INDEX. 



Abney, results in photographing spec- 

 tra, 211 



and Festing, observations on or- 

 ganic radicals, 271 

 Absorption, chlorine vapour, 280 



gaseous, 41 



general and selective, 39 



iodine vapour, 202 



lines, in solar spectrum due to 

 aqueous vapour, 66 



trumpeting of, 381 



due to earth's atmosphere, 64 



Frankland's observation on, 378 



in arc non-symmetrical, 381 



liquid, 40 



location of, 380 



phenomena, 276, 382 



selective, increased at sun's limb, 

 104 



solar, locus of, 163 



and radiation, equivalent of, law 



of, 63 

 Aldebran, elements in, Huggins and 



Miller, 187 



Allotropy, conditions of, 269 

 Alloys, gold-copper, research on, 152 

 Angstrom announces existence of 

 sodium in the sun, 53 



basic lines, 372 



comparison of lines of elements 

 with Fraunhofer lines, 177 



observations on spectra of limb of 

 sun, 102 



on Janssen's telluric lines, 66, 68 



reason for employing diffraction, 

 86 



spectrometer, 85 



statement on the variations of 

 intensities of lines due to temp- 

 erature, 178 



Angstrom (continued] 



view on multiple spectra, 191 

 work on spectrum of limb, 102 

 work on the solar spectrum, 83 

 Arc, absorption lines in, non-symmetri- 

 cal, 381 

 electric," 83 



flame of, and core compared, 386 

 flame of, spectrum, 381 

 lines in electric, origin of pheno- 

 mena of, 379 

 naked absorption lines, 381 ; bright 



lines, 383 



shielded, experiments with, 388 

 spectrum of, as compared with that 



of sun-spots, 340 

 Atom, Clerk-Maxwell's definition of 



an, 400. See also Elements 

 Atomicity, 271 



Atmosphere, solar, condition of, che- 

 mical and physical, 80 

 composition of, 167 

 constitution of, 169 

 currents in, 303 

 description of, 169 

 iron in, spectrum of, 362 

 Kirchhoff', 81 



new metals in, 200. See Metals. 

 - spectrum of, 253 

 statement on, Forbes, 46 

 views of, held in 1873, 167 

 terrestrial, cause of illumination 

 of, 106 



Barium present in solar atmosphere, 77 



Basic lines, Thalen, 371 



Becquerel's experiments in photo- 

 graphy of solar spectrum, 47 



Berthelot's remarks on the elements, 

 204, 289 



G G 



