EMANATION X AND THE BIRTH OF HELIUM. 



125 



to hydrogen to lightness. However that may be, if, as 

 seems to be the case, helium is produced from the radium 

 decomposition, the world, in this experiment, has witnessed 

 the greatest triumph of modern science no more nor less 

 than the transmutation of matter. The dream of the al- 

 chemists is, true. Whether helium is the final product of 

 the radium disintegration, or a by-product from the emana- 

 tion, is to-day unknown. 



Fig. 40. The five characteristic bright lines of the spectrum of helium. 



We may now sum up the series of radio-active changes 

 in radium by the following tabulation, remembering that 

 between the emanation X and the final product there prob- 

 ably exists several intermediate forms, and that somewhere 

 in the chain helium appears. 



Radium containing 25 per cent, of non-separable activity 

 in the form of alpha-rays. 



Radium emanation containing 18 per cent, of the activ- 

 ity in the form of alpha-rays. 



Radium emanation X containing 57 per cent, of the to- 

 tal activity as alpha-, beta- and gamma-rays. 



Final 





