The Groundwork of the Universe, Sec. 81 



pose very sluggishly, so that uranium in one year only yields us 

 1-10,000,000,000 part of the total energy of transformation. 



It will be necessary, if this great store is to be opened, that 

 ordinary element some not (normally radioactive) should be used, 

 as the available quantity of the radioactive elements is so small. 

 If, or when, this power be placed in the hands of science its 

 potentialities alike for good or evil will be quite unlimited. It is 

 impossible to forecast the effect of such a discovery upon national 

 or social existence. 



It may be noted that radioactivity is almost entirely a 

 Franco-British science. First came the work of Sir William 

 Crookes, Sir J. J. Thomson, Becquerel, Debierne, and the Curies ; 

 then the great generalisations due to the labours of Sir Ernest 

 Ruthei'ford, Sir William Ramsay, Fleck, Moseley and Soddy. 

 Germany has contributed nothing to this great advance in our 

 knowledge. 



Note. — A full account of radioactivity, written for the non-expert, will 

 be found in Professor Soddy's Interpretation of Radium. In 

 connection with problems of power the reader will find much of 

 interest in Matter and Energy, by the same author (in the Home 

 University Library). An account of the Periodic Law is to be 

 found in Professor Letts' Chemistry Old and New. 



