﻿the 
  Unit-Steve 
  Theory. 
  11 
  

  

  seen 
  that 
  the 
  differences 
  for 
  H 
  2 
  in 
  the 
  acetates 
  and 
  chlorides 
  

   are 
  about 
  the 
  same 
  as 
  in 
  the 
  other 
  compounds. 
  Their 
  volume 
  

   relations 
  are 
  thus 
  clearly 
  additive. 
  The 
  fact 
  that 
  such 
  small 
  

   differences 
  as 
  those 
  of 
  H 
  2 
  are 
  fairly 
  concordant, 
  and 
  that 
  the 
  

   volume 
  of 
  H 
  is 
  found 
  by 
  this 
  means 
  to 
  be 
  equal 
  to 
  S, 
  and 
  

   consequently 
  to 
  H 
  in 
  the 
  paraffin 
  hydrocarbons 
  at 
  the 
  boiling- 
  

   point, 
  is 
  sufficiently 
  remarkable. 
  The 
  numbers 
  3*7 
  and 
  14*8 
  

   for 
  hydrogen 
  and 
  carbon 
  respectively 
  thus 
  replace 
  the 
  numbers 
  

   5*5 
  and 
  11 
  in 
  Kopp's 
  scheme. 
  

  

  Diamylene 
  C 
  10 
  H 
  20 
  is 
  a 
  derivative 
  of 
  the 
  olefine 
  series 
  and 
  

   is 
  formed 
  by 
  the 
  polymerization 
  of 
  two 
  molecules 
  of 
  amylene. 
  

   It 
  is 
  not, 
  however, 
  supposed 
  to 
  belong 
  to 
  the 
  olefine 
  series, 
  

   but 
  to 
  possess 
  the 
  formula 
  

  

  ™ 
  3 
  >CH— 
  CH— 
  CH 
  2 
  

  

  CH/ 
  | 
  I 
  

  

  CH 
  2 
  -CH-CH<fg 
  {Ber 
  1890? 
  xxix> 
  p 
  1550) 
  

  

  Diamylene 
  is 
  thus 
  a 
  ring 
  compound, 
  which- 
  fact 
  may 
  be 
  

   expected 
  to 
  be 
  indicated 
  by 
  its 
  molecular 
  volume. 
  

  

  M.V. 
  of 
  C 
  10 
  H 
  20 
  at 
  B.P 
  211-7 
  

  

  2 
  vols, 
  of 
  amylene 
  C 
  5 
  H 
  10 
  220'3 
  

  

  Contraction 
  8*6 
  

  

  This 
  contraction 
  is 
  far 
  too 
  considerable 
  to 
  be 
  ascribed 
  to 
  

   unsaturation, 
  and 
  must 
  be 
  attributed 
  to 
  the 
  profound 
  change 
  

   in 
  its 
  chemical 
  constitution 
  indicated 
  by 
  its 
  ring 
  structure. 
  

   The 
  real 
  contraction 
  is, 
  however, 
  greater 
  than 
  that 
  shown 
  

   above, 
  for 
  the 
  value 
  of 
  8 
  in 
  a 
  compound 
  of 
  the 
  complexity 
  

   C 
  10 
  H 
  20 
  is 
  3-71 
  (cp. 
  Octane 
  C 
  8 
  H 
  10 
  W50 
  S 
  = 
  3'72, 
  tripropyl- 
  

   amine 
  N(C 
  3 
  H 
  7 
  ) 
  3 
  W 
  60 
  S 
  = 
  3"71). 
  The 
  normal 
  volume 
  of 
  

   O 
  10 
  H 
  20 
  is 
  thus 
  3-71x60 
  = 
  222-6. 
  Contraction 
  10'9. 
  Con- 
  

   tractions 
  such 
  as 
  the 
  above 
  are 
  a 
  second 
  departure 
  from 
  the 
  

   principle 
  of 
  additivity, 
  and 
  are 
  due 
  to 
  the 
  effect 
  of 
  ring- 
  

   structure 
  on 
  molecular 
  volumes, 
  a 
  matter 
  which 
  will 
  be 
  

   discussed 
  more 
  fully 
  when 
  aromatic 
  and 
  hydroaromatic 
  com- 
  

   pounds 
  are 
  considered. 
  

  

  The 
  Aromatic 
  Hydrocarbons 
  and 
  other 
  Cyclic 
  Compounds 
  

  

  at 
  the 
  Boiling-Point, 
  

  

  (i.) 
  A 
  consideration 
  of 
  the 
  apparent 
  Atomic 
  Volumes 
  of 
  

  

  Carbon 
  and 
  Hydrogen 
  in 
  the 
  Side 
  Chains 
  at 
  the 
  

  

  Bailing-Point. 
  

  

  The 
  compounds 
  that 
  are 
  commonly 
  called 
  aromatic 
  and 
  

  

  hydroaromatic 
  belong 
  to 
  a 
  totally 
  different 
  class 
  to 
  those 
  

  

  which 
  have 
  been 
  discussed 
  in 
  previous 
  papers. 
  Whereas 
  

  

  