458 



INDEX 



FRESNEL 

 Fresnel, history of, 311 : on polarisation 



of light, 311 ; on circular poljirisation, 



314 

 Freyberg, Werner's lectures at, 217 

 Friction, ice melted and water boiled by, 



333 

 Friendship of Ray and Willughby, 143 

 Frog's leg, electricity in, 259-61 



GALEN, physiology of, 34 ; corrected 

 by Vesalius, 67 

 Galileo on the pendulum, 79 ; on falling 

 bodies, 80 ; on motion of heavy bodies, 82 ; 

 on secondary light of the moon, 89 ; on 

 Jupiter's moons, 91 ; on phases of Venus, 

 91 ; on sun-spots and rotation of sun on 

 its axis, 91 ; demonstrates the truth of 

 Copernican theory, 91, 102 ; his telescope, 

 89 ; his recantation, 93 ; his blindness 

 and death, 94 ; on rising of water in a 

 pump, 1 16; makes a water thermometer, 

 120 ; compared with Tycho and Kep- 

 ler, 102 

 Galle finds Neptune, 294 

 Galvani on animal electricity, 259 ; his 

 controversy with Volta, 260; his death, 

 261 

 Galvanism, 260 



Galvanometer invented by Ampere, 351 

 Ganges, mud carried down by the, 407 

 ' Gas,' term used by Van Helmont, 73 ; 



Nebulae composed of, 275 

 Gases, Boyle's law of, 128 ; Bacon on, 52 ; 

 Mayow on, 132 ; discovery of the four 

 important, 225 ; spectra of, 322 ; atmo- 

 sphere of, round the sun, 325 

 Gassendi observes transit of Mercury, 157 

 Gauss rediscovers Ceres, 290 

 Gay-Lussac on multiple volumes, 377 

 Geber the founder of chemistry, 43-45 

 Geist, word ' gas ' derived from, 73 

 Geography, Ptolemy's work on, 33 ; Strabo 



on, 33 

 Geology, definition of, 2 ; of Pythagoras, 

 II, 215 ; neglected in dark ages, 214 ; 

 Lazzaro Moro on, 216 ; Werner on, 217 ; 

 Hutton on, 219 ; W. Smith on, 223 ; Sir 

 C. Lyell on, 405 ; of eighteenth cer.tury, 

 281 ; prejudices retarding, 404 

 George II. founds Gottingen University, 



196 

 Geranium, Linnaeus's definition of the, 



209 

 Gerbert introduces Arabic numerals into 

 Europe, 46 



GUTENBERG 



Germ, growth of the, 141 



Germany, Imperial Academy in, 126 



Gesner, his life and character, 69-70 ; hitl 

 cabinet and garden, 69 ; his history ( 

 animals, 69 ; his botanical classificationj 

 70 



Gilbert, first experiments on electricity, 77J 

 123 



Gioja discovers mariner's compass, 53 



Glacial period, 414 



Glacier, term explained, 411 ; illustration 

 of a, 412; of Switzerland, 413; carrying 

 blocks to the Jura, 413 



Gladstone, Dr., his life of Faraday, 349 



Glass, angle of polarisation of light from, 

 310 ; index of refraction foi-. oi ; different? 

 dispersive powers of, 169 



Graham on variations of magft>:iic needle, 

 355 



Granite. Hutton on formation of, 221 ; vemsl 

 in Glen Tilt, 222 



Gravitation, law of, explained, 148-155 ;J 

 discovered by Newton, 148 ; its action on) 

 the planets, 151; attraction acts froraj 

 the centre of bodies, 150 ; decreases with j 

 the square of the distance, 152 ; problems : 

 explained by, 155; holding distant stars ^ 

 together, 274 



Gravity, action of, explained, 151 



Glen Tilt, granite veins in, 222 



Gnomon at Alexandria, 28 



Gold separated from amalgam by Paracel- \ 

 sus, 72 



Goethe on metamorphosis of plants, 381 ;| 

 on discussion between Cuvier and St.-] 

 Hilaire, 395 



Gottingen University founded, 196 



Gough the patron of Dalton, 371 



Graicus, Marcus, discovers gunpowder, 42 



Gratz, Kepler professor at, 95 



Greece, Roman conquest of, 35 



Greek colonies in Ionia, 8 



Greeks deficient in natural knowledge, 8 ; 

 believed the sun moved round the earth, 

 19 ; knew electric nature of amber, 77 ; 

 general remarks on science of the, 34 



Grew on vegetable anatomy, 141 ; 

 stomates, 141 ; on cellular tissue, 140 



Grove cited, 434 



Guericke's air-pump, 121 ; Magdeburg 

 hemispheres, 122 ; first electrical ma- 

 chine, 123 ; his experiments on electricity, 

 124 



Gunpowder known to the Arabs, 42 



Gutenberg, John, the printer, 55 



I 



