INDEX. 



46J 



PARABOLAS 



Parabolas described by comets, 155 



Paracelsus, chemistry of, 72 



Paris, Cuvier on fossil animals of, 397 



Pascal on pressure of the amosphere, 119 



Pecquet on thoracic duct, 114 



Pericles pleads for Anaxagoras, 14 



Perrier, M., carries a barometer up the 



Puy de Dome, 119 

 Pendulum, Galileo on the, 79 

 Phases of moon, 10 ; of Venus, 91 

 Philosopher, name first given to Pytha- 

 goras, 12 

 Philosophical transactions begun, 127 

 Phlogiston, theory of, 135 ; destroyed by 



Lavoisier, 238 

 Photography explained, 317 

 Physics, definition of, 2 ; of sixteenth cen- 

 tury, 83 ; of seventeenth century, 114 ; 

 of eighteenth century, 282 

 Physical, forces, correlation of the, 435 ; 



geography, Humboldt on, 386 

 Physiology, beginning of the 5tudy of, 



110-115 

 Piazzi discovers Ceres, 289 

 Picart, size of the earth measured by, 150 

 Pierre-a-Bot, an erratic block, 413 

 Pigeons, common descent of different 



varieties of, 392 

 Pisa, Galileo and the men of, 81 

 Pith of elder, cells in, 140 ; ball attracted 

 and repelled by rubbed sealing-wax, 124 

 Planets, Anaxagoras on, 14 ; Eudoxus on, 



15 ; Kepler's laws concerning the, 97- 

 100 ; held in their orbits by gravitation, 

 151 ; minor, or asteroids, 289; stability 

 of their orbits proved by Lagrange, 270 : 

 their weight and size calculated by 

 Leverrier, 294 



Plants, Aristotle on low organisation of, 



16 ; Theophrastus on, 17 ; microscopic 

 structure of, 140 ; ashes of, examined by 

 Boerhaave, 193 ; Hales on breathing of, 

 193 ; Bonnet on leaves of, 200 ; Gesner 

 on, 70 ; Csesalpinus on, ^x ; Ray on, 142 ; 

 Linnaeus, artificial system of, 208 ; 

 Jussieu, natural system of, 211, 382 ; 

 specific names given to, 209 ; Humboldt 

 on distribution of, 385 ; metamorphosis 

 of, 381 ; Priestley on breathing of, 232 



Playfair's illustrations of Hutton, 219 

 Polarizr.tion of light, 181 ; by reflection, 



309 ; circular, 314 

 Porta, his meetings in Naples, 74 ; his 



camera obscura, 75 ; on the eye, 76 ; his 



engine, 246 

 Positive and negative electricity, 256, 26a 



RED 



Potassium discovered by Davy, 365 

 Potter, Humphrey, ties the engine-cocks 



247 

 Ptolemaic system, 32 

 Ptolemies patrons of learning, 18 

 Ptolemy, astronomy of, 32 ; geography of, 



33 ; ' cloudy stars ' seen by, 274 

 Precession of equinoxes discovered by 



Hipparchus, 30; Newton on, 154 

 Pressure and volume, relations of, 130 

 Prestwich on flint implements, 416 

 Priestley, his discoveries, 232 ; calls oxygen 



' dephlogisticated air,' 234 ; his troubles 



and death, 235 

 Prism, light dispersed in a, 165 

 Prismatic colours, Newton on, 167 

 'Principia,' some problems discussed in 



the, 153 

 ' Principles of Geology ' published, 410 

 Printing, invention of, 55 

 Proctor on shooting stars, 299 

 Proportions, law of definite, 373 

 Proust on chemical law of proportions, 373 

 Pulmonary circulation of the blood, 113 

 Pulse studied by Herophilus, 27 

 Pump, height that water will rise in, 117 

 Pythagoras, science of, 11, 215 

 Pythagorean system, 21 



QUADRANT made by Copernicus, 66 

 Quadrupeds, Ray's work on, 143 

 Quicklime, nature of, 226 



RAP.P.TTS descended from one wild 

 stock, 392 

 Radiata, term explained, 396 

 Rain, denuding effects of, 406 

 Rainbow, De Dominis on, 164 

 Ramsay, Prof., cited, 218 

 Ray, on geology, 216 ; and Willughby, 

 history of, 142 ; on quadrupeds, 143 ; on 

 birds, fishes, and insects, 144 ; on plants, 



145 

 Rays of light, index of refraction of, 108 ; 

 Euclid on, 21 ; Alhazen on refraction of, 

 47 : Kepler on, 96 ; Young and Fresnel 

 on, 305-309 ; Newton on refraction of 

 coloured, 166 ; non-interference of ordi- 

 nary and extraordinary, 312 ; paths of 

 through a crystal, 313; discovery of 

 chemical and heat, 315 

 Reaumur's scale, freezing point of, 120 

 Red fire made by burning strontium, 322 



