﻿the 
  Unit-Steve 
  Theory. 
  

  

  79 
  

  

  nucleus 
  in 
  derivatives 
  o£ 
  this 
  kind 
  remains 
  the 
  same 
  as 
  that 
  

   of 
  the 
  free 
  nucleus. 
  It 
  follows 
  that 
  the 
  volume 
  of 
  combined 
  

  

  • 
  22'2 
  

  

  hydrogen 
  is 
  — 
  — 
  = 
  3-7 
  and 
  of 
  combined 
  carbon 
  11*8 
  as 
  

  

  before. 
  

  

  (ii.) 
  The 
  volumes 
  of 
  the 
  six 
  extra 
  Hydrogen 
  atoms 
  in 
  

   Hydroaromatic 
  Compounds. 
  

  

  The 
  six 
  extra 
  hydrogen 
  atoms 
  in 
  hydroaromatic 
  compounds 
  

   may 
  be 
  viewed 
  in 
  the 
  light 
  of 
  side 
  chains, 
  in 
  which 
  case 
  they 
  

   might 
  be 
  supposed 
  to 
  possess 
  volumes 
  similar 
  to 
  those 
  of 
  

   hydrogen 
  atoms 
  in 
  the 
  paraffin 
  hydrocarbons 
  under 
  similar 
  

   circumstances. 
  It 
  will 
  be 
  found 
  that 
  they 
  usually 
  do. 
  

   Exceptions 
  are 
  found 
  in 
  the 
  cases 
  of 
  hexamethylene 
  and 
  

   hexahydropyridine 
  or 
  piperidine. 
  The 
  extra 
  hydrogens 
  in 
  

   these 
  compounds 
  appear 
  to 
  be 
  more 
  closely 
  associated 
  with 
  

   the 
  nucleus 
  than 
  is 
  the 
  case 
  with 
  hydrocarbon 
  side 
  chains. 
  

  

  Table 
  XVI. 
  

  

  Table 
  showing 
  the 
  Volume 
  of 
  H 
  6 
  in 
  Hydroaromatic 
  

  

  Compounds. 
  I. 
  

  

  Compound. 
  V. 
  

  

  6E 
  

  

  H. 
  

  

  

  20-3 
  

   19-5 
  

  

  3-38 
  

   325 
  

  

  Hexamethylene, 
  C 
  6 
  H 
  12 
  | 
  1163 
  

  

  Pyridine, 
  C 
  5 
  H 
  5 
  N 
  89 
  -3 
  

  

  Piperidine 
  Q 
  5 
  H 
  U 
  N 
  108*8 
  

  

  The 
  smaller 
  value 
  of 
  H 
  found 
  by 
  difference 
  indicates 
  that 
  

   the 
  six 
  extra 
  hydrogens 
  are 
  closely 
  associated 
  with 
  the 
  

   nucleus. 
  A 
  more 
  extended 
  study 
  of 
  benzene 
  and 
  hexamethy- 
  

   lene 
  under 
  corresponding 
  conditions 
  shows 
  that 
  this 
  con- 
  

   clusion 
  is 
  correct. 
  

  

  This, 
  however, 
  ceases 
  to 
  hold 
  when 
  one 
  or 
  more 
  side 
  chains 
  

   are 
  added 
  to 
  the 
  nuclei, 
  as 
  the 
  following 
  table 
  will 
  show. 
  

  

  Table 
  XVII. 
  

   Table 
  showing 
  the 
  Volume 
  of 
  H 
  6 
  in 
  Substituted 
  Aromatic 
  

   Compounds. 
  II. 
  

  

  1 
  

  

  Compound. 
  

  

  V. 
  

  

  6H 
  

  

  H. 
  

  

  Toluene, 
  7 
  H 
  8 
  .... 
  

   Hydrotoluene, 
  C 
  7 
  H 
  li 
  .... 
  

  

  ) 
  118-3 
  

   J 
  142-1 
  

  

  23-8 
  

  

  3-97 
  

  

  Xylene, 
  C 
  8 
  H 
  10 
  ... 
  

   Hexabydroxylene, 
  C 
  8 
  H 
  16 
  .... 
  

  

  . 
  140-3 
  

   J 
  164-3 
  

  

  24-0 
  

  

  4-00 
  

  

  Naphthalene, 
  C 
  10 
  H 
  S 
  .... 
  

   Naphthyl 
  hydride, 
  C 
  10 
  H 
  U 
  . 
  

  

  .; 
  147-2 
  

   . 
  171-2 
  

  

  240 
  

  

  4-00 
  

  

  