﻿Constitution 
  of 
  Atoms 
  and 
  Molecules. 
  857 
  

  

  stated 
  that 
  cases 
  exist 
  in 
  which 
  the 
  field 
  makes 
  that 
  potential 
  

   increase. 
  

  

  That 
  is 
  jnst 
  what 
  occurs 
  with 
  the 
  tubes 
  having 
  a 
  lateral 
  

   anode 
  used 
  for 
  the 
  experiments 
  dealt 
  with 
  in 
  the 
  present 
  

   paper. 
  

  

  An 
  electrometer 
  of 
  convenient 
  sensibility 
  is 
  enough 
  to 
  

   show 
  that, 
  when 
  the 
  magnetic 
  field 
  generates 
  the 
  magnetic 
  

   rays, 
  the 
  deviation 
  of 
  the 
  electrometer 
  is 
  much 
  greater 
  than 
  

   before, 
  often 
  more 
  than 
  double. 
  Now, 
  the 
  new 
  explanation 
  

   proposed 
  by 
  the 
  authors 
  named 
  has, 
  as 
  starting 
  point, 
  a 
  

   supposed 
  diminution 
  of 
  the 
  cathode 
  fall 
  of 
  potential 
  produced 
  

   by 
  the 
  field. 
  I 
  can 
  therefore 
  refrain 
  from 
  discussing 
  it. 
  

  

  I 
  shall 
  then 
  point 
  out 
  lastly, 
  in 
  connexion 
  with 
  the 
  remark 
  

   on 
  p. 
  266, 
  that 
  it 
  is 
  necessary 
  to 
  prove 
  the 
  legitimacy 
  of 
  the 
  

   application 
  to 
  the 
  cnse 
  of 
  rarefied 
  gases 
  of 
  the 
  result 
  obtained 
  

   bv 
  Sir 
  J. 
  J. 
  Thomson 
  dealing 
  with 
  the 
  question 
  of 
  the 
  

   transport 
  of 
  ions 
  in 
  a 
  magnetic 
  field, 
  as 
  such 
  statement 
  is 
  

   based 
  on 
  the 
  hypothesis 
  that 
  the 
  viscosity 
  of 
  the 
  medium 
  in 
  

   which 
  an 
  ion 
  moves, 
  is 
  such 
  as 
  to 
  render 
  its 
  speed 
  pro- 
  

   portional 
  to 
  the 
  force 
  acting 
  on 
  it 
  ; 
  which 
  does 
  not 
  seem 
  

   always 
  admissible 
  in 
  the 
  case 
  of 
  a 
  rarefied 
  gas. 
  

  

  LXXIIL 
  On 
  the 
  Constitution 
  of 
  Atoms 
  and 
  Molecules. 
  

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

  

  Part 
  III. 
  — 
  Systems 
  containing 
  Several 
  Nuclei 
  f. 
  

  

  § 
  1. 
  Preliminary. 
  

  

  ACCORDING 
  to 
  Rutherford's 
  theory 
  of 
  the 
  structure 
  of 
  

   atoms, 
  the 
  difference 
  between 
  an 
  atom 
  of 
  an 
  element 
  

   and 
  a 
  molecule 
  of 
  a 
  chemical 
  combination 
  is 
  that 
  the 
  first 
  

   consists 
  of 
  a 
  cluster 
  of 
  electrons 
  surrounding 
  a 
  single 
  

   positive 
  nucleus 
  of 
  exceedingly 
  small 
  dimensions 
  and 
  of 
  a 
  

   mass 
  great 
  in 
  comparison 
  with 
  that 
  of 
  the 
  electrons, 
  while 
  

   the 
  latter 
  contains 
  at 
  least 
  two 
  nuclei 
  at 
  distances 
  from 
  e*ich 
  

   other 
  comparable 
  with 
  the 
  distances 
  apart 
  of 
  the 
  electrons 
  in 
  

   the 
  surrounding 
  cluster. 
  

  

  The 
  leading 
  idea 
  used 
  in 
  the 
  former 
  papers 
  was 
  that 
  the 
  

   atoms 
  were 
  formed 
  through 
  the 
  successive 
  binding 
  by 
  the 
  

   nucleus 
  of 
  a 
  number 
  of 
  electrons 
  initially 
  nearly 
  at 
  rest. 
  

  

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

   t 
  Part 
  I. 
  and 
  Part 
  II. 
  were 
  published 
  in 
  PhiL 
  Mag. 
  xxvi. 
  p. 
  1 
  & 
  p. 
  476 
  

   (1913). 
  

  

  