62 



INORGANIC EVOLUTIOX. 



[CHAP. 



FIG. 27.- Map of chemical substances present in stars of different temperatures. 



defined by 7 Argus, the hottest star so far known. On the left the 

 stars named are those of increasing temperature, on the right those of 

 decreasing temperature. Those on the same horizon represent equal 

 mean temperatures so far as the cleveite gas and enhanced lines help 



