116 Prof. J. N. Lockyer. [May 9, 



attempt has been made to separate the possibly new gases from the 

 known ones which come over with them ; hence, the lines are in 

 some cases very dim, and the application of high dispersion is 

 impossible. The wave-lengths therefore, especially in the visible 

 spectrum, are approximations only ; but the view that we are really 

 dealing with gases operative in the solar atmosphere, like the helium 

 which produces D 3 , is strengthened by the fact that of the sixty 

 lines so far recorded as new in the various minerals examined, about 

 half occur near the wave-lengths assigned to chromospheric lines in 

 Young's table. I am aware that most of the chromospheric lines have 

 been recently referred to as due to iron,* but I believe this result 

 does not depend upon direct comparisons, and it is entirely opposed 

 to the conclusions to be drawn from the work of the Italian observers, 

 as well as from my own. 



II. " On the new Gas obtained from Uraniuite. Third Note." 

 By J. NORMAN LOCKYER, C.B., F.R.S. Received May i, 

 1895. 



In my preliminary note communicated to the Royal Society on the 

 25th ult., I gave the wave-lengths of the lines which had been 

 observed both at reduced and at atmospheric pressure in the gas (or 

 gases) produced by the method to which I then referred of heating 

 the uraninite mineral (broggerite) in vacuo. 



As a short title in future, I shall term this the distillation method. 



Since then the various photographs obtained have been reduced, 

 and the wave-lengths of the lines in the structure spectrum of 

 hydrogen observed beyond the region mapped by Hasselberg. I have 

 further observed the spectra of other minerals besides uraninite for 

 the purpose of determining whether any of them gave lines indicating 

 the presence of the gas in uraninite or of other gases. 



I now give a table of the lines so far measured in the spectra of 

 eighteen minerals between XX 3889 and 4580 (Rowland), the region 

 in which, with the plates employed, the photographic action is most 

 intense. 



On this table I may remark that of the lines given in my paper of 

 April 25, the final discussion has shown that the following lines are 

 hydrogen structure-lines in the region beyond that mapped by 

 Hasselberg, XX 4479, 4196, 4156, and 4152-5. The line 4368 is also 

 omitted from this list as it has not been finally determined whether 

 it coincides with a line of oxygen. 



In the table, besides the wave-lengths on Angstrom's and Row- 

 land's scale, I give lines which have been observed in the sun's 



* Schemer's 'Astronomical Spectroscopy,' Frost's translation, p. 184. 



