The Reason Why. Robert Kemp Philp

why are valleys and low places chiefly subject to it, 353

       Dew, what bodies receive little of it, 355

       Dew, what bodies receive most of it, 354

       Dew, at what period of the night is it chiefly formed, 356

       Dew, why is it chiefly formed at that period, 357

       Dew, in what parts of the world is the greatest quantity formed, 358

       Dew, in what parts of the world is the least quantity formed, 359

       Dew, why is it seldom formed at sea, 360

       Dew, why is it, when heavy, regarded as a precursor of rain, 361

       Dew, what is honey-dew, 364

       Dew, why does it lie on the exposed sides of screens of plants, 401

       Dew, why does it rest upon the upper surfaces of leaves, 402

       Dews, why are cultivated lands more subject to them than those that are uncultivated, 403

       LESSON XXII.

       Dew, why does the gravel-walk receive less dew than the grass, 404

       Dew, why does little of it form at the base of hedges, walls, and trees, 406

       Dews, why do morning dews and mists usually come together, 407

       Dew, what effect have winds upon its formation, 408

       Dew, why does it form in round drops upon leaves, 794

       Diamond, what causes the brilliant colours of the, 501

       Digestion, why does food flow more freely to the stomach during, 879

       Digestion, why does excess in eating impair, 880

       Digestion, what changes occur to food in the stomach, 881

       Digestion, what causes bilious attacks, 882

       Digestion, how is the nutritious matter taken from that which is innutritious, 885

       Digestion, what becomes of the nutrition when it enters into the circulation, 886

       Dish-covers, why should they be plain in form, and have bright surfaces, 203

       Dogs, geographical distribution of, 1333

       Dream, why do we, 1020

       Drowsiness, why is it felt in crowded rooms, 22

       LESSON XXIII.

       Ducks and geese, why do they dash water over their backs on the approach of rain, 1105

       Ducks and geese, why have they square-pointed bills, 1044

       Dyes, vegetable, what are they, 1259

       Ear, why is it spread out externally, 984

       Ears, why do hairs grow across them, 986

       Ear-wig, why is it so called, 986

       Ears, why is wax secreted in the, 987

       Ears, why do singing noises occur in the, 988

       Ears, why do people become deaf, 989

       Ears, why do people accustomed to loud noises feel no inconvenience from them, 990

       Ears of animals of prey, why do they bend forward, 1063

       Ears of animals of flight, why do they bend backward, 1064

       Earth, why is it warmer than air during sunshine, 398

       Earth, why is it colder than air after sunset, 399

       LESSON XXIV.

       Earth, how can man weigh the, 784

       Earth, what is the weight of the, 788

       Earth-worms, why have they no feet, 1085

       Echoes, why do some occur immediately after the sounds, 742

       Echoes, why do some occur at a considerable interval after the sound, 743

       Echoes, why do some change the tone and quantity of sounds, 744

       Echoes, why are there sometimes several to one sound, 745

       Echoes, are they caused only by distant objects, 746

       Echoes, what are they, 741

       Electricity, what is it, 561

       Electricity, why is it so called, 562

       Electric fluid, why is it so called, 566

       Electrics, what substances are, 567

       Electricity, what is positive, 568

       Electricity, what is negative, 569

       Electricity, what is vitreous, 570

       Electricity, what is resinous, 570

       Electrical phenomena, what produces them, 571

       Electricity, how does its equilibrium become disturbed, 572

       Electricity, how does it seek to regain its equilibrium, 573

       Electricity, what substances are conductors, 574

       Electricity, what substances are non-conductors, 575

       Electricity, what substances are insulators, 576

       LESSON XXV.

       Electricity, what is the effect when a current of electricity meets with an insulator, 577

       Electric sparks, what is the cause of, 578

       Electricity, why does lightning attend it, 584

       Electricity, why does it affect the shape of clouds, 613

       Electric storms, why are they more frequent in hot than in cold weather, 624

       Electric storms, why do they frequently occur after dry weather, 625

       Electric storms, why do they purify the air, 629

       Electricity, what is Voltaic, 636

       Electrical attraction, what is it, 778

       Elementary body, what is meant by, 19

       Element, what is the most abundant in nature, 756

       Elephant, why has it a short unbending neck, 1076

       Elephant, why has it a trunk, 1077

       Elephants' hind legs, why do they bend forward, 1078

       Etna, what are the botanical regions of Mount, 1240

       Endogenous stems, what are they, 1280

       LESSON XXVI.

       Endogenous stems, why do they abound in tropical climates, 1281

       Endogenous stems, why have they no bark, 1282

       Endogenous stems, why do they grow to a great height, 1283

       Exogenous stems, what are they, 1279

       Exercise, why does it promote health, 1016

       Exercise, why does it make us feel warm, 839

       Explosions of gas, what is the best method of preventing, 65