﻿'828 
  Dr. 
  H. 
  Wilde 
  on 
  the 
  Atomic 
  Weight 
  of 
  

  

  I 
  take 
  this 
  opportunity 
  of 
  remarking, 
  as 
  a 
  principle 
  of 
  

   scientific 
  reasoning, 
  that 
  when 
  the 
  number 
  of 
  recurring 
  facts 
  

   are 
  sufficient 
  to 
  establish 
  the 
  relation 
  of 
  cause 
  and 
  effect, 
  or, 
  

   in 
  other 
  words, 
  the 
  general 
  accuracy 
  of 
  a 
  law, 
  the 
  road 
  to 
  

   further 
  discovery 
  lies 
  rather 
  in 
  the 
  direction 
  of 
  explaining 
  

   the 
  anomalous 
  departures 
  from 
  it 
  than 
  in 
  challenging 
  the 
  

   truth 
  of 
  the 
  law 
  itself. 
  I 
  would 
  also 
  emphasize 
  the 
  fact, 
  the 
  

   importance 
  of 
  which 
  is 
  hardly 
  yet 
  realized 
  by 
  chemists, 
  that 
  

   as 
  the 
  received 
  atomic 
  weights 
  are 
  all 
  expressed 
  in 
  units 
  of 
  

   hydrogen, 
  and 
  are 
  equivalents 
  of 
  this 
  element, 
  the 
  multiple 
  

   relations 
  subsisting 
  among 
  the 
  higher 
  atomic 
  weights, 
  as 
  

   shown 
  in 
  my 
  tables, 
  have 
  an 
  immensely 
  greater 
  validity 
  in 
  

   determining 
  the 
  question 
  of 
  their 
  being 
  whole 
  numbers 
  of 
  

   hydrogen, 
  than 
  when 
  the 
  atomic 
  weights 
  were 
  compared 
  

   directly 
  with 
  the 
  hydrogen 
  unit 
  alone 
  by 
  Stas 
  and 
  the 
  older 
  

   chemists. 
  

  

  It 
  will 
  be 
  observed 
  that 
  there 
  are 
  gaps 
  in 
  the 
  positive 
  series 
  

   Hn, 
  to 
  be 
  occupied 
  by 
  two 
  elements 
  with 
  atomic 
  weights 
  154 
  

   and 
  177, 
  and 
  also 
  one 
  in 
  the 
  series 
  H 
  2n, 
  with 
  an 
  atomic 
  weight 
  

   1 
  ('><>. 
  which 
  remain 
  to 
  be 
  discovered 
  or 
  identified 
  with 
  known 
  

   radioactive 
  or 
  other 
  elements. 
  

  

  The 
  multiple 
  relations 
  subsisting 
  among 
  the 
  series 
  H3n 
  

   are 
  highly 
  interesting 
  on 
  account 
  of 
  the 
  additions 
  that 
  have 
  

   been 
  made 
  to 
  them 
  by 
  the 
  aid 
  of 
  spectral 
  analysis, 
  and 
  the 
  

   questions 
  raised 
  respecting 
  the 
  classification 
  and 
  valency 
  of 
  

   some 
  of 
  its 
  members, 
  which, 
  from 
  their 
  rarity, 
  have 
  not 
  been 
  

   sufficiently 
  investigated. 
  The 
  atomic 
  weights 
  of 
  this 
  series 
  

   are 
  calculated 
  on 
  the 
  same 
  principle 
  as 
  those 
  shown 
  in 
  the 
  

   series 
  Hn 
  and 
  H2n, 
  and 
  are 
  multiples 
  of 
  H3. 
  It 
  will 
  be 
  

   seen 
  that 
  where 
  the 
  numbers 
  in 
  the 
  table 
  differ 
  from 
  the 
  

   experimental 
  determinations, 
  the 
  differences 
  are 
  either 
  mul- 
  

   tiples 
  or 
  submultiples 
  of 
  the 
  received 
  atomic 
  weights. 
  More- 
  

   over, 
  as 
  the 
  theoretic 
  atomic 
  weights 
  of 
  thorium, 
  thallium, 
  

   aluminium, 
  as 
  carbon 
  are 
  identical 
  with 
  the 
  actual 
  deter- 
  

   minations, 
  and 
  as 
  triads 
  are 
  formed 
  by 
  Tl, 
  In, 
  Ga, 
  Sc, 
  and 
  

   Th, 
  Er, 
  Y, 
  Ce, 
  as 
  in 
  the 
  series 
  Hn, 
  H2n, 
  there 
  is 
  a 
  high 
  

   degree 
  of 
  probability 
  that 
  all 
  the 
  theoretical 
  atomic 
  weights 
  

   in 
  this 
  series 
  are 
  also 
  correct. 
  

  

  While 
  the 
  atomic 
  weights 
  of 
  the 
  remaining 
  series 
  H4n- 
  

   H7n 
  are 
  multiples 
  of 
  their 
  typical 
  molecules 
  at 
  the 
  head 
  of 
  

   each 
  series, 
  their 
  other 
  numerical 
  relations 
  differ 
  from 
  those 
  

   in 
  the 
  preceding 
  series. 
  The 
  possible 
  causes 
  of 
  the 
  departure 
  

   from 
  the 
  simple 
  law 
  observable 
  in 
  these 
  series 
  have 
  been 
  

   briefly 
  stated 
  in 
  my 
  paper 
  " 
  On 
  the 
  Origin 
  of 
  Elementary 
  

   Substances,"" 
  published 
  in 
  the 
  Memoirs 
  of 
  the 
  Manchester 
  

   Literary 
  and 
  Philosophical 
  Society 
  in 
  1887. 
  

  

  