Vital Effects of Radium and other Rays. 



[Feb. 2, 



Conclusion. — There is a war in this world which ceases neither 

 day nor night. It is the war against disease and death. Those 

 engaged in this battle, whether they be in the crowded city or in the 

 lonely swamp, are ever seeking some new weapons with which to 

 meet the foe, and it has been my privilege to-night to explain, how- 

 ever imperfectly, some few of the most recent additions to the scien- 

 tific armoury of medicine. 



Notes. 



Radium, life 

 Emanation, average life 

 Active deposit . 



2500 years 

 5-57 days 

 3 hours 



Thorium, average life 

 INIeso-thorium I., average life 

 Meso-thorium II. ,, ,, 



unknown 

 7 • 9 years 

 8 • 9 hours 



Radiation, Beta cmcl Gamma Rays. 



Radio-thorium, life 

 Alpha rays 

 Thorium X 

 Alpha rays 

 Actinium 

 Emanation 



2 • 91 years 

 5" 35 days 



5"6 seconds 



Rutherford gives the following : — 



