iv MODERN EVOLUTION 165 



wherein the assumed absence of oxygen and nitrogen 

 in the sun's spectrum is adduced as an argument 

 against the theory of the common origin of the 

 bodies of the solar system. Speaking of the pre- 

 dominant proportion of oxygen in the solid and 

 liquid substances of the earth, and of the pre- 

 dominance of nitrogen in our atmosphere, his lord- 

 ship asked, * If the earth be a detached bit whisked 

 off the mass of the sun, as cosmogonists love to tell 

 us, how comes it that, in leaving the sun, we cleaned 

 him out so completely of his nitrogen and oxygen 

 that not a trace of these gases remains behind to 

 be discovered even by the searching vision of the 

 spectroscope ? ' If Lord Salisbury had consulted Sir 

 W. Huggins, or some foreign astronomer of equal 

 rank, as Dun6r or Scheiner, he would not have 

 put a question exposing his ignorance, and unmask- 

 ing his prejudice. These authorities would have 

 told him that when a mixture of the incandescent 

 vapours of the metals and metalloids (or non- 

 metallic elementary substances, to which class both 

 oxygen and nitrogen belong), or their compounds, 

 is examined with the spectroscope, the spectra of 

 the metalloids always yield before that of the 

 metals. Hence the absence of the lines of oxygen 

 and other metalloids, carbon and silicon excepted, 

 among the vast crowd of lines in the solar spectrum. 

 Then, too, in extreme states of rarefaction of the 

 sun's absorbing layer, the absorption of the oxygen 

 is too small to be sensible to us. 



' While the genesis of the Solar System, and of 

 countless other systems like it, is thus rendered com- 

 prehensible, the ultimate mystery continues as great 





