58 INORGANIC EVOLUTION. [CHAP. 



The enhanced lines of the above substances seem to account for 

 almost all of the more marked lines in a Cygni. It is on this ground 

 that I have investigated their behaviour in other stars before waiting 

 for the results of the complete inquiry. Another reason has been that, 

 although in addition to the enhanced lines of the metals shown in the 

 foregoing table, those of barium, cadmium, molybdenum, lanthanum, 

 antimony, lead, palladium, tantalum, erbium and yttrium, tungsten, 

 cerium, uranium, cobalt, and bismuth have already been investigated 

 with lower dispersion, and a spark obtained with the use of a much 

 less jar capacity, so far as I have no certainty that any of these sub- 

 stances exist in the reversing layers of stars of intermediate tem- 

 perature. 



The temperature ranges of the arc lines of some of the metals have 

 also been investigated, and the results are shown in the following 

 table : 



So much, then, for the metals. I now turn to the gases. 



Proto-liydrogen. 



Some little time ago Professor Pickering, of the Harvard Observa- 

 tory, found on examining the spectra of the southern stars, that one of 

 them on the poop (Lat. Puppis), hence called f Puppis, of the ship which 

 forms the constellation Argo, contained a system of lines not hitherto 

 recognised, and he naturally concluded that it indicated a new 

 element.* On further inquiry he found reason to suppose that this 

 new series was in some way connected with hydrogen, since the lines 

 occupied the same positions as those computed from the same formula 

 and constants from which the ordinary series of hydrogen was calcu- 



invisibility. On the meteoritic hypothesis this is explained by the great differences 

 of velocity and direction of the meteoritic streams, the special broadening of the 

 lines of the cleveite gases indicating that these gases are chiefly concerned in dis- 

 turbances at high temperatures. 



On account of the indistinctness of many of its lines, Tauri is omitted from 

 the present discussion. 



* See Astrophysical Journal, vol. iv. p. 369, and vol. 5, p. 95. 



