254  ANALYSIS  OF   OILS  BY  MEANS  OF  SULPHURIC  ACID. 
certain  parts,  contain  racemic  acid,  as  well  as  those  of  Italy,  Au- 
stria, and  Hungary,  and  that  this  acid  accumulates  in  the  mother 
liquors  of  tartaric  acid  manufactories. 
M.  Kestner  presented,  through  M.  Biot,  to  the  Paris  Academy 
of  Sciences,  January  3,  about  nine  pounds  of  the  racemic  acid  so 
obtained,  on  which  occasion  the  facts  contained  in  this  notice  were 
communicated  to  the  Academy. 
In  a  notice  of  paratartaric  (racemic)  acid,  which  appeared  in  the 
Pharmaceutical  Journal,  of  February,  1851,  the  author  of  the 
paper  states,  that  "  recent  investigations,  have  led  to  the  conclu- 
sion that  most  tartars  contain  a  certain  portion  of  this  acid,  which 
is  lost  in  the  process  at  present  employed  in  the  manufacture  of 
tartaric  acid.  This  fact  may  serve  to  account  for  the  deficient  re- 
sults sometimes  obtained." — Ann.  ofPharm.  Feb.,  1853. 
ANALYSIS  OF  OILS  BY  MEANS  OF  SULPHURIC  ACID. 
By  Maumene. 
When  fixed  oils  are  mixed  with  sulphuric  acid,  they  evolve  heat. 
This  reaction  can  be  employed  to  distinguish  the  drying  oils  from 
those  which  do  not  possess  this  property. 
Olive  Oil. — Into  an  ordinary  test  glass,  50  grms.  of  the  oil  are 
poured ;  a  thermometer  is  placed  therein,  and  10  cub.  cent,  of 
boiled  sulphuric  acid  are  carefully  added.  The  temperature  of  the 
acid  and  oil  was  77°  Fahr.  After  being  mixed,  the  temperature 
had  risen  to  153°.  The  elevation  of  temperature  in  repeated  ex- 
periments is  constant,  that  is,  76°.  The  mixture  is  made  within 
two  minutes,  and  the  temperature  has  within  one  minute  reached 
its  maximum.    It  evolves  no  sulphuric  acid. 
Rape  Oil. — Oil  and  acid  had  79°.  After  being  mixed,  the 
thermometer  rose  to  213°.  Elevation  of  temperature  134°.  The 
mixture  swelled,  and  evolved  sulphurous  acid.  With  this  oil,  the 
elevation  of  temperature  is  also  constant,  but  the  true  elevation 
amounts  to  155°.  The  difference  of  the  observed  and  the  true 
temperatures  is  caused  by  the  loss  of  heat  which  the  mixture  suffers 
by  the  evolution  of  the  sulphurous  acid  gas. 
Ben  Oil  and  Tallow  Oil  exhibit  very  nearly  the  same  elevation 
of  temperature  as  olive  oil. 
