66 Master Minds of Modern Science 



went on. The ore had to be boiled, filtered, decanted, 

 and crystallized, over and over again. At last a strongly 

 radio-active substance was obtained. Mme Curie called 

 it polonium, after her own native land. But this was not 

 the end of the search, for it was clear that there was 

 something even more powerful connected with the barium 

 residue of the mass they had treated. 



Mme Curie kept on steadily, and at last in 1902 suc- 

 ceeded in isolating a salt of radium. The amount ob- 

 tained was just about enough to fill a small salt-spoon. 

 The work had taken four years, and had been not only 

 difficult, but also dangerous, for Pierre Curie's hands were 

 in a sad state as the result of handling tubes of radium. 

 At that date no one had yet realized the danger of the 

 rays emitted at such enormous speed. 



In 1903, before the Paris Faculty of Science, Mme Curie 

 read a paper on her researches, and woke up next day to 

 find herself famous. She received her doctor's degree, 

 and was besieged by reporters and photographers. The 

 latter she dodged as best she could, for Mme Curie is 

 modest. 



A few months later the Curies visited London at the 

 invitation of Lord Kelvin ; the Davy Gold Medal of the 

 Royal Society, one of the greatest honours Science can 

 bestow, was awarded them. Later in the same year 

 another reward came their way; this was the Nobel 

 Prize, a sum of nearly six thousand pounds, a fortune to 

 two people of tastes as simple as theirs. 



While in London, M. Curie lectured on radium before 

 the Royal Institution. His hands were so sore and blis- 

 tered that he was unable to dress himself, yet he managed 

 to handle his apparatus, and his lecture created a tre- 

 mendous sensation. To prove that radium throws off 

 heat continually he took two glass vessels, one containing 

 a thermometer and a tube of radium, the other a thermo- 

 meter but no radium. The thermometer in the former 



