SCIENTIFIC HYPOTHESIS 251 



RADIUM a 4- slow ft 



Emanation a 



Radium A a 



Radium B 



Radium C 



V. C/2 



RADIUM D 



RADIO-LEAD S W 



Radium E 

 Radium F 

 Polonium 



\ 

 j 



) 

 J 



THORIUM o 



MESOTHORIUM 1 no rays 



Meso thorium 2 



RADIOTHORIUM a 



Thorium X a 



Emanation a 



Thorium A a 



Thorium B slow 

 f 1 



i 







C 2 a 



Thorium D 



ACTINIUM no rays 



Radio-actinium a 4- ft 



Actinium X a 



Emanation a 



Actinium A a 



Actinium B slow 8 



Actinium C a 



Actinium D a-f-y 



