vegetation, 69, 226, 356; their 

 influence on climate, natural produc- 

 tions, and on the human race, its 

 trade, civilization, and social condi- 

 tion, 295, 296, 304, 305, 334; zones 

 of vegetation on the declivities of, 8, 

 9, 331336; snow line of, 911, 

 338. 



Mud volcanoes. See Salses and Vol- 

 canoes. 



Miiller, Johannes, on the modifications 

 of plants and animals within certain 

 limitations, 363. 



Muncke, on the appearance of auroras 

 in certain districts, 193. 



Murchison, Sir R., account of a large 

 fissure through which melaphyre j 

 had been ejected, 258; classification 

 of fossiliferous strata, 280; on the 

 age of the Palseosaurus and Theco- 

 dontosaurus of Bristol, 276. 



Muschenbroek, on the frequency of 

 meteors in August, 1 13. 



Myndius, Apollonius, on the Pytha- 

 gorean doctrine of comets, 89. 



Nature, result of a rational inquiry 

 into, 3; emotions excited by her 

 contemplation, 3; striking scenes, 4; 

 their sources ol enjoyment, 5; magni- 

 ficence of the tropical scenery, 11, 

 12, 13, 14, 353; religious impulses 

 from a communion with nature, 17; I 

 obstacles to an active spirit ol inquiry, ' 

 17 : mischief of inaccurate observa- I 

 tions, 17; higher enjoyments of her ' 

 study, 18; narrow minded views of j 

 nature, 18; lofty impressions pro- I 

 duced on the minds of laborious ! 

 observers, 19, 20; nature denned, j 

 21 ; her studies inexhaustible, 21 ; ' 

 general observations, their great ad- ; 

 vantages, 22; how to be correctly 

 comprehended, 55; her most vivid 

 impressions earthly, 65. 



Nature, philosophy of, 2, 16; physical 

 description of, 48, 49, 55. 



Nebula?, 67 69; Nebulous milky way 

 at right angles with that of the 

 stars, 141 143; Nebulous spots, 

 conjectures on, 67 69; Nebulous 

 stars and planetary nebulae, 68, 69, 

 142; Nebulous vapour, 6769, 70, 

 71, 142; their supposed condensa- 



tion in conformity with the laws of 

 attraction, 67, 68. 



Neilson, gradual depression of the 

 southern part of Sweden, 300. 



Nericat, Andrea de, popular belief in 

 Syria on the fall of aerolites, 110. 



Newton, discussed the question on the 

 difference between the attraction of 

 masses and molecular attraction, 44; 

 Newtonian axiom confirmed by 

 Bessel, 46 ; his edition of the Geo- 

 graphy of Varenius, 49; Principia 

 Mathematica, 49; considered the 

 planets to be composed of the same 

 matter with the Eurth, 120; com- 

 pression of the Earth. 156. 



Nicholl, J. P., note from his account 

 of the planet Neptune, 74 76. 



Nicholson, observations of lightning 

 clouds, unaccompanied by thunder 

 or indications of storm, 345. 



Nobile, Antonio, experiments of the 

 height of the barometer, and its in- 

 fluence on the level of the sea, 303. 



Noggerath counted 792 annual rings 

 in the trunk of a tree at Borrn, 287. 



Nordmann, on the existence of animal- 

 cules in the fluids of the eyes of 

 fishes, 354. 



Norman, Robert, invented the inclina- 

 torium, 172. 



Observations, scientific, mischief of 

 inaccurate, 17; tendency of uncon- 

 nected, 20. 



Ocean, general view of, 296 316; its 

 extent as compared with the dry 

 land, 292; its depth, 151, 307; tides, 

 310. 311; decreasing temperature at 

 increased depths, 307 ; uniformity 

 and constancy of temperature in the 

 same spaces, 308; its currents and 

 their various causes, 311 314; its 

 phosphorescence in the torrid zone, 

 197 ; its action on climate, 308, 325 

 337 ; influence on the mental and 

 social condition of the human race, 

 153,295,296, 298, 315,316; rich- 

 ness of its organic life, 314, 315; 

 oceanic microscopic forms, 350, 361 ; 

 sentiments excited by its contempla- 

 tion, 315, 316. 



Oersted, electro-magnetic discoveries, 

 182, 185. 



