THE TRANSFORMATION OF ELEMENTS 243 



that radioactive disintegration releases an enormous amount of 

 energy (p. 79) seems fatal to their argument just quoted. 



It is highly probable that ultimately some theory of evolution 

 and devolution of elements will be put forward, which will 

 approximate to the truth, especially as our knowledge of the 

 facts is increasing rapidly. It is just as certain that no such 

 theory has yet made its appearance. 



The following are the chief papers consulted in the prepara- 

 tion of Part III. of this paper : 



Ramsay and Soddy, On the Production of Helium from Radium, Proc. Roy. Soc. 



1903, 73, 345- 

 Curie and Dewar, The Gas from Radium Bromide, Compt. Rendus, 1904, 138, 



190. 

 Himstedt and Meyer, Formation of Helium from Radium Emanation, Annalen 



der Physik, 1904, 15, 184 ; 1905, 17, 1005. 

 Giesel, A Simple Proof of the Formation of Helium from Radium, Berichte, 1907, 



40, 301 1. 

 Debierne, On the Gases produced by Actinium, Compt. Rendus, 1905, 141, 383. 

 Ramsay and Cameron, The Chemical Action of Radium Emanation, Parts II. 



and IV., /. Chem. Soc. 1907, 91, 1593, and 1908, 93, 992. 

 Mme. Curie and Mlle. Gleditsch, The Action of Radium Emanation on 



Solutions of Copper Salts, Compt. Rendus, 1908, 147, 345. 

 Boltwood, On the Ultimate Disintegration Products of the Radioactive Elements, 



Amer.J. Science, 1905, 20, 253. 



The Origin of Radium, Phil. Mag. 1905, 9, 599. 



Strutt, On the Radioactive Minerals, Proc. Roy. Soc, 190;, 76, A, 88. 



On the Association of Helium and Thorium in Minerals, Proc. Roy. Soc. 1907, 



80, a. 572. 

 Helium and Radioactivity in Rare and Common Minerals, Proc. Roy. Soc. 



1908, 80, a, 56. 

 Cady and McFarland, The Occurrence of Helium in Natural Gas, J. Amer. 



Chem. Soc. 1907, 29, 1523. 

 Moureu, On the Gases from Hot Springs, Compt. Rendus, 1906, 142, 1 1 55. 

 Moureu and Biquard, On the Analysis of Rare Gases from Mineral Waters, 



Compt. Rendus, 1906, 143, 795, and 1908, 146, 435. 

 McCoy, The Occurrence of Copper and Lithium in Radium-bearing Minerals, 



Nature, 1907, 77, 79. 

 Mlle. Gleditsch, On the Lithium in Radioactive Minerals, Compt. Rendus, 



1908, 146, 331. 

 A. C. and A. E. Jessup, The Evolution and Devolution of the Elements, Phil. 



Mag. 1908, 15, 21. 



