INDEX. 



505 



MOCHA. 



Mocha, meteors falling at, 421. 



Moignot, M., crystals compressed by, 

 189. 



Moisture, an indispensable requisite 

 for vegetation, 248 ; transmission 

 of electricity effected by, 284, 288. 



Molecular polarity, produced by elec- 

 tricity, 282 ; attraction, electricity 

 developed by destruction of, 284. 



structure affecting transmission 



of electricity, 803. 



vortices, hypothesis of, account- 

 ing for the absorption of light. 

 177. 



Molecules, material, attraction and 

 repulsion of, 103 ; effect of elasti- 

 city and cohesion on, 104-106 ; 

 uniting to form crystals, 107-109 ; 

 extreme minuteness of ultimate, 

 110; of ether, modes of their vi- 

 bration in natural and polarized 

 light, 193 ; in fluorescent light, 

 196, 197 ; images traced by the 

 mutual action of, 219-222 ; ar- 

 rangement of, connected with mag- 

 netism, 350-352. 



Mollusks, distinct species of, 254. 



Monocerotis 11, a triple star, 395. 



Monsoons, theory of the, 123, 124. 



Months, antiquity of, as a measure of 

 time, 85. 



Moon, the, force restraining, 4, 5; 

 mean distance of, from the earth, 

 4 ; results effected by her nearness 

 to the earth, 7 ; annual rate of de- 

 crease in her orbit's excentricity, 

 17/; average distance of, from the 

 earth's centre, period of her circuit 

 of the heavens, 34 ; her periodic 

 perturbations, 35-38 ; causes as- 

 signed for acceleration of her mean 

 motion, 36, 37 ; eclipses of, 39, 

 40 ; longitudes determined by ob- 

 servations of, 42, 43 ; her mean 

 horizontal parallax, 52 j sources 

 whence her mass may be deter- 

 mined, 55, 56 ; her diameter, 56 ; 

 rotation of, 68 ; librations, 69 ; 

 mountains, 70 ; precession result- 

 ing from her attraction, 79-81 ; 

 influence of, producing tides, 91, 

 92, 96-98 ; period of her declina- 



MUSIC. 



tions, 97 ; atmospheric equilibrium 

 disturbed by her attraction, 121 ; 

 cause of her apparent increased 

 magnitude in the horizon, 158 ; 

 photographic image of, 214 ; com- 

 parative amount of light emitted 

 by, 225 ; cause of the rarity of 

 her atmosphere, 226 ; increased 

 intensity of light at full, ib. ; effect 

 of the terrestrial atmosphere on 

 heat radiated from, 227 ; cause of 

 acceleration in the mean motion 

 of, 366 ; light reaching the earth 

 from, 404. 



Moorcroft, herbarium collected by, 

 250, 251. 



Moser, Professor, mutual influence of 

 bodies in contact tested by, 219, 

 220. 



Mossotti, Professor, his analysis to 

 prove the identity of the cohesive 

 force with gravitation, 103, 104 ; 

 his definition of gravity, 355. 



Motion, a law of the universe, 274 ; 

 perpetual, impossible, 279 . 



Mountains, anomalies in measurement 

 caused by, 48 ; rarity of atmo- 

 sphere on, 118 ; cause of perpetual 

 snow, 119 ; modes of determining 

 heights of, 120 ; becoming new 

 centres of motion in hurricanes, 

 126 ; influence of chains on tem- 

 perature, 241, 242 ; cause of 

 e'boulemens in, 271; tops of, fused 

 by lightning, 293. 



, lunar, effect of solar rays pass- 

 ing between, in eclipses, 41 ; in- 

 fluence of, on the moon's motions, 

 96 ; three classes of, 70. 



Mu Herculis, direction of solar motion 

 with regard to, 406. 



Multiple systems of stars, 395. 



Mundy, Captain, mirage described 

 by, 157. 



Music, comparison instituted of sym- 

 pathetic notes in, 2 ; regulated un- 

 dulations of sound producing, 142 ; 

 instruments of, 143 ; experiments 

 by means of vibrating plates, 144- 

 146 ; sympathetic vibrations, 147, 

 148 ; experiments showing, 148, 

 149. 



