46 



THE ORIGIN AND EVOLUTION OF LIFE 



widely distributed in the solar spectrum. Therefore, before 

 examining the properties of these elements, it is interesting to 

 trace them back from the earth into the sun and thus into 

 the cosmos. It is through these "properties" which in life 



■|] .1 : 



i.i 



FT 



M-46NE5IUM 



55M ip ?IC 3i5 JKT 



' 1 i i'H'i||ii,!Mi| 



IRON 



iin 



HI 



jSCO 10 



J.O i^ 



TT 



i i 



I III " r 



Fig. 4. Chemical Life Elements in the Sun. 



Three regions of the solar spectrum with lines showing the presence of such essential life 

 elements as carbon, nitrogen, calcium, iron, magnesium, sodium, and hydrogen. From 

 the Mount Wilson Observatory. 



subserve "functions" and "adaptations" that all forms of life, 

 from monad to man, are linked with the universe. 



Excepting hydrogen and oxygen, the principal elements 

 which enter into the formation of living protoplasm are minor 

 constituents of the mass of matter sown throughout space in 

 comparison with the rock-forming elements.^ Again excepting 

 hydrogen, their lines in the solar spectrum are for the most 



1 Russell, Henry Norris, letter of March 6, 1916. 



