Index 



Bread making, chemical action in, 365. 

 Breath, cause of visibility of, on cold 



days, 288, 289*. 

 Bronze, an alloy, 310. 

 Burning, explanation of, 308, 312-313. 



Calcium chlorid, 114. 



Camera, lens of, 143, 148; human eye 

 as a small, 151*^-153; explanation 

 of, 327-332. 



Capillary attraction, 36*~4o; differ- 

 ence between adhesion, cohesion, 

 and, 47. 



Carbon, in electric battery, 203-206; 

 resistance of, to electric current, 

 231 ; an element, 293, 299 ; one of 

 chief elements in fuel, 315-316. 



Carbon dioxid, in seltzer siphon, 17; 

 produced by joining of carbon with 

 oxygen, 315; combining of water 

 and, by plants, 332-333; releasing 

 of, in baking powder, 349-350; 

 bubbling of, in effervescence, 365 

 366; in soda water, springs, and 

 baking soda, 366-367; limewater 

 test for, 375-376. 



Carbonic acid gas, commercial name 

 for pure carbon dioxid, 365-366. 



Cat's hairs, static electricity in, 201. 



Caustic soda, a common base, 356.' . 



Center of weight, 30-33*. 



Centrifugal force, 5, 72-74; law of, 

 74-75- 



Charcoal, production of, 316. 



Charging water with carbon dioxid, 

 366. 



Chemical analysis, 370-376. 



Chemical change, and energy, 293 ff. ; 

 burning (oxidation), 312-322; 

 caused by heat, 323-325; caused 

 by light, 326-335; caused by elec- 

 tricity, 335-339; energy released 

 by, 340-34 1 ; helped by solution, 

 3497351- 



Chemical equations, 297-299. 



Chlorine, an element, 299. 



Chlorophyll in plants, work of, 332. 



Cigar-box telegraph, construction of, 

 249*, 380-381*. 



Circuits, electric, 219-220*; breaking 



and making, 220221 ; connecting 



in parallel, 221-223*; grounded, 



225-229*; short, 240-245*. 

 Cloth, action of acids on, 354*; action 



of an alkali on, 356, 357*. 

 Clouds, how formed, 277-278. 

 Coal, carbon and hydrogen in, 315. 

 Cohesion, 39, 44* 49. 

 Cold, caused by expansion, 94; is 



the absence of heat, 95, 120. 

 Color, 161-172*, 

 Comb, electricity produced by rubbing, 



197-198. 



Compass, use of, 190-195*. 

 Complete electric circuits, 219-224*. 

 Compounds, how elements hide in, 



300; definition of, 308-309; mix- 

 tures distinguished from, 309-310. 

 Concave mirrors, 154*, 155*, 157; 



magnification by, 157; in reflecting 



telescopes, 157. 

 Conduction, of heat, 116-118; of 



electricity, 213218. 

 Conductors of electricity, good and 



poor, 213. 



Conduits for electric wires, 237. 

 Conservation of energy, 57 ff. 

 Convection, carrying of heat by, 118- 



119. 

 Convex lens, 148-149*; in microscope, 



155-157*; in telescope, 157. 

 Cooling from expansion, 94-96. 

 Coolness at night and in winter, 127- 



128. 

 Copper, a good conductor of electricity, 



215; an element, 299; nickel 



plating of, 336-339*; etching of, 



with acid, 352*~353. 

 Copper nitrate, salt called, 353. 

 Cream, separating from milk, by 



centrifugal force, 75-76. 

 Crystals, formation of, 265-268. 

 Cylinder of engine, 344*. 



Dead Sea, reason for salt in, 104- 



105*. 



Decay, a kind of oxidation, 313. 

 Dew, 275; how formed, 287. 

 Dictaphone, working of, 175, 178, 179*. 

 Diffusion, 268-274; of light, 158-161. 



