﻿and 
  the 
  Constitution 
  of 
  the 
  Atom. 
  303 
  

  

  energy 
  quanta 
  Jwk 
  should 
  be 
  necessary 
  to 
  produce 
  the 
  

   K-radiation. 
  If 
  so, 
  an 
  atom 
  should 
  have 
  the 
  power 
  of 
  

   accumulating 
  energy 
  until 
  it 
  had 
  taken 
  up 
  a 
  sufficient 
  

   number 
  of 
  quanta 
  to 
  break 
  the 
  whole 
  ring. 
  In 
  trying 
  

   to 
  explain 
  the 
  mutual 
  relation 
  between 
  7- 
  and 
  /3-rays 
  

   Rutherford 
  * 
  has 
  supposed 
  that 
  several 
  quanta 
  can 
  accu- 
  

   mulate 
  to 
  give 
  energy 
  to 
  one 
  /3-particle 
  ; 
  but 
  the 
  assumption 
  

   of 
  such 
  an 
  accumulation 
  would, 
  on 
  the 
  other 
  hand, 
  make 
  it 
  

   very 
  difficult 
  indeed 
  to 
  understand 
  why 
  a 
  certain 
  frequency 
  

   at 
  all 
  should 
  be 
  necessary 
  to 
  produce 
  the 
  K-radiation. 
  

  

  Also 
  the 
  transformation 
  of 
  cathode-ray 
  energy 
  to 
  that 
  of 
  

   Rontgen 
  rays 
  gives 
  a 
  similar 
  result. 
  The 
  most 
  important 
  

   investigations 
  of 
  Whiddington 
  f 
  and 
  the 
  more 
  recent 
  mea- 
  

   surements 
  of 
  Webster 
  % 
  by 
  means 
  of 
  the 
  reflexion 
  method 
  

   have 
  proved, 
  that 
  in 
  order 
  to 
  excite 
  the 
  K-radiation 
  the 
  

   energy 
  of 
  one 
  cathode 
  ray 
  must 
  surpass 
  the 
  energy 
  quantum 
  

   hv 
  K 
  . 
  If 
  we 
  suppose 
  that 
  a 
  single 
  cathode 
  particle 
  can 
  

  

  produce 
  radiation, 
  the 
  assumption 
  of 
  four 
  electrons 
  is 
  

   therefore 
  not 
  justified 
  ; 
  but 
  the 
  assumption 
  of 
  Debye 
  should 
  

   be 
  in 
  accordance 
  with 
  physical 
  facts. 
  The 
  fact 
  that 
  we 
  can 
  

   deduce 
  two 
  formulae 
  which 
  both 
  give 
  a 
  satisfactory 
  agree- 
  

   ment 
  with 
  observations 
  is 
  still 
  of 
  some 
  importance, 
  as 
  it 
  

   shows 
  that 
  we 
  should 
  be 
  cautious 
  in 
  relying 
  too 
  much 
  on 
  a 
  

   mere 
  numerical 
  agreement. 
  

  

  The 
  Explanation 
  of 
  the 
  L-Radiation. 
  

  

  § 
  4. 
  Although 
  the 
  agreement 
  between 
  observed 
  and 
  

   calculated 
  values 
  was 
  less 
  good 
  in 
  the 
  case 
  of 
  K^, 
  there 
  is 
  

   probably 
  no 
  doubt 
  that 
  also 
  this 
  line 
  is 
  caused 
  by 
  a 
  recom- 
  

   bination 
  to 
  the 
  inner 
  circle, 
  from 
  a 
  three-quantical 
  secondary. 
  

   Kossel's 
  relation 
  (6), 
  if 
  it 
  indicates 
  a 
  physical 
  connexion 
  

   between 
  the 
  K- 
  and 
  the 
  L-lines, 
  would 
  indicate 
  that 
  L 
  a 
  

   should 
  be 
  produced 
  by 
  an 
  electron 
  recombining 
  towards 
  

   the 
  K-circles, 
  between 
  the 
  two 
  secondaries 
  corresponding 
  

   to 
  t=3 
  and 
  t 
  = 
  2. 
  This 
  assumption 
  would 
  indeed 
  give 
  the 
  

  

  right 
  factor 
  ( 
  -^ 
  — 
  w. 
  2 
  ) 
  to 
  N 
  2 
  in 
  the 
  formula 
  for 
  L 
  a 
  . 
  

  

  This 
  assumption, 
  however, 
  does 
  not 
  agree 
  with 
  the 
  

   absorption 
  phenomena. 
  According 
  to 
  Barkla§ 
  and 
  Sadler 
  || 
  

   an 
  L-absorption 
  takes 
  place 
  when 
  the 
  hardness 
  of 
  the 
  

  

  * 
  E. 
  Rutherford, 
  Phil. 
  Mag. 
  (6) 
  xxviii. 
  p. 
  305 
  (1914). 
  

  

  t 
  R. 
  Whiddington, 
  Proc. 
  Roy. 
  Soc. 
  1911. 
  

  

  % 
  D. 
  L. 
  Webster, 
  Proc. 
  Amer. 
  Acad. 
  vol. 
  ii. 
  p. 
  90 
  (1916). 
  

  

  § 
  C. 
  G. 
  Barkla, 
  Phil. 
  Mag. 
  xxiii. 
  p. 
  987 
  (1912). 
  

  

  ft 
  C. 
  A. 
  Sadler. 
  Phil. 
  Mag. 
  xviii. 
  p. 
  107 
  (1909). 
  

  

  