﻿406 
  Dr. 
  H. 
  S. 
  Allen 
  on 
  Molecular 
  

  

  to 
  correspond 
  with 
  the 
  atom 
  of 
  sodium 
  (N 
  = 
  ll), 
  and 
  the 
  

   latter 
  with 
  the 
  atom 
  of 
  chlorine 
  (N 
  = 
  17), 
  we 
  find 
  for 
  the 
  

   sodium 
  atom 
  Nv 
  = 
  3 
  x 
  20 
  "5 
  x 
  10 
  12 
  and 
  for 
  the 
  chlorine 
  atom 
  

   Ny 
  = 
  5 
  x 
  21*7 
  x 
  10 
  12 
  . 
  If, 
  however, 
  we 
  associate 
  the 
  chlorine 
  

   atom 
  with 
  the 
  stronger 
  line 
  and 
  the 
  sodium 
  atom 
  with 
  the 
  

   weaker, 
  we 
  obtain 
  for 
  the 
  products 
  95*1 
  x 
  10 
  12 
  and 
  70*4 
  x 
  10 
  12 
  , 
  

   which 
  are 
  not 
  integral 
  multiples 
  of 
  21 
  x 
  10 
  12 
  . 
  

  

  XC1. 
  For 
  sylvinf 
  similar 
  results 
  are 
  found, 
  but 
  in 
  this 
  case 
  

   the 
  stronger 
  line 
  (62"0/4 
  or 
  4*84 
  x 
  10 
  12 
  sec. 
  _1 
  )imust 
  be 
  associated 
  

   with 
  chlorine, 
  the 
  weaker 
  (70*3//, 
  or 
  4*27 
  x 
  10 
  12 
  sec." 
  1 
  ) 
  with 
  

   potassium 
  (N 
  = 
  19) 
  . 
  In 
  this 
  case 
  we 
  find 
  Nv 
  = 
  4 
  x 
  20" 
  6 
  x 
  10 
  12 
  

   and 
  Ni> 
  = 
  4 
  x 
  20'3 
  x 
  10 
  12 
  respectively. 
  The 
  products 
  obtained 
  

   when 
  the 
  atoms 
  are 
  interchanged 
  are 
  91'9 
  x 
  10 
  12 
  and 
  

   72*6 
  x 
  10 
  12 
  , 
  which 
  are 
  not 
  integral 
  multiples 
  of 
  21 
  x 
  10 
  12 
  . 
  

  

  KBr. 
  The 
  stronger 
  line* 
  is 
  at 
  86-5/4 
  (v 
  = 
  3'47 
  x 
  lO^sec" 
  1 
  ), 
  

   the 
  weaker 
  at 
  756/4 
  (i> 
  = 
  3'97 
  X 
  HPsec." 
  1 
  ). 
  The 
  former 
  

   must 
  be 
  associated 
  with 
  the 
  potassium 
  atom, 
  giving 
  

   Nv 
  = 
  3x21*9x 
  10 
  12 
  , 
  the 
  latter 
  with 
  the 
  bromine 
  atom, 
  giving 
  

   Nz> 
  = 
  6£x 
  21*4 
  xlO 
  12 
  . 
  The 
  occurrence 
  of 
  i 
  in 
  the 
  latter 
  

   case 
  is 
  noteworthy, 
  as 
  it 
  is 
  supported 
  by 
  independent 
  evi- 
  

   dence 
  in 
  connexion 
  with 
  specific 
  heats. 
  

  

  It 
  may 
  be 
  noted 
  that 
  for 
  these 
  three 
  compounds 
  the 
  

   stronger 
  line 
  is 
  associated 
  with 
  the 
  element 
  of 
  smaller 
  

   atomic 
  number. 
  

  

  KI. 
  The 
  residual 
  radiation 
  has 
  not 
  been 
  separated 
  into 
  

   two 
  rays 
  of 
  different 
  strengths, 
  but 
  it 
  is 
  stated 
  by 
  the 
  expe- 
  

   rimenters 
  f 
  that 
  such 
  a 
  constitution 
  is 
  possible. 
  In 
  such 
  a 
  

   case 
  we 
  may 
  call 
  v 
  t 
  and 
  v 
  2 
  the 
  frequencies 
  corresponding 
  to 
  

   elements 
  having 
  atomic 
  numbers 
  Nj, 
  and 
  N 
  2 
  , 
  and 
  put 
  

  

  'S 
  1 
  v 
  1 
  = 
  n 
  1 
  v 
  jL 
  , 
  N 
  2 
  v 
  2 
  = 
  ?? 
  2 
  v 
  A 
  . 
  

   By 
  addition, 
  

  

  NjV! 
  -f 
  N 
  2 
  v 
  2 
  = 
  (wi 
  + 
  n 
  2 
  )v 
  A 
  . 
  

  

  But 
  if 
  vi 
  and 
  v 
  2 
  are 
  not 
  very 
  different, 
  we 
  may 
  replace 
  either 
  

   frequency 
  by 
  the 
  arithmetic 
  mean 
  ^ 
  (yi 
  + 
  v 
  2 
  ), 
  and 
  so 
  obtain 
  

  

  The 
  observed 
  wave-length 
  for 
  KI 
  is 
  96*7/4, 
  so 
  that 
  we 
  have 
  

   |( 
  I 
  ; 
  1 
  + 
  z; 
  2 
  ) 
  = 
  3-10xl0 
  12 
  sec.- 
  1 
  . 
  

  

  For 
  Nj 
  + 
  Na 
  we 
  may 
  substitute 
  N 
  the 
  " 
  molecular 
  number.-" 
  

   Taking 
  N 
  x 
  = 
  19 
  and 
  N 
  2 
  = 
  53, 
  the 
  product 
  is 
  found 
  to 
  be 
  

   11 
  x 
  20*3 
  x 
  10 
  12 
  , 
  which 
  is 
  in 
  satisfactory 
  agreement 
  with 
  the 
  

   suggested 
  relation. 
  

  

  * 
  Rubens 
  and 
  Hollnagel, 
  loc. 
  cit. 
  

   f 
  Rubens 
  and 
  Hollnagel, 
  loc. 
  cit. 
  

  

  