THE PHILOSOPHER'S STONE. 



The questions arise, What becomes of the 

 parts which fly out from the disintegrating 

 atom ? And what becomes of the part which 

 remains behind ? 



A partial solution of the first of these ques- 

 tions was obtained, about three years ago, by 

 Sir William Ramsay, at University College, 

 London. He had the satisfaction of witnessing 

 in his experiment the most interesting event, 

 theoretically, that has occurred in the whole 

 history of science. Having placed in a tiny 

 tube a small quantity of the emanation from 

 radium, he discovered, in a week, the spectrum 

 of helium, a gas which he had himself previously 

 been the first to discover in the world, though 

 astronomers had long since learned by spectro- 

 scopic observations of its presence in the sun. 



Radium, then, had changed during a week 

 into helium. 



Now, radium and helium are, so far as 

 chemical and physical tests can decide the 

 matter, different elements. 



Here, then, we have the transmutation of 

 one element into another in principle, the 

 discovery of the philosopher's stone and the 

 realisation of the dream of the alchemists. 



How far it will lead no one can say, or 

 whether we shall ever be able to deal so freely 

 with the transmutation of elements as we can 

 now with the analysis and synthesis of com- 

 pounds. 



213 



