﻿80 
  

  

  Mr. 
  Gervaise 
  Le 
  Bas 
  on 
  

  

  The 
  volume 
  of 
  a 
  single 
  hydrogen 
  in 
  these 
  compounds 
  is 
  

   about 
  4, 
  that 
  is, 
  a 
  little 
  higher 
  than 
  its 
  volume 
  in 
  the 
  paraffins. 
  

   The 
  number 
  is, 
  however, 
  much 
  higher 
  than 
  that 
  found 
  in 
  the 
  

   unsubstituted 
  hydroaromatic 
  compounds, 
  and 
  this 
  may 
  be 
  

   attributed 
  to 
  the 
  effect 
  of 
  the 
  side 
  chains 
  or 
  to 
  spatial 
  con- 
  

   siderations. 
  Curiously 
  enough, 
  the 
  unsaturated 
  part 
  of 
  the 
  

   naphthalene 
  has 
  precisely 
  the 
  same 
  effect 
  as 
  that 
  of 
  an 
  

   aliphatic 
  side 
  chain. 
  

   It 
  is 
  thus 
  concluded 
  — 
  

  

  (a) 
  That 
  the 
  volume 
  of 
  CH 
  2 
  is 
  22*2 
  on 
  the 
  average 
  in 
  

  

  the 
  homologues 
  of 
  benzene. 
  

   (V) 
  The 
  volume 
  of 
  the 
  extra 
  hydrogens 
  in 
  the 
  hydro- 
  

   aromatic 
  hydrocarbons 
  varies 
  from 
  3'25 
  to 
  4 
  at 
  the 
  

   boiling-point. 
  

  

  (iii.) 
  The 
  apparent 
  Atomic 
  Volumes 
  in 
  the 
  Nucleus 
  at 
  the 
  

   Boiling 
  and 
  the 
  Critical 
  Points. 
  

  

  Having 
  studied 
  the 
  volumes 
  of 
  carbon 
  and 
  hydrogen 
  in 
  

   the 
  side 
  chains, 
  it 
  is 
  now 
  necessary 
  to 
  examine 
  the 
  nuclei 
  

   more 
  particularly. 
  It 
  is 
  natural 
  to 
  suppose 
  that 
  the 
  apparent 
  

   volumes 
  of 
  carbon 
  and 
  hydrogen 
  still 
  stand 
  in 
  the 
  relation 
  of 
  

   4 
  to 
  1 
  in 
  the 
  nucleus, 
  although 
  their 
  absolute 
  values 
  might 
  

   differ 
  from 
  those 
  in 
  the 
  paraffins 
  under 
  similar 
  circumstances. 
  

   The 
  following 
  table 
  gives 
  the 
  value 
  of 
  V/W 
  for 
  a 
  number 
  

   of 
  single 
  ring 
  compounds, 
  none 
  of 
  the 
  hydrogens 
  being 
  dis- 
  

   placed 
  by 
  substituents. 
  Thus 
  the 
  relation 
  C 
  = 
  4 
  H 
  is 
  assumed. 
  

   Nitrogen 
  in 
  pyridine 
  and 
  piperidine 
  is 
  considered 
  to 
  possess 
  

   the 
  volume 
  3 
  8 
  in 
  accordance 
  with 
  its 
  fundamental 
  valency 
  

   number, 
  that 
  is 
  to 
  say, 
  it 
  is 
  equal 
  to 
  3 
  H. 
  

  

  Table 
  XVIII. 
  

  

  Table 
  showing 
  the 
  values 
  of 
  V/W 
  for 
  a 
  number 
  of 
  simple 
  

  

  cyclic 
  arrangements. 
  

  

  Compound. 
  

  

  v,,,. 
  

  

  W. 
  

  

  V 
  \Y. 
  

  

  v 
  K 
  . 
  w. 
  v/w. 
  

  

  Benzene, 
  C 
  G 
  H 
  e 
  

  

  Hexaliydroben/.ene, 
  0,11,., 
  

  

  Pyridine, 
  6 
  H 
  B 
  N 
  ... 
  

   Piperidine, 
  (' 
  !l,,N... 
  

   Paraflins 
  

  

  90 
  

   1163 
  

  

  89-3 
  

   108-8 
  

  

  30 
  

   36 
  

  

  28 
  

   34 
  

  

  3-20 
  

   323 
  

   3-19 
  

   8-20 
  

   3-70 
  

  

  2563 
  

   306-7 
  

  

  A 
  = 
  49-0 
  

   H 
  

  

  30 
  8-54 
  

   30 
  s 
  52 
  

  

  for 
  II 
  ... 
  

  

  = 
  83. 
  

   9-66 
  

  

  

  

  The 
  above 
  table 
  shows 
  very 
  clearly 
  that 
  the 
  relation 
  

   between 
  the 
  volumes 
  of 
  carbon 
  and 
  hydrogen 
  is 
  the 
  same 
  in 
  

   the 
  nucleus 
  as 
  in 
  (he 
  side 
  chains, 
  and 
  a- 
  in 
  the 
  paraffins. 
  

  

  