﻿Radioactivity 
  of 
  Potassium 
  and 
  oilier 
  Alkali 
  Metals. 
  379 
  

  

  directly 
  proportional 
  to 
  the 
  areas 
  of 
  the 
  salt 
  exposed. 
  From 
  

   this 
  result 
  it 
  was 
  evident 
  that 
  the 
  substance 
  which 
  constituted 
  

   the 
  source 
  of 
  the 
  radiation 
  was 
  uniformly 
  distributed 
  through- 
  

   out 
  the 
  mass 
  of 
  the 
  salt. 
  

  

  Table 
  I. 
  

  

  Area 
  of 
  salt 
  exposed 
  in 
  

   sq. 
  cm. 
  

  

  Saturation 
  current. 
  

   Arbitrary 
  Scale. 
  

  

  5x18 
  

  

  17-87 
  

  

  10x18 
  

  

  35-5 
  

  

  15x18 
  

  

  53-8 
  

  

  20x18 
  

  

  71-5 
  

  

  25x18 
  

  

  89-75 
  

  

  30x18 
  

  

  106 
  

  

  35x18 
  

  

  123 
  

  

  Fiar. 
  2. 
  

  

  