436 



Nebulae : Herschel's catalogue of, i. 

 98 ; Dunlop's catalogue of, ii. 334. 



Needle, compass, on the best kind of 

 steel and form for, ii. 141. 



, horizontal and dipping, on 



the diurnal changes of, ii. 197, 293, 

 344. 



, magnetic: on the variation of, 



i. 187. ii. 108, 109, 110, 130, 141, 

 197, 218, 225, 244, 293, 318, 321, 

 347, 391 ; on the dip of, i. 244 ; on 

 the dip of in London, in 1821, ii. 

 154, in August 1828, ii. 357. 



Negro, on the black rete mucosum of 

 the, ii. 135. 



Nerves : on the irritability of, i. 33 ; 

 in the lens, probability of, i. 38 ; mi- 

 croscopical observations on, ii. 137; 

 structure and functions of, ii. 153, 

 171 ; influence of the eighth pair on 

 the stomach, i. 486 ; on their influ- 

 ence upon the action of the arte- 

 ries, i. 513; of respiration, on the, 

 ii. 153, 171 ; influence of the voltaic 

 battery in obviating the effects of 

 the division of the eighth pair of, ii. 

 156; of the orbit, on the, ii. 195 ; 

 optic, on semi-decussation of, ii. 211 ; 

 on their existence in the placenta, 

 ii. 226; of the lungs, on the effects of 

 dividing, ii. 320 ; and ganglions, on 

 their influence in producing animal 

 heat, ii. 238 ; animal heat influ- 

 enced by the, ii. 259 ; of the face, 

 ii. 266, 380. 



Nervous affections cured by pressure 

 of the carotids, i. 390. 



circle, which connects the vo- 

 luntary muscles with the brain, ii. 

 266. 



system, inquiry how far the 



power of the heart is influenced by, 

 ii. 8, 29 ; on the functions of, ii. 373. 



Nests of the Java swallow, some ac- 

 count of, ii. 77. 



Newry pitch-stone, on the, ii. 172. 



Nitre, on the production of, i. 509. 



Nitrogen, experiments on, i. 351. 



Numbers, new instrument for perform- 

 ing the involution and evolution of, 

 ii. 2. 



O. 



Oak trees, on the different qualities of 

 the alburnum of spring- and winter- 

 felled, ii. 127. 



Object-glass, triple, on the concentric 



adjustment of, ii. 157. 

 Object-glasses and compound lenses, 



on the aberrations of, ii. 1 10. 



, achromatic, method for 



determining the dispersive ratio of 

 glass, and computing the radii of 

 curvature for, ii. 316 ; on their pro- 

 perties as applicable to the improve- 

 ment of the microscope, ii. 399. 



Obliquity of the ecliptic, observations 

 for determining the, ii. 114. 



Ocean, on the temperature of the, ii. 

 73. 



Ocythoe Cranchii, a new species, taken 

 in a small Argonauta, ii. 75. 



Ocythoe of Rafinesque, observations 

 on, ii. 75, 108. 



Oil gas, ii. 119, 143. 



Oil of wine, ii. 273. 



Olbers (Dr.), nature of the new planet 

 (Vesta) discovered by, i. 271. 



Ophiognathus, description of the, ii. 

 302. 



Opossum and ornithorhynchus, on the 

 ova of the tribes of, ii. 114. 



Optic nerves, on semi-decussation of, 

 ii. 211. 



Optics : physical, experiments and 

 calculations relative to, i. 131 ; op- 

 tical effects of heated glass, ii. 33 ; 

 optical properties of tabasheer, ii. 

 115; on the manufacture of glass 

 for optical purposes, ii. 383 ; opti- 

 cal deception in the appearance of 

 the spokes of a wheel seen through 

 vertical apertures, explanation of, 

 ii. 230. 



Oreston, on some fossil bones found in 

 caverns at, ii. 186. 



Organic remains found near Brentford, 

 account of, i. 459. 



Ornithorhynchus and opossum, on the 

 ova of the tribes of, ii. 1 14. 



Ornithorhynchus Hystrix, on the ana- 

 tomy of, i. 89. 



Ornithorhynchus paradoxus, on the 

 head of, i. 29 ; anatomy of the, i. 

 68 ; on the fossil remains of an ani- 

 mal resembling the, i.512. ii.51,82. 



Osier (E.) on burrowing and boring 

 marine animals, ii. 278. 



Osmium, a new metal, i. 162. ii. 353. 



Ostrich of Africa, i. 450. 



Ova: of the Sepia, and of the Vermes 

 testacea, distinguishing characters 



