Am.  Jour  Pharrn.\ 
May,  1889.  J 
Olive  Oil 
227 
the  oil  when  treated  with  alcoholic  solution  of  iodine  and  mercuric 
chloride.    The  test  was  strictly  applied  as  given  in  Allen. 
Fusing  point  of  the  fatty  acids  obtained  by  using  thin  glass  tubes 
closed  at  one  end  and  charged  with  about  1  cm.  of  the  fused  acid  by 
heating  the  tube  and  holding  below  the  surface  of  the  acid,  as  the 
tube  cools  the  acid  rises ;  by  inverting  the  tube  and  tapping  it  the 
acid  will  flow  to  the  bottom,  and  now  by  a  little  clever  management 
the  acid  can  be  divided  in  two  parts,  separated  by  an  air  bubble ;  the 
tube  is  then  set  aside  for  a  few  hours  at  a  temperature  below  the 
solidifyiug  point  of  the  fat.  To  take  the  fusing  point,  the  little  tube 
is  attached  to  a  thermometer  and  placed  in  a  beaker  of  water,  which, 
in  turn,  is  placed  in  another  beaker  of  water,  and  heat  applied  to  the 
latter  by  placing  on  a  hot  iron  plate.  The  temperature  indicated 
when  the  two  portions  of  the  acid  run  together  is  that  figure  given 
first,  the  second  figure  representing  the  temperature  when  the  fused 
acids  become  transparent.  Under  the  head  "  Standard "  are  given 
such  results  as  have  been  constantly  obtained  in  the  examination  of 
pure  oils  (all  European),  and  hence  used  for  comparison. 
Some  of  the  above  tests  were  also  made  with  a  so-called  salad  oil, 
a  mixture  of  arachis  and  sesame  oils,  and  with  cotton-seed  oil. 
From  the  results  of  all  of  the  tests  would  appear  the  purity  of  all 
the  olive  oils  examined  ;  the  California  oils  differing  from  the  foreign 
oils  decidedlv  in  some  of  the  accepted  tests  of  purity,  it  may  be  well 
to  mention  these  in  detail. 
1.  A  high  specific  gravity;  L.  Archbutt,  in  89  samples  examined 
found  few  oils  to  reach  0.917,  his  variations  are  stated  between  0.9136 
and  0.917  ;  the  U.  S.  P.  and  Pharm.  Germ,  adopted  0.915  to  0.918; 
if  the  presence  of  free  acid  is  considered  in  the  California  oils  the 
specific  gravities  found  are  exceptionally  high,  the  presence  of  free 
acid  reducing  the  specific  gravity  considerably. 
2.  Intenser  reactions  with  the  acids  ;  these  tests  should  not  be  relied 
upon  too  implicitly  for  two  reasons ;  firstly,  pure  oils  when  fresh  may 
be  affected  but  little  by  acids,  but  after  a  time  may  be  affected  consider- 
ably ;  secondly,  the  oils  used  as  adulterants  which  at  one  time  gave 
unmistakable  color  reactions  are  now  so  fully  purified  as  to  give  little 
reaction  with  these  same  tests ;  of  eight  samples  of  cotton-seed  oil  ex- 
amined no  two  gave  like  reactions  with  the  acids. 
3.  The  elaidin-reaction  requires  a  longer  time  than  with  the  Eu- 
ropean oils. 
