﻿Commissioner 
  of 
  Agricultuke. 
  473 
  

  

  of 
  heat 
  on 
  the 
  oil. 
  The 
  figure 
  of 
  boiled 
  oil 
  will 
  iiciially 
  be 
  below 
  

   5, 
  but 
  is 
  more 
  uncertain 
  than 
  that 
  of 
  raw 
  oil. 
  A 
  figure 
  higher 
  

   than 
  10.0 
  will 
  almost 
  certainly 
  be 
  found 
  due 
  to 
  the 
  presence 
  of 
  

   rosin. 
  The 
  acid 
  figin-e 
  of 
  rosin 
  is 
  variously 
  given 
  by 
  Benedikt, 
  Wil- 
  

   liams, 
  and 
  Schmidt 
  & 
  Erban, 
  from 
  145.5 
  to 
  179.2. 
  Samples 
  ex- 
  

   amined 
  by 
  the 
  author 
  (Jour. 
  Amer. 
  Chem. 
  Soc, 
  16, 
  275) 
  gave 
  fig- 
  

   ures 
  from 
  155.7 
  to 
  168.5. 
  Fortunately, 
  rosin 
  is 
  also 
  indicated 
  by 
  a 
  

   high 
  Bromine 
  Substitution 
  Figure 
  and 
  a 
  low 
  Bromine 
  Addition 
  

   Figure, 
  and, 
  if 
  all 
  three 
  point 
  to 
  rosin, 
  it 
  is 
  probably 
  there, 
  but 
  

   .the 
  safest 
  course 
  is 
  the 
  actual 
  isolation 
  of 
  the 
  rosin 
  bv 
  Twitx?hell's 
  

   or 
  Gladding's 
  process. 
  

  

  6. 
  The 
  Percentage 
  of 
  Insoluble 
  Bromine 
  Derivatives. 
  

   This 
  determination 
  is 
  proposed 
  by 
  Hehner 
  and 
  Mitchell 
  (Analyst 
  

   Dec, 
  1898, 
  Vol. 
  23, 
  p. 
  310). 
  It 
  depends 
  upon 
  the 
  fact 
  that 
  lin- 
  

   seed 
  oil 
  gives, 
  when 
  dissolved 
  in 
  ether 
  and 
  treated 
  with 
  bromine, 
  

   compounds 
  of 
  glycerides 
  and 
  bromine, 
  which 
  are 
  insoluble 
  in 
  the 
  

   ether, 
  while 
  oil 
  containing 
  glycerides 
  of 
  oleic 
  acid 
  only, 
  and 
  even 
  

   semi-di*ying 
  oils 
  like 
  cottonseed 
  and 
  com 
  oils, 
  give 
  soluble 
  com- 
  

   pounds. 
  Ilelmer 
  and 
  liitchell 
  obtain 
  the 
  following 
  percentages 
  of 
  

   insoluble 
  bromine 
  compounds 
  from 
  different 
  oils: 
  

  

  Qjj 
  Per 
  cent 
  of 
  irsoluble 
  

  

  ' 
  bromide 
  compounds. 
  

  

  Linseed 
  oil 
  23 
  . 
  86 
  to 
  25.0 
  

  

  Poppy 
  oil 
  0.0 
  

  

  Com 
  oil 
  0.0 
  

  

  Cottonseed 
  oil 
  0.0 
  

  

  Olive 
  oil 
  0.0 
  

  

  Almond 
  oil 
  0.0 
  

  

  Rapeseed 
  oil 
  0.0 
  

  

  Whale 
  oil 
  25.0 
  

  

  Code 
  oil 
  35.5 
  

  

  Codliver 
  oil 
  42.9 
  

  

  Shark 
  oil 
  22.0 
  

  

  The 
  process 
  Avhich 
  seems 
  to 
  be 
  a 
  valuable 
  one 
  in 
  detecting 
  adulte- 
  

   rations 
  of 
  linseed 
  oil 
  with 
  otl*Q^-seed 
  oils, 
  w^as 
  not 
  published 
  until 
  

  

  