﻿124 
  

  

  Mr. 
  C. 
  A. 
  Sadler 
  on 
  the 
  

   Table 
  VI. 
  

  

  

  Values 
  of 
  . 
  E 
  . 
  calculated 
  from 
  

   the 
  total 
  Ionization 
  in 
  the 
  

   lonization-chamber 
  I. 
  

  

  Values 
  of 
  . 
  R'. 
  calculated 
  

   from 
  the 
  normal 
  tertiary 
  

   Ionization 
  alone 
  in 
  the 
  

   lonization-chamber 
  I. 
  

  

  Tertiary 
  Radiators. 
  

  

  Secondary 
  

   Eadiators. 
  

  

  Or. 
  

  

  Fe. 
  

  

  Co. 
  

  

  m. 
  

  

  Cu. 
  

  

  Zn. 
  

  

  Cr. 
  

  

  Fe. 
  

  

  Co. 
  

  

  •366 
  

   2-90 
  

   3-27 
  

  

  3-47 
  

   3-01 
  

  

  Ni. 
  

  

  •472 
  

   3^42 
  

  

  3-68 
  

   3^36 
  

  

  Cu. 
  

  

  •488 
  

  

  3*86 
  

   3-50 
  

  

  1-24 
  

  

  Zn. 
  

  

  3*9*2 
  

   3-76 
  

  

  1-29 
  

  

  ! 
  

  

  Cr 
  

  

  •076 
  

   1-76 
  

   1-81 
  

   1-95 
  

   1-92 
  

   202 
  

  

  2-02 
  

   1-86 
  

  

  •107 
  

  

  •076 
  

  

  •42 
  

  

  2-64 
  

  

  2-64 
  

  

  2-88 
  

  

  3-ib 
  

  

  2-87 
  

  

  •109 
  

   •091 
  

   •097 
  

   •466 
  

   300 
  

   3-37 
  

  

  3-57 
  

   3-11 
  

  

  •143 
  

   •118 
  

   •118 
  

   •101 
  

   •582 
  

   3^53 
  

  

  3-79 
  

   3-47 
  

  

  •126 
  

   •100 
  

   •084 
  

   •093 
  

  

  •628 
  

  

  3-97 
  

   3-61 
  

  

  1-35 
  

  

  •124 
  

   •106 
  

   •087 
  

   •110 
  

   •115 
  

  

  4-03 
  

   3-86 
  

  

  ... 
  

  

  ... 
  

  

  ... 
  

   1*40 
  

  

  1-68 
  

   1-73 
  

  

  1-87 
  

   1-84 
  

   r94 
  

  

  1-94 
  

   r78 
  

  

  •327 
  

   2-45 
  

   2 
  55 
  

   2-79 
  

  

  3*01 
  

  

  2^78 
  

  

  Fe 
  

  

  Co 
  

  

  IS'i 
  

  

  Cu 
  

  

  Zn 
  

  

  Ga? 
  

  

  Ge?.. 
  

  

  As 
  

  

  Se 
  

  

  Ag 
  

  

  However, 
  it 
  is 
  found 
  that 
  when 
  zinc 
  is 
  used 
  as 
  a 
  tertiary 
  

   radiator 
  and 
  the 
  secondary 
  beams 
  from 
  iron 
  to 
  zinc 
  fall 
  upon 
  

   it 
  successively, 
  a 
  small 
  value 
  R 
  is 
  obtained, 
  even 
  though 
  none 
  

   of 
  the 
  characteristic 
  homogeneous 
  radiation 
  is 
  excited 
  by 
  

   these 
  secondary 
  beams. 
  The 
  ionization 
  in 
  the 
  chamber 
  I 
  in 
  

   these 
  cases 
  is 
  due, 
  partly 
  to 
  the 
  scattering 
  of 
  the 
  secondary 
  

   radiation, 
  partly 
  to 
  the 
  production 
  of 
  tertiary 
  radiation 
  by 
  

   the 
  small 
  percentage 
  of 
  scattered 
  primary 
  radiation 
  in 
  the 
  

   secondary 
  beam 
  employed, 
  and 
  possibly 
  in 
  part 
  to 
  the 
  pro- 
  

   duction 
  of 
  a 
  feeble 
  type 
  of 
  very 
  easily 
  absorbed 
  radiation 
  

   much 
  softer 
  than 
  the 
  normal 
  homogeneous 
  radiation 
  from 
  

   zinc. 
  

  

  All 
  evidence 
  obtained 
  up 
  to 
  the 
  present 
  points 
  to 
  the 
  

   persistence 
  of 
  these 
  residual 
  effects 
  even 
  when 
  the 
  exciting 
  

   secondary 
  beam 
  is 
  sufficiently 
  penetrating 
  to 
  produce 
  the 
  

   characteristic 
  zinc 
  radiation, 
  and 
  since 
  in 
  the 
  calculation 
  of 
  k 
  

   we 
  only 
  require 
  a 
  measure 
  of 
  the 
  homogeneous 
  tertiary 
  radia- 
  

   tion 
  excited 
  by 
  the 
  homogeneous 
  secondary 
  beam, 
  these 
  residual 
  

   effects 
  have 
  been 
  estimated 
  and 
  subtracted 
  in 
  each 
  case. 
  

  

  The 
  values 
  of 
  R 
  finally 
  obtained, 
  which 
  we 
  may 
  denote 
  by 
  

   R^, 
  are 
  given 
  in 
  Table 
  VI. 
  

  

  