On the Arc $/>'/ /-m/i of Iron Meteorite*. [Fob. 1">. 



Tin- wave-lentrtlis, intensities, and origins of the lines in tlie 

 spectra are given in tabular form. 



The following genei-al conclusions have been airived at : 



1 . The spectra of the two meteorites closely agree, both as regards 

 the number and intensities of the lines, the slight difference iu 

 number being probably due to a difference of exposure. 



2. The meteoritic spectra and the solar spectrum show considerable 

 similarity. The iron lines in each have about the same relative 

 intensity, thus indicating that the temperature of the iron vapour in 

 the sun which produces the majority of the iron lines is about the 

 same as that of the electric arc. 



3. The results of the inquiry into the origin of the lines, in addition 

 to those of iron, may be thus summarised: 



Substances certainly present. Substances probably present. 



Manganese. Strontium. 



Cobalt. Lead. 



Nickel. Lithium. 



Chromium. Cerium. 



Titanium. Molybdenum. 



Copper. Vanadium. 



Barium. Didymium. 



Calcium. Uranium. 



Sodium. Tungsten. 

 Potassium. 



4. Of the few faint lines in the tables, for which no origins have 

 been found from the Kensington maps of metallic arc spectra, the 

 majority are apparently coincident with lines mapped by Messrs. 

 Kayser and Runge in the iron spectrum. These do not appear in the 

 Kensington photographs, probably on account of insufficient exposure. 



5. By noting the difference in intensity of identical lines in the 

 two spectra, a rough approximation can be made to the relative 

 quantities of the different substances present in the meteorites. Thus 

 it is found that the chief chemical difference between the two meteor- 

 ites is that there is a preponderance of calcium in the Nejed, and of 

 nickel, barium, and strontium in the Obernkirchen, meteorite. 



