Printing, color designs in cloth, 248, 249. electrotype, 317. Prisms, 135. refraction through, 117. Proteids, 66. Pulleys, 166-169. applications of, 169. Pump, 187-205. air, 201-205. force, 192, 193. lifting, 189-192. Pupil of the eye, 122. Pure food laws, bleaching, 242. preservatives, 252. Purification of water, 77, 196. Push button, 321. Radiator, 19-21. Railroads, grading of, 165-166. Rain, 36, 37. Rainbow, 134. Rain water, 225. Reflection, angle of, 110. of light, 109-112. of sound, 278, 279. Refraction, angle of, 114. by atmosphere, 114. of light, 113. uses of, 115-116. Relay, telegraph, 325. Reservoir, 214. artificial, 211. construction of, 214-216. natural, 211. Resistance, electrical, 312. internal, of cell, 343. unit of, 345. Resonance, 276. River, volume and value of, 180. Roads, application of inclined plane to, 165-166. Rochelle salt, 227, 231. Rocks, effect of freezing water on, 42-43. water as a solvent, 71. Rosin, obtained by distillation, 35. Safety matches, 47-48. Salicylic acid, 253. Salt, 227-228. Salts, 227. general properties, 227. in ocean, 227. smelling, 222. Saturation of air, 37. Scale, musical, 282. Screw, and inclined plane, 166. Seaweed, 265. Seidlitz powder, 231. Self-raising flour, 231. Sewage, disposition of, 198-199. of camps, 196. source of revenue, 201. Sewer gas, 57. Silk, bleaching, 241. dyeing, 245-247. Silver chloride, 127-131. Simple colors, 138. Simple substances, 103. Siren, 280. Smelling salts, 222. Snow, 36-37. Soap, 222-224. and hard water, 225. liquid, 223-224. preparation, 223. Soda, baking, 227, 228-229. benzoate, 253. caustic, 218, 222, 223, 227. washing, 225, 226, 229. Soda mints, 231. Sodium, bicarbonate, 56, 227, 228, 230-231. carbonate, 228. chloride, 228. Soil, deposited by streams, 73. Solenoid, 318. Solution, 70. Soothing sirup, 258. Sound, and motion, 266, 278. musical, 278. nature of, 266. reflection, 277. speed of, 271-272. transmission of, 267-271. velocity of, 271-272. waves, 272-274. Sounder, telegraph, 324. Sounding board, 277. Sour milk in cooking, 230. Specific heat, 28-29. Spectrum, 134-135. Speed, of sound, 271, 272. Spontaneous combustion, 52. Stains, removal of, 226, 243. Standpipes, 212. Starch, 65. Steam, and work, 183-184. engine, 183-185. heat of vaporization, 32. heating by, 33. turbine, 183-184. Steel, forging and annealing, 16. Stoves, 18-19.