1895.1 On the new Gases obtained from Uraninite. 



7 



spheric one. In this case also, the chromosphere was observed at the 

 sun's poles, in order to eliminate the effects due to the sun's rotation. 



In a former note,* I have pointed out that this line does not appear 

 in the spectra of the gases obtained from all minerals which give the 

 yellow line. 



Besides appearing in the spectrum of the chromosphere, the line in 

 question is one of the first importance in the spectra of nebulas, bright 

 line stars, and of the white stars such as Bellatrix and Rigel. 



The Infra-red Line, \ 7065'5. — In addition to D 3 and the line at 

 4471*8, there is a chromospheric line in the infra-red which also has 

 a frequency of 100, according to Young. On May 28, 1 communicated 

 a note to the Royal Society stating that this line had been observed 

 in the spectrum of the gases obtained from broggerite and euxenite,f 

 solar comparisons having convinced me that the wave-length of the 

 gas line corresponded with that given by Young; and I added " it 

 follows, therefore, that besides the hydrogen lines, all three ehromo- 

 • spheric lines in Young's list which have a frequency of 100 have 

 now been recorded in the spectra of the new gas or gases obtained 

 from minerals by the distillation method." 



M. Deslandres, of the Paris Observatory, has also observed the line 

 at 7065 in the gas obtained from cleveite.I 



Other Lines. — Determinations of the wave-lengths of many other 

 lines in the spectra of the new gases have been made, chiefly with 

 the aid of]a Steinheil spectroscope having four prisms, and the results 

 leave little doubt as to the coincidence of several lines with those 

 appearing in the chromosphere, nebulas, and white stars. 



It seems very probable, also, that many lines which have been noted, 

 and for which no origins have yet been traced, belong to gases which 

 have not hitherto been recorded in the chromosphere. 



The following table summarises the chief lines which have so far 

 been recorded in the new gases from various minerals, some of which 

 show D 3 while others do not. Only those lines which also appear in 

 the spectrum of the chromosphere, nebulas, or Orion stars, are given 

 in the first instance. There are other lines which are probably also 

 associated with chromospheric ones, but further investigation of 

 them is considered desirable before they are included in the list. 



The first column of the table gives the wave-lengths of the lines on 

 Rowland's scale, while the second gives the wave-lengths on Ang- 

 strom's scale ; the third gives the frequency of the lines in the 

 chromosphere according to Young. In the fourth column lines photo- 

 graphed with the prismatic camera during the total eclipse of April 

 16, 1893, are shown ; these have been included because in some cases 



* ' Koy. Soc. Proc.,' vol. 58, p. 114. 

 f « Koy. Soc. Proc.,' vol. 58, p. 192. 

 t ' Comptes Eendus,' June 17, 1895, p. 1331. 



