﻿1044 
  Dr. 
  Norman 
  Campbell 
  on 
  the 
  Electrical 
  

  

  XCV. 
  Structure 
  of 
  the 
  Atom. 
  

   To 
  the 
  Editors 
  of 
  the 
  Philosophical 
  Magazine. 
  

   De.4r 
  Sirs, 
  

  

  In 
  my 
  paper 
  on 
  the 
  Structure 
  of 
  the 
  Atom 
  (Phil. 
  Mag. 
  

   Oct. 
  1913) 
  I 
  supposed 
  that 
  the 
  regions 
  within 
  which 
  the 
  

   electrical 
  forces 
  inside 
  the 
  atom 
  were 
  supposed 
  to 
  be 
  confined 
  

   were 
  bounded 
  by 
  conical 
  surfaces. 
  I 
  find 
  on 
  further 
  invest- 
  

   igation 
  that 
  with 
  such 
  surfaces 
  the 
  period 
  of 
  a 
  corpuscle 
  

   inside 
  the 
  region 
  would 
  increase 
  as 
  its 
  energy 
  increased, 
  and 
  

   the 
  corpuscle 
  would 
  cease 
  to 
  be 
  in 
  unison 
  with 
  the 
  light 
  

   before 
  it 
  had 
  acquired 
  enough 
  energy 
  to 
  escape 
  from 
  the 
  

   region 
  of 
  electrical 
  force. 
  If, 
  however, 
  the 
  boundaries 
  of 
  

   these 
  regions 
  are 
  cylindrical 
  instead 
  of 
  conical, 
  the 
  period 
  

   will 
  be 
  independent 
  of 
  the 
  kinetic 
  energy 
  of 
  the 
  corpuscle, 
  

   and 
  the 
  latter 
  will 
  be 
  in 
  resonance 
  with 
  the 
  light 
  until 
  it 
  

   has 
  acquired 
  enough 
  energy 
  to 
  escape 
  from 
  the 
  region 
  ; 
  

   assuming 
  cylindrical 
  instead 
  of 
  conical 
  boundaries, 
  the 
  results 
  

   given 
  in 
  the 
  paper 
  can 
  apply 
  without 
  further 
  modification. 
  

  

  Yours 
  very 
  truly, 
  

  

  J. 
  J. 
  Thomson. 
  

  

  Cambridge, 
  Nov 
  8, 
  1913. 
  

  

  XCVI. 
  The 
  Electrical 
  Resistance 
  of 
  Mixtures 
  of 
  Xy 
  ') 
  'ol 
  and 
  

   Alcohol. 
  By 
  Norman 
  Campbell, 
  Sc.'l).* 
  

  

  1. 
  CjOME 
  further 
  experiments 
  have 
  been 
  made 
  on 
  the 
  high 
  

   O 
  resistances 
  consisting 
  of 
  mixtures 
  of 
  xylol 
  and 
  ethyl 
  

   alcohol 
  in 
  glass 
  tubes 
  to 
  which 
  reference 
  has 
  been 
  made 
  in 
  

   previous 
  papers 
  t« 
  The 
  investigation 
  was 
  undertaken 
  mainly 
  

   with 
  the 
  object 
  of 
  obtaining 
  information 
  bearing 
  on 
  their 
  use 
  

   in 
  practice, 
  but 
  at 
  the 
  outset 
  a 
  point 
  of 
  theoretical 
  interest 
  

   was 
  determined. 
  It 
  is 
  to 
  be 
  expected 
  tbat 
  the 
  mechanism 
  of 
  

   conduction 
  in 
  such 
  a 
  mixture 
  should 
  be 
  similar 
  to 
  that 
  in 
  an 
  

   electrolyte, 
  but 
  the 
  previous 
  experiments 
  had 
  shown 
  that 
  the 
  

   conductivity 
  of 
  the 
  mixtures 
  differed 
  from 
  that 
  of 
  electrolytes 
  

   in 
  two 
  particulars. 
  First, 
  the 
  conductivity 
  decreased 
  with 
  

   the 
  temperature, 
  like 
  that 
  of 
  a 
  metal 
  ; 
  second, 
  it 
  appeared 
  to 
  

   be 
  unaccompanied 
  by 
  polarization. 
  

  

  However, 
  a 
  little 
  consideration 
  shows 
  that 
  the 
  second 
  and 
  

   most 
  remarkable 
  feature 
  does 
  not 
  indicate 
  that 
  the 
  conduction 
  

   is 
  not 
  electrolytic 
  ; 
  polarization 
  does 
  not 
  appear 
  simply 
  because 
  

  

  * 
  Communicated 
  by 
  the 
  Author. 
  

  

  t 
  Campbell, 
  Proc. 
  Camb. 
  Phil. 
  Soc. 
  xv. 
  p. 
  322 
  (1909) 
  ; 
  Phil. 
  Mag. 
  

   An-. 
  1911, 
  p. 
  301, 
  and 
  April 
  1912, 
  p. 
  6fi8. 
  

  

  