Coprolites: impure varieties of phosphate of lime found in brick-earths, 51 Cornish granite, 35 Cornwall, china-clays, 35, 36, 37 Cracks formed in bricks, 52 Crayford, brick-earth at, 1 Dartmoor granite, 55 Denudation, agents of, described, 6, 7 of sea-cliffs, 22 Devon, china-clays, 35 Diatomaceous earth, 42, 91 Dinas bricks, 52, 81 Discolouration of bricks, 114, 135 Dolomite in brick-earths, 55 micro-structure of, 131 under blow-pipe, 74 Drying bricks, 94 Durability of bricks, 103 Efflorescence on bricks, 110 Electric furnace, 33 Elephants’ remains, found in brick-earth, 2, 3 Erith, brick-earth at, 1 Estuarine brick-earths, 21 Expansion of bricks and variations of temperature, 115 Felspar, 34 chemical composition of, 34 micro-structure of, 129 under blow-pipe, 73 Ferruginous matter (see Iron) Fire-bricks, Dinas, 52 earths suitable for making, 21 effect of lime in, 53 Kieselguhr for, 42, 91 strength of, 136 Fire-clays, chemical composition of, 80, 81 Newcastle-on-Tyne, 80 tests, 148 Welsh localities, 81 Fishes, fossil, 25 Flint, 39, 41 behaviour of in the kiln, 42, 43 implement: an implement, or tool, made of flint--in the sense indicated in this work an implement made by pre-historic man. implements, found in brick-earths, 3, 5 micro-structure of, 129 origin of, 41 Fluid inclusions in quartz, 41 Fluorine in clays, 59 Fluviatile brick-earths: brick-earths that have been deposited in rivers Fossil shells, carbonate of lime in, 50 shells found in brick-earths, 4 sponges, in flint, 42 Fusion of brick-earths in the kiln, 29, 31 Gault clay, 51 Glaze, micro-structure of, 119, 120 Glazing, salt, 57 Granite, Cornish, 35 Dartmoor, 35 Granites, weathering of, 36 Greece, magnesite in, 56 Green bricks, 101 Grizzly bear’s remains found in brick-earth, 2 Gypsum in brick-earths, 54 under blow-pipe, 74 Heat, bricks affected by, 117 Hippopotamus remains found in brick-earth, 2 Ilford, brick-earth at, 1 Infusorial earth, Tuscany, 92 Iron, 44 a constituent of brick-earths, 44 behaviour in the kiln, 45 bricks, Saarbrücken, 92 micro-structure of, 130 mode of occurrence in brick-earths, 45 under blow-pipe, 73, 74 vapour in the kiln, 46 pyrites, 46, 131 pyrites, behaviour in the kiln, 48 pyrites, under blow-pipe, 74 pyrites, weathering of in bricks, 48 Jurassic estuarine clays, 21 Kangaroo rats, fossil, 25 Kaolin: a hydrous silicate of alumina, derived chiefly from the decomposition of felspars Kaolin, 31 behaviour in the kiln, 32, 33 chemical composition of, 78 micro-structure, 32, 33 under blow-pipe, 73 “Kaolinised” matter, 33 Kilns, temperature in, 98 Kieselguhr: a diatomaceous earth