﻿348 
  

  

  i 
  Dr. 
  H. 
  S. 
  Allen 
  on 
  Molecular 
  

  

  Table 
  IX. 
  

   Aromatic 
  Compounds. 
  

  

  Name. 
  

  

  Formula. 
  

  

  N. 
  

  

  rxio- 
  12 
  . 
  

  

  NvXHT 
  12 
  

  

  Xylidene 
  (1:4:2) 
  

  

  Chlorquinoline 
  (py 
  2) 
  ... 
  

   Chlorquinoline 
  (py 
  4)... 
  

  

  Naphthalene 
  

  

  Triphenyl 
  phosphine 
  ... 
  

  

  (CH 
  3 
  ) 
  2 
  C 
  6 
  H 
  3 
  .NH 
  2 
  

  

  C 
  9 
  H 
  6 
  C1N 
  

  

  C 
  9 
  H 
  6 
  C1N 
  

  

  C 
  6 
  H 
  4 
  . 
  C 
  4 
  H 
  4 
  

  

  (C 
  6 
  H 
  5 
  ) 
  3 
  P 
  

  

  C 
  6 
  H 
  5 
  .NH.NH.C 
  6 
  H 
  5 
  

  

  O 
  10 
  H 
  16 
  O 
  

  

  N0 
  2 
  . 
  C 
  6 
  H 
  4 
  . 
  NH 
  2 
  

  

  CgXX 
  2 
  Cl 
  1 
  

  

  C 
  8 
  H 
  14 
  (C0 
  2 
  H) 
  2 
  

   C 
  10 
  H 
  14 
  O 
  3 
  

  

  C 
  6 
  H 
  4 
  :(CO) 
  2 
  :C 
  G 
  H 
  4 
  

  

  66 
  

   84 
  

   84 
  

   68 
  

  

  138 
  

   98 
  

   84 
  

   72 
  

  

  106 
  

  

  108 
  

   98 
  

  

  108 
  

  

  0-954 
  

   0-842 
  

   0-858 
  

   1062 
  

   0-592 
  

   0-842 
  

   0-989 
  

   1-173 
  

   0-874 
  

   0-859 
  

   0-949 
  

   0-961 
  

  

  3 
  X21-0 
  

   3ix20-2 
  

   3ix206 
  

   3ix20-5 
  

  

  4 
  X20-4 
  

   4 
  X20-6 
  

   4 
  X20-8 
  

  

  4 
  X21-1 
  

   4ix20-6 
  

   4ix20-6 
  

   4ix207 
  

  

  5 
  X207 
  

  

  Camphor 
  

  

  Nitraniline 
  (p) 
  

  

  Tetrachlor 
  benzene 
  (s)... 
  

  

  Camphoric 
  acid 
  (d) 
  

  

  Camphoric 
  anhydride... 
  

   Anthraquinone 
  

  

  

  It 
  has 
  been 
  mentioned 
  already 
  that 
  for 
  a 
  considerable 
  

   number 
  of 
  organic 
  compounds 
  the 
  proposed 
  relation, 
  in 
  its 
  

   simple 
  form, 
  does 
  not 
  hold. 
  One 
  possible 
  suggestion 
  as 
  to 
  

   the 
  reason 
  for 
  this 
  failure 
  will 
  be 
  considered 
  in 
  the 
  following 
  

   section. 
  

  

  § 
  7. 
  Molecular 
  Association 
  in 
  Solids. 
  

  

  A 
  question 
  of 
  great 
  importance, 
  which 
  can 
  only 
  be 
  con- 
  

   sidered 
  briefly 
  in 
  this 
  paper, 
  is 
  the 
  determination 
  of 
  the 
  true 
  

   value 
  of 
  the 
  molecular 
  weight 
  of 
  a 
  solid 
  compound. 
  Nernst 
  

   has 
  shown 
  how 
  the 
  constitution 
  of 
  the 
  molecule 
  may 
  be 
  

   inferred 
  from 
  the 
  correspondence 
  between 
  the 
  molecular 
  heat 
  

   at 
  low 
  temperatures 
  and 
  the 
  value 
  calculated 
  by 
  Debye's 
  

   formula. 
  For 
  example, 
  he 
  concludes 
  that 
  the 
  molecule 
  of 
  ice 
  is 
  

   not 
  hydrol 
  (#/ 
  = 
  227) 
  but 
  dihydrol 
  (/3v 
  = 
  155). 
  On 
  the 
  first 
  

   supposition 
  we 
  find 
  Ni>=47*5 
  x 
  10 
  12 
  , 
  which 
  cannot 
  be 
  ex- 
  

   pressed 
  as 
  a 
  multiple 
  of 
  v 
  M 
  but 
  the 
  second 
  supposition 
  gives 
  

   Ni/= 
  64:'$ 
  xl0 
  12 
  = 
  3x 
  21*6 
  xlO 
  12 
  , 
  showing 
  good 
  agreement 
  

   with 
  the 
  new 
  relation. 
  

  

  If, 
  in 
  the 
  next 
  place, 
  we 
  apply 
  the 
  formula 
  of 
  Lindemann 
  

   to 
  ice 
  (T 
  s 
  = 
  273°-1 
  K, 
  /o 
  = 
  0'917), 
  we 
  find 
  that 
  neither 
  H 
  2 
  

   nor 
  (H 
  2 
  0) 
  2 
  gives 
  satisfactory 
  agreement. 
  When, 
  however, 
  

   we 
  assume 
  that 
  the 
  ice 
  molecule 
  at 
  the 
  melting-point 
  is 
  

   trihydrol, 
  (H 
  2 
  0) 
  3 
  , 
  we 
  find 
  Ni/ 
  = 
  2J 
  x 
  21-4 
  x 
  10 
  12 
  . 
  The 
  method 
  

   does 
  not 
  give 
  a 
  unique 
  determination 
  of 
  the 
  degree 
  of 
  asso- 
  

   ciation, 
  for 
  equally 
  good 
  concordance 
  is 
  obtained 
  by 
  assuming 
  

   that 
  the 
  ice 
  molecule 
  contains 
  9 
  groups 
  of 
  H 
  2 
  0, 
  which 
  makes 
  

   Ni/ 
  = 
  3x21-4xl0 
  12 
  . 
  

  

  On 
  general 
  grounds 
  it 
  seems 
  most 
  probable 
  that 
  ice 
  at 
  the 
  

   melting-point 
  is 
  pure 
  trihydrol. 
  This 
  was 
  the 
  conclusion 
  

  

  