" conductors 37 Thunder-storms 38 Rainbow 39 Air, the source of nourishment 40 " carbonic acid of 41 " the source of coal 41 THE EARTH. Elements, list of 45 Earths, list of 46 Silica 46 Alumina, Lime, Potassa 47 Soda 48 The Earth, surface of 49 Strata 49 " diagram of 50 " various positions of 51 Faults or dykes 52 Granite 53 Gneiss 54 Strata, primary 54 Earth, primary period of 55 Stalagmites, formation of 58 Terebratula 58 Secondary system 59 Trilobites 59 Mountains, formation of 61 Earth, section of part of 62 Volcanoes, formation of 62 Coral polypi 64 Encrinites 65 Mountain limestone 65 Basalt 66 Tree-ferns, Pines, &c. 66 Air, purification of 67 Coal, formation of 67 " consumption of 68 Coal shales, ferns found in 69 Earth's surface, alterations of 69 Labyrinthodon 70 Red Sandstone, impressions in 70 Saliferous system 71 Lias and oolite 71 Ammonites and pentacrinites 72 Cretaceous system (chalk) 72 Ichthyosaurus and plesiosaurus 73 Coprolites 74 Chalk, organic remains in 75 " flints of 76 Strata, tertiary 78 Alluvium and diluvium 78 " quadrupeds of 78 Dinotherium 79 Mammoth, &c. 80 Irish elk, paleotherium 81 Boulder formation 82 Fossil leaves 83 Man, as yet unformed 83 " his remains only in upper strata 83 Sculptures from Nineveh 84 Earth's surface, always changing 84 " as it is 86 Earth, temperature of 86 Europe 87 Asia and Africa 88 America 88 Australia 89 The Great Desert 89 Oceans 90 THE WATERS. The waters 91 Sea-weeds, &c. 92 The horizon 93 The cliffs 93 The waters, their divisions 93 The sea, always the same level 94 " waters poured into it 94 Rain, how produced 95 Rivers and streams 96 " causes of their overflowing 97 Lakes 97 Chalk downs, &c., once a sea bottom 98 Sea, its encroachments 98 " waves of 99 " Sargasso 101