TX] EXCITED RADIO-ACTIVITY 257 
Time in hours Current 
0 100 
79 64 
11°8 47-4 
23°4 19°6 
29:2 13°8 
32°6 10°3 
49-2 3°7 
62°1 1°86 
71:4 0°86 
The results are shown graphically in Fig. 49, Curve A. 
100 


80 


60 
Ourrent 

40 



20 











(0) 20 40 60 80 100 
Time in Hours 
Fig, 49. 
The intensity of the radiation J after any time ¢ is given by 
— =e where X is the radio-active constant. 
0 
The rate of decay of excited activity, like that of the activity of 
other radio-active products, is not appreciably affected by change of 
conditions. The rate of decay is independent of the concentration of 
the excited activity, and of the material of the body in which it is 
produced. It is independent also of the nature and pressure of the 
iy Leese L7/ 
