Circulation, why does the blood impart vitality, 891
Circulation, how do we know the blood is alive, 892
Circulation, why does the blood circulate, 893
Circulation, how is the body renewed by the blood, 894
Circulation, how does the blood return to the lungs after it has reached the extremities, 895
Circulation, why are the veins more perceptible than the arteries, 897
Circulation, why when we prick the flesh does it bleed, 893
Circulation, what becomes of the matter collected by the blood, 901
Circulation, how is the blood propelled through the arteries, 916
Circulation, why are the capillary vessels capable of receiving the quantity of blood sent through larger vessels, 917
Cleanliness, why does it promote health, 1015
Clothes on fire, why should persons throw themselves down, 252
Clothing, why do some articles feel cold, and others warm, 120
Clothing, are conductors or non-conductors the warmer, 121
Clothing, why are white and light-coloured articles cool, 218
Clothing, why are dark-coloured dresses worn in winter, and light in summer, 230
Clouds, why do we not see them ascend, 375
Clouds, why are they invisible when they rise, but become visible when they have ascended, 376
Clouds, why do they not descend to the earth, 377
Clouds, at what altitudes do they fly, 378
Clouds, how many descriptions are there, 379
Clouds, what produces their various shapes, 380
Clouds, how are they affected by winds, 382
Clouds, what do Cirro-cumulus foretell, 393
Clouds, what do Cirro-stratus foretell, 394
Clouds, what do Cumulo-stratus foretell, 395
Clouds, why are cloudy days colder than sunny days, 396
Clouds, why are cloudy nights warmer than clear nights, 397
Cloudy days and nights, why are they not always wet, 432
Clouds, why are they sometimes yellow, 533
Clouds, what develops the electricity in the, 581
Clouds, why do they sometimes move towards each other from opposite directions, 778
Clouds, why do they gather around mountain tops, 781
Coal, why do we know that it is of vegetable origin, 273
Coal, what are the chemical components of, 274
Coals, why do they produce yellow flame, 279
Cockles, why have they stiff muscular tongues, 1087
Coffee-pot, why has it a wooden handle, 125
Coke-fires, why do they not give flames, 107