Camel, why has its stomach a number of distinct bags, 1065
Candles, why do tallow require snuffing, 264
Candles, why do composite and wax not require snuffing, 265
Candle, what becomes of it after it is burnt, 269
Capillary blood-vessels, why are they found in every part of the system, 919
Carbonic acid gas, what becomes of it, 10
Carbonic acid gas, is it heavier or lighter than air, 11
Carbonic acid gas, what are the chief sources of, 16
Carbonic acid gas, what is its effect upon the human system, 21
Carbonic acid gas, what becomes of that formed by combustion, 59
Carbonic acid gas, what proportion is dangerous to life, 60
Carbonic acid, where does it chiefly exist, 799
Carbonic acid, what are its pure states, 800
Carbon, will it produce flame when burnt in oxygen, 106
Carbon and hydrogen, what differences characterise the combustion of, 268
Carbon, what is the purest form of it, 277
Card, why do the images on each side blend while a card is revolving, 846
Caterpillars, why do they appear in the spring, 1289
Caterpillars, why do they eat voraciously, 1290
Caterpillars, why do they pass into the state of the chrysalis, 1291
Caterpillars, why do they become torpid in the chrysalis, 1292
Caterpillars, why do they attach themselves to the leaves of plants when in the chrysalis, 1294
Cats, &c., why do they see in the dark, 981
Cats' eyes, why are the pupils of nearly closed by day, 982
Cattle, why if they run round in meadows may thunder be expected, 1122
Ceiling, how did Mr. Sands walk on the, 664
Champagne, why do bubbles rise from it in two or three columns, 807
Charcoal, why is it dangerous to burn it in rooms, 20
Charcoal fires, why do they not give flames, 107
Charcoal, why does it act as a disinfectant, 809
Chimney, why does it cease smoking after the fire has been lighted a little while, 680
Chimney, why does a long one create a better draught than a short one, 681
Chimneys, why do some smoke when windows and doors are closed, 683
Chimneys that stand under elevated objects, why do they smoke, 685
Chimneys, why do they smoke in damp and gusty weather, 688
Chimney, why does it smoke when first lighted, 679
Circulation, why are the venous blood and chyle sent to the lungs, 887
Circulation, what is the course of the arterial blood, 888