﻿Positive 
  Rays. 
  659 
  

  

  coming 
  from 
  B 
  and 
  passing 
  down 
  the 
  hole 
  in 
  A, 
  or 
  with- 
  

   drawn 
  into 
  the 
  tube 
  ; 
  the 
  obstacle 
  is 
  in 
  metallic 
  connexion 
  

   with 
  a 
  wire 
  leading 
  out 
  of 
  the 
  tube, 
  so 
  that 
  it 
  can 
  be 
  used 
  as 
  

   a 
  cathode 
  if 
  required. 
  The 
  discharge 
  through 
  the 
  tube 
  was 
  

   produced 
  in 
  some 
  cases 
  by 
  a 
  large 
  induction-coil, 
  in 
  others 
  

   by 
  a 
  Wiinshurst 
  machine. 
  

  

  If 
  the 
  stopper 
  carrying 
  the 
  electrode 
  B 
  was 
  turned 
  so 
  that 
  

   the 
  normal 
  to 
  the 
  electrode 
  coincided 
  with 
  the 
  axis 
  of 
  the 
  

   tube 
  A, 
  or 
  made 
  only 
  a 
  small 
  angle 
  with 
  it, 
  and 
  if 
  B 
  were 
  

   made 
  cathode 
  and 
  a 
  discharge 
  sent 
  through 
  the 
  tube, 
  then 
  

   in 
  addition 
  to 
  the 
  cathode 
  rays 
  other 
  rays 
  passed 
  through 
  

   the 
  tube 
  in 
  A 
  and 
  excited 
  phosphorescence 
  on 
  the 
  screen. 
  

   'The 
  direction 
  of 
  the 
  deflexions 
  of 
  the 
  phosphorescence 
  under 
  

   •electric 
  and 
  magnetic 
  forces 
  showed 
  that 
  these 
  rays 
  were 
  

   charged 
  with 
  positive 
  electricity. 
  

  

  If 
  A 
  were 
  made 
  cathode, 
  the 
  ordinary 
  Canalstrahlen 
  pro- 
  

   duced 
  bright 
  phosphoresence 
  on 
  the 
  screen. 
  The 
  first 
  point 
  

   investigated 
  was 
  to 
  make 
  sure 
  that 
  the 
  positive 
  rays 
  observed 
  

   when 
  A 
  was 
  anode, 
  were 
  not 
  due 
  to 
  reversals 
  of 
  the 
  induction- 
  

   coil 
  making 
  A 
  at 
  times 
  a 
  cathode 
  and 
  sending 
  ordinary 
  Canal- 
  

   strahlen 
  down 
  the 
  tube. 
  Very 
  simple 
  observations, 
  however, 
  

   showed 
  that 
  this 
  could 
  not 
  be 
  the 
  explanation. 
  In 
  the 
  first 
  

   place, 
  the 
  positive 
  rays 
  still 
  passed 
  down 
  the 
  tube 
  when 
  A 
  

   was 
  disconnected 
  from 
  the 
  coil 
  and 
  the 
  auxiliary 
  electrode 
  C 
  

   used 
  as 
  an 
  anode 
  ; 
  secondly, 
  A 
  being 
  connected 
  with 
  the 
  

   coil, 
  the 
  rays 
  down 
  the 
  tube 
  disappeared 
  when 
  B 
  was 
  twisted 
  

   round, 
  so 
  that 
  the 
  normal 
  to 
  its 
  plane 
  made 
  a 
  considerable 
  

   angle 
  with 
  the 
  axis 
  of 
  the 
  tube 
  ; 
  and 
  thirdly, 
  the 
  rays 
  down 
  

   the 
  tube 
  were 
  stopped 
  when 
  the 
  obstacle 
  in 
  the 
  side 
  tube 
  was 
  

   pushed 
  forward 
  so 
  as 
  to 
  be 
  in 
  the 
  line 
  between 
  the 
  cathode 
  

   and 
  the 
  aperture 
  in 
  the 
  anode. 
  

  

  The 
  next 
  point 
  investigated 
  was 
  to 
  see 
  whether 
  the 
  effect 
  

   might 
  not 
  be 
  due 
  to 
  A 
  acting 
  at 
  times 
  as 
  a 
  cathode 
  in 
  virtue 
  

   of 
  the 
  negative 
  charge 
  given 
  up 
  to 
  it 
  by 
  the 
  cathode 
  

   rays 
  starting 
  from 
  B. 
  That 
  this 
  is 
  not 
  the 
  explanation 
  is 
  

   proved 
  by 
  the 
  following 
  experiments. 
  When 
  the 
  cathode 
  

   rays 
  were 
  diverted 
  by 
  a 
  magnet 
  so 
  that 
  they 
  no 
  longer 
  fell 
  

   upon 
  A, 
  the 
  brightness 
  of 
  the 
  phosphorescent 
  patch 
  due 
  to 
  

   the 
  positive 
  rays 
  going 
  down 
  the 
  tube 
  in 
  A 
  was 
  not 
  appre- 
  

   ciably 
  diminished, 
  although 
  the 
  tendency 
  for 
  A 
  to 
  become 
  

   cathode 
  must 
  have 
  been 
  almost 
  entirely 
  removed. 
  The 
  con- 
  

   clusions 
  drawn 
  from 
  this 
  experiment 
  were 
  confirmed 
  by 
  the 
  

   results 
  obtained 
  when 
  the 
  obstacle 
  in 
  the 
  side 
  tube 
  was 
  used 
  

   as 
  a 
  cathode 
  instead 
  of 
  B. 
  When 
  the 
  obstacle 
  was 
  not 
  pushed 
  

   far 
  enough 
  across 
  the 
  tube 
  for 
  its 
  normal 
  to 
  pass 
  down 
  the 
  

   tube 
  in 
  A, 
  no 
  positive 
  rays 
  passed 
  down 
  the 
  tube, 
  but 
  as 
  

  

  2X2 
  

  

  