﻿Commissioner 
  of 
  Agriculture. 
  459 
  

  

  The 
  tests 
  wliicli 
  are 
  valuable 
  particularly 
  in. 
  determiiiing 
  the 
  

   freedom 
  from 
  adulteration 
  are: 
  

  

  1. 
  Specific 
  gTavity. 
  

  

  2. 
  The 
  action 
  of 
  bromine 
  or 
  iodine 
  on 
  the 
  oil. 
  Hubl 
  and 
  bro- 
  

   mine 
  Figures. 
  

  

  3. 
  The 
  percentage 
  of 
  unsaponifiable 
  organic 
  matter. 
  

  

  4. 
  The 
  amount 
  of 
  alkali 
  required 
  to 
  convert 
  the 
  oil 
  intoi 
  soap. 
  

   Koettstofer 
  Figure. 
  

  

  5. 
  The 
  amount 
  of 
  alkali 
  required 
  to 
  neutralize 
  tlie 
  acids 
  in 
  the 
  

   oik 
  Acid 
  Figiire. 
  

  

  6. 
  The 
  percentage 
  of 
  insoluble 
  bromine 
  derivatives. 
  

  

  7. 
  The 
  amount 
  of 
  volatile 
  oil 
  (turpentine 
  and 
  benzine) 
  contained 
  

   in 
  the 
  oil. 
  

  

  Other 
  tests 
  often 
  applied 
  to 
  linseed 
  oil 
  are 
  the 
  ^laumene 
  test, 
  

   which 
  is 
  the 
  measurement 
  of 
  the 
  temperature 
  caused 
  by 
  mixing 
  

   measiu'ed 
  amounts 
  of 
  the 
  oil 
  and 
  sulphuric 
  acid, 
  the 
  amount 
  of 
  

   oxygen 
  absorbed 
  by 
  the 
  oil 
  when 
  exposed 
  to 
  the 
  air 
  in 
  thin 
  films, 
  

   called 
  Livache's 
  test, 
  the 
  index 
  of 
  refraction, 
  and 
  the 
  action 
  on 
  

   polarized 
  light. 
  

  

  1. 
  The 
  Specific 
  Gravity. 
  

  

  Linseed 
  oil 
  is 
  heavier 
  than 
  most 
  other 
  oils. 
  Its 
  specific 
  gravity 
  

   is 
  expressed 
  in 
  terms 
  of 
  water 
  at 
  4°,C. 
  or 
  15°. 
  5C., 
  or 
  water 
  may 
  

   be 
  taken 
  as 
  unity 
  at 
  whatever 
  temperature 
  the 
  determination 
  

   of 
  specific 
  gi'avity 
  is 
  made. 
  It 
  is 
  adAnsable 
  that 
  some 
  standard 
  of 
  

   temperature 
  should 
  be 
  set 
  and 
  adhered 
  to 
  in 
  future 
  determinations, 
  

   as 
  exactness 
  and 
  simplicity 
  are 
  above 
  all 
  else 
  necessary 
  in 
  work 
  

   that 
  may 
  be 
  submitted 
  as 
  evidence 
  in 
  a 
  court 
  of 
  law. 
  It 
  is 
  at 
  all 
  

   events 
  advisable 
  that, 
  even 
  if 
  the 
  actual 
  determiniation 
  is 
  made 
  

   at 
  a 
  temperature 
  different 
  from 
  the 
  standard, 
  it 
  should 
  be 
  expressed 
  

   in 
  terms 
  of 
  water 
  at 
  the 
  sitandard 
  temperature. 
  Unfortunately 
  

   many 
  of 
  the 
  recorded 
  determinations 
  do 
  not 
  state 
  either 
  the 
  tem- 
  

   I^erature 
  at 
  which 
  the 
  determination 
  was 
  made, 
  or 
  the 
  temperature 
  

   at 
  which 
  water 
  is 
  taken 
  as 
  unity. 
  These 
  detemiinations 
  have 
  con- 
  

   sequently 
  little 
  legal 
  value. 
  I 
  should 
  recommeaid 
  as 
  the 
  conditions 
  

  

  