On the Chemical Classification of the Stars. 



189 



plex, it is natural to suppose that the many sharp changes of spectra 

 observed in a series of stars from the highest temperature to the lowest, 

 bring us in presence of a series of chemical forms which become more 

 complex as the temperature is reduced. Hence we can in the stars 

 study the actual facts relating to the workings of inorganic evolution 

 on lines parallel to those which have already been made available in 

 the case of organic evolution. 



If then we regard the typical stars as the equivalents of the typical 

 strata, such as the Cambrian, Silurian, &c, it is convenient that the 

 form of the words used to define them should be common to both; 

 hence I suggest an adjectival form ending in fan. If the typical star is 

 the brightest in a constellation, I use its Arabic name as root ; if the 

 typical star is not the brightest, I use the name of the constellation. 



The desideratum referred has to a certain extent determined the 

 choice of stars where many were available. I have to express my 

 great obligations to Dr. Murray for help generously afforded in the 

 consideration of some of the questions thus raised. The table runs as 

 follows : — 



Classification of Stars into Genera depending ufon their 

 Chemistry and Temperature. 



Highest temperature, simplest chemistry. 



Argonian. 

 Alnitamian. 



Crucian. 



Taurian. 

 ^ Eigelian. 

 !ss Cygnian. 



§ Polarian. 

 Aldebarian. 

 Antarian. 



Achernian. 



Algolian. 



Markabian. 



«5i 



Sirian. 

 Procyonian. 

 Arcturian. 

 Piscian. 



The chemical definitions of the various groups or genera are as 

 follows : — 



Definitions of Stellar Genera. 



Argonian. 



Predominant. — Hydrogen and proto-hydrogen. 

 Fainter. — Helium, unknown gas (\ 4451, 4457), proto-niagne- 

 sium, proto-calcium, asterium. . 



Alnitamian. 



Predominant. — Hydrogen, helium, unknown gases (A 4089'2, 

 4116-0, 4649-2). 



Painter. — Asterium, proto-hydrogen, proto-magnesium, proto- 

 calcium, oxygen, nitrogen, carbon. 



