Famous Scientists 



569 



she received the degree of Doctor of Science. In 1895 she mar- 

 ried Pierre Curie, a professor of physics in this school, and 

 together they spent much time in scientific research. 



About this time many scientists were engaged in following up 

 the research work of Henri Becquerel, a noted French scientist, 

 who had discovered that the mineral uranium and its compounds 

 possessed the property of 

 throwing out rays which were 

 able to enter into opaque ob- 

 jects and to act on photo- 

 graphic plates in a way similar 

 to X-rays. It was found that 

 this property of uranium re- 

 mained even when its com- 

 pounds were kept in darkness 

 for several months. The ques- 

 tion was whence came this 

 energy constantly given off by 

 uranium compounds. 



Madame Curie, among 

 other scientists, became great- 

 ly interested in this phenome- 

 non and determined to make 

 investigations of it. Accord- 

 ingly she examined all the 

 known elements and discov- 

 ered that compounds of thorium were the only ones that would 

 give off rays similar to those of uranium. She proposed the term 

 radio activity for this newly discovered property of matter, and 

 the term has been generally accepted. 



At this stage, her husband, Pierre Curie, became interested in 

 the search for this unknown substance. Abandoning other work, 

 he joined her, and together they continued their investigations for 

 several years. Having observed that pitch blende, the crude ore 

 from which uranium is obtained, was more radioactive, that is, 

 capable of giving off stronger rays than uranium, they suspected 

 there was an unknown element in pitch blende which caused this. 



Jrown Brothers. 



MADAME CURIE 



She discovered radium. 



