﻿408 
  

  

  Mr. 
  L. 
  Vegard 
  : 
  Researches 
  upon 
  

   5 
  5. 
  Results. 
  

  

  15. 
  The 
  equilibrium 
  pressures 
  tt 
  ' 
  for 
  cane-sugar 
  are 
  given 
  

   n 
  the 
  following 
  table 
  : 
  — 
  

  

  Experiment 
  

  

  7T 
  '. 
  

  

  o 
  16 
  . 
  

  

  to- 
  

  

  5 
  

  

  atm. 
  

   2-88 
  

   12-15 
  

   23-17 
  

   28-80 
  

   28-85 
  

   31-57 
  

   39-85 
  

   63-SO 
  

  

  gr./litre. 
  

   40 
  

   159-9 
  

   268-9 
  

   3199 
  

   3200 
  

   337-5 
  

   396-2 
  

   520-0 
  

  

  centigrade. 
  

   00 
  

  

  o-o 
  

  

  9-25 
  

  

  o-o 
  

  

  00 
  

  

  4-4 
  

  

  7-0 
  

  

  11-5 
  

  

  lb 
  

  

  2 
  

  

  IT. 
  

  

  Ill 
  

  

  4 
  

  

  3 
  

  

  I 
  

  

  

  15 
  

  

  II 
  

  

  Ill 
  

  

  12-48 
  

  

  28-67 
  

   29-29 
  

  

  161-7 
  

   319-9 
  

   3200 
  

  

  10-3 
  

   11-3 
  

  

  11-8 
  

  

  In 
  the 
  table 
  the 
  pressures 
  are 
  given 
  at 
  the 
  temperature 
  at 
  

   which 
  the 
  measurements 
  were 
  made. 
  This 
  is 
  done 
  simply 
  

   because 
  we 
  have 
  no 
  experimental 
  determination 
  of 
  the 
  tem- 
  

   perature 
  effect 
  for 
  the 
  greatest 
  concentrations. 
  Further, 
  we 
  

   shall 
  see 
  that 
  the 
  temperature 
  effect 
  upon 
  the 
  pressure 
  7r 
  / 
  

   is 
  smaller 
  than 
  the 
  effect 
  upon 
  tt 
  . 
  

  

  The 
  curve 
  fig. 
  8 
  represents 
  the 
  relation 
  between 
  ttq 
  and 
  C. 
  

   The 
  points 
  given 
  are 
  directly 
  taken 
  from 
  the 
  first 
  part 
  of 
  the 
  

   table. 
  On 
  the 
  figure 
  are 
  also 
  marked 
  some 
  of 
  the 
  points 
  

   determined 
  by 
  Berkeley 
  and 
  Hartley 
  and 
  Moore 
  and 
  Frazer. 
  

   As 
  to 
  the 
  points 
  determined 
  by 
  the 
  latter, 
  I 
  have 
  taken 
  

   those 
  determined 
  at 
  the 
  lowest 
  temperature 
  as 
  giving 
  com- 
  

   paratively 
  the 
  highest 
  pressure. 
  We 
  see 
  that 
  the 
  deter- 
  

   minations 
  are 
  in 
  very 
  good 
  agreement. 
  The 
  pressure 
  w 
  ' 
  

   appears 
  to 
  be 
  very 
  nearly 
  a 
  single-valued 
  function 
  of 
  the 
  

   concentration. 
  

  

  All 
  of 
  these 
  measurements 
  correspond 
  to 
  a 
  very 
  small 
  leak, 
  

   often 
  so 
  small 
  as 
  not 
  to 
  be 
  detectable 
  by 
  the 
  method 
  used. 
  

   And 
  as 
  we 
  have 
  strong 
  reason 
  to 
  believe 
  that 
  7r 
  ' 
  is 
  continuous 
  

   with 
  regard 
  to 
  the 
  leaks 
  the 
  values 
  found 
  should 
  then 
  very 
  

   nearly 
  give 
  the 
  osmotic 
  pressure 
  ir 
  . 
  The 
  study 
  of 
  the 
  leak 
  

   would 
  require 
  a 
  more 
  accurate 
  testing 
  of 
  the 
  w 
  T 
  ater 
  in 
  the 
  cell. 
  

   Only 
  in 
  experiment 
  1 
  is 
  there 
  a 
  somewhat 
  considerable 
  leak, 
  

   but 
  still 
  the 
  pressure 
  tt 
  ' 
  gives 
  a 
  value 
  corresponding 
  to 
  a 
  

   very 
  small 
  leak. 
  This 
  is 
  easily 
  explained 
  from 
  the 
  theory, 
  

   for 
  it 
  would 
  only 
  mean 
  that 
  the 
  leak 
  in 
  this 
  case 
  is 
  very 
  

   nearly 
  a 
  solution 
  leak 
  that 
  has 
  very 
  little 
  power 
  to 
  influence 
  

   the 
  osmotic 
  activity. 
  

  

  