INDEX. 



407 



Magnetic disturbances, periodical varia- 

 tions of, 174; coincident -with varia- 

 tion of solar spots ; contrast between 

 those of day and night, 175 ; period- 

 ical, inequality of, 176; increase of, 

 correspondent with increase of declina- 

 tion, ] 77. 



, periodical laws in the larger, 287 ; 



differences of maxima and minima of, 

 at different stations ; greater by day 

 than night, 288. 



Magnetic forces, dependence of, on in- 

 duction, 87 ; limit of induced; decrease 

 of intensity of, 88 ; changes in the laws 

 of, 89 ; an action between opposed sur- | 

 faces ; identity of, -with gravitation, 91. i 



, definition of lines of, 128 ; how ■ 



recognizable, 129 ; amoimt of deter- I 

 minate, 130 ; relation of currents to j 

 conducting power, 131. | 



Magnetic force of earth, results of expe- \ 

 riments on ; intersection of lines of, by ' 

 rotated wire, 166 ; coalescence and de- j 

 lineation of the hnes of, 167. 



Magnetic hues in Eastern Archipelaso, 

 21. ^ ! 



Magnetic meridian, direction of, to indi- I 

 cate, 213. ' 



, determination of, on board ship, i 



303. I 



Magnetic needle, action of mass of iron on, I 

 to detennine ; deviations of. to correct, 

 213. 



Magnetic survey of the Eastern Archi- 

 pelago ; area of minimum intensity ; 

 stations of observation, 15 ; dechna- i 

 tion changes; maxima and minima, 16; 

 horizontal force, 17 ; observations of 

 barometer; tension of vapour, 18 ; ob- 

 servations of thermometer, 19 ; results, 

 20 ; hue of no dip, 21. 



Magnetism, identity of, with Hght, heat 

 and electricity, 92 ; unity of force de- 

 monstrated by, 94. 



, terrestrial, correction of the con- 

 stants of, 45 ; tables of observations 

 of, 47-49 ; of determination of ele- 

 ments of, 50, 51 ; experiments on;va- j 

 nation and inclination, 52 ; errors in \ 

 observation, to correct, 54. j 



, terrestrial, discussion by Prof, i 



Kamtz, 300. 



Magnetometer, automatic temperature- 

 compensation of, 85. 



Manganese, method of detecting and of 

 obtaining its combinations, 386. I 



Mantell (G. A.), obituary notice of, 252 ; 

 list of -works of, 254. 



M'^Donald (J. D.), observations on the 

 anatomy of the antennae in a small 

 species of crustacean, 295. 



Megatherium, anatomy of, 57 ; compari- 

 son with other animals, 60 ; habits 

 and food of, 62 ; causes of degenera- 

 tion and exrincrion of, 64. 



— — , drawings of the, 237. 



Menstruarion, escape of ovule from ovary 

 of Tvoman during, 56. 



Metals, musical tones produced bv, 

 392. 



]^Ieteorite, explosive, accoimt of, 276. 



^^leteorological observations, cooperation 

 of different nations in, 188 ; taken in 

 different parts of Europe, 189 ; at sea, 

 scheme for, 190; value of, 191. 



— — in four balloon ascents, 309. 



Miller (J. F.) on the meteorology of the 

 lake district, 4th paper, 34 ; 5th paper, 

 170 ; 6th paper, 290. 



MoUusca, cephalous, morphology of, 192 ; 

 symmetrical archetype of; anatomy of, 

 193 ; curious differences of, 195. 



Moon, secular variation of mean motion 

 of, 321 ; determination of amount of, 

 324. 



, influence of, on the magnetic di- 

 rection, 338. 



Moseley (Rev. H.) on the rolling motion 

 of a cylinder, 35. 



Motion, rolhng, of a cylinder ; time of 

 oscillation, 35 ; jumps and slips ; rela- 

 rion to centre of g^a^-ity, 36 ; cranked 

 axles, danger of; influence on railway 

 trains, 37. 



MmTav (J.) on the tides, bed and coasts 



of the Xorth Sea, 201. 

 Muscle of the eye, 23 ; how to display 



the fibres of; action of the choroid, 24 ; 



analogies, 25. 

 Mysterious cu'cles, explanation of, 33. 



Xebulse, resolurion and phenomena of, 

 113. 



, catalogue of, 347 ; importance of 



observation of, 348. 



Nelson (H.) on the reproduction of 

 Ascaris jfystax, 86. 



Nerve fibres, two orders of, 1. 



, changes in form of, 2. 



Nerves, spmal ; posterior roots, three 

 kinds of; roots not directly connected 

 with brain, 297. 



of the heart, 337. 



Xesodon, description of extinct species 

 of ; herbivorous habit of, proved by 

 teeth, 272 ; form and species of, de- 

 fined, 273. 



Newport (G.) on the impregnation of 

 the ovum in the amphibia, 2nd series, 

 82. 



, Royal medal awarded to, 114. 



