78 THE CHEMISTRY OF THE SUN. [CHAP. 



I was unable to determine their position with sufficient accuracy to 

 reproduce them in my drawing. The two bright green bands do not 

 -correspond to dark bands in the solar spectrum, so that, as far as 

 I have been able to determine, silicium is not visible in the solar 

 atmosphere." 



Confining his observations to the region of the solar spectrum 

 between F and D, Kirclihoff found the following coincidences 

 between lines in the spectra of certain elements and the Fraun- 

 hofer lines : 



Lines. Lines. 



Sodium. ... 2 Iron .... 42 



Calcium ... 13 Chromium ... 4 



Barium ... 7 Nickel .... 28 



Strontium . . 2 Cobalt . . . . 10 



Magnesium . . 3 Zinc 2 



Copper. ... 3 Gold. .... 1 



It will be seen from the foregoing that Kirclihoff' deals 

 mainly with the brightest lines, although the test failed him 

 in the case of cobalt, for a reason I shall show further on. 

 Hence, as a result of Kirchhoff's work, we had in the solar 

 atmosphere 



Present. Doubtful. Absent. 



Sodium. Cobalt. Gold. 



Iron. Silver. 



Calcium. Mercury. 



Magnesium. Aluminium. 



Nickel. Cadmium. 



Barium. Tin. 



Copper. Lead. 



Zinc. Antimony. 



Chromium. Arsenic. 



Strontium. 



Lithium. 



Silicium, 



