1895.] On the Gases obtained from the Mineral Eliasite. 



3 



Addendum. Received November 18. 



The results in the foregoing paper depend upon eye observations 

 on the red end of the spectrum. Since it was communicated to the 

 Society the blue end has been investigated photographically. Many 

 specimens of eliasite have been distilled, and numerous photographs 

 of the spectra of the gases given oft' have been taken. 



The work has been rendered difficult by the very small quantity of 

 what I believe to be a new gas, and the large quantity of carbonic 

 acid, nitrogen, and hydrogen given off from the mineral. Attempts 

 have been made to get rid of the known gases, in order to make the 

 lines of the new gas better visible, and then the amount of gas was 

 in most cases' very small and at times admixed with argon produced 

 by the sparking. 



The photographs have been measured and reduced, and it is prob- 

 able that the lines, or some of them, which cannot be ascribed to any 

 known gases, may belong to the same gas as that giving the lines 

 observed in the red. I append a table of some of these lines, which 

 suggesTf possible coincidences in stellar and solar spectra ; the numbers 

 in brackets indicate the intensities of the lines, 6 being the maximum 

 in the case of a Cygni, and 10 the maximum in the case of the eclipse 

 spectrum. 



Wave-lengths 

 (Rowland). Coincidences. 



3961-4 a Cygni (6) 



4035-2 Eclipse (2) 



4058-6 „ (1) 



4128-3 1 « Cygni (3) 



4131-4/ „ (3) 



4224-0 Eclipse (1) 



4255-7 „ (1) 



4442-5 „ (3) 



In addition to the above lines there are others with which no 

 celestial coincidences have been traced. 



Some of the unknown lines at first noted in the red have been 

 observed again in the gases obtained from other specimens ; it is 

 important to note that remarkable variations in the spectra have 

 been observed in passing from one specimen to another. 



Although the evidence in favour of a new gas is already very 

 strong, no final verdict can be given until the sjDectra of all the 

 known gases, including argon, have been photographed at atmospheric 

 pressure and the lines tabulated. This part of the inquiry is well in 

 hand. - -• - - ■- ' . 



b .2 



