INDEX. 



419 



Oxides, metallic, 326. 

 Oxidizable metals, 305. 

 Oxygen gas magnetic, 259. 



and nitrogen, uses of, 321. 



and carbon in animals, 396. 

 Ozone, 299. 



and electricity, 217. 



PALLADIUM maintaining slow com- 

 bustion, 309. 

 Parathermic rays, 74. 



rays, influence in nature, 377- 

 Particles, Dumas on, 39. 



Peach on phosphorescence of the sea, 



159. 



Pearsall on phosphorescence, 160. 

 Pendulum, oscillation of, indicates the 



earth's motion, 13. 

 Perkins on repulsion of heat, 108. 

 Permeation of heat, 96. 

 Perturbations of Uranus, 31. 

 Pestilential diseases, 216. 

 Phenomena of vision, 148. 

 , natural, of electricity, 194. 

 , recent geological, 349. 

 Phosphorescence of animals, 154. 



of plants, 156. 

 Phosphorescent spectrum, 184. 

 Phosphoric acid detected in the oldest 



rocks, 337. 



Photosphere of the sun, 123. 

 Photography, 170. 

 , its importance, 180. 

 Physiological influences of electricity, 



219. 

 Physical forces, action of, 4, 45. 



forces, modes of motion, 7- 



properties of polarized light, 142. 

 Physiological influences of magnetism 



268. 



Pilchard, on the, by Couch, 315. 

 Plants, distribution of, dependent on 



light, 133. 

 , phosphorescence of, 156. 



respiration of, 312. 



and animals, dependence of, 313. 

 , growth of, 368. 



bend to the light, 373. 



distribution of, 378. 



Plants of the Tropics, 381. 



Plane polarization, 141. 

 Plastic nature" of Cudworth, 10. 



Plateau's experiment on bodies relieved 

 from gravitation, 33. 



Platinum maintaining slow combus- 

 tion, 309. 



Plato on motion, 10. 



on light, 119. 

 Plesiosaurus, the, 341. 

 Pliocene formations, 346. 



Pliicker on crystallo-maguetic force ,57. 



on diamagnetic bodies, 256. 

 Plumule, use of, 369. 

 Plutonic rocks, 334. 

 Polarization, circular and elliptical, 



143. 



Polarization of light, 139. 

 Polar condition of matter, 265. 

 Polypes and infusoria, 387. 

 Porosity of matter, 41. 

 Porta,Baptista camera obscura, 149. 

 Powers, active, in nature, 405. 

 Prevost, theory of, on heat, 96. 

 Primary origin of our planet, 334. 

 Principles of motion, 10. 

 Prismatic refraction, 121. 



rays, heat of, 67. 



analysis of sunbeam, 134. 

 Principle of gravitation, 29. 

 , elementary, 38. 

 Properties, essential, of matter, 5. 

 Pseudomorphism, 54. 

 Psychology of flowers, 357. 

 Pterodactyl, the, 342. 

 Pythagorean doctrine of motion, 10. 



QUININE, solution, influence of, on 

 light, 129. 



RADIANT heat, 69. 



Radiation and absorption of heat, 77- 

 , nocturnal, 83. 

 Raia torpedo, 211. 



Raymond, Du Bois, on animal elec- 

 tricity, 221. 

 Refrangibility, rays of high, 130. 



of solar forces, 168. 

 Refraction, prismatic, 121. 



