22 



GENERAL INDEX. 



Curvature of lenses, method of calculating their force . 

 Curves, magnetic, properties of, and means of delineating 

 Cushions for electrical machines, first used by Winkler 



amalgams, recommended for .... 



CUTHBERTSON'S balance electrometer described 

 Cylinder, reflecting surface of, ustid ire restoring anamor- 

 phoses . . . 



DANIELL'S pyrometer, description of . 



hygrometer ... .... 



^ . table of temperatures- ..... 



Dark chamber (camera obscura), invented by Friar Bacon 



Day telescopes, account of their construction 



Day and night thermometer of II u therford . . . 



Days and Nights, why they vary in their lengths 



Dead animals, muscular motions excited in by galvanism 



Decay of sight in age, how remedied .... 



DE BUTT'S differential thermometers described 

 Decomposition of solar light, experiments on . . . 



and re-composition of water by the voltaic pile 

 . . of water, why not effected by the common elec- 

 tric machine ........ 



. . of neutral salts by the voltaic pile . . 



of metallic solutions by . - . . 



of acids, alkalis, and earths, by . . 



DE DOMINIS, his theory of the rainbow . 



Definition of magnetism . i 



DE LA LAND'S proposed thermometer .... 



DE LISLE'S thermometer as used in Russia . 



DE Luc's microscopic pyrometer . 



metallic thermometers . . . 



electrical column described .... 



Density and rarity of bodies denned .... 



DESAGULIERS' pyrometer, description of ... 



' . . his theory of the rainbow . . . 



his unfair plagiarisms from Snellius . 

 Development of Electricity by changes of temperature and 

 form ......... 



. . by contact, compression, and other 



mechanical means ....... 



Deviation of the Compass on account of local attraction, ex- 

 periments and observations on . 



Table of, observed in different ships 



Dew, vapours, and rain, their distinction and causes . . 

 . . temperature at which it falls .... 



DE WJLDT'S table of expansions of spirit and of mercurial 

 thermometers . . . . . . . 



Diameters of the planets proportionally represented . 

 Diamond aplanatic lenses . . . . . . 



microscopes, Pritchard's .... 



Different effects of the electric and the galvanic batteries 

 Differential thermometers and their modifications 



of Leslie .... 



of De Butt .... 



hygrometer and photometer, improvements sug- 

 gested on . . . 



galvanometer, description of ... 

 Diffraction of light, account of . . . 



Grimaldi's discovery of . . . 

 Dip of the magnetic needle, observations on ... 



its progressive changes . . 

 Dipping-needle, description and construction of, &c. 



remarks on that formerly used by the Royal 



Society 



sources of errors to which it is liable 

 method of obviating those errors . 

 Gambey's, described , 



Mayer's i , 

 Sabine's 



OPT. INST. 

 MAGN. 



ELEC. . 



OPT. INST. 

 THERM. 



OPT. INST. 



THERM. 

 POP. INT. 

 GALV. . 

 POP. INT. 

 THERM. 

 NEW. OPT. 

 GALV. 



NEW. OPT. 



MAGN. 



THERM. 



GALV. 

 POP. INT. 

 THERM. 

 NEW. OPT. 



ELECT. 



MAGN. 



POP. INT. 

 THERM. 



POP. INT. 

 OPT. INST. 



GALV. . 

 THERM. 



ELECT. >i 



NEW.' 



Page 

 6 



1922 

 15 



. 16 



38, 39 



16 



49,50 

 32 

 52 



. 10 



36, 37 



4448 



19 



. 97 

 41 



, 11,12 

 15 



27 



. 15 

 16 



. 17 

 4 

 1 

 9 

 9 



23,24 

 24 



. 26 

 4 



. 16 



9 



. 7 



5355 

 5557 



6165 



66 



5 



49 



55 



35 



13 



. 39 



