﻿Resistance 
  oj 
  Mixtures 
  of 
  Xylol 
  and 
  Alcohol. 
  

  

  1049 
  

  

  of 
  the 
  mixture 
  is 
  always 
  less 
  than 
  that 
  calculated 
  by 
  an 
  

   additive 
  law 
  from 
  the 
  proportions 
  and 
  conductivities 
  of 
  the 
  

   constituents. 
  

  

  Table 
  I. 
  

  

  y- 
  

  

  y 
  (mhos 
  .cm.) 
  

  

  y- 
  

  

  y 
  (mhos 
  . 
  cm.) 
  

  

  1-000 
  

  

  6-95 
  xlO 
  -6 
  

  

  09 
  

  

  8-dOxIO- 
  10 
  

  

  025 
  

  

  4-47 
  xl0~ 
  7 
  

  

  0-08 
  

  

  3-76 
  X 
  10 
  " 
  10 
  

  

  0-20 
  

  

  l-00xl0~ 
  r 
  

  

  007 
  

  

  1-GOxlO- 
  10 
  

  

  0-18 
  

  

  5-31 
  Xl0- 
  3 
  

  

  006 
  

  

  5-92xl0" 
  u 
  

  

  0-16 
  

  

  2-81 
  X 
  10- 
  8 
  

  

  0-05 
  

  

  2-12x10-11 
  

  

  0-14 
  

  

  1-44X10- 
  8 
  

  

  004 
  

  

  7-08x10-12 
  

  

  0-12 
  

  

  5-77 
  x 
  10 
  ~ 
  9 
  

  

  o-oo 
  

  

  <;io-i5 
  

  

  o-io 
  

  

  1-68X10 
  -9 
  

  

  

  

  Usually 
  after 
  the 
  mixture 
  has 
  been 
  introduced 
  into 
  the 
  cell 
  

   its 
  resistance 
  changes 
  for 
  the 
  first 
  3 
  or 
  4 
  days; 
  the 
  change 
  is 
  

   usually 
  an 
  increase 
  in 
  resistance, 
  but 
  in 
  some 
  cases 
  the 
  

   resistance 
  decreased 
  ; 
  the 
  greatest 
  change 
  observed 
  was 
  

   40 
  per 
  cent. 
  If 
  the 
  mixture 
  is 
  prepared 
  a 
  week 
  before 
  it 
  is 
  

   put 
  in 
  the 
  cell 
  and 
  stored 
  in 
  a 
  sealed 
  vessel, 
  its 
  resistance 
  

   still 
  changes 
  after 
  it 
  is 
  put 
  in 
  the 
  cell. 
  Mixtures 
  for 
  which 
  

   y 
  is 
  about 
  0*12 
  suffer 
  very 
  little 
  change 
  of 
  resistance 
  and 
  

   are, 
  therefore, 
  specially 
  suitable 
  for 
  the 
  preparation 
  of 
  

   resistances. 
  The 
  conductivities 
  given 
  in 
  the 
  table 
  are 
  those 
  

   observed 
  immediately 
  after 
  filling 
  ; 
  it 
  was 
  too 
  tedious 
  to 
  

   wait 
  until 
  the 
  resistance 
  became 
  constant 
  ; 
  but, 
  since 
  7 
  varies 
  

   so 
  rapidly 
  with 
  y, 
  the 
  form 
  of 
  the 
  relation 
  between 
  y 
  and 
  y 
  

   would 
  be 
  little 
  changed 
  if 
  the 
  final 
  conductivities 
  were 
  

   substituted. 
  

  

  Some 
  observations 
  were 
  made 
  on 
  the 
  effect 
  of 
  impurities 
  

   in 
  the 
  alcohol 
  or 
  the 
  xylol. 
  Water 
  is., 
  of 
  course, 
  the 
  impurity 
  

   which 
  is 
  of 
  most 
  importance. 
  If 
  the 
  xylol 
  was 
  shaken 
  up 
  

   with 
  water 
  and 
  then 
  separated 
  from 
  it, 
  the 
  specific 
  con- 
  

   ductivity 
  remained 
  less 
  than 
  10 
  ~ 
  15 
  mho. 
  cm. 
  and 
  no 
  differ- 
  

   ence 
  in 
  the 
  conductivity 
  of 
  the 
  mixtures 
  prepared 
  from 
  it 
  

   could 
  be 
  detected. 
  Water, 
  therefore, 
  is 
  an 
  impurity 
  of 
  no 
  

   importance 
  so 
  far 
  as 
  the 
  xylol 
  is 
  concerned. 
  Several 
  spe- 
  

   cimens 
  of 
  alcohol 
  were 
  examined 
  ; 
  one 
  of 
  these 
  was 
  com- 
  

   mercial 
  " 
  absolute 
  alcohol/' 
  the 
  others 
  prepared 
  from 
  this 
  

   specimen 
  by 
  one 
  or 
  more 
  distillations 
  from 
  lime 
  or 
  calcium. 
  

   The 
  specific 
  conductivities 
  of 
  these 
  specimens 
  varied 
  from 
  

  

  Phil. 
  Mag. 
  S. 
  6. 
  Vol. 
  26. 
  No. 
  156. 
  Dec. 
  1913. 
  4 
  B 
  

  

  

  