﻿508 
  Dr. 
  R. 
  D. 
  Kleenican 
  on 
  some 
  

  

  furnished 
  the 
  data 
  from 
  which 
  the 
  value 
  of 
  Bc^ 
  for 
  each 
  of 
  

   the 
  atoms 
  H, 
  C, 
  0, 
  F, 
  CI, 
  Br, 
  Sn, 
  I, 
  was 
  calculated. 
  The 
  

   upper 
  half 
  of 
  the 
  seventh 
  column 
  of 
  the 
  table 
  contains 
  the 
  

   values 
  of 
  Bc^, 
  and 
  the 
  lower 
  half 
  the 
  values 
  of 
  Ca. 
  The 
  values 
  

   of 
  Sc„ 
  for 
  the 
  remaining 
  liquids 
  were 
  calculated 
  by 
  means 
  of 
  

   the 
  values 
  of 
  Bc^, 
  and 
  are 
  given 
  in 
  the 
  sixth 
  column 
  of 
  the 
  

   table. 
  They 
  agree 
  very 
  well 
  with 
  the 
  values 
  contained 
  in 
  

   the 
  fifth 
  column 
  which 
  have 
  been 
  calculated 
  from 
  experi- 
  

   mental 
  data, 
  except 
  in 
  the 
  case 
  of 
  water, 
  methyl 
  alcohol, 
  and 
  

   propyl 
  alcohol, 
  the 
  values 
  for 
  these 
  liquids 
  showing 
  a 
  con- 
  

   siderable 
  disagreement 
  between 
  calculation 
  and 
  experiment. 
  

  

  The 
  reason 
  that 
  these 
  liquids 
  do 
  not 
  fit 
  in 
  with 
  the 
  others 
  

   is 
  probably 
  due 
  to 
  polymerization 
  of 
  their 
  molecules. 
  The 
  

   existence 
  of 
  such 
  an 
  effect 
  would 
  modify 
  the 
  various 
  quantities 
  

   in 
  equation 
  (12) 
  to 
  a 
  certain, 
  though 
  at 
  present 
  unknown, 
  

   extent. 
  The 
  evidence 
  on 
  the 
  polymerization 
  of 
  liquids 
  founded 
  

   on 
  the 
  deviations 
  from 
  the 
  laws 
  of 
  osmotic 
  pressure, 
  and 
  of 
  

   surface-tension, 
  &c., 
  show^s 
  that 
  each 
  of 
  the 
  three 
  liquids 
  in 
  

   question, 
  besides 
  a 
  few 
  others, 
  is 
  polymerized 
  to 
  a 
  certain 
  

   degree 
  which 
  depends 
  on 
  the 
  nature 
  of 
  the 
  liquid 
  and 
  its 
  

   temperature. 
  The 
  deviations 
  from 
  equation 
  (12) 
  thus 
  seem 
  

   to 
  indicate 
  the 
  same 
  thing 
  ; 
  and 
  another 
  method 
  is 
  thus 
  

   furnished 
  for 
  testing 
  whether 
  a 
  liquid 
  is 
  polymerized 
  or 
  not. 
  

  

  Equation 
  (12) 
  may 
  be 
  transformed 
  into 
  one 
  involving 
  Ti 
  

   instead 
  of 
  Lj. 
  The 
  internal 
  heat 
  of 
  evaporation 
  of 
  a 
  liquid 
  

   is 
  given 
  by 
  the 
  well-known 
  thermodynamical 
  relation 
  

  

  Li+pO'i-^^s) 
  = 
  (t'i-i;2)Ti^, 
  

  

  where 
  t'l, 
  ^2, 
  denote 
  the 
  volume 
  of 
  one 
  gram 
  of 
  vapour 
  and 
  

   liquid 
  respectively 
  at 
  the 
  pressure 
  p 
  and 
  temperature 
  T. 
  

   Consider 
  the 
  temperature 
  taken 
  so 
  low 
  that 
  the 
  vapour 
  obeys 
  

   approximately 
  Boyle's 
  law. 
  The 
  equation 
  then 
  becomes 
  

  

  -r 
  , 
  RTi 
  RTi^ 
  dp 
  

  

  m 
  m 
  dli 
  

  

  which 
  may 
  be 
  written 
  

  

  Ti 
  ~ 
  ^"^p 
  ^Ti' 
  

  

  Substituting 
  for 
  p 
  and 
  T 
  on 
  the 
  right-hand 
  side 
  of 
  this 
  

   equation 
  from 
  the 
  equations 
  T 
  = 
  0Tc, 
  p 
  = 
  ypc, 
  we 
  obtain 
  

  

  W!!^_I^^.^^^,,^,^,,3tant 
  . 
  . 
  (13) 
  

   Ti 
  7 
  dp 
  

  

  for 
  liquids 
  at 
  corresponding 
  states. 
  (Modified 
  Trouton's 
  law.) 
  

  

  