Liassic clays and shales, 57, 125, 132
Lime, 7, 10, 102, 159
Lime compounds, 10, 11, 38, 41, 47, 113, 115, 116, 121, 127, 139, 142, 143, 145, 155, 157, 162, 164
Limestone, 10, 11, 52, 59, 61, 62, 88, 102, 117, 127, 132, 139
Lime troubles, 11
Loam, 57, 67, 88
London clay, 62, 63, 125
Ludwig's chart, 35
Magnesium compounds, 7, 10, 11, 41, 47, 113, 115, 116, 121, 133, 155
Malm-bricks, 11
Malms, 10, 68
Marcasite, 10, 13
Marine clays, 61, 93
Marls, 10, 51, 54, 55, 57, 67, 68, 88, 130, 132, 166
Mechanical analysis, 137
Medway mud, 132
Melting point, 31, 32
Mica, 7, 8, 76, 104, 105, 116, 140, 141, 144, 160
Microscopical examination, 18, 105, 143, 158
Millstone grit, 54, 55, 117
Mineral nature of clay, 3
Minerals resembling clay, 158
Mining ball clay, 111
Modelling clays, 130
Moisture, 15, 144
Molecular attraction, 22
Molecular constitution of clay, 21, 156
Montmorillonite, 134
Mundic, 13
Muscovite, 105
Newtonite, 158
Nodules, 121, 127
Non-plastic material, 43, 121, 151
Non-refractory clays, 166
Occurrence of clays, 48, 116
Ocean currents, action of, 89
Odour of clay, 19
Oil, bleaching, 134
Oil shales, 61, 122, 123
Oolite clays, 59, 134
Ooze, 95, 99
Organic matter, 19, 119
Origins of clays, 48, 71, 160, 165
Oxford clay, 59, 95, 164
Oxides in clay, 10, 82
Paint, clays for, 109
Paper, clays for, 109
Particles, nature of, 18, 31, 106, 107, 150
Paving brick clays, 166
Pelagic ooze, 95, 99
Pelinite, 83, 148, 149
Permian clays and shales, 57, 112, 124
Pholerite, 117
Physical characters of clays, 17
Picking clay, 121
Pipe clays, 64, 65, 82, 109, 166
Plant-extracts in clays, 26
Plastic clays, 2, 43, 65, 67, 82, 88, 102, 112, 123, 147, 148, 160
Plasticity, 20-27, 41, 46, 97, 98, 99, 108, 109, 112, 117, 123, 125, 127, 151, 160
Pleistocene clays, 67
Pockets, 65, 85, 101, 116, 166
Porcelain, 37, 46, 73, 109, 110, 125, 129
Pores in clay, 30, 114
Porosity, 30, 39, 121, 131, 155
Portland cement, 131
Potash compounds, 7, 10, 113, 115, 116, 121, 157,
see Alkalies
Pottery clays, 1, 5, 31, 46, 66, 100, 101, 104, 110, 112, 114, 125, 129, 162, 166
Precambrian clays, 51
Precipitated clays, 97, 152
Primary clays, 70, 71, 84, 165
Proximate analysis, 16, 144
Purbeck clays, 59
Pure clays, 5, 6, 7, 142, 155, 156
Purification of clay, 7, 66, 78, 104, 113, 128, 140
Pyrites, 10, 13, 44, 56, 57, 119, 124, 128
Quartz, 8, 104, 110, 118, 140, 141, 143
Rain, 44, 85, 86
Rational analysis, 141
Reading clays, 63
Recent clays, 67
Rectorite, 158
Re-deposited clays, 98
Red bricks, 12
Red burning clays, 141, 142, 166
Red iron oxide, 12
Red ware, 113
Reduction in volume, 30
Refractoriness, 34, 119, 120, 123, 155
Refractory articles, 5, 119
Refractory clays, 9, 32, 33, 35, 38, 52, 65, 82, 104, 116, 165, 166
Residual clays, 70, 84, 166
Resistance to abrasion, 119
Resistance to corrosion, 119
Resistance to crushing, 46
Resistance to cutting, 119
Resistance to temperature, see Refractoriness
Resistance to weathering, 76
Ringing sound, 110
River-deposited clays, 88
Rivers, 85, 87
Rock binds, 53
Rockingham, 113
Rock-like clays, 2
Rocks associated with clay, 48
Roman cements, 133
Roofing tiles, 57, 63, 126, 128
Sagger marls, 54
Sand, 7, 31, 41, 62, 82, 89, 100, 101, 117, 133, 138, 144
Sandstones, 53
Sandy clays, 68
Sandy loams, 88
Sandy marls, 88
Sanitary articles, 5, 113
Sawdust, 40
Scum, 10
Sea, action of, 85, 89, 99
Sea-deposited clays, 93
Secondary clays, 70, 82, 83, 166
Sedimentary rocks, 48
Sedimentation of clay, 43, 88, 90, 104
Seger cones, 33, 34
Selection of clay, 122
Selenite, 10
Separation of clays, 90, 145
Settling, 43
Sewerage pipes, 113
Shale oil, 15, 61
Shale tar, 123
Shales, 2, 5, 51, 52, 53, 57, 61, 96, 104, 122, 130, 132, 138, 151, 162, 166
Shrinkage, 11, 29, 58, 68, 102, 110, 117, 119, 121, 127, 131, 153
Sifting, 7, 138
Silica, 6, 7, 80, 154, 155, 161
Silica rock, 118
Silicates, 8, 82
Siliceous clays, 117
Sillimanite, 46, 154
Silt, 90, 91, 99, 139, 144
Silurian clays and shales, 51, 124
Sintering, 38
Size of particles, 18, 21, 31, 106, 107, 150
'Skeleton,' 115
'Skin' on ware, 131
Slag in bricks, etc.11, 13, 119, 155
Slates, 51
Slurry, 39, 43, 152
Snow, 85
Soda compounds, 7, 10, 113, 115, 116, 121, 157,
see Alkalies
Softening point, 33
Soil, see Agriculture
Solubility of clay, 151, 159
Soluble salts, 10
Sorting, 90
Sources of clays, 85
Specification of fire clays, 120
Specific gravity, 18, 106, 151
Staffordshire bricks, 13, 56
Standard clay, 4
Stone, Cornish, 110, 116
Stoneware clays, 104, 112, 113, 156, 165, 166
Stones, 7, 65, 100, 102, 128, 138, 144
Streams, 85, 86
Strength, 23, 45, 113
Sub-surface clays, 5
Sulphates in clay, 10, 12, 82
Sulphides in clay, 10, 82
Sulphuric acid, 124
Sunlight, 45
Surface clays, 2, 5, 52, 112
Suspension of clay, 43, 90, 140, 152
Swelling, 15, 102
Tannin in clay, 25, 26, 41
Telluric water, 165
Temperature, resistance to, 119, 120
Tensile strength, 23, 45
Terra-cotta clays and shales, 5, 10, 12, 31, 46, 56, 63, 91, 104, 123, 124, 129, 166
Tertiary clays, 62
Texture, 112, 130
Thermal reactions, 146, 154, 158
Tiles, 1, 5, 57, 91, 101, 129
Titanium compounds, 121
Tourmaline, 76, 104
Transportation of clays, 49, 86, 98, 99, 100
Transported clays, 70
Triassic clays, 57, 112, 130
True clay, 144, 146, 149, 150, 160
Twisted ware, 114, 129, 131
Types of clay, 82
Ultimate analysis, 16, 144
Ultra-marine, clays for, 109
Underclays, 53, 117, 118
Uses of clay, 1, 165
Valuation of clay, 103, 109, 123, 126, 162, 165
Vegetable matter, 15, 119
Veins, 85
Viscosity, 152
Verifiable clays, 113, 156, 166
Vitrification, 15, 20, 37, 112, 113, 114, 156
Vitrification range, 38, 114, 115, 116,
About This Book
This work surveys clays as natural materials, outlining their chemical and physical properties, the elusive character of plasticity, and behavior during drying and high-temperature treatment. It examines origins and modes of accumulation, offers a stratigraphic classification of clay-bearing deposits, and reviews commercially important varieties and their uses in ceramics, bricks, tiles, and terra cotta. Experimental and theoretical perspectives are combined, with discussion of applied physical chemistry concepts such as hydrolysis and ionization, alongside practical considerations for extraction and processing. Geological descriptions, laboratory observations, illustrative figures, and a concise bibliography frame current knowledge and remaining problems in the study and industrial use of clays.