﻿120 
  

  

  Mr. 
  C. 
  A. 
  Sadler 
  on 
  the 
  

  

  In 
  order 
  to 
  deduce 
  values 
  of 
  k 
  from 
  the 
  experimental 
  data, 
  

   it 
  is 
  necessary 
  to 
  know 
  the 
  values 
  of 
  a, 
  /3y 
  X, 
  and 
  Xg 
  for 
  each 
  

   of 
  the 
  tertiary 
  radiators 
  employed, 
  a 
  and 
  /3 
  are 
  readily 
  

   obtained 
  for 
  the 
  whole 
  series 
  and 
  likewise 
  Xi 
  and 
  X2 
  for 
  Zn, 
  

   Cu, 
  Ni, 
  and 
  Fe. 
  In 
  the 
  case 
  of 
  Cr 
  and 
  Co, 
  being 
  unable 
  to 
  

   obtain 
  thin 
  plates 
  of 
  these 
  substances, 
  the 
  values 
  for 
  Xj 
  and 
  

   X2 
  could 
  not 
  be 
  obtained 
  directly 
  but 
  were 
  deduced 
  by 
  the 
  

   following 
  method. 
  

  

  If 
  the 
  values 
  of 
  — 
  (where 
  X2 
  is 
  the 
  absorption 
  coefficient 
  

  

  by 
  a 
  substance 
  of 
  its 
  own 
  characteristic 
  radiation 
  and 
  p 
  its 
  

   density) 
  for 
  the 
  substances 
  Fe, 
  Ni, 
  Gu, 
  and 
  Zn 
  are 
  plotted 
  

  

  Fig. 
  2. 
  

  

  70 
  

  

  60 
  

  

  

  50 
  

  

  40 
  

  

  \ 
  C?:83-7 
  

  

  

  

  

  N 
  

  

  \ 
  

  

  

  

  

  N 
  

  

  ^Cp.61-3 
  

  

  

  ' 
  

  

  

  \ 
  

  

  

  • 
  

  

  

  

  \ 
  

  

  

  

  

  

  400 
  

  

  300 
  200 
  ,100 
  

  

  /\Bsoppr/on 
  Cosrna£rifTS 
  byM. 
  

  

  as 
  ordinates, 
  against 
  the 
  absorption 
  coefficients 
  for 
  the 
  radia- 
  

   tions 
  from 
  these 
  substances 
  by 
  Al 
  as 
  abscissse, 
  it 
  is 
  found 
  that 
  

   the 
  points 
  obtained 
  lie 
  on 
  a 
  straight 
  line, 
  as 
  shown 
  in 
  fig. 
  2. 
  

  

  