﻿Frequency 
  and 
  Molecular 
  Number. 
  459 
  

  

  Group 
  VIII. 
  

   Iron 
  Compounds 
  (N 
  = 
  26). 
  

  

  Xame. 
  Formula. 
  IS. 
  VxlCT 
  12 
  . 
  NvXlO 
  -12 
  . 
  

   Iron 
  

  

  disulphide 
  FeS* 
  58 
  3-748 
  104x2u-7 
  

  

  phosphide 
  Fe 
  2 
  P 
  67 
  3653 
  12'x204 
  

  

  r 
  FRRTP 
  

  

  chloride 
  FeCl 
  83 
  1-498 
  6 
  x207 
  

  

  oxide 
  Fe 
  2 
  3 
  76 
  3'330 
  12 
  x21 
  1 
  

  

  Ferrous 
  

  

  sulphide 
  FeS 
  42 
  4-856 
  10x20-4 
  

  

  Ferroso-Ferric 
  

  

  oxide 
  Fe 
  3 
  4 
  110 
  2762 
  15 
  x203 
  

  

  Cobalt 
  Compounds 
  (N=27). 
  

   Cobalt 
  

   carbouyl 
  Co(CO) 
  4 
  83 
  0-927 
  3£x20-5 
  

  

  CoBALTOUS 
  

  

  sulphate 
  CoS0 
  4 
  75 
  2477 
  9 
  X20-6 
  

  

  Nickel 
  Compound 
  (N 
  = 
  28). 
  

  

  Nickel 
  

   sulphide 
  mono- 
  NiS 
  44 
  3-914 
  8ix20-3 
  

  

  Ruthenium 
  Compound 
  (N 
  = 
  44). 
  

   Ruthenium 
  

   tetroxide 
  Eu0 
  4 
  76 
  P399 
  5 
  X213 
  

  

  Osmium 
  Compound 
  (N=76). 
  

   Osmium 
  

   tetroxide 
  Os0 
  4 
  108 
  1079 
  5£x212 
  

  

  In 
  the 
  foregoing 
  pages 
  a 
  number 
  of 
  cross-correspondences 
  

   between 
  the 
  values 
  of 
  the 
  frequency 
  numbers 
  for 
  related 
  

   compounds 
  have 
  been 
  noticed. 
  But 
  instances 
  might 
  also 
  be 
  

   cited 
  in 
  which 
  the 
  frequency 
  number 
  has 
  not 
  the 
  value 
  which 
  

   might 
  have 
  been 
  predicted 
  for 
  it 
  by 
  analogy. 
  For 
  example, 
  

   the 
  chlorides 
  of 
  potassium 
  and 
  rubidium 
  have 
  the 
  same 
  

   frequencv 
  number 
  6, 
  but 
  though 
  the 
  frequency 
  number 
  for 
  

  

  calcium 
  chloride 
  is 
  6 
  that 
  for 
  strontium 
  chloride 
  is 
  7_ 
  

   again 
  the 
  iodides 
  of 
  calcium, 
  strontium, 
  barium 
  give 
  the 
  

   unexpected 
  sequence 
  of 
  numbers 
  9, 
  8£, 
  9. 
  In 
  view 
  of 
  the 
  

   hypothesis 
  that 
  has 
  been 
  put 
  forward 
  relating 
  the 
  frequency 
  

   number 
  to 
  the 
  number 
  of 
  valency 
  electrons, 
  it 
  may 
  be 
  sug- 
  

   gested 
  that 
  the 
  frequency 
  number 
  determined 
  from 
  the 
  

   melting-point 
  may 
  not 
  have, 
  in 
  all 
  cases, 
  a 
  unique 
  value, 
  

  

  