56 



Dr. W. Huggins and Mrs. Huggins. [May 2, 



says : " I have never seen the line at \ 4703 in the spectrum of the 

 magnesium flame. As it is a conspicuous line in the arc and spark, 

 we looked for it in the flame, but did not find it." 



With reference to the second nebular line at X 4957, Mr. Lockyer 

 says :* <l The lines at 500 and 495 have been seen in the glow of the 

 Dhurmsala meteorite when heated, but the origin of 495 has not yet 

 been determined." And further (at p. 135) : " I should add that the 

 line at 495 makes its appearance much more rarely than the one at 

 500 in meteorite glows." In the diagram on the same page this line 

 is represented as coincident with the nebular line. 



The circumstance of a line appearing at 495 can scarcely be 

 regarded, considering the very great number of spectral lines, as 

 amounting to a presumption that the material to which it is due 

 in the meteorite is the same as that present in the nebulae which gives 

 the line at 4957. Tf it should be shown that the unknown substance 

 in the meteorite gives rise to a line at the position of the nebular line, 

 namely, X 4957, in that case the observation would have sufficient 

 importance to make it desirable to compare the spectrum of the 

 meteorite directly with that of the nebula. 



Lines Observed and Photographed in the Spectrum of the Nebula. 



Line measured by Dr. Copeland, probably D 3 



Brightest line 



Second line 



Third line, H/3 



Fourth line, H7 



Line measured by Dr. Copeland 



X 5874*0 

 5004-6 to 5004-8 

 4957-0 

 48607 

 4340-1 

 4476-0 



Strong line in photographs 1882 and 1888 about 3724-0 



Line in photographs 1888 about „ 3709'0 



„ 3699-0 

 3752-0 

 3741-0 

 3285-0 

 3275-0 

 3060-0 

 3053-0 

 30470 

 4116-0 

 41230 

 4130-0 

 4142-0 

 4154-0 

 4167-0 



5> >? 55 



Photograph 1889. 1st pair. . { about 



„ 2nd pair. . < " 



t ?> 



Line at. . ,, 



„ 3rd pair. . < " 



Photograph 1888 



Lines across star spectra, lst< 

 gi^P 



* < Koy. Soc. Proc.,' vol. 43, p. 133. 



