8  Oleic  Acid  and  the  Oleates.  [{^ffiSj?" 
OLEIC  ACID  AND  THE  OLEATES. 
By  L.  Wolff. 
Read  at  the  Pharmaceutical  Meeting,  December  17. 
Since  the  reading  and  publication  of  my  article  on  the  use  of  benzin 
in  pharmacy  ("  Amer.  Journ.  Pharm.,"  Jan.,  1877),  in  which  I 
pointed  out  the  important  utility  of  the  latter  substance  for  the  manu- 
facture of  oleic  acid,  I  have  still  further  continued  my  experiments  in 
that  direction,  and  submit  some  of  the  results  below. 
The  fact  that  the  purified  oleic  acid  now  offered  in  the  market  by 
some  of  even  the  most  reliable  manufacturers  is  merely  the  crude  acid 
as  derived  in  the  manufacture  of  candles,  deprived  of  its  coloring  mat- 
ter by  means  of  charcoal,  and  consists  to  a  large  extent  of  stearic  acid, 
has  led  to  much  disappointment  in  the  preparation  of  the  so-called 
oleates.  If  the  crude  acid  were  saponified  with  lead  oxide,  and  the 
lead  stearate  separated  therefrom  by  benzin  or  ether,  as  I  had  origi- 
nally suggested,  many  disadvantages  might  be  obviated,  and  an  acid 
obtained  that  would  answer  sufficiently  for  all  pharmaceutical  purposes; 
but  that  stearic  or  palmitic  acid  must  prove  objectionable  for  preparing 
oleates  is  quite  evident. 
The  separation  of  the  lead  oleate  from  the  lead  stearate  is  so  difficult 
when  stearic  or  palmitic  acid  is  present  to  any  extent,  that  I  was  soon 
led  to  abandon  the  crude  oleic  acid  and  the  cheaper  oils,  such  as  lard 
oil  or  even  olive  oil,  as  a  source  for  the  acid,  and  have  as  yet  found 
none  better,  more  economical  or  practicable  in  this  process  than  the 
-  oil  of  sweet  almonds.  I  have  also  abandoned  the  primary  saponifica- 
tion with  a  caustic  alkali,  and  have  at  once  saponified  the  oil  of  sweet 
almonds  with  the  lead  oxide  in  the  manner  as  directed  by  the  Pharma- 
copoeia process  for  lead  plaster,  employing  one-half  the  quantity  more 
of  litharge  to  ensure  the  complete  saponification  of  the  oil.  The 
plaster — or  better  the  oleo-palmitate  of  lead — so  obtained  is  readily 
soluble  in  benzin,  and  deposits  from  this  solution  the  lead  palmitate, 
leaving  the  lead  oleate  tc  be  decanted.  This  benzin  solution  of  lead 
oleate,  shaken  repeatedlv  with  diluted  hydrochloric  acid  (1  to  7),  sepa- 
rates the  lead  chloride  and  leaves  a  benzin  solution  of  oleic  acid,  which, 
after  expulsion  of -the  benzin,  yields  an  acid  that  gives  oleates,  remain- 
ing liquid  and  clear,  and  showing  a  marked  distinction  from  the  prepa- 
rations with  the  commercial  acids,  which,  even  when  containing  only 
