﻿82 
  Mr. 
  Gervaise 
  Le 
  Bas 
  

  

  on 
  

  

  s 
  

  

  Kopp's 
  reasoning 
  was 
  somewhat 
  as 
  follow? 
  

  

  M.V. 
  of 
  Benzene, 
  C 
  H 
  6 
  96 
  

  

  M.V. 
  of 
  Butane, 
  C 
  4 
  H 
  10 
  96 
  

  

  Thus 
  2 
  vols, 
  of 
  C 
  = 
  4 
  vols, 
  of 
  H, 
  and 
  C 
  = 
  2 
  H. 
  

  

  But 
  1 
  vol. 
  of 
  CH 
  2 
  = 
  22. 
  

  

  Therefore 
  

  

  22 
  11 
  

  

  1 
  vol. 
  of 
  = 
  -~- 
  =11, 
  and 
  1 
  vol. 
  of 
  H 
  = 
  -^ 
  = 
  5*5. 
  

  

  The 
  similarities 
  found 
  in 
  the 
  above 
  table, 
  however, 
  are 
  

   illusive, 
  for 
  the 
  two 
  series 
  are 
  not 
  comparable 
  : 
  that 
  is 
  to 
  say, 
  

   the 
  apparent 
  volumes 
  of 
  the 
  atoms 
  in 
  the 
  nucleus 
  of 
  aromatic 
  

   compounds 
  are 
  not 
  the 
  same 
  in 
  size 
  as 
  those 
  in 
  the 
  paraffin 
  

   hydrocarbons. 
  The 
  well-known 
  difference 
  in 
  their 
  constitutions 
  

   is 
  marked 
  by 
  a 
  very 
  important 
  difference 
  in 
  their 
  volumes, 
  a 
  

   constitutive 
  effect 
  which 
  is 
  of 
  the 
  nature 
  of 
  a 
  contraction. 
  

  

  The 
  complex 
  C 
  6 
  H 
  6 
  inthe 
  paraffin 
  hydrocarbon 
  series 
  possesses 
  

   a 
  volume 
  of 
  30x3'7 
  = 
  lll 
  at 
  the 
  boiling-point, 
  so 
  that 
  on 
  

   passing 
  from 
  the 
  aliphatic 
  to 
  the 
  aromatic 
  series 
  a 
  contraction 
  

   of 
  111 
  — 
  96 
  = 
  15 
  occurs. 
  This 
  is 
  characteristic 
  of 
  all 
  com- 
  

   pounds 
  possessing 
  the 
  hexacyclic 
  ring. 
  

  

  Vol. 
  of 
  complex, 
  C 
  6 
  H 
  6 
  96 
  + 
  15 
  = 
  111. 
  

  

  Vol. 
  of 
  butane, 
  C 
  4 
  H 
  10 
  96. 
  

  

  Therefore 
  2 
  vols, 
  of 
  C 
  = 
  4 
  vols, 
  of 
  H 
  + 
  15 
  = 
  8 
  vols, 
  of 
  H, 
  

   and 
  1 
  vol. 
  of 
  C 
  =4 
  vols, 
  of 
  H 
  =4 
  S. 
  

  

  But 
  1 
  vol. 
  of 
  H 
  = 
  ~ 
  =3-66; 
  1 
  vol. 
  of 
  C 
  =22-7'3 
  = 
  14-7 
  

   b 
  =4x3-67. 
  

  

  It 
  must 
  be 
  remarked 
  that 
  the 
  similarity 
  between 
  the 
  amount 
  

   of 
  the 
  contraction 
  and 
  an 
  integral 
  number 
  of 
  unit-steres 
  of 
  

   hydrogen 
  volumes 
  is 
  quite 
  a 
  coincidence 
  and 
  does 
  not 
  hold 
  

   under 
  other 
  conditions. 
  

  

  Direct 
  evidence 
  for 
  the 
  above 
  contraction 
  is 
  found 
  in 
  the 
  

   following 
  : 
  — 
  

  

  M.V. 
  of 
  Heptylene, 
  7 
  H 
  14 
  154-8 
  

  

  M.V. 
  of 
  6 
  Hydrotoluene, 
  C 
  7 
  H 
  U 
  142-3 
  

  

  M.V. 
  of 
  Octylene, 
  8 
  H 
  lfl 
  177'6 
  

  

  lo'o 
  

   M.V. 
  of 
  6 
  Hydroxylene, 
  O 
  8 
  H 
  10 
  1043 
  

  

  The 
  above 
  comparisons 
  have 
  already 
  been 
  made 
  by 
  Horst- 
  

   mann 
  (Ber. 
  1890, 
  xx. 
  p. 
  766). 
  The 
  following 
  further 
  

   evidence 
  may 
  be 
  adduced 
  : 
  — 
  

  

  M.V. 
  of 
  Benzene. 
  C,H, 
  +fiH= 
  (O 
  ir,.,) 
  = 
  964-22-2=118'2 
  ^ 
  

  

  M.V. 
  of 
  Hexylene,C,ir,., 
  1824 
  

  

  M.V. 
  of 
  p 
  Xylene, 
  O 
  8 
  H 
  10 
  +6H=(O 
  7 
  H 
  u 
  )=140'6+22-2=162-7 
  {[{) 
  

   M.V. 
  ofOctylene, 
  C 
  7 
  ll 
  n 
  177*6 
  

  

  