110 UNIVERSITY OF MISSOURI BULLETIN 



of the most ancient of sciences, the chemistry of the sun and 

 stars is a branch of astronomy which was created during the 

 past century. The composition of the heavenly bodies is partly 

 revealed to us by the spectroscope. If the light from one of 

 these bodies passes through a narrow slit and then through a 

 prism and a system of lenses, it is spread out into a colored 

 band, red at one end and violet at the other, with orange, yel- 

 low, green, blue, etc., shading into one another between. This 

 band, however, is not continuous, but is broken by many dark 

 gaps, which we can prove are caused by the absorption of 

 certain colors by the gases surrounding the luminous body. 

 Moreover, by noting the positions of these gaps we can tell 

 what gases formed them, and in this way we identify in most 

 of the heavenly bodies many of the same elements that we 

 find on the earth. The positions of the dark gaps also show 

 us whether the star is moving toward or away from us, and 

 how fast. 



The relation between astronomy and geology can best be 

 stated by saying that the one leaves off where the other begins. 

 The astronomer attempts to explain the formation of the 

 earth out of an original nebula, or in some other way, and 

 then hands the subject over to the geologist, realizing that the 

 history of the earth since its formation is well worthy of a 

 special science. 



As to the relation between astronomy and biology little 

 can be said. All the astronomer can do is to make a guess 

 whether any of the other planets, or the bodies outside of our 

 system, possess the characteristics necessary for the support 

 of life as we know it ; and also to suggest some way by which 

 small organisms can conceivably be transferred from one 

 sphere to another. Here on the earth, we have never known 

 life to generate spontaneously out of perfectly sterile matter ; 

 consequently, if a planet, for instance, is supposed to have 

 developed plant and animal life, we suspect that germs have 

 been carried to it from some other planet where life already 



