Am.  Jour.  Pharm. 
Jan.,  1884. 
Acidum  Oleicum. 
17 
ethereal  solution  filtered,  and  the  ether  distilled  off  in  a  water  bath 
gradually  heated  to  boiling,  and  boiled  actively  for  half  an  hour.  The 
acid  was  then  of  a  pale  yellow  color,  but  had  a  fatty  odor.  Trans- 
ferred to  a  flask  which  it  filled  to  the  middle  of  the  neck  to  diminish 
contact  with  the  air,  it  was  then  heated  in  a  sand  bath  to  210°  C.  == 
410°  F.  At  about  100°  C.  vapor  was  given  off  with  the  appearance 
of  gentle  boiling,  and  this  boiling  continued  to  the  end  of  the  heating, 
diminishing  as  the  temperature  arose,  and  had  not  entirely  ceased,  but 
nearly  so,  when  the  heating  was  discontinued.  The  vapor  given  off 
had  at  first  a  slight  odor  of  ether,  and  afterward  seemed  to  be  mainly 
steam  with  a  fatty  odor.  Toward  the  end  of  the  heating  a  visible  vapor 
came  off  with  an  odor  suggesting  acrolein,  and  as  this  evidence  of  decom- 
position became  distinct  and  unmistakable,  the  heating  was  arrested 
before  the  bubbles  of  vapor  had  entirely  ceased  to  arise  from  the 
bottom  and  sides  of  the  flask.  The  flask  was  then  corked  and  cooled. 
During  the  heating,  which  required  about  an  hour  and  a  quarter  for 
about  150  grammes  of  the  acid,  the  color  became  much  deeper,  so  that 
the  acid  was  much  deeper  in  color  than  the  original  almond  oil,  and 
quite  brown;  and  the  volume  was  reduced  by  5  to  8  p.  c.  (estimated). 
The  s.  g.  at  15°  C.  =  59°  F.  was  '8984,  and  at  25°  C.  =  77°  F.,  -8917. 
When  cooled  down  to  3*4°  C.  =  38°  F.  it  congealed  at  the  surface 
first,  and  during  the  congelation  the  temperature  rose  to  5*2°  C.  = 
41*4°  F.,  and  the  whole  became  a  soft  solid  mass  from  which  no  liquid 
would  flow. 
A  part  of  the  same  acid  which  had  been  saponified  only  once,  as 
before-mentioned,  the  soap  decomposed  with  tartaric  acid  in  excess,  and 
the  resulting  mixed  acids  separated  by  cold  at  8°C.  =  46*4°  F.  when 
cooled  remained  perfectly  transparent  to  2*5°  C.  =  37°  F.,  and  then 
began  to  crystallize  in  distinct  white  groups  on  the  sides  and  bottom 
of  the  flask.  These  groups  were  few  and  small,  and  the  mass  of  acid 
did  not  crystallize  at  that  temperature.  It  was  therefore  concluded  that 
these  small  groups  were  palmitic  acid  crystallizing  out.  Each  then 
stood  for  eight  hours  at  a  temperature  of  3°C.  =  37*4°  F.  when  the 
last  portion  was  filled  with  crystals,  though  still  liquid,  and  had  a 
temperature  of  4'6°C.  The  portion  which  had  been  resaponified, 
ether  extracted  and  heated,  was  so  nearly  solid  that  the  thermometer 
could  only  just  be  pushed  through  the  mass,  and  its  temperature  was 
4-4°  C. 
The  marked  difference  in  s.  g.  of  this  acid,  before  and  after  the  second 
2 
