242 
INDEX 
Norfolk, Virginia, Dismal Swamp 
in, 183 
Notes of music, 142 
OIL, its heat and light, 47 
Oils in coal, 188, 189 
in plants, 154, 159, 189 
Orange-cells, 154 
Orchis mascula, its structure, 231 
Otoliths, or ear-stones, 139 
Oxygen in air, 53 
Ovules of plants, 163 
PAN-PIPES, 145 
Paper, pressure of air on square 
inch of, 60 
Paraffin from coal, 189 
Peat, formation of, 184 
Petrifactions, 115 
Pelargoniums, 222 
Pennine Hills causing rainfall, 8 1 
Peter Bell on a primrose, 7 
Phosphoric acid, 53 
Phosphorus burning in air, 53 
Photography, 47 
Pimpernel, closing for rain, 217 
Plant-cells, 155 
Plant, food of a, 156 
water rising in a, 157 
Plants absorbing rain, 81 
annual and perennial, 161 
contrivances for protection in, 
219 
effect of light on, 45 
fertilized by wind, 215 
in a coal-mine, 1 74 
light and heat imprisoned in, 
169 
remains in coal-nodules, 177 
Poker, sound of a vibrating, 128 
Pollen-dust carried by bees, 215 
of flowers, 227, 229 
Pollen, gathering of, 201 
use of, 164 
Pollinia of an orchis, 23 1 
Polyps, coral, 21 
Poole's Cavern, 115 
Popgun, compressing air ia, 57 
Potash formed, 17 
Potassium in water, 16 
Pot-holes, 109 
Pressure, making coal hard, 187 
Primrose, corolla falling off, 167 
Protoplasm, 155 
green granules of, 157 
Primrose, the life of a, 150 
two forms of, 163 
Princess-bees, slaughter of, 2oS 
Prism giving coloured light, 39 
Propolis, or bee-cement, 297 
QUEEN-BEE, flight of, 202 
laying eggs, 203 
Queenstown, cliffs at, no 
RAIN, causes of, 79, 80 
fairies working in, 8 
fall of barometer before, 66 
Ravine worn by water, 107 
Reflection of light, 43 
Resonance in a jar, 145 
Rhine, amount of lirce carried by, 
1 06 
Roches moutonnees, 121 
Rock hurled by waves, 117 
ST. JOHN'S WOOD, explosion in, 
133 
St Paul's railings of Sussex iron, 
191 
, Niagara falls only half the 
height of, 109 
Salvia, bee entering the, 225 
Sap of plants, 157 
