Napoleon III, 221. Natural history, 23, 37, 52, 61. Navigation, 3, 16, 26, 54, 126, 231. Nebular hypothesis, 147, 150. Neptune, 184 _et seq._ Neptunist, 131. _New Atlantis_, 71, 100, 183. Newton, 110, 135, 158. Nicholson, 177. Nietzsche, 277 _et seq._ Nitric oxide, 156, 161. Nitrous oxide, 174. _Novum Organum_, 70, 72. Numerals, 6, 11, 34, 49, 87, 231. Observatories, 4, 49. Occupations, 12, 51, 58, 68 _et seq._, 107. Optics, 50, 54, 93. Organic remains, 126, 140. Origin of the sciences, 1 _et seq._ _Origin of Species_, 201. Pansophy, 100. Pascal, 95, 117. Pasteur, 213 _et seq._ Pearson, Karl, 60. Peirce, 195. Pepys, 110. Petty, 103, 122. Peurbach, 55. _Philosophical Transactions_, 109. Philosophy, 15 _et seq._, 134. Physics, 21, 28, 31, 32, 50, 54, 74 _et seq._, 94 _et seq._, 110 _et seq._, 128, 155 _et seq._, 170 _et seq._, 231 _et seq._, 245 _et seq._ Physiology, 6, 21, 38, 78, 173 _et seq._, 225 _et seq._ Picard, 111. Plato, 18, 270 _et seq._ Playfair, 133, 137. Pliny, 37. Pneumatic Institution, 173. Poincaré, Henri, 255, 267. Port Royal, 116, 279. Potash, 23, 51, 179. Potassium, 179. Precession of the equinoxes, 10, 112. Priestley, 126, 156. Primitive man, 206. _Principia_, 110, 114. Prism, 40. _Protyl_, 254. Psychology, 23, 256 _et seq._ Ptolemy, 45, 55. Pythagoras, 17. Quadrants, 50, 86. Quintilian, 39. Rabies, 227 _et seq._ Racemic acid, 215. Radioactivity, 245 _et seq._ Ramsay, 246. Ray, 110. Regiomontanus, 55. Religion, 3, 8, 10, 40, 43 _et seq._, 142 _et seq._ Rey, 94. Rhind papyrus, 6. Röntgen rays, 231. Rousseau, 270. Royal Institution, 176. Royal Society of Edinburgh, 133. Royal Society of London, 99 _et seq._ Rumford, 166. Rutherford, 247 _et seq._ St. Benedict, 52. St. Thomas Aquinas, 53. Saturn, 2, 92, 145. Saussure, 133. Scheele, 156, 180. Scientific apparatus, 17, 49, 86 _et seq._ Scotus Erigena, 53. Seneca, 40. Shaftesbury, 117. Signs of zodiac, 9, 33. Silkworm, 109, 221 _et seq._ Siphon, 95. Sirius, 4. Smith, Adam, 121, 133, 256. Smith, William, 139 _et seq._ Smithsonian Institution, 195, 233, 238. Socrates, 44, 117. Soda, 8, 51, 179. Soddy, 248 _et seq._ Sodium, 179. Sosigenes, 36. Sound, 33. Species, 24, 197 _et seq._ Specific gravity, 28, 36, 50. Spectrum analysis, 153, 231. Sphericity of the earth, 26, 37. Spontaneous generation, 25, 218. Sprat, 105, 109. Steel, 8, 23. Sundial, 13. Survival, 206. _Syntaxis_, 45. Tables, astronomical, 49, 50, 91, 185 _et seq._ Tanning, 177. Technology, 5, 16, 20, 27, 30 _et seq._, 50, 68 _et seq._, 86 _et seq._, 103, 107, 126, 129, 130, 139-41, 156, 160, 167, 177, 182, 231. Thales, 15. Theology, 47, 62, 172. Theon, 46. Theophrastus, 26, 39. Theory, 30, 41; _T. of the Earth_, 133. Tides, 38, 112. Torricelli, 95.