﻿470) 
  Seventh 
  A^•^•UAL 
  Report 
  of 
  the 
  

  

  different 
  observers 
  with 
  different 
  apparatus 
  have 
  varied 
  with 
  the 
  

   same 
  oil, 
  and 
  each 
  apparatus 
  must 
  be 
  standardized 
  by 
  the 
  observer 
  

   by 
  testing 
  with 
  a 
  number 
  of 
  oils 
  of 
  kno\\Ti 
  purity, 
  or 
  else 
  by 
  adopt- 
  

   ing 
  the 
  suggestion 
  of 
  Thomson 
  and 
  Ballantyne 
  (J. 
  Soc. 
  Chem. 
  Ind, 
  

   1891, 
  10, 
  233), 
  and 
  expressing 
  the 
  results 
  in 
  terms 
  of 
  rise 
  of 
  tem- 
  

   perature 
  produced 
  by 
  substituting 
  an 
  equal 
  volume 
  of 
  water 
  for 
  

   oil, 
  tlie 
  results 
  obtained 
  with 
  water 
  being 
  taken 
  as 
  100. 
  As 
  stated 
  

   above, 
  the 
  "Maumcne 
  figure 
  is 
  usually 
  higher 
  the 
  higher 
  the 
  halogen 
  

   absorption. 
  In 
  the 
  case 
  of 
  menhaden 
  oil, 
  however, 
  and 
  i>erhaps 
  

   other 
  fish 
  oils, 
  the 
  Maumeno 
  figure 
  is 
  higher 
  than 
  would 
  corre- 
  

   spond 
  w^th 
  its 
  iodine 
  or 
  bromine 
  absorption. 
  A 
  sample 
  having 
  a 
  

   bromine 
  addition 
  figiu-e 
  of 
  95, 
  as 
  against 
  linseed 
  oil, 
  which 
  would 
  

   have 
  a 
  figure 
  usually 
  about 
  102, 
  would 
  give 
  a 
  Maumene 
  figure 
  

   higher 
  than 
  that 
  of 
  the 
  linseed 
  oil. 
  Thomson 
  and 
  Ballantyne 
  find 
  

   that 
  the 
  specific 
  rise 
  of 
  temperature 
  of 
  four 
  samples 
  of 
  linseed 
  oil, 
  

   which 
  they 
  examined, 
  varied 
  from 
  270 
  to 
  349, 
  while 
  the 
  corre- 
  

   sponding 
  figure 
  for 
  a 
  sample 
  of 
  menhaden 
  oil 
  was 
  306. 
  Allen 
  

   found 
  the 
  rise 
  of 
  temperature 
  with 
  sulphuric 
  acid 
  to 
  be 
  104 
  to 
  111 
  

   in 
  the 
  case 
  of 
  linseed 
  oil, 
  and 
  126 
  in 
  the 
  case 
  of 
  menhaden 
  oil. 
  

  

  It 
  will 
  be 
  seen 
  from 
  these 
  facts 
  that 
  if 
  an 
  oil 
  is 
  found 
  to 
  give 
  a 
  

   distinctly 
  lower 
  bromine 
  addition 
  figure, 
  and, 
  at 
  the 
  same 
  time 
  a 
  

   Maumene 
  figm-e 
  distinctly 
  higher 
  than 
  specimens 
  of 
  pure 
  linseed 
  

   oil 
  tested 
  in 
  the 
  same 
  aj^paratus, 
  very 
  strong 
  evidence 
  of 
  the 
  pres- 
  

   ence 
  of 
  fish 
  oil 
  is 
  at 
  hand. 
  It 
  is 
  advisible 
  before 
  testing 
  a 
  sample 
  

   of 
  oil 
  in 
  this 
  way 
  to 
  remove 
  from 
  the 
  oil 
  all 
  impurities, 
  as 
  far 
  as 
  

   possible. 
  Volatile 
  oil 
  is 
  removed 
  witli 
  comparative 
  ease. 
  Free 
  

   rosin 
  can 
  be 
  largely 
  removed 
  by 
  repeated 
  treatment 
  wdtli 
  moderately 
  

   strong 
  alcohol, 
  and 
  subsequent 
  removal 
  of 
  any 
  alcohol 
  that 
  may 
  

   remain 
  dissolved 
  in 
  the 
  oil 
  by 
  treatment 
  with 
  water 
  and 
  settling, 
  

   keeping 
  the 
  vessel 
  hot. 
  Unsaponifiable 
  matter 
  and 
  soaps 
  cannot 
  

   be 
  easily 
  removed, 
  but 
  in 
  extremely 
  important 
  cases 
  it 
  might 
  be 
  

   ad^dsable 
  to 
  jDrepare 
  a 
  quantity 
  of 
  the 
  fatty 
  acids 
  of 
  the 
  sample 
  to 
  

   be 
  examined 
  by 
  saponifying 
  and 
  then 
  acidifying 
  the 
  oil, 
  after 
  free- 
  

   ing 
  it 
  from 
  rosin, 
  as 
  far 
  as 
  possible. 
  Volatile 
  oil 
  could 
  be 
  removed 
  

   during 
  the 
  saponification. 
  This 
  sample 
  of 
  fatty 
  acids 
  could 
  then 
  

   be 
  tested 
  under 
  the 
  same 
  conditions 
  as 
  the 
  fatty 
  acids 
  prepared 
  

   from 
  samples 
  of 
  pure 
  linseed 
  oil. 
  

  

  