﻿476 
  Dr. 
  N. 
  Bohr 
  on 
  the 
  Constitution 
  

  

  effect. 
  However, 
  later 
  measurements 
  which 
  they 
  made 
  after 
  

   the 
  tube 
  had 
  been 
  differently 
  treated 
  led 
  to 
  a 
  higher 
  value 
  of 
  

   b, 
  and 
  the 
  investigation 
  referred 
  to 
  is 
  not 
  yet 
  completed, 
  so 
  

   that 
  the 
  difference 
  in 
  the 
  value 
  of 
  cf> 
  given 
  by 
  the 
  two 
  methods 
  

   may 
  not 
  be 
  significant. 
  

  

  In 
  concluding 
  we 
  wish 
  to 
  correct 
  an 
  erroneous 
  statement 
  

   on 
  p. 
  643 
  of 
  the 
  former 
  paper. 
  Maturer 
  consideration 
  has 
  

   led 
  us 
  to 
  conclude 
  that 
  the 
  small 
  systematic 
  error 
  referred 
  to 
  

   in 
  the 
  last 
  paragraph 
  but 
  two 
  makes 
  the 
  measured 
  value 
  of 
  

   <j> 
  too 
  large 
  at 
  high 
  temperatures 
  and 
  not 
  too 
  small 
  as 
  is 
  there 
  

   stated. 
  In 
  consequence 
  we 
  do 
  not 
  now 
  regard 
  the 
  suggested 
  

   increase 
  of 
  </> 
  with 
  6 
  as 
  definitely 
  established 
  by 
  the 
  experi- 
  

   ments. 
  They 
  are, 
  in 
  fact, 
  insufficiently 
  accurate 
  for 
  the 
  

   purpose. 
  

  

  We 
  are 
  glad 
  to 
  be 
  able 
  to 
  take 
  this 
  opportunity 
  of 
  thanking 
  

   Messrs. 
  W. 
  P. 
  Schenck 
  and 
  W. 
  K. 
  Wensley, 
  who 
  took 
  most 
  

   of 
  the 
  observations 
  under 
  our 
  direction. 
  

  

  Palmer 
  Physical 
  Laboratory, 
  

   Princeton, 
  N.J. 
  

  

  XXXVII. 
  On 
  the 
  Constitution 
  of 
  Atoms 
  and 
  Molecules. 
  

   By 
  N. 
  Bohr, 
  Dr.phil. 
  Copenhagen*. 
  

  

  Part 
  II. 
  — 
  Systems 
  containing 
  only 
  a 
  Single 
  Nucleus 
  t- 
  

   § 
  1. 
  General 
  Assumptions. 
  

  

  FOLLOWING 
  the 
  theory 
  of 
  Rutherford, 
  we 
  shall 
  assume 
  

   that 
  the 
  atoms 
  of 
  the 
  elements 
  consist 
  of 
  a 
  positively 
  

   charged 
  nucleus 
  surrounded 
  by 
  a 
  cluster 
  of 
  electrons. 
  The 
  

   nucleus 
  is 
  the 
  seat 
  of 
  the 
  essential 
  part 
  of 
  the 
  mass 
  of 
  the 
  

   atom, 
  and 
  has 
  linear 
  dimensions 
  exceedingly 
  small 
  compared 
  

   with 
  the 
  distances 
  apart 
  of 
  the 
  electrons 
  in 
  the 
  surrounding 
  

   cluster. 
  

  

  As 
  in 
  the 
  previous 
  paper, 
  we 
  shall 
  assume 
  that 
  the 
  cluster 
  

   of 
  electrons 
  is 
  formed 
  by 
  the 
  successive 
  binding 
  by 
  the 
  

   nucleus 
  of 
  electrons 
  initially 
  nearly 
  at 
  rest, 
  energy 
  at 
  the 
  

   same 
  time 
  being 
  radiated 
  away. 
  This 
  will 
  go 
  on 
  until, 
  when 
  

   the 
  total 
  negative 
  charge 
  on 
  the 
  bound 
  electrons 
  is 
  numeri- 
  

   cally 
  equal 
  to 
  the 
  positive 
  charge 
  on 
  the 
  nucleus, 
  the 
  system 
  

   will 
  be 
  neutral 
  and 
  no 
  longer 
  able 
  to 
  exert 
  sensible 
  forces 
  on 
  

   electrons 
  at 
  distances 
  from 
  the 
  nucleus 
  great 
  in 
  comparison 
  

   with 
  the 
  dimensions 
  of 
  the 
  orbits 
  o£ 
  the 
  bound 
  electrons. 
  

   We 
  may 
  regard 
  the 
  formation 
  o£ 
  helium 
  from 
  a 
  rays 
  as 
  an 
  

  

  * 
  Communicated 
  by 
  Prof. 
  E. 
  Rutherford, 
  F.R.S. 
  

  

  t 
  Part 
  I. 
  was 
  published 
  in 
  Phil. 
  Mag 
  1 
  , 
  xxvi. 
  p. 
  1 
  (1913). 
  

  

  