INDEX. 



1271 



Page. 

 NepheUte, occurrence of 293 



sources and modes of formation of 266, 



267,292,371,386,408 

 Nephelite and halite, alterations and alteration 



products of 388,400 



Nephelite and quartz, alterations and alteration 



products of 388,406 



Nepheline-syenite, weathered formsof. 528-529 



Nernst, "Walter, on chemical changes produced by 



mechanical action 49 



on chemical reactions 87,88,89,90 



on chemical systems, homogeneous and hetero- 

 geneous , 90-91 



on diffusion of substances in solution _ 82, 83 



on electrolytic dissociation as a measure of re- 

 action capacities of substances 94 



on freezing and crystallization, identical char- 

 acter of 113 



on freezing point of solutions, lowering of by 



crystallization of contained materials 116 



on heat effects connected with chemical action. 81, 



105,106,107 



on molecular attraction in gases 660 



on osmotic pressure 72 



on precipitation by reactions between solutions 



and solids 1*. 120 



on precipitation, la ws of _ 118 



on pressure, effect of, on chemical reactions 100 



on pressure, relations of, to solubility 77, 101 



on proportion of volume of liquids occupied by 



their molecules 365 



on separation of salts into their ions 66 



on solubility, increase of, by increase of temper- 

 ature 79 



Nevada, lake deposits in 553 



Nevada City, Cal., gold veins of, constant tenor 



of 1137 



New Caledonia, nickel ore of 1131 



Newell, F. H., on proportion of run-off to rainfall.. 414 



Newman, George, on number of bacteria in soil 455 



New Mexico, copper deposits of 1056 



New South Wales, gold deposits of 1098-1099 



Newtonite, chemical and physical constants of 199 



sources and mode of formation of 253, 254, 371, 389 



New Zealand, magnetite beach sands of _ 1039 



Nicaragua, depth of disintegration of rocks in 531 



Nickel in earth's crust 936,1002 



Nickel ores, formation of 1046-1048 



Nickel silicate, occurrence of 1131 



Nickel sulphides, formation of ores of __ 1046-1048 



Nicolson, J. T., and Adams, F. D., on deformation 



of calcite crystals 675 



on deformation of rocks under pressure. . . 49, 670, 681, 

 696, 747, 772, 809, 811, 812, 814, 815, 816, 1012 



on mobility of calcite ._ 754 



Niles, "W. H., on strain in rocks 598 



Niter family of rocks, deposits composing ' 787 



Nitrates, occurrence and origin of 542-543, 980 



Nitrogen in atmosphere _- 944 



in earth's crust 980 



in ocean 936 



occurrence of 980 



oxidation of, consumption of oxygen of air by._ 954 



methods and products of 465-466 



sources of, for plants 452 



Nonfragmental rocks, classification of 784-853 



Page. 



Norites, nickelif erous, deposits of 1046-1047 



Noselite, alterations and alteration products of _ 298-299, 



374,388,399 



occurrence of... 297-298 



chemical and physical constants of 199, 295 



Novaculite, character of 865 



Nova Scotia, gold ores of 1213 



O. 



Ocoee series, metamorphism in, variations of 919,920 



Octahedrite, alterations and alteration product 



of 230-231,374,388 



chemical and physical constants of 199, 230 



occurrence of 230 



sources and modes of formation of _ _ 227, 228, 



230-231, 355, 371, 385, 386, 393, 396, 405 



Ocean, carbon dioxide in 967 



chemical composition of 944 



limestone formations deposited in 1 793-795 



salts in _. 942,943,944 



source of water of 953-954 



Oligoclase, character, occurrence, formation, and 



alterations of _ 259-265 



See also Andesine. 

 Olivine, alteration of, to serpentine, magnetite, and 



quartz, volume change incident to. ._ 633 



alterations and alteration products of 308-311, 



354, 366, 374, 388, 399, 404, 405 



chemical and physical constants of _ _ _ _ 199, 308 



occurrence of 308,367 



sources and modes of formation of 308, 367, 380, 386 



Olivine and anorthite, alterations and alteration 



products of 388,408 



Olivine and quartz, alterations and alteration prod- 

 ucts of... 388,406 



Olivine, calcite, and quartz, alterations and altera- 

 tion products of 388,407 



Omphacite, alterations and alteration products 



^ of 274 



Opal, alterations and alteration products of 221-222, 



388,389,400 



chemical and physical constants of _ 199, 221 



occurrence of , _ 221 



sources and modes of formation of 221, 



309,349,371,391,540 

 Openings in rocks, character, distribution, forms, 



and sizes of _ 129-136, 



143-146, 155, 618, 658, 1201, 1202 



filling of _ 564-565 



flow and work of water in 136-143, 154-155 



second concentration of ores favored by 1177-1179 



Ore deposits, classification of 1005,1232 



contiguous, difference in mineral content of. 1202-1203 



derivation of, from igneous rocks 1030, 1034 



from sedimentary rocks __ 1033,1036 



genetic classification of, table showing. 1232 



igneous, enumeration of _ _ 1233 



metamoi-phic, enumeration of __ 1233 



openings occupied by, character of 1078,1201,1202 



position of, as affected by topography _ 1217-1221 



present formation of _ 1233 



relations of metamorphism to 1004-1332 



rich upper belts of 1182-1193 



sedimentary, enumeration of 1333 



superficial alteration of _ 1190 



