Название | The Reason Why |
---|---|
Автор произведения | Robert Kemp Philp |
Жанр | Математика |
Серия | |
Издательство | Математика |
Год выпуска | 0 |
isbn | 4064066154523 |
Otters, seals, &c., why have they web-feet, 1062
Owls, why does their screeching denote change of weather, 1111
Owls, why does their moping foretell death, 1112
Oxen, sheep, deer, &c., why do they ruminate, 1088
Oxen, and other quadrupeds, why have they a tough elastic ligament in their necks, 1138
Oxygen, why is it necessary to life, 5
Oxygen, what is its union with carbon called, 7
LESSON LIII.
Oxygen, what is it, 25
Oxygen of the air, why does it not take fire, 28
Oxygen, why do we know that it will not burn of itself, 29
Oxygen, why do we know that it is necessary to our existence, 30
Oxygen, where is it found, 31
Oxygen, why is it mixed with nitrogen in the air, 32
Oxygen of water, why does it not support fire, 307
Oxygen, in what way does man use it, 757
Ozone, what is it, 630
Ozone, why do we know that electricity produces it, 631
Ozone, what are the properties of, 632
Paleness, what is the cause of, 914
Palms, what are their characteristics, 1221
Paper held over a candle-flame, why does it become scorched, 244
Paper held below a candle-flame, why does it scarcely become warm, 245
Paper, why does it more readily ignite than wood, 294
Paper, why, if it is laid flat upon the fire, will it "char" before it ignites, 304
LESSON LIV.
Paper on a fire, why will it ignite when you send a puff of air to it, 305
Parachutes, why do they fall gradually to the ground, 834
Parrots, &c., why have they crooked bills, 1047
Parrots, why can they move their upper as well as their lower beak, 1048
Particles of matter, why do they draw near each other, 776
Particles of matter, why will they attach themselves to sealing-wax excited by friction, 779
Pea and pin, why do they rotate upon a jet of air blown through a tobacco-pipe, 845
Peg-top, why does it make less noise than a humming-top, 811
Peg-top, why does it sometimes hum, and at other times not, 812
Pelican, why has it a large pouch under its bill, 1093
Pepper, where is it produced, 1229
Perspiration, why does it cool the body, 173
Perspire, why do we, 1009
Perspiration, how is it formed, 1010
Perspiration, what is insensible, 1011
Perspiration, what is sensible, 1012
LESSON LV.
Phosphorous, why does it look luminous, 94
Phosphorous, does it ignite spontaneously when placed upon a hot surface, 314
Phosphorous, why does it ignite when sprinkled with powdered charcoal, 315
Photographic pictures, how does light produce them, 556
Photographic rooms, why are they glazed with blue glass, 557
Pith-tumblers, why do they always pitch on one end, 868
Planets, how can man weigh them, 785
Planets, how can man measure their distances, 786
Plants, do they absorb heat, 225
Plants, how do we know that they absorb heat, 226
Plants, why do screens prevent frost from killing them, 400
Plants, why, if we cut across their stems, do we see tubes arranged in parallel lines, 1159
Plants, why do some droop and turn to the earth after sunset, 1167
Plants, why are the seeds of many enclosed in rich juice or pulp, 1172
Plants, why have some tough curly tendrils, 1173
LESSON LVI.
Plants, why have peas tendrils, and beans none, 1174
Plants, why have grasses, &c., joints or knots in their stalks, 1176
Plants, what is the circulation of sap in, 1179
Plants, why does their sap ascend and descend, 1180
Plants, why do they suffer from the smoke of cities, 1188
Plants, why is it understood that some of them feel, 1141
Plants, why is it understood that some of them move, 1142
Plants, of what elementary substances are they composed, 1143
Plants, whence do they derive their elementary substances, 1144
Plants, how do they obtain carbon, 1145
Plants, how do they obtain oxygen, 1146
Plants, their decomposition of gases by day and by night, 1147
Plants, how do they obtain hydrogen, 1147
Plants, how do they obtain nitrogen, 1148
Plants, how do they apply their elements to the formation of their structures, 1149
Plants, how is their nutritive sap applied to their growth and nourishment, 1150
LESSON LVII.
Plants, why do they grow, 1154
Plants, why if we break the stem of a hyacinth do we see a glutinous fluid exude, 1155
Plants, why if we split the petal of a tulip do we see cells containing different colouring matters, 1156
Plants, why if we break a pea-shell across do we find a transparent