THE DISCOVERY OF RADIO-ACTIVITY. 89 



years ago, rubbed a piece of amber on his coat-sleeve and 

 noticed that it attracted bits of paper, unknowing that this 

 bit of amber was equal to the lamp of Aladdin, or to that 

 Paleolithic savage, who, the first of all men, noticed the at- 

 tractive powers of lodestone. New properties of matter are 

 not so common that their significance can be exaggerated. 

 This new property of matter was called radio-activity, and as 

 such it takes its place beside magnetism, electricity, light and 

 heat. 



