Phthalic acid, 143

Picric acid, 136

Pitch, 81, 176

Plants, growth of, 26

Ponceaux, 151

Primary azo-dyes, 156

Primuline, 160

Propiolic acid, 128

Purpurin, 169

Pyrazole, 183

Pyridine, 87

Pyridine bases, 179

Pyrogallol, 146

Quinaldine, 182

Quinic acid, 189

Quinoline, 180

Quinoline green, 182

Quinoline red, 188

Quinoline yellow, 182

Quinones, 172

Read Holliday's lamp, 72

Rectification of hydrocarbons, 84

Resorcinol, 145

Rhodamines, 148

Roccellin, 151

Roman coal-mining, 57

Rosaniline blues, 92

Rosaniline from rosolic acid, 133

Rosolic acid, 132

Runge, kyanol, 75

Runge, phenol in tar, 131

Saccharin, 186

Saffranine, 108

Salicylic acid, 134

Salicylic aldehyde, 185

Salols, 179

Schiendl, Magdala red, 149

Scotland, shale-oil industry, 53

Sea coal, 58

Secondary azo-dyes, 156

Shale, nature of, 51

Shale-oil industry, 50

Skraup, quinoline, 181

Sodium nitrite, 119

Solar energy, 28

Soluble blue, 93

Solvent naphtha, 86

Steam-engines, 20

Stilbene azo-dyes, 137

Structure of coal, 15

Sulphanilic acid, 150

Sulphuric acid, 45

Sunlight, source of energy in coal, 30

Surgery, antiseptic, 131

Tar distilling, 77

Tar, first utilization, 69

Tar from coke-ovens, 49

Tar, quantity obtained from coal, 45

Tartrazine, 184

Tertiary coal, 12

Thalline, 182

Thermifugine, 182

Thiazines, 113

Thiodiphenylamine, 113

Thiorubin, 160

Timber pickling, 70

Tolidine, 136

Toluene from tar, 81

Torbane Hill coal, 52

Transformation of wood into coal, 31

Triassic coal, 12

Trimethylamine, 99

Trinitrophenol, 136

Triphenylmethane, 97

Tubercle bacillus, 193

Turkey red, 170

Underclay, 13

Unverdorben, crystallin, 75

Uses of coal, 16

Vanillin, 185

Vegetable deposits, recent, 13

Verguin, red from aniline, 90

Victoria blue, 106

Victoria yellow, 137

Vinasse, 99

Vincent, methyl chloride, 100

Violaniline, 121

Wasteful use of coal, 32, 203

Water, composition of, 25

Water gas, 203

Watson, Bishop, coke-oven tar, 50

Watson, Bishop, distils coal, 37

Wealden iron industry, 17

Whitaker, W., coal in S.-E. England, 60

Winsor, promotes introduction of gas