478 



POPULAR SCIENCE MONTHLY. 









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not recommended when an operation is 

 practicable. Numerous other cases of 

 the beneficial results of the radium 

 treatment have been reported in this 

 country and England. 



More exact measurements by other 

 observers corroborate the conclusion of 

 Rutherford that the radiations from 

 radium which are the least penetrating 

 of the three types present, but repre- 

 sent the greater part of the energy, 



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consist of positively charged particles 

 of about twice the mass of the hydro- 

 gen atom, and moving with a velocity 

 about one tenth that of light. 



The supply of radium on the market 

 is very uncertain. All of it is imported 

 from France or Germany, and the price 

 has recently been going higher. Many 

 efforts are being made to extract 

 radium in this country from carnotite, 

 an ore of uranium that is found in 

 considerable abundance in Colorado and 



