﻿Osmosis 
  and 
  Osmotic 
  Pressure. 
  

  

  Cell 
  N. 
  

   Mean 
  Potential 
  115 
  volts. 
  

  

  2o< 
  

  

  Jan. 
  

  

  8. 
  

  

  Jan. 
  9. 
  

  

  Temperature 
  0° 
  -9. 
  

  

  Temperature 
  14° 
  '3. 
  

  

  Temperature 
  1°-1. 
  

  

  Time. 
  

  

  Resistance. 
  

  

  Time. 
  

  

  Resistance. 
  

  

  Time. 
  

  

  Resistance. 
  

  

  h 
  m 
  

  

  

  h 
  m 
  

  

  

  h 
  m 
  

  

  

  11 
  55 
  a.m. 
  

  

  24-5 
  X 
  10 
  3 
  ohms 
  

  

  6 
  15 
  r.M. 
  

  

  73 
  x 
  10 
  3 
  ohms 
  

  

  12 
  48 
  p.m. 
  

  

  10-8xl0 
  3 
  ohms 
  

  

  12 
  40 
  p.m. 
  

  

  88-5 
  „ 
  

  

  6 
  25 
  „ 
  

  

  62-2 
  „ 
  

  

  1 
  o 
  „ 
  

  

  170 
  „ 
  

  

  1 
  25 
  „ 
  

  

  109 
  

  

  6 
  35 
  „ 
  

  

  56-5 
  „ 
  

  

  

  1 
  15 
  „ 
  

  

  270 
  „ 
  

  

  2 
  30 
  „ 
  

  

  119 
  „ 
  

  

  6 
  45 
  ,, 
  

  

  53-0 
  „ 
  

  

  

  1 
  45 
  „ 
  

  

  2S-2 
  „ 
  

  

  3 
  10 
  „ 
  

  

  135 
  „ 
  

  

  7 
  „ 
  

  

  520 
  „ 
  

  

  

  2 
  15 
  „ 
  

  

  353 
  „ 
  

  

  3 
  40 
  ., 
  

  

  143 
  „ 
  

  

  7 
  30 
  „ 
  

  

  486 
  „ 
  

  

  

  4 
  25 
  „ 
  

  

  46-0 
  „ 
  

  

  4 
  15 
  „ 
  

  

  147 
  „ 
  

  

  8 
  5 
  „ 
  

  

  425 
  „ 
  

  

  , 
  

  

  

  

  4 
  55 
  „ 
  

  

  147 
  „ 
  

  

  8 
  30 
  ,; 
  

  

  440 
  „ 
  

  

  , 
  

  

  

  

  5 
  45 
  „ 
  

  

  128 
  „ 
  

  

  9 
  30 
  „ 
  

  

  38-5 
  „ 
  

  

  ' 
  

  

  

  

  In 
  both 
  cases 
  the 
  temperature 
  has 
  a 
  great 
  influence 
  upon 
  

   the 
  maximum 
  resistance. 
  We 
  see 
  from 
  the 
  last 
  experiment 
  

   that 
  the 
  effect 
  of 
  temperature 
  partly 
  consists 
  in 
  a 
  weakening 
  

   of 
  the 
  membrane. 
  The 
  resistance 
  is 
  broken 
  down 
  and 
  does 
  

   not 
  regain 
  its 
  original 
  size 
  when 
  going 
  back 
  to 
  the 
  low 
  

   temperature. 
  

  

  In 
  the 
  first 
  experiment 
  the 
  membrane 
  seems 
  to 
  have 
  kept 
  

   more 
  constant 
  during 
  the 
  treatment 
  ; 
  but 
  still 
  we 
  notice 
  a 
  

   very 
  great 
  temperature 
  effect 
  upon 
  the 
  maximum 
  resistance. 
  

   The 
  membrane 
  is, 
  however, 
  not 
  unaltered, 
  so 
  the 
  maximum 
  

   resistance 
  will 
  not 
  exactly 
  correspond 
  to 
  equal 
  membranes. 
  

   Comparing 
  the 
  two 
  curves 
  for 
  the 
  low 
  temperature, 
  we 
  see 
  

   that 
  the 
  cell 
  during 
  the 
  treatment 
  has 
  undergone 
  a 
  change; 
  

   for 
  in 
  the 
  last 
  curve 
  the 
  resistance 
  increases 
  more 
  slowly. 
  

  

  Unfortunately 
  the 
  experiment 
  could 
  not 
  be 
  continued 
  till 
  

   maximum 
  was 
  reached 
  ; 
  but 
  when 
  the 
  experiment 
  was 
  broken 
  

   off 
  (ll 
  h 
  30 
  m 
  p.m.) 
  the 
  resistance 
  was 
  still 
  increasing, 
  and 
  

   the 
  curve 
  seems 
  to 
  show 
  that 
  the 
  resistance 
  has 
  a 
  tendency 
  

   to 
  regain 
  a 
  value 
  near 
  to 
  its 
  original 
  maximum 
  value. 
  

  

  It 
  seems 
  then 
  that 
  the 
  temperature, 
  even 
  if 
  the 
  mechanical 
  

   structure 
  could 
  be 
  kept 
  constant, 
  would 
  exercise 
  a 
  great 
  

   influence 
  upon 
  the 
  resistance 
  at 
  the 
  membrane. 
  

  

  That 
  this 
  is 
  the 
  fact 
  is 
  brought 
  to 
  full 
  evidence 
  by 
  an 
  

   experiment 
  carried 
  out 
  at 
  the 
  Cavendish 
  Laboratory. 
  

  

  The 
  cell 
  A 
  was 
  first 
  electrolysed 
  at 
  11°*3 
  up 
  to 
  maximum 
  

   of 
  resistance, 
  then 
  the 
  temperature 
  was 
  brought 
  down 
  to 
  1° 
  C. 
  

   During 
  the 
  time-interval 
  the 
  temperature 
  was 
  lowered 
  the 
  

  

  