﻿260 
  The 
  Series 
  Law 
  of 
  Resonance 
  Spectra. 
  

  

  The 
  variation 
  is 
  irregular, 
  and 
  it 
  is 
  obvious 
  that 
  the 
  series 
  

   is 
  o£ 
  a 
  different 
  type 
  from 
  the 
  one 
  excited 
  by 
  the 
  green 
  line, 
  a 
  

   portion 
  of 
  which 
  at 
  least 
  was 
  well 
  represented 
  by 
  a 
  formula. 
  

  

  In 
  the 
  case 
  of 
  the 
  excitation 
  by 
  the 
  5790*7 
  line, 
  we 
  ob- 
  

   tained 
  different 
  values 
  of 
  \ 
  in 
  the 
  case 
  of 
  the 
  Cooper- 
  Hewitt 
  

   lamp, 
  consequently 
  these 
  values 
  only 
  are 
  given 
  in 
  the 
  table. 
  

   It 
  is 
  probable 
  that 
  in 
  the 
  case 
  of 
  the 
  quartz 
  lamp 
  at 
  115 
  volts 
  

   reversal 
  of 
  the 
  line 
  causes 
  the 
  disappearance 
  of 
  the 
  doublets 
  

   excited 
  by 
  the 
  lamp 
  running 
  at 
  a 
  lower 
  temperature 
  : 
  — 
  

  

  Excitation 
  by 
  Cooper-Hewitt 
  5790*7 
  (5792*3 
  Reduced 
  

   to 
  Vacuum.) 
  

  

  I 
  Dif. 
  

  

  63 
  

  

  X. 
  

  

  

  

  - 
  2 
  Order. 
  

  

  5658-6 
  

   5660-3 
  

  

  1767221 
  

   669 
  J 
  

  

  

  — 
  1 
  Order. 
  

  

  5722-1 
  

   5723-2 
  

  

  174761 
  1 
  

   727/ 
  

  

  

  Order. 
  

  

  5792-3 
  

   5797*9 
  

  

  172644 
  1 
  

   476/ 
  

  

  

  First 
  Order. 
  

  

  5871-3 
  

   5873-4 
  

  

  170320 
  1 
  

   259 
  J 
  

  

  

  Second 
  Order. 
  

  

  5936-8 
  

   38-9 
  

  

  168441 
  1 
  

   380] 
  

  

  

  Third 
  Order. 
  

  

  34 
  

  

  168 
  

  

  61 
  

  

  61 
  

  

  69 
  

  

  X. 
  

  

  1 
  

   X 
  

   Fourth 
  Order. 
  

  

  1-Dif. 
  

  

  A 
  

  

  6084-3 
  

   88-3 
  

  

  164357 
  1 
  

  

  249/ 
  

  

  Fifth 
  Order. 
  

  

  108 
  

  

  61639 
  

   661 
  

  

  162235 
  "1 
  

   177/ 
  

  

  Sixth 
  Order. 
  

  

  58 
  

  

  6242-3 
  

   45-0 
  

  

  1601971 
  

  

  128/ 
  

  

  Seventh 
  Order. 
  

  

  69 
  

  

  6325-8 
  

   29-2 
  

  

  158083 
  1 
  

   157997 
  J 
  

  

  Eighth 
  Order. 
  

  

  86 
  

  

  6404-0 
  

   06-7 
  

  

  156152 
  \ 
  

   086J 
  

  

  66 
  

  

  6010-8 
  166367 
  "I 
  

  

  13-3 
  298/ 
  

  

  In 
  the 
  case 
  of 
  the 
  series 
  excited 
  by 
  this 
  line 
  the 
  doublets 
  

   are 
  present 
  in 
  all 
  orders, 
  but 
  the 
  1/A, 
  difference 
  between 
  

   their 
  components 
  varies 
  in 
  a 
  very 
  irregular 
  manner 
  from 
  a 
  

   minimum 
  value 
  of 
  34 
  to 
  a 
  maximum 
  value 
  of 
  168. 
  

  

  The 
  spacing 
  of 
  the 
  series 
  along 
  the 
  spectrum 
  i§ 
  more 
  

   regular, 
  however, 
  the 
  1/X, 
  differences 
  being 
  as 
  follows 
  (the 
  

   last 
  significant 
  figure 
  is 
  omitted) 
  : 
  

  

  196 
  

   211 
  

   232 
  

   188 
  

   207 
  

   203 
  

   209 
  

  

  205 
  

   211 
  

   193 
  

   212 
  

   200 
  

   209 
  

  

  