5oo 



INDEX. 



CRABTREE 



Crabtree sees transit of Venus, 154 



Critical point of gases, 406 



Crookes discovers thallium, 338 ; on ultra- 

 gaseous state of matter, 365 ; on meta- 

 elements, 405 



Crown of cups, Volta's, 260 



Crown-glass, dispersion of light in, 166 



Crystals, double refraction in, 179 ; pass- 

 age of light-waves in, 326; circular 

 polarization in quartz, 327 



Currents, from an electric battery, 261 ; 

 Humbolflt on ocean, 424 



Curtis, Dr., on carnivorous plants, 473 



Cuvier, history of, 427 ; on creation of 

 animals, 431 ; on comparative anatomy, 

 433 ; on fossil animals of Paris, 435 ; 

 death of, 437 



Cycloidal pendulums, 175 



DABURON, Ampere's visit to, 370 

 Daguerre fixes sun-pictures, 332 



Dalton, life of, 399; law of multiple pro- 

 portions, 401 ; atomic theory, 402 



Dark Ages, science of, 39 et seq. 



Darwin, 463 ; on origin of species, 464 ; on 

 causes of natural selection, 467 



Daubenton's anatomical work, 204 



Davy, Sir H., his history, 390 ; his experi- 

 ments on nitrous oxide, 391 ; on electro- 

 lysis, 392 ; discovers potassium and 

 sodium, 393 ; his safety lamp, 391 ; on 

 sun-pictures, 331 ; melts ice by friction, 

 352 ; cited, 409 



De Dominis on the rainbow, 161 



Ue la Rue cited, 343 



Deli-le's method of measuring transit ol 

 Venus, 276 



Deltas, growth of, 12 



Democritus on the Milky Way, 15 



Denudation, Hutton on, 218 



Descartes on light, 104, 161 ; on the value 

 of doubt, 103 



Development of animals, Lamarck on, 429 

 Von Baer on, 439 



Diagram showing how distances can be 

 measured on the sun's face, 157 



Diagrams of bent and broken rocks, 216, 217 



Diameter of the sun, 158 



D ia mond,nature of, pro ved by Lavoisier, 237 



Djafer, orGeber, Arabian alchemist, 43 



Dia:<:ious plants explained by Ca^salpinus,7o 



Dicotyledons, term explained, 141 



Differential calculus, by Leibnitz, 145 



Disc, Newton's rotating, 165 



Dispersion of light discovered by Newton 

 161 ; in different kinds of glass, 166 



Dissipation of Energy, 360 



Di t illation known to Geber, 43, 

 3uffoi 

 plants, Humboldt on, 424 



Distribution of animals, Buffbn, 205 ; o 



Dogmatism of the sixteenth century, 64 



78,81 



ENCKE 



Dollinger, anatomist, 438 



Dollond, Mr., makes achromatic telescoi*, 



166 ^ 



Donati obtains spectrum of a comet, 345 

 Dopier on movements of stars, 346 

 double refraction, 179 

 Doubt, Descartes on the value of. 103 

 draper photographs a nebula, 347 

 Drebbel makes alcohol thermometer, 118 

 Ducts of plants, 137 

 Du Faye on electricity, 253 

 Dynamical theory of heat, 357 



CARL'S COURT, Hunter kept wild 



- L -' animals at, 198 



Earth declared by Aristotle to be a globe, 

 16 ; circumference of, measured, 28 ; 

 Picart measures the size of the, 147 ; 

 Newton on shape of the, 151 ; measure- 

 ment of density of the, 287 



E-.mh-light on the moon, 88 



Earthquakes, Pythagoras on, 12 ; Strabo 

 on causes of, 33 ; changes of level caused 

 by, 445 



Ebn Junis, Arabian astronomer, 45 



Eclipses explained by Anaxagoras, 13 



Ecliptic or sun's path, how traced out by 

 the Greeks, 18 ; Anaxagoras discovers 

 obliquity of, 21 



Egyptians, early science of, 4 



Eighteenth century, work of the, 478 ; 

 summary of science of, 289 



Elective affinities, Bergmann on, 227 



Electric currents causing magnetic field, 

 371; making electro - magnets, 372; 

 power of, to conquer chemical affinity, 392 

 ectrical machines, Guericke's, 121 ; 

 Hawksbee's, 121 



Electric spark observed by Guericke, 122 



Electric telegraph, invention of, 382 ; 

 Bain's set on fire by magnetic storm, 

 381 ; Morse's and Steinheil's, 383 ; 

 Bain's and Cowper's, 386 



Electricity, Gilbert on, 74, 121 ; attraction 

 and repulsion by, 122 ; Du Faye on dif- 

 ferent kinds of, 253 ; Franklin on, 254 ; 

 and lightning, 255 ; animal, 257 ; chemi- 

 cal or voltaic, 259 ; chemical theory of, 

 394 ; produced by heat, 377 



Electrolysis, discovery of, 392 



Electro - magnetism, Oersted discovers, 

 367 ; Ampere on, 370 ; Faraday on, 374 



Electro-magnets made by electric current, 



' Electron,' root of word ' electricity,' 75 

 Elements, chemical, 398 ; dissociation oij 



405 



Ellipses, planets move in, 96 

 Embryology, Von Baer's law of, 437 

 Embryos of animals alike in structure, 43 

 Emission theory of light, 174, 316 

 Encke's comet, 300 



Elc'c 



