THE JOURNEYING ATOMS 



planation. Herein again is where life differs from 

 fire; we can describe combustion in terms of chemis- 

 try, but after we have described life in the same 

 terms something — and this something is the main 

 thing — remains untouched. 



The facts of radio-activity alone demonstrate 

 the truth of the atomic theory. The beta rays, or 

 emanations from radium, penetrating one foot of 

 solid iron are very convincing. And this may go on 

 for hundreds of years without any appreciable 

 diminution of size or weight of the radio-active sub- 

 stance. "A gram of such substance," says Sir Oliver 

 Lodge, "might lose a few thousand of atoms a sec- 

 ond, and yet we could not detect the loss if we con- 

 tinued to weigh it for a century." The volatile 

 essences of organic bodies which we detect in odors 

 and flavors, are not potent like the radium emana- 

 tions. We can confine them and control them, but 

 we cannot control the rays of radio-active matter 

 any more than we can confine a spirit. We can 

 separate the three different kinds of rays — the 

 alpha, the beta, and the gamma — by magnetic 

 devices, but we cannot cork them up and isolate 

 them, as we can musk and the attar of roses. 



And these emanations are taking place more or less 

 continuously all about us and we know it not. In 

 fact, we are at all times subjected to a molecular 

 bombardment of which we never dream; minute 

 projectiles, indivisible points of matter, are shot 



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