﻿164 
  Prof. 
  A. 
  Battelli 
  on 
  the 
  Analogy 
  between 
  

  

  From 
  this 
  lie 
  concludes 
  that 
  there 
  must 
  exist 
  internally 
  

   the 
  above-said 
  special 
  rays 
  (those 
  deviated 
  through 
  the 
  effect 
  

   of 
  the 
  magnet), 
  which, 
  according 
  to 
  the 
  author, 
  are 
  of 
  a 
  

   different 
  nature 
  not 
  only 
  from 
  those 
  of 
  Rontgen 
  but 
  also 
  

   from 
  the 
  cathode 
  rays, 
  only 
  as 
  they 
  do 
  not 
  follow 
  the 
  regular 
  

   laws 
  of 
  reflexion. 
  

  

  Now 
  Thompson's 
  experiment 
  as 
  regards 
  the 
  rays 
  eman- 
  

   ating 
  from 
  the 
  focus-tube 
  is 
  perfectly 
  similar 
  to 
  what 
  I 
  had 
  

   already 
  had 
  occasion 
  to 
  observe 
  in 
  1896 
  in 
  conjunction 
  with 
  

   Prof. 
  Garbasso* 
  respecting 
  the 
  cathode 
  rays. 
  We 
  were 
  

   thereby 
  led 
  to 
  admit, 
  as 
  most 
  probable, 
  that 
  the 
  Rontgen 
  and 
  

   cathodic 
  rays 
  were 
  of 
  an 
  identical 
  nature, 
  with 
  this 
  difference, 
  

   however, 
  that 
  the 
  first 
  only 
  constitute 
  a 
  part 
  of 
  the 
  latter. 
  

  

  It 
  seems 
  to 
  me 
  that 
  Thompson's 
  experiment 
  may 
  agree 
  

   with 
  this 
  hypothesis 
  without 
  the 
  necessity 
  of 
  recurring 
  to 
  a 
  

   third 
  species 
  of 
  rays 
  of 
  a 
  different 
  nature. 
  In 
  fact, 
  reflexion 
  

   of 
  cathodic 
  rays 
  cannot 
  be 
  spoken 
  of, 
  if 
  we 
  admit 
  that 
  when 
  

   they 
  strike 
  against 
  any 
  kind 
  of 
  fluorescent 
  plate 
  they 
  are 
  

   converted 
  into 
  other 
  sorts 
  of 
  radiation. 
  Whilst 
  on 
  the 
  other 
  

   hand, 
  if 
  such 
  reflexion 
  be 
  admitted 
  it 
  cannot 
  indeed 
  be 
  said 
  

   that 
  in 
  its 
  complex 
  action 
  it 
  follows 
  the 
  laws 
  of 
  regular 
  re- 
  

   flexion. 
  We 
  can 
  instead 
  observe 
  in 
  the 
  focus-tubes 
  other 
  

   facts 
  which 
  I 
  shall 
  forthwith 
  describe, 
  and 
  which 
  are 
  more 
  in 
  

   harmony 
  with 
  our 
  hypothesis 
  than 
  with 
  Prof. 
  Thompson's. 
  

  

  For 
  the 
  study 
  of 
  these 
  facts 
  I 
  have 
  made 
  use 
  of 
  u 
  focus-" 
  

   tubes 
  or 
  bulbs, 
  in 
  the 
  inside 
  of 
  which 
  we 
  could 
  place, 
  in 
  

   various 
  positions, 
  photographic 
  films 
  covered 
  with 
  black 
  paper 
  

   impenetrable 
  to 
  light, 
  folded 
  (as 
  I 
  had 
  done 
  in 
  preceding 
  

   experiments) 
  round 
  small 
  metallic 
  cylinders. 
  

  

  The 
  bulbs 
  were 
  of 
  spherical 
  form 
  (fig. 
  1) 
  ; 
  from 
  the 
  hori- 
  

   zontal 
  tubes 
  A 
  and 
  B 
  penetrated 
  the 
  anode 
  and 
  cathode, 
  

   from 
  the 
  vertical 
  tube 
  C 
  a 
  small 
  glass 
  rod 
  supporting 
  the 
  

   small 
  reflector. 
  

  

  Through 
  the 
  same 
  tube 
  C 
  one 
  of 
  the 
  small 
  photographic 
  

   cylinders 
  projected 
  into 
  the 
  spherical 
  bulb 
  ; 
  and 
  through 
  the 
  

   other 
  vertical 
  tube 
  D 
  one 
  or 
  more 
  similar 
  cylinders 
  were 
  

   introduced 
  into 
  the 
  bulb. 
  

  

  The 
  reflector 
  and 
  the 
  small 
  cylinders 
  were 
  supported 
  by 
  

   appropriate 
  framing 
  joined 
  to 
  the 
  respective 
  supports 
  by 
  means 
  

   of 
  small 
  hinges, 
  so 
  that 
  one 
  could 
  easily 
  give 
  to 
  the 
  reflector 
  

   and 
  to 
  the 
  cylinders 
  any 
  desired 
  position 
  and 
  inclination. 
  

  

  * 
  A. 
  Batelli, 
  " 
  Richerche 
  sulle 
  azioni 
  fotografiche 
  nell' 
  interno 
  dei 
  tubi 
  di 
  

   scarica," 
  N. 
  Cimento, 
  ser. 
  4, 
  vol. 
  iii. 
  p. 
  193 
  (1896) 
  ; 
  A. 
  Battelli 
  ed 
  A. 
  Gar- 
  

   basso, 
  "Raggi 
  catodici 
  e 
  raggi 
  X," 
  torn. 
  cit. 
  p. 
  289 
  (1896); 
  A. 
  Battelli 
  

   ed 
  A. 
  Garbasso, 
  " 
  Azioni 
  dei 
  raggi 
  catodici 
  sopra 
  conduttori 
  isolati," 
  

   ibid. 
  vol. 
  iv. 
  p. 
  129 
  (1896). 
  

  

  