﻿538 
  Mr. 
  G. 
  H. 
  Livens 
  on 
  the 
  Intrinsic 
  

  

  the 
  solution 
  is 
  increased 
  the 
  specific 
  rotation 
  approximates 
  

   more 
  and 
  more 
  to 
  the 
  value 
  

  

  r 
  ■] 
  _ 
  ^V 
  " 
  

   L< 
  ° 
  J 
  "~(l-a/«r) 
  2 
  ' 
  

  

  where 
  cr 
  now 
  refers 
  to 
  the 
  density 
  of 
  the 
  pure 
  solvent. 
  Such 
  

   a 
  value 
  is 
  quite 
  independent 
  of 
  the 
  nature 
  of 
  the 
  inactive 
  

   constituent 
  of 
  the 
  dissolved 
  compound. 
  

  

  We 
  thus 
  see 
  that 
  our 
  theoretical 
  formula 
  leads 
  directly 
  to 
  

   an 
  explanation 
  of 
  all 
  of 
  the 
  above-mentioned 
  facts, 
  without 
  

   any 
  additional 
  hypothesis 
  regarding 
  the 
  effect 
  of 
  dissociation 
  

   on 
  the 
  active 
  ion. 
  It 
  would 
  thus 
  appear 
  that 
  such 
  facts 
  

   cannot 
  in 
  any 
  way 
  be 
  used 
  to 
  support 
  this 
  hypothesis. 
  On 
  

   the 
  other 
  hand, 
  as 
  similar 
  phenomena 
  have 
  been 
  observed 
  

   also 
  with 
  undissociated 
  substances, 
  we 
  may 
  conclude 
  that 
  

   simple 
  dissociation 
  of 
  the 
  active 
  from 
  the 
  inactive 
  ion 
  in 
  the 
  

   molecule 
  can 
  have 
  no 
  effect 
  on 
  the 
  specific 
  rotation 
  of 
  the 
  

   solution, 
  provided 
  that 
  the 
  asymmetric 
  group 
  remains 
  intact 
  

   in 
  either 
  of 
  the 
  ions. 
  

  

  In 
  a 
  further 
  attempt 
  to 
  distinguish 
  the 
  effect 
  of 
  electro- 
  

   lytic 
  dissociation 
  on 
  the 
  rotativity, 
  Landolt 
  and 
  Oudemanns 
  

   found 
  that 
  by 
  decreasing 
  the 
  degree 
  of 
  dissociation 
  of 
  the 
  

   active 
  substance 
  by 
  adding 
  to 
  the 
  solution 
  other 
  electrolytes 
  

   the 
  rotation 
  was 
  altered. 
  For 
  example, 
  it 
  was 
  found 
  that 
  

   the 
  specific 
  rotation 
  of 
  tartaric 
  acid 
  was 
  altered, 
  and 
  in 
  

   different 
  ways, 
  by 
  replacing 
  the 
  simple 
  water 
  solvent 
  by 
  

   solutions 
  of 
  hydrochloric, 
  sulphuric, 
  or 
  other 
  acid. 
  The 
  

   explanation 
  of 
  their 
  results 
  is, 
  however, 
  very 
  simple 
  if 
  we 
  

   rewrite 
  the 
  above 
  formula 
  in 
  a 
  suitable 
  way. 
  If 
  the 
  water 
  

   solvent 
  is 
  replaced 
  by 
  a 
  solution 
  containing 
  any 
  inactive 
  

   substance 
  at 
  a 
  partial 
  density 
  <r 
  2 
  * 
  n 
  water 
  at 
  a 
  density 
  <r 
  1? 
  we 
  

   must 
  replace 
  in 
  the 
  above 
  formula 
  yua 
  by 
  (ftiO'i+faG'z), 
  an 
  d 
  

   the 
  specific 
  rotation 
  is 
  accordingly 
  altered 
  to 
  

  

  L 
  J 
  (1— 
  a\p 
  — 
  afji 
  1 
  a 
  l 
  — 
  a/^ 
  2 
  t7 
  2 
  ) 
  2 
  ' 
  

   a 
  formula 
  which 
  clearly 
  indicates 
  the 
  effect 
  of 
  the 
  altered 
  

   solvent. 
  

  

  Numerous 
  other 
  experimental 
  results 
  of 
  a 
  similar 
  nature 
  

   admit 
  of 
  similar 
  simple 
  explanations 
  based 
  on 
  the 
  above 
  

   formula, 
  but 
  it 
  seems 
  unnecessary 
  to 
  detail 
  them 
  all 
  here. 
  

   The 
  formula 
  appears 
  sufficiently 
  general 
  to 
  include 
  the 
  

   greatest 
  majority 
  of 
  them, 
  if 
  not 
  all. 
  It 
  might, 
  however, 
  

   be 
  mentioned 
  that 
  Walden 
  has 
  found 
  that 
  in 
  very 
  dilute 
  

   solutions 
  of 
  compounds 
  in 
  which 
  the 
  anion 
  and 
  cathion 
  are 
  

   both 
  active 
  the 
  rotation 
  is 
  the 
  sum 
  of 
  the 
  separate 
  rotations 
  

   of 
  the 
  separate 
  ions. 
  This 
  is, 
  of 
  course, 
  an 
  immediate 
  

   deduction 
  from 
  our 
  formula. 
  

  

  