﻿256 
  

  

  Mr. 
  L. 
  Vegard 
  : 
  Researches 
  upon 
  

  

  For 
  general 
  use 
  I 
  have 
  found 
  that 
  the 
  least 
  voltage 
  is 
  about 
  

   115 
  volts. 
  When 
  the 
  maximum 
  resistance 
  has 
  reached 
  a 
  value 
  

   of 
  about 
  50,000 
  ohms, 
  I 
  have 
  found 
  it 
  to 
  have 
  a 
  good 
  effect 
  

   for 
  about 
  20 
  or 
  30 
  minutes, 
  to 
  use 
  the 
  double 
  voltage 
  (230 
  

   volts). 
  After 
  this 
  treatment 
  I 
  have 
  generally 
  observed 
  a 
  

   considerable 
  increase 
  in 
  the 
  maximum 
  resistance 
  when 
  going- 
  

   back 
  to 
  115 
  volts. 
  

  

  For 
  the 
  cell 
  A 
  the 
  solutions 
  have 
  been 
  interchanged, 
  the 
  

   copper-sulphate 
  solution 
  being 
  used 
  on 
  the 
  outside. 
  Before 
  

   the 
  change 
  the 
  cell 
  ought 
  to 
  be 
  placed 
  for 
  one 
  or 
  two 
  days 
  in 
  

   distilled 
  water 
  ; 
  further, 
  in 
  the 
  electrolyses 
  I 
  had 
  repeatedly 
  

   to 
  change 
  the 
  solution 
  of 
  potassium 
  f 
  errocyanide 
  as 
  to 
  prevent 
  

   action 
  from 
  potassium 
  hydrate. 
  This 
  was 
  also 
  done 
  for 
  one 
  

   of 
  my 
  other 
  cells, 
  and 
  effected 
  in 
  both 
  cases 
  a 
  considerable 
  

   increase 
  in 
  the 
  maximum 
  resistance. 
  

  

  The 
  Effect 
  of 
  Temperature 
  upon 
  the 
  Membrane. 
  

   6. 
  The 
  temperature 
  has 
  a 
  great 
  influence 
  upon 
  the 
  maxi- 
  

   mum 
  resistance 
  obtainable. 
  In 
  order 
  to 
  examine 
  the 
  effect 
  

   more 
  closely 
  I 
  have 
  made 
  some 
  experiments 
  with 
  my 
  two 
  

   other 
  cells, 
  which 
  I 
  may 
  call 
  M 
  and 
  N. 
  The 
  experiments 
  

   were 
  in 
  the 
  following 
  manner 
  : 
  — 
  The 
  cell 
  was 
  electrolysed 
  at 
  

   first 
  at 
  a 
  temperature 
  near 
  0° 
  until 
  maximum 
  was 
  reached. 
  

   Then 
  the 
  temperature 
  was 
  raised 
  as 
  quickly 
  as 
  possible 
  and 
  

   the 
  electrolysis 
  continued 
  until 
  maximum. 
  By 
  this 
  some- 
  

   what 
  hard 
  treatment 
  the 
  cell 
  might 
  change 
  its 
  original 
  

   quality, 
  and 
  for 
  that 
  reason 
  the 
  electrolysis 
  was 
  repeated 
  by 
  

   going 
  down 
  to 
  0°. 
  The 
  results 
  of 
  these 
  measurements 
  are 
  

   given 
  in 
  the 
  following 
  tables 
  and 
  graphically 
  represented 
  by 
  

   the 
  curve 
  fig. 
  6 
  (PI. 
  VIII.) 
  . 
  

  

  Cell 
  M. 
  

   Jan. 
  7, 
  1908.— 
  Mean 
  Potential 
  118 
  volts. 
  

  

  Temperature 
  0°-9. 
  

  

  Temperature 
  12° 
  # 
  2. 
  

  

  Temperature 
  1°'3. 
  

  

  Time. 
  

  

  Resistance. 
  

  

  Time. 
  

  

  Eesistance. 
  

  

  Time. 
  

  

  Resistance. 
  

  

  h 
  m 
  

  

  

  h 
  m 
  

  

  

  h 
  m 
  

  

  

  10 
  48 
  a.m. 
  

  

  13X10 
  3 
  obms 
  

  

  o 
  25 
  p.m. 
  

  

  48 
  x 
  103 
  ohms 
  

  

  8 
  30 
  p.m. 
  

  

  45 
  X 
  10 
  3 
  ohms 
  

  

  11 
  8 
  „ 
  

  

  53 
  „ 
  

  

  5 
  44 
  ., 
  

  

  48 
  „ 
  „ 
  ! 
  

  

  8 
  40 
  „ 
  

  

  49 
  

  

  11 
  30 
  „ 
  

  

  74 
  „ 
  

  

  

  6 
  4 
  „ 
  

  

  58 
  „ 
  „ 
  

  

  9 
  45 
  „ 
  

  

  74 
  

  

  

  11 
  55 
  „ 
  

  

  100 
  „ 
  

  

  

  6 
  14 
  „ 
  

  

  62 
  „ 
  „ 
  

  

  10 
  „ 
  

  

  78 
  

  

  

  12 
  25 
  p.m. 
  

  

  122 
  „ 
  

  

  

  6 
  24 
  „ 
  

  

  67 
  „ 
  

  

  10 
  15 
  „ 
  

  

  83 
  

  

  

  12 
  55 
  „ 
  

  

  133 
  „ 
  

  

  

  6 
  34 
  „ 
  

  

  68-8 
  „ 
  

  

  10 
  30 
  „ 
  

  

  £0-7 
  „ 
  

  

  

  1 
  40 
  „ 
  

  

  139 
  ., 
  

  

  

  6 
  44 
  „ 
  

  

  71-8 
  „ 
  „ 
  | 
  

  

  10 
  45 
  „ 
  

  

  93 
  „ 
  , 
  

  

  

  2 
  30 
  „ 
  

  

  150 
  ., 
  

  

  

  6 
  49 
  „ 
  

  

  78 
  

  

  11 
  10 
  „ 
  

  

  100 
  

  

  

  3 
  10 
  „ 
  

  

  150 
  „ 
  

  

  

  7 
  14 
  „ 
  

  

  83 
  

  

  11 
  30 
  „ 
  

  

  106 
  

  

  

  3 
  40 
  „ 
  

  

  150 
  „ 
  

  

  ' 
  

  

  7 
  30 
  „ 
  

  

  78 
  

  

  

  

  