﻿296 
  Dr. 
  L. 
  Vegard 
  on 
  the 
  X-Ray 
  Spectra 
  

  

  other 
  by 
  a 
  force 
  inversely 
  proportional 
  to 
  the 
  square 
  of 
  the 
  

   distance. 
  When 
  other 
  forces 
  come 
  into 
  play, 
  or 
  if 
  the 
  

   masses 
  are 
  not 
  to 
  be 
  regarded 
  as 
  constant, 
  the 
  H-lines 
  

   produced 
  in 
  the 
  different 
  possible 
  ways 
  will 
  no 
  longer 
  be 
  

   identical. 
  

  

  In 
  fact, 
  when 
  the 
  mass 
  of 
  the 
  electron 
  is 
  supposed 
  to 
  vary 
  

   with 
  the 
  velocity 
  according 
  to 
  the 
  law 
  given 
  by 
  Lorentz 
  or 
  

   the 
  principle 
  of 
  relativity, 
  Sommerfeld 
  finds 
  that 
  the 
  lines 
  

   are 
  split 
  up, 
  and 
  carrying 
  out 
  the 
  calculation 
  he 
  has 
  been 
  

   able 
  to 
  explain 
  even 
  quantitatively 
  the 
  splitting 
  up 
  of 
  the 
  

   hydrogen 
  lines 
  and 
  to 
  give 
  a 
  general 
  theory 
  of 
  the 
  formation 
  

   of 
  multiple 
  lines. 
  

  

  Further, 
  we 
  see 
  that 
  the 
  frequency 
  formula 
  of 
  Sommerfeld 
  

   gives 
  us 
  a 
  possibility 
  of 
  explaining 
  the 
  Stark-effect, 
  for 
  when 
  

   a 
  uniform 
  electrostatic 
  field 
  is 
  introduced 
  into 
  the 
  system 
  the 
  

   various 
  ways 
  in 
  which 
  a 
  certain 
  line 
  may 
  be 
  produced 
  will 
  

   no 
  longer 
  give 
  the 
  same 
  frequency. 
  

  

  A 
  complete 
  determination 
  of 
  the 
  Stark-efTect 
  was 
  finally 
  

   given 
  by 
  Epstein 
  *, 
  by 
  an 
  ingenious 
  method 
  of 
  selecting 
  

   the 
  generalized 
  coordinates 
  by 
  means 
  of 
  the 
  equations 
  of 
  

   Hamilto 
  n- 
  Jacobi. 
  

  

  Application 
  of 
  Bohr's 
  Conceptions 
  to 
  the 
  High 
  Frequency 
  

   Spectra 
  of 
  the 
  Elements. 
  

  

  § 
  2. 
  The 
  law 
  connecting 
  the 
  high-frequency 
  spectra 
  of 
  

   the 
  elements 
  which 
  was 
  brought 
  out 
  through 
  the 
  beautiful 
  

   experiments 
  of 
  Moseley 
  t 
  was 
  simply 
  explained 
  by 
  the 
  

   atomic 
  model 
  of 
  Rutherford 
  J 
  and 
  snowed 
  that 
  the 
  atomic 
  

   number 
  played 
  a 
  fundamental 
  part 
  in 
  the 
  constitution 
  of 
  

   atoms. 
  In 
  fact, 
  we 
  may 
  say 
  that 
  the 
  evidence 
  gathered 
  

   from 
  various 
  sources 
  leaves 
  no 
  doubt 
  as 
  to 
  the 
  correctness 
  

   of 
  Rutherford's 
  conception 
  of 
  the 
  atom. 
  I 
  think 
  we 
  may 
  

   safely 
  take 
  it 
  as 
  a 
  fact 
  that 
  the 
  normal 
  atom 
  has 
  a 
  positive 
  

   nucleus 
  of 
  charge 
  ~Ne, 
  surrounded 
  by 
  N 
  electrons. 
  

  

  The 
  atomic 
  problem 
  is 
  then 
  resolved 
  into 
  the 
  following 
  

   two 
  questions 
  : 
  — 
  

  

  1. 
  The 
  arrangement 
  of 
  the 
  electrons 
  which 
  surround 
  the 
  

  

  nucleus 
  and 
  the 
  laws 
  that 
  govern 
  this 
  arrangement. 
  

  

  2. 
  The 
  constitution 
  of 
  the 
  nucleus. 
  

  

  The 
  nucleus 
  is 
  the 
  seat 
  of 
  gravitation 
  and 
  the 
  radioactive 
  

   transformations, 
  and 
  a 
  possible 
  theory 
  of 
  the 
  nucleus 
  would 
  

   have 
  to 
  gather 
  evidence 
  from 
  these 
  two 
  phenomena. 
  The 
  

  

  * 
  P. 
  Epstein, 
  I 
  c. 
  

  

  t 
  H. 
  G. 
  J. 
  Moseley, 
  Phil. 
  Mag. 
  xxvi. 
  p. 
  1024 
  (1913), 
  and 
  xxvii. 
  

   p. 
  703 
  (1914). 
  

   X 
  Loc. 
  cit. 
  

  

  