The Experiments of Ramsay 



Moreover, these facts agree with what we know 

 regarding the origin of helium on the earth ; this 

 gas has always been found in radio-active 

 minerals, and its presence has been also recog- 

 nised in the gases emitted by deep mineral 

 springs, which must have been in contact under- 

 ground with similar minerals. 1 We have, there- 

 fore, the following incontestable fact: radium 

 and its congeners are elements in a state of 

 constant disintegration; they transform spon- 

 taneously under our very eyes into the emanation 

 which in its turn becomes helium. This evolu- 

 tion is predetermined and absolute; we can 

 neither accelerate nor retard it, and still less 

 reverse it and revert from helium to the 

 emanation or to radium. As Ramsay has him- 

 self pointed out: "Although the analogies 

 derived from ordinary chemistry are insufficient 

 to represent completely these new phenomena 

 they may help us to define our ideas; it is pos- 

 sible to remove the chlorine from ammonium 

 chloride NH 4 Cl when one would obtain the 

 group NH 4 , but this group is instable even in the 



1 The spring of Bourbon- Lancy sets free yearly ten 

 thousand litres of helium. 



77 



