386,402,408 



chemical and physical constants of 198 , 266 



occurrence of 266 



sources and modes of formation of 266 



Leucite, albite, and anorthite, alterations and alter- 

 ation products of 375, 376, 386, 397 



Level lands, decomposition of rocks in 602-503 



Leverett, Frank, on artesian waters, flow of. 142,587 



on underground water 578 



Levy, A. Michel, on pegmatization 726 



Lewy, B., and Boussingault, J. B., on sodium dioxide 



in soils 474 



Lichens, disintegrating effects of, on rocks .444-445 



Life, work of, in metamorphism .. 503-504, 505-506, 557-558 

 See also Plants; Animals; Vegetation. 



Light and heat, metamorphic effect of 51-56 



Lime, in earths crust 934,937,938 



in grain and straw 454 



in salts of sea water 942 



Limestone, analyses of __ 938 



cherty, features and origin of 



weathered forms of 



dolomitization of 



volume changes involved in 209 



formation of, mode of 558, 791-795, 991-992 



formation of Wallastonite from, chemical reac- 

 tion involved in _ 822 



losses in, by production of clay 523-524 



by weathering 513,523,524 



material of, source of 791 



metallic ores associated with 1086-1087 



metamorphism of 795-797,822 



photomicrogra ph of _ 814 



