﻿V 
  

  

  the 
  Unit- 
  St 
  ere 
  Theory. 
  71 
  

  

  is 
  equal 
  to 
  the 
  mean 
  value 
  o£ 
  the 
  unit-stere, 
  viz. 
  2"970. 
  

  

  The 
  difference 
  for 
  C 
  2 
  H 
  4 
  is 
  35'6, 
  which 
  equals 
  12x2*967. 
  

   It 
  follows 
  that 
  the 
  volumes 
  for 
  hydrogen 
  and 
  carbon 
  are 
  the 
  

   same 
  in 
  the 
  acetylenes 
  at 
  the 
  melting-point 
  as 
  in 
  the 
  normal 
  

   saturated 
  paraffins 
  under 
  similar 
  circumstances. 
  

  

  The 
  contraction 
  for 
  unsaturation 
  is 
  evidently 
  not 
  far 
  from 
  

   3 
  units 
  per 
  gramme 
  molecule 
  — 
  a 
  number 
  which 
  happens 
  to 
  

   be 
  about 
  equal 
  to 
  the 
  apparent 
  volume 
  of 
  hydrogen 
  at 
  the 
  

  

  y 
  

   melting-point. 
  The 
  significance 
  of 
  the 
  ratio 
  -nr 
  i 
  is 
  thus 
  

  

  obvious. 
  The 
  contraction 
  for 
  the 
  acetylenes 
  also 
  appears 
  to 
  

   be 
  a 
  little 
  larger 
  than 
  that 
  for 
  the 
  olefines. 
  

  

  Owing 
  to 
  the 
  fact 
  that 
  data 
  exist 
  for 
  the 
  formulation 
  of 
  

   interpolation 
  equations 
  similar 
  to 
  those 
  which 
  have 
  been 
  

   used 
  in 
  the 
  discussion 
  of 
  the 
  members 
  of 
  the 
  two 
  former 
  

   series, 
  it 
  is 
  possible 
  to 
  examine 
  the 
  volumes 
  of 
  the 
  acetylenes 
  

   above 
  the 
  melting-point 
  in 
  a 
  similar 
  way. 
  

  

  The 
  ranges 
  of 
  temperature 
  over 
  which 
  Krafft's 
  deter- 
  

   minations 
  extend 
  are 
  sufficiently 
  restricted 
  to 
  justify 
  

   the 
  use 
  of 
  linear 
  formulae, 
  as 
  a 
  comparison 
  between 
  the 
  

   observed 
  and 
  the 
  calculated 
  specific 
  gravities 
  show. 
  Inter- 
  

   polation 
  formulae 
  have 
  been 
  worked 
  out 
  for 
  the 
  three 
  acety- 
  

   lenes 
  dodecylidene 
  Oi 
  2 
  H 
  22 
  l=|. 
  tetradecylidene 
  C 
  U 
  H 
  26 
  l 
  = 
  (, 
  

   and 
  hexadecylidene 
  C 
  l6 
  H 
  30 
  1 
  

   appear 
  in 
  the 
  appended 
  table. 
  

  

  the 
  constants 
  for 
  which 
  

  

  Table 
  IX. 
  

   Table 
  of 
  Constants. 
  

  

  1. 
  

  

  Acetylene, 
  C 
  n 
  H2?i-2 
  | 
  = 
  i 
  • 
  

  

  W. 
  

  

  70 
  

  

  M.W. 
  

  

  M.V. 
  

  

  <#T 
  • 
  

  

  Oi. 
  

  

  Dodecylidene, 
  C 
  12 
  H 
  22 
  | 
  = 
  | 
  ... 
  

  

  166 
  

  

  264 
  

  

  •8097 
  

  

  -•00092 
  

  

  2. 
  

  

  Tetradecylidene, 
  C 
  U 
  H 
  26 
  | 
  = 
  | 
  ... 
  

  

  82 
  

  

  194 
  

  

  279-5 
  

  

  •8064 
  

  

  -•00090 
  

  

  3. 
  

  

  Hexadecylidene, 
  C 
  16 
  H 
  32 
  | 
  = 
  | 
  ... 
  

  

  94 
  

  

  222 
  

  

  293 
  

  

  •8039 
  

  

  -•00087 
  

  

  As 
  before, 
  V 
  represents 
  the 
  molecular 
  volume 
  of 
  the 
  

   acetylene, 
  and 
  V 
  that 
  of 
  the 
  corresponding 
  saturated 
  normal 
  

   paraffin 
  under 
  similar 
  circumstances. 
  

  

  