THE BREATH OF LIFE 



sodium are not found in a free or separate state; they 

 hunted each other up long ago, and united to pro- 

 duce the enormous quantities of rock salt that the 

 earth holds. One can give his imagination free range 

 in trying to picture what takes place when two or 

 more elements unite chemically, but probably there 

 is no physical image that can afford even a hint of 

 it. A snake trying to swallow himself, or two fishes 

 swallowing each other, or two bullets meeting in the 

 air and each going through the centre of the other, 

 or the fourth dimension, or almost any other impos- 

 sible thing, from the point of view of tangible bodies, 

 will serve as well as anything. The atoms seem to 

 get inside of one another, to jump down one an- 

 other's throats, and to suffer a complete transforma- 

 tion. Yet we know that they do not; oxygen is still 

 oxygen, and carbon still carbon, amid all the strange 

 partnerships entered into, and all the disguises as- 

 sumed. We can easily evoke hydrogen and oxygen 

 from water, but just how their molecules unite, how 

 they interpenetrate and are lost in one another, it 

 is impossible for us to conceive. 



We cannot visualize a chemical combination be- 

 cause we have no experience upon which to found 

 it. It is so fundamentally unlike a mechanical mix- 

 ture that even our imagination can give us no clew 

 to it. It is thinkable that the particles of two or 

 more substances however fine, mechanically mixed, 

 could be seen and recognized if sufficiently magni- 



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