FIELD AND STUDY 



large proportion of the earth's crust is composed of 

 oxygen united with the mineral salts. The breath of 

 life goes to make up the rocks and the sea and the 

 soil we till. When two elements combine chemi- 

 cally, there is a mysterious interlocking of the 

 atoms of which these elements are composed. But 

 as the atom itself is inconceivable, — a solid particle 

 of matter non-divisible, — one cannot picture to 

 himself, or visualize, just what takes place. His ac- 

 quaintance with a mechanical world does not help 

 him. No more can he conceive what takes place 

 when the mere presence of a third body in some 

 cases causes two other bodies to unite chemically, 

 as if certain substances in relation to certain other 

 substances were capable of a sort of priestly func- 

 tion. This power is called catalysis. 



A Swedish chemist has said that the third sub- 

 stance seemed to act by arousing the slumbering 

 aflfinities of the two other substances. So far as is 

 known, it does not part with an atom of its own sub- 

 stance; by its magical presence alone it hastens the 

 chemical union of the two other bodies. This fact 

 of catalysis is now largely made use of in the arts 

 of manufacture. 



If we had the vision of the biochemist we should 

 see ourselves living in a world made up of two hos- 

 tile camps — the micro-organisms that build up 

 and the micro-organisms that pull down. An inces- 

 sant war is waged between them, but final victory 



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