INDEX. 



491 



Dollond (G.) on a concave achromatic 

 lens adapted to the wired micro- 

 meter, 268. 



, achromatic eye-pieces, 89. 



Douglas (Mr.), observations taken on 

 the western coast of N. America, 471. 



Dover (Lord), notice of, 228. 



Dreaming, on the cause of, 179. 



Drummond light, on the, 474. 



Dry-rot in ships, on, 482. 



Dukhun, atmospheric tides and me- 

 teorology of, 296. 



Dunlop (J.), magnetical observations, 

 297. 



Dunlop (W.) on computing the longi- 

 tude at sea, 332. 



Dyar (H. J.) on the propagation of 

 waves, 414. 



Dynamics, on a general method in, 

 275, 315. 



Earth, the, considered as a magnet, 

 23. 



, magnetism of the, 23, 38, 95, 



166, 185, 220, 368, 394, 400, 418. 



, number of points at which a 



needle can take a position vertical 

 to its surface, 368. 



Earth and Venus, inequality of long 

 period in the motions of, 77, 108. 



Earthquake at Chili in 1835, 347. 



at Chichester, 338. 



Edwards (Dr.), batrachian reptiles 

 killed by immersion in hot water, 

 quoted, 45, 47. 



Egypt, on the mummy cloth of, 298. 



Elasticity of gases, 260. 



Electricity, on the absolute quantity of 

 electricity with the particles of mat- 

 ter, 263. 



, a continuous current of, 183, 



371, 385. 



, Arago's magnetic phenomena, 



93. 



, atmospheric, chemical action of, 



29. 



, chemical decompositions, 99, 



183, 198, 211, 262. 



, compact slate an excellent con- 

 ductor of, 124. 



, conducting powers of wires, 482. 



, construction and use of the vol- 

 taic battery, 343, 410. 



, definite nature and extent of elec- 

 tro-chemical decomposition, 262. 



, definite chemical action of, 371, 



385. 



Electricity, discovery of the law of con- 

 duction, 198. 



, duration of electric light, 299. 



, electric currents, 91, 95, 113, 



124, 161, 183, 198, 381, 461,469. 

 . electric origin of the phenomena 



of terrestrial magnetism, 23. 

 , electrical phenomena elicited by 



magneto-electricity, 162. 

 , electrical relations of metals and 



minerals, 317. 

 , electro-chemical influence of 



electric currents of low tension, 461 . 



, elementary laws of, 277, 414. 



, endosmose and exosmose, on, 



61. 



from magnetism, evolution of, 92. 



, identity of electricities derived 



from different sources, 191. 



, induction, electrical, defined, 91 ; 



induction of electricity in motion, 

 113 ; influence of terrestrial induc- 

 tion in giving rise to electrical cur- 

 rents, 95 ; laws of magneto-electric 

 induction, 177. 



, is electricity due to contact or 



chemical action, 288. 



, its evolution from magnetism, 92. 



■ , laws of action of the voltaic bat- 

 tery, 100. 



, measuring the velocity of, 299. 



, new electrical condition of mat- 

 ter, 92. 



■ of the torpedo, 119, 293. 



, phenomena relating to the ac- 

 tion of an electric current upon it- 

 self, 318. 



, positive and negative electric 



currents, 381. 



, relation, by measure, of common 



and voltaic, 193. 



, researches in, 91, 95, 113, 161, 



198, 211, 259, 288, 318, 343. 



, the constant battery, 373. 



, the dissected battery, 372. 



, the electro-tonic state, 116. 



, volta-electrometer for measuring 



electric currents, 262. 



, voltaic, 99 ; voltaic combina- 

 tions, 371, 385, 469. 



, magneto-electric intensity in dif- 

 ferent masses of the same metal, 

 178. 



, magneto-electric induction, phe- 

 nomena of, 96. 



, magnetic electrical machines, 



and voltaic batteries, 412. 



