﻿COMMISSIOKER 
  OF 
  AgKICULTURE. 
  461 
  

  

  The 
  change 
  in 
  gravity, 
  with 
  change 
  in 
  temperature, 
  of 
  linseed 
  

   oil, 
  and 
  of 
  some 
  other 
  oils, 
  has 
  been 
  determined 
  by 
  Allen, 
  Oonun. 
  

   Org. 
  Anal., 
  3d 
  ed.. 
  Vol. 
  2, 
  Part. 
  1, 
  p. 
  33, 
  and 
  the 
  following 
  are 
  some 
  

   of 
  his 
  resnlts. 
  

  

  Cor 
  ection 
  for 
  

   Nature 
  of 
  oil. 
  1° 
  C. 
  

  

  Linseed 
  . 
  000649 
  

  

  Menliaden 
  000654 
  

  

  Cottonseed 
  '. 
  000629 
  

  

  Rap€ 
  . 
  000620 
  

  

  According 
  to 
  the 
  results 
  obtained 
  by 
  Saussnre, 
  the 
  coefficient 
  of 
  

   expansion 
  of 
  linseed 
  oil 
  is 
  not 
  nniform 
  between 
  12° 
  C. 
  and 
  94° 
  O. 
  

   He 
  records 
  the 
  following 
  resnlts 
  (Benedikt, 
  p. 
  428): 
  

  

  Specific 
  

   gravity. 
  

  

  12° 
  C 
  939 
  

  

  25° 
  O 
  930 
  

  

  50° 
  O 
  921 
  

  

  94° 
  C 
  881 
  

  

  Calculating 
  from 
  tbese 
  results 
  we 
  obtain, 
  as 
  the 
  yariation 
  for 
  

   1° 
  C, 
  between 
  12° 
  0. 
  and 
  25° 
  C, 
  .000692; 
  between 
  25° 
  C. 
  and 
  

   50° 
  C, 
  .000360, 
  and 
  between 
  50° 
  C. 
  and 
  94° 
  C, 
  .000909. 
  It 
  

   will 
  be 
  seen 
  from 
  the 
  table 
  giving 
  tbe 
  results 
  of 
  determinations 
  

   of 
  specific 
  gravity 
  at 
  different 
  temperatures 
  that 
  I 
  do 
  not 
  find 
  in 
  

   the 
  oils 
  examined 
  a 
  similar 
  change 
  in 
  the 
  rate 
  of 
  expansion. 
  The 
  

   averages 
  of 
  the 
  figures 
  obtained 
  vnth. 
  raw 
  oils, 
  'Nos. 
  52 
  and 
  73, 
  

   and 
  boiled 
  oil, 
  j^o. 
  72, 
  show 
  that 
  the 
  change 
  in 
  specific 
  gravity 
  for 
  

   1° 
  C, 
  between 
  15°. 
  5 
  C. 
  and 
  28° 
  C, 
  was 
  .000654; 
  between 
  28° 
  O. 
  

   and 
  100° 
  C, 
  .000720, 
  and 
  beween 
  15°. 
  5 
  C. 
  and 
  100° 
  C, 
  

   .000712. 
  

  

  A 
  low 
  specific 
  gravity 
  in 
  an 
  oil 
  under 
  examination 
  might 
  be 
  

   caused 
  by 
  the 
  presence 
  of 
  (1) 
  turpentine 
  or 
  benzine 
  (indicated 
  

   also 
  by 
  odor); 
  (2) 
  heavier 
  petroleum 
  oils; 
  (3) 
  com 
  or 
  cottonseed 
  oils. 
  

  

  A 
  high 
  specific 
  gravity 
  would 
  point 
  to 
  (1) 
  rosin 
  or 
  other 
  resin; 
  

  

  