INDEX. 



PAGE 



Amphibole 42 



Andrews 31 



Apatite 49 



Aragonite 37 



Argentite 21 



Asphalt 52 



Augite 4 i 



Azurite 38 



Bauerman 33 



Biotite 46, 47 



Bridgeport 1 1 



Bunsen 22 



Calcite 34 



Carbonates 34 



Chert. 29 



Conditions favoring study of Cook 



Co. minerals 15 



Copper 20 



Corundum 31 



Cuprite 30 



Dana 16, 22, 30, 33, 41 



Diamond 17 



Dikes ii 



Dolomite 36 



Drainage Canal n, 19, 27 



Economical Geol. of Illinois 36 



Elements 17 



Emigrant minerals 12 



Evanston 12,15,26,31, 52 



Fahlbaader 26 



Feldspars 38 



Galena 21 



Garnet : . . . 44 



Gas 51 



Gold 19 



Graphite 17 



Groth 33 



Gypsum 50 



Haloids 27 



Hematite 31 



Hintze 41, 42 



Hobbs 17 



Hornblende 43 



Hudson River Shale n, 55 



Hunt 52 



Hydrocarbon compounds 51 



Hypersthene 42 



Ilmenite 31 



Interest in the subject 9 



Kaolinite 48 



Klochmann 33 



Lacroix 22, 23 



Leverett n, 12 



Localities 15 



Magnesian Limestone "... n 



Magnetite 32 



Malachite 37 



Mallard 41 



Maltha.... 52 



PAGE 



Marcasite 24 



M arcy 31 



Melanterite 51 



Metarnorphic phenomena 12 



Methods of estimating quantity of 



minerals 12 



Methods of collecting minerals.. 15 



Mica 46 



Microcline 40 



Microperthite 40 



Muscovite 46 



Natural Gas 51 



Naumann 22, 33 



Niagara formation 1 1, 12 



Ordovician 1 1 



Organic acids . .. 51 



Orton 52 



Oxides 27 



Oxygen Salts 34 



Peat 53 



Petroleum 52 



Phlogopite 46 



Phosphates 49 



Plagioclase 41 



Pyrite 23 



Pyroxene 42 



Quartz 27 



" amount of 12 



" impurities in 29 



Relation of Cook Co. Mineralogy 



to the science of Mineralogy. . . 9 

 Result of recrystallizing materials 



composing mud 9 



Rocks of the region 1 1, 12 



Ruskin 9 



Rutile 33 



Serpentine 48 



Siderite 37 



Silicates 38 



Silicon 13, 20, 29 



Solubilitv of Minerals 12 



Source of Minerals 12 



Sphalerite . . 22 



Species to be expected 1 1 



Stony Island 9, n 



St. Peter Sandstone , . . . n 



Sulphates 50 



Sulphides 20 



Sulpho-salts 27 



Sulphur 17 



Szabo 41 



Talc 48 



Tourmaline 45 



Trenton Limestone 11 



Tschermak 30, 33, 40 



Vermiculites 48 



Wallerant 33 



Willow Springs 27 



