1887.] Researches on the Spectra of Meteorites. 135 



fully explain all the spectroscopic phenomena presented by luminous 

 meteors, comets, and nebulas. 



I published many years ago an experiment in which I had found 

 that the gases evolved from meteorites under some conditions gave us 

 the spectrum of hydrogen and under others the spectrum of carbon ; 

 but in the globes I then used I was not enabled to study the spectrum 

 of the glow itself. 



I should add that the line at 495 makes its appearance much more 

 rarely than the one at 500, in meteorite glows. 



Map 5 shows the positions of three of the nebula lines as compared 

 with well-known lines. 



1 



49 



nihil 



1 5 I° 1 



i IJ 1 1 1 l ul l r 



NITROGEN 



MAGNESIUM 





BARIUM 





HYDROGEN 





ill 





MET. GLOW 





li 





NEBULA 





ll 





Map 5. — Diagram showing the positions of the nebula lines as compared with lines 

 of N, Mg, Ba, H, and meteorite glow. 



/3. " Stars ■ ' with bright Lines. 



On reference to the map which I exhibit to the Society, though 

 they and the discussion of them are yet incomplete, it will be seen 

 that the principal lines which are seen bright in star spectra are, if 

 we make due allowance for the discrepancies likely to occur in obser- 

 vations attended with great difficulties, lines which either have been 

 observed in the vapours and gases given off by meteorites in vacuum- 

 tubes, or which we might expect to see in a combined series of 

 observations on meteorites having different chemical constituents. 

 Among these lines are H*, H/3, H 7 , HS, 464, 540, 570, 580, 587 ; in 



VOL. XLIII. L 



