﻿848 
  Prof. 
  A. 
  Righi: 
  New 
  Experiments 
  on 
  tlie 
  

  

  the 
  polarization 
  was 
  measured 
  by 
  compensating 
  plates 
  of 
  

   glass. 
  The 
  following 
  values 
  were 
  obtained 
  :- 
  — 
  

  

  Polarization 
  of 
  Resonance 
  Spectrum 
  

   of 
  Iodine 
  in 
  vacuo. 
  

  

  Polarization 
  of 
  Resonance 
  Spectrum 
  

  

  of 
  Iodiue 
  in 
  Helium 
  at 
  3'8 
  mm. 
  

  

  pressure. 
  

  

  With 
  exciting 
  light 
  polarized: 
  

  

  11 
  per 
  cent. 
  

  

  With 
  exciting 
  light 
  unpolarized 
  : 
  

  

  6' 
  4 
  per 
  cent. 
  

  

  With 
  exciting 
  light 
  unpolarized: 
  

   4 
  per 
  cent. 
  

  

  The 
  important 
  point 
  to 
  notice 
  is 
  that 
  the 
  polarization 
  is 
  the 
  

   same 
  for 
  all 
  of 
  the 
  lines. 
  This 
  seems 
  to 
  prove 
  that 
  the 
  

   numerous 
  vibrations 
  giving 
  rise 
  to 
  lines 
  of 
  the 
  resonance 
  

   spectrum 
  are 
  set 
  up 
  within 
  the 
  atom 
  or 
  molecule 
  by 
  the 
  

   vibration 
  of 
  the 
  electron 
  which 
  responds 
  to 
  the 
  monochromatic 
  

   exciting 
  light, 
  in 
  other 
  words, 
  it 
  does 
  not 
  result 
  from 
  anything 
  

   like 
  dissociation 
  and 
  recombination. 
  

  

  J. 
  Stark 
  has 
  attempted 
  to 
  adapt 
  his 
  dissociation 
  theory 
  of 
  

   fluorescence 
  to 
  cases 
  where 
  the 
  vapour 
  shows 
  polarization 
  by 
  

   assuming 
  that 
  the 
  electron, 
  expelled 
  by 
  the 
  action 
  of 
  the 
  

   absorbed 
  light, 
  falls 
  back 
  into 
  the 
  atom 
  in 
  practically 
  the 
  

   same 
  direction, 
  — 
  in 
  other 
  words, 
  that 
  it 
  never 
  gets 
  away 
  

   from 
  the 
  field 
  of 
  force 
  of 
  the 
  atom. 
  This 
  is 
  an 
  interesting 
  

   suggestion, 
  but 
  it 
  appears 
  to 
  me 
  to 
  be 
  a 
  compromise, 
  for 
  we 
  

   can 
  regard 
  the 
  expulsion 
  of 
  the 
  electron 
  under 
  such 
  conditions 
  

   as 
  a 
  vibration 
  of 
  large 
  amplitude. 
  It 
  may 
  be 
  possible 
  to 
  

   obtain 
  some 
  experimental 
  evidence 
  of 
  the 
  phenomenon 
  (as, 
  

   for 
  example, 
  the 
  reduction 
  of 
  the 
  percentage 
  of 
  polarization 
  

   by 
  collisions 
  with 
  helium 
  molecules), 
  but 
  until 
  such 
  evidence 
  

   is 
  obtained 
  it 
  appears 
  to 
  me 
  to 
  be 
  simpler 
  to 
  regard 
  the 
  

   resonance 
  spectra 
  as 
  produced 
  by 
  vibrations 
  originated 
  in 
  a 
  

   more 
  or 
  less 
  direct 
  manner 
  by 
  the 
  exciting 
  light. 
  

  

  LXXIT, 
  JSew 
  Experiments 
  on 
  the 
  Virtual 
  Anode 
  in 
  the 
  Tithes 
  

   jvr 
  Magnetic 
  Rays. 
  By 
  Augusto 
  Righi, 
  of 
  the 
  University, 
  

   Bologna 
  *. 
  

  

  Q1NCE 
  I 
  published 
  my 
  Note: 
  "On 
  Magnetic 
  Rays 
  in 
  

   iO 
  Different 
  Gases 
  " 
  f, 
  in 
  reply 
  to 
  that 
  bearing 
  the 
  same 
  

   title 
  by 
  Messrs. 
  L. 
  T. 
  More 
  and 
  E. 
  Rieman 
  j, 
  I 
  had 
  proposed 
  

   to 
  examine 
  again 
  the 
  experiments 
  on 
  magnetic 
  rays 
  which 
  

  

  * 
  Communicated 
  by 
  the 
  Author. 
  

  

  t 
  Phil. 
  Mag., 
  November 
  1912, 
  p. 
  804. 
  

  

  X 
  Phil. 
  Mag., 
  August 
  1912, 
  p. 
  307. 
  

  

  