INDEX. 



513 



REFRANGIBILITY. 



capability of producing fluorescence, 

 196 ; capability of, in rays, affect- 

 ing their chemical action, 209- 

 212 ; effect of, on the lunar atmo- 

 sphere, 226 ; influence of, on 

 transmission of heat, 258 ; of rays 

 of heat, 261-264; heat polarized 

 by, 266. 



Refrangibility, substances diminishing, 

 of light, 196 ; affecting the che- 

 mical action of rays, 209-212 ; 

 affecting radiation of heat, 257 ; 

 affecting transmission of radiant 

 heat, 261-263. 



Reich, Professor, temperature of mines 

 observed by, 228 ; mean increase 

 calculated by, 230. 

 Reptiles, distribution of distinct species 



of, 254. 



Repulsion of electricities, 283; expe- 

 riments determining the laws of 

 electrical, 286, 287 ; modes of, in 

 static and in Voltaic electricity, 

 317 ; de veloping comets' tails, 375- 

 377. 

 Resistance, a cause of accelerated 



motion, 367. 



Retina, the, action of, in receiving im- 

 pressions, 166 ; comparative sen- 

 sibility of its fibres to light, 

 178. 

 Retrograde motion of comets, 359, 



368, 373, 379. 



Rhodiola rosea, identical species of, 

 found in Tartary and in Scotland, 

 251. 

 Rhombohedrons of carbonate of lime, 



109. 



Richman, Professor, killed by light- 

 ning, 293. 

 Richter, variation in length of the 



pendulum observed by, 51. 

 Rings of Saturn, 66-68 ; Saturn's, 

 diamagnetic, 347 ; luminous, sur- 

 rounding comets, 374, 375; sur- 

 rounding Donati's, 379. 

 Ritchie, Professor, electrical experi- 

 ments of, 314. 



Ritter, M., chemical properties of the 

 solar spectrum observed by, 203 ; 

 oxydizing effect of red rays, 209. 

 Rive, M. Auguste de la, rate of in- 



RUSSIA. 



crease of temperature in wells ob- 

 served by, 230. 



Rivers, curvature of the land proved 

 by, 46 ; influence of, on the earth's 

 rotation, 71 ; rising of tides in, 

 98 ; effect of, in cooling the atmo- 

 sphere, 243. 



Roget, Dr., phenomena of electro- 

 magnetism explained by, 313. 

 Rome, observations on lunar moun- 

 tains made at, 70 ; era fixed 

 at, 85 ; comet discovered from, 

 370. 



Ross, Sir James, stratum in the ocean 

 discovered by, 101 ; depressure of 

 the barometer observed by, 120 ; 

 volcanic region discovered, 232. 

 Rosse, Lord, nebnlaB resolved by his 

 telescope, 407, 408 ; spiral nebula, 

 409, 410 ; annular nebulae dis- 

 covered by, 410 ; nebulous star, 

 411; planetary nebulse, 412 ; ne- 

 bulae resolved by, 415. 

 Rotation affecting winds, 122-127; of 

 winds, 124, 125; of hurricanes, 

 125, 126 ; produced by the Voltaic 

 current acting on iron, 305 ; of 

 stratifications of electrical light, 

 307; caused by electricity, 313, 

 314; of light caused by an electric 

 current, 319 ; of magnets pro- 

 ducing electricity, 330 - 332 ; 

 changes produced in comets by, 

 376. 



Rotations of the solar system, 7 ; of the 

 sun, 65 ; of the planets, 66 ; of satel- 

 lites, 68 ; of Jupiter's satellites, 70 ; 

 of the earth, a measure of time, 71 ; 

 influence of temperature on, 72 ; 

 axis of, invariable, 76, 77. 

 Rotatory motion, form indicating, 65 ; 

 of Donati's comet, 379. 



[ Roux, M. le, observations on magnetic 

 action in crystals, 350. 



i Rudberg, M., refrangibility of sub- 

 stances ascertained by, 201, 202. 

 Ruhmkorff, M., improvements on his 

 electro-inductive apparatus, 328. 



; Russell, Scott, Mr., velocity of the 

 tidal wave estimated by, 95. 



i Russia, arc of the meridian measured 

 in, 48 ; climates of, 244. 



