Ud [ntfiiselij Radwaclioe Gas from Metallic Mcrcuri/. 115 

 The results wore as follows : — 



Time (days)... 04 ID -31 '44 94 144 1-94 244 294 

 Leak IIG 140 138 134 118 112 94-5 94-1 78-7 



Tinie(aays)... 3-40 394 4-4() 49() 5-44 6*04 7*01 7-96 8-95 

 Leak 69-3 ()G-3 60-6 517 457 40-6 31-l> 26-0 21-5 







C 



Lirve of 



Decay 



of Mercury Eiiianation. 







teo 



f\ 



\ 

















— 





1 





• 



\^ 





















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Irn 











\ 



































^ 











^% 













^ 40 













-^ 











CO 























^^^==== 





The results are graphically exhibited on the diagram. It 

 will be noticed that the leak rises to a maximum value, about 

 J; part greater than its initial value, after "15 day; it then 

 dhninishes in geometrical progression with the time. Taking 

 successive ^-day intervals on the smoothed curve, after the 

 first I day, we find for the successive ratios of initial to final 

 leak : — 



1-12 1-11 1-10 1-10 1-11 1-11 

 1-12 1-14 1-U 1-11 l-U 1-11 



1-10 1-12 1-12 

 1-10 1-10 



So that the geometrical law is closely followed. The leak 

 falls to i value in 3*18 days. This is not very different from 

 the value for the radium emanation. Rutherford gives for it 

 3' 7 days, Curie 4*0 days. The initial increase of leak exactly 

 corresponds to Rutherford^s observation on the radium ema- 

 nation*, and may be referred to the same explanation. 



Many important points remain to be investigated, but 



Phil. Mag. vol. 

 i'2 



44S. 



