﻿474 
  Seventh 
  Annual 
  Report 
  of 
  the 
  

  

  late 
  in 
  the 
  progress 
  of 
  this 
  investigation, 
  and 
  it 
  was 
  impossible 
  to 
  

   carry 
  on 
  all 
  the 
  experiments 
  with 
  it 
  that 
  it 
  deserves. 
  It 
  has 
  seemed 
  

   inadvisable, 
  therefore, 
  to 
  present 
  in 
  full 
  the 
  results 
  obtained. 
  Two 
  

   samples 
  of 
  raw 
  linseed, 
  six 
  samples 
  of 
  boiled 
  linseed, 
  two 
  of 
  corn, 
  

   and 
  one 
  of 
  cottonseed 
  oil, 
  gave 
  results 
  agreeing 
  substantially 
  "vvith 
  

   those 
  of 
  Hehner 
  and 
  Mitchell. 
  Two 
  samples 
  of 
  mineral 
  oil, 
  one 
  

   light 
  and 
  one 
  heavy, 
  one 
  sample 
  of 
  rosin 
  oil, 
  and 
  one 
  sample 
  of 
  

   turpentine 
  failed 
  to 
  give 
  any 
  precipitate 
  of 
  insoluble 
  bromine 
  

   del•i^'atives. 
  

  

  7. 
  The 
  Percentage 
  of 
  Volatile 
  Oil. 
  

  

  The 
  presence 
  of 
  even 
  a 
  small 
  percentage 
  of 
  turpentine 
  in 
  linseed 
  

   oil 
  is 
  distinctly 
  indicated 
  by 
  the 
  odor 
  of 
  the 
  oil 
  when 
  placed 
  in 
  a 
  

   vessel 
  which 
  it 
  about 
  half 
  fills, 
  the 
  vessel 
  closed, 
  and 
  heated 
  in 
  

   boiling 
  water 
  for 
  a 
  few 
  minutes. 
  The 
  smell 
  of 
  turpentine 
  will 
  

   then 
  be 
  noticed 
  on 
  opening 
  the 
  vessel. 
  Benzine 
  is 
  indicated, 
  

   though 
  not 
  quite 
  so 
  distinctly, 
  in 
  the 
  same 
  way. 
  

  

  To 
  determine 
  the 
  amount 
  present, 
  a 
  convenient 
  quantity, 
  say 
  

   300 
  grams, 
  is 
  heated 
  by 
  means 
  of 
  a 
  paraffin 
  or 
  air 
  bath 
  to 
  about 
  

   130° 
  C, 
  in 
  a 
  flask 
  provided 
  with 
  an 
  outlet 
  tube 
  for 
  vapors, 
  an 
  

   inlet 
  tube 
  reaching 
  nearly 
  to 
  the 
  bottom 
  of 
  the 
  vessel, 
  and 
  a 
  ther- 
  

   mometer 
  inserted 
  into 
  the 
  oil. 
  When 
  the 
  oil 
  has 
  reached 
  the 
  de- 
  

   sired 
  temperatui'e 
  a 
  current 
  of 
  dry 
  steam 
  is 
  passed 
  through 
  the 
  

   oil 
  and 
  the 
  vapors 
  condensed 
  in 
  a 
  Liebig 
  condenser. 
  Tbie 
  distillate 
  

   ■will 
  separate 
  into 
  a 
  lower 
  layer 
  of 
  w^ater 
  and 
  an 
  upper 
  layer 
  of 
  

   volatile 
  oil, 
  which 
  is 
  separated 
  and 
  measured 
  or 
  weighed. 
  The 
  

   aqueous 
  pai-t 
  of 
  the 
  distillate 
  -^all 
  inevitably 
  carry 
  with 
  it 
  a 
  smaU 
  

   quantity 
  of 
  volatile 
  oil, 
  but 
  the 
  quantity 
  is 
  very 
  small. 
  The 
  

   amount 
  of 
  turpentine 
  either 
  dissolved 
  or 
  permanently 
  held 
  in 
  sus- 
  

   pension 
  by 
  water 
  was 
  found 
  in 
  one 
  experiment 
  made 
  by 
  the 
  author 
  

   (Jour. 
  Amer. 
  Chcm. 
  Soc. 
  16, 
  273) 
  to 
  amount 
  to 
  0.300 
  grams 
  in 
  

   90 
  c. 
  c. 
  of 
  water. 
  

  

  A 
  separation 
  of 
  the 
  benzine 
  and 
  tui'pentine 
  in 
  the 
  volatile 
  oil 
  

   found 
  is 
  best 
  effected 
  by 
  the 
  method 
  of 
  Burton 
  (Amer. 
  Chem. 
  J. 
  

   12, 
  102), 
  which 
  depends 
  upon 
  the 
  difference 
  between 
  the 
  action 
  of 
  

   fuming 
  nitric 
  acid 
  upon 
  benzine 
  and 
  upon 
  turpentine, 
  the 
  former 
  

   remaining 
  practically 
  unattacked.h^'ile 
  the 
  latter 
  is 
  strongly 
  acted 
  

  

  