— 15 — 



les: celles du sodium et du carbone (la grande comète 



1882) Le spectre de la queue reproduisait l'aspect 



de celui du noyau, les raies étaient seulement beaucoup 

 plus faibles, quoique bien visibles, tant celles du sodium 

 que du carbone». 



Copeland etLohse (Copernicus; № 24, pgg. 236 — 243): 

 «Judging from the totality of the appearance presented 

 by these four large comets (1881 et 1882), we are 

 strongly inclined to think, that the difference of spectra 

 of nucleus, coma and tail is only one of intensity, ho 

 wever that may be brought about»... 



«On June 6 the whole Comet Wells was seen brilli- 

 antly in the light of sodium in an open slit, the tail as 

 well as the head, and in the spectrum of the great co- 

 met of 1882 all the brighter lines extended through the 

 whole length of the slit, being, however, fuller of light 

 in the nucleus, thus indicating their presence in the nuc- 

 leus as well as in the commencement of the tail»... 



«But not merely an odd one, nay, all the six brighter 

 lines observed in th& green and yellow (la grande co- 

 mète de 1882) correspond to the most prominent Iron 

 lines in that part of the spectrum and even the two 

 broad bands, noticed there, fall into a group of nume- 

 rous Tron lines». — 



Il me parait que par rapport aux observations spec- 

 troscopiques on peut encore ajouter la remarque, que 

 les bandes de l'hydrogène pur, plus faibles que celles de 

 ses combinaisons avec le carbone, doivent se placer sur 

 les bandes obscures correspondantes du spectre continu 

 (solaire) et par cela il sera toujours impossible de les 

 discerner, sauf quelques circonstances exclusives.— 



5. M. Meyer, dans sa recherche intéressante sur la ré- 

 fraction des rayons lumineux dans l'intérieur d'une со- 



