﻿856 
  Virtual 
  Anode 
  in 
  the 
  Tubes 
  for 
  Magnetic 
  Rays. 
  

  

  instead 
  a 
  transport 
  o£ 
  negative 
  electricity, 
  of 
  course 
  due 
  to 
  

   the 
  cathodic 
  rays, 
  which 
  exist 
  in 
  abundance 
  in 
  that 
  flash 
  of 
  

   light 
  which 
  is 
  called 
  a 
  beam 
  of 
  magnetic 
  rays. 
  

  

  Certain 
  difficulties 
  of 
  explanation 
  pointed 
  out 
  by 
  the 
  

   authors 
  remain 
  then 
  excluded, 
  when 
  the 
  charges 
  acquired 
  by 
  

   the 
  walls 
  of 
  the 
  tube 
  are 
  taken 
  into 
  consideration. 
  They 
  

   may, 
  for 
  example, 
  explain 
  the 
  concentration 
  of 
  the 
  light 
  

   towards 
  the 
  axis. 
  Certain 
  other 
  difficulties 
  do 
  not 
  exist 
  

   for 
  those 
  who 
  take 
  notice 
  of 
  the 
  fact 
  that 
  the 
  doublets 
  

   ion-electron 
  may 
  break 
  at 
  every 
  region 
  of 
  the 
  tube, 
  and 
  that 
  

   therefore 
  the 
  virtual 
  anode 
  may 
  be 
  extended 
  and 
  spread 
  

   about. 
  Lastly, 
  it 
  must 
  not 
  be 
  forgotten 
  that 
  the 
  production 
  

   of 
  the 
  virtual 
  anode 
  constitutes 
  necessarily 
  a 
  non-continuous 
  

   phenomenon, 
  and 
  its 
  manifestations 
  must, 
  according 
  to 
  the 
  

   theory, 
  alternate 
  with 
  the 
  production, 
  rendered 
  intermittent 
  

   by 
  the 
  field, 
  of 
  the 
  principal 
  discharge. 
  

  

  I 
  must, 
  besides, 
  point 
  out 
  that 
  what 
  is 
  said 
  at 
  the 
  beginning 
  

   of 
  page 
  263 
  is 
  incorrect, 
  namely, 
  that 
  I 
  have 
  made 
  the 
  strange 
  

   statement 
  of 
  the 
  magnetic 
  field 
  being 
  indispensable 
  for 
  

   the 
  discharge 
  to 
  be 
  intermittent. 
  In 
  fact 
  I 
  showed 
  among 
  

   other 
  things 
  in 
  preceding 
  publications 
  that 
  when 
  a 
  small 
  

   spark 
  in 
  free 
  air 
  is 
  inserted 
  between 
  the 
  tube 
  and 
  the 
  

   electric 
  source, 
  it 
  may 
  occasion 
  a 
  lighting 
  up 
  of 
  the 
  whole 
  

   tube 
  and 
  mislead 
  one 
  from 
  the 
  fact 
  that, 
  under 
  the 
  action 
  

   of 
  the 
  exploring 
  coil, 
  there 
  may 
  be 
  doublings 
  and 
  twistings 
  

   of 
  the 
  luminous 
  column. 
  

  

  But 
  even 
  without 
  the 
  small 
  spark 
  one 
  is 
  liable 
  to 
  make 
  

   mistakes. 
  If, 
  in 
  fact, 
  after 
  the 
  secondary 
  column 
  has 
  

   lengthened 
  down 
  to 
  the 
  end 
  of 
  the 
  tube 
  by 
  the 
  gradual 
  

   increasing 
  of 
  the 
  field, 
  the 
  magnetic 
  field 
  is 
  further 
  

   augmented, 
  a 
  state 
  of 
  things 
  is 
  produced 
  similar 
  to 
  the 
  one 
  

   due 
  to 
  the 
  small 
  spark. 
  

  

  In 
  the 
  experiments 
  described 
  in 
  the 
  last 
  of 
  the 
  quoted 
  

   papers 
  the 
  authors 
  have 
  employed 
  a 
  Wehnelt 
  cathode. 
  That 
  

   had 
  already 
  been 
  done 
  by 
  Mr. 
  Berti*, 
  who 
  found 
  effects 
  

   mostly 
  similar 
  to 
  those 
  described 
  by 
  me, 
  and 
  principally 
  the 
  

   transport, 
  decreasing 
  with 
  the 
  increase 
  of 
  the 
  field, 
  of 
  negative 
  

   electricity. 
  

  

  At 
  the 
  end 
  of 
  More 
  and 
  Mauchly's 
  paper, 
  in 
  order 
  

   to 
  contradict 
  my 
  hypothesis, 
  they 
  oppose 
  to 
  it 
  their 
  

   different 
  point 
  of 
  view, 
  on 
  the 
  basis 
  of 
  the 
  variation 
  of 
  the 
  

   potential 
  of 
  discharge 
  due 
  to 
  the 
  field. 
  

  

  They 
  quote 
  the 
  works 
  of 
  Paalzow 
  and 
  Neesen, 
  of 
  Almy 
  

   and 
  others 
  showing 
  a 
  diminution 
  of 
  the 
  fall 
  of 
  cathodic 
  

   potential, 
  but 
  not 
  mine 
  on 
  the 
  same 
  subject, 
  in 
  which 
  it 
  is 
  

   * 
  Rend, 
  del 
  li. 
  Istituto 
  Lombardo, 
  10 
  febbraio, 
  1912. 
  j 
  

  

  