Am.  Jour.  Pharm. 
Jan.,  1890. 
Casto?*  Oil  Adulteration. 
43 
with  the  alcohol  test,  where  a  solvent  has  the  power,  in  combination 
with  a  substance  which  it  freely  dissolves,  to  take  up  a  third  sub- 
stance which,  without  the  aid  of  the  second,  it  could  not  dissolve. 
Therefore  a  sample  containing  much  more  than  20  per  cent,  of  cocoa- 
nut  oil  or  other  adulterant  would  in  conjunction  with  the  petroleum 
ether  carry  the  castor  oil  into  solution. 
As  a  quantitative  test,  my  experience  of  this  method  is  only  of  a 
few  days'  standing  and  I  do  not  wish  to  speak  too  dogmatically  upon 
it,  but  I  do  think  that  if  carefully  carried  out  at  a  temperature  of  60° 
F.  it  is  capable  of  yielding  very  trustworthy  results. 
I  have  alluded  to  the  high  density  of  castor  oil  as  being  one  of  its 
distinctive  characteristics,  and  in  this  instance,  where  the  adulterant  is 
cocoanut  oil,  it  is  possible  to  arrive  at  the  percentage  of  adulterant 
present  by  the  specific  gravity  process  quite  as  accurately  as  by  either 
the  saponification  equivalent  or  the  iodine  absorption  test,  and  with 
far  greater  facility. 
The  specific  gravity  of  castor  oil  at  a  temperature  of  60°  F.  is  *964. 
I  have  never  found  any  higher,  and  the  lowest  that  I  have  met  with 
was  a  sample  of  French  oil  which  gave  '9625  at  the  same  tempera- 
ture. There  is  a  greater  range  than  this  given  in  text  books,  but  I 
much  doubt  their  accuracy,  and  in  my  experience  *963  to  '964  is  the 
correct  density  for  genuine  oil.  When  castor  oil  is  adulterated  with 
10  per  cent,  and  over  of  cocoanut  oil,  the  latter  separates  when  the 
temperature  falls  to  60°  F.,  and  it  becomes  necessary  in  such  cases  to 
take  the  density  at  a  higher  temperature.  I  have  therefore  taken  a 
sample  of  castor  oil  possessing  a  density  of  *964  at  60°  F.  and  found 
its  density  to  be  "949  at  100°  F.  A  sample  of  cocoanut  oil  at  the 
same  temperature  (100°  F.)  I  found  to  be  '912.  Both  densities  were 
taken  by  means  of  an  accurate  1,000  grain  bottle.  From  this  it  will 
be  seen  that  the  difference  between  the  two  densities  is  sufficient  to 
enable  one  to  arrive  at  a  very  accurate  estimation,  by  a  very  simple 
calculation,  of  the  amount  of  cocoanut  oil  present. 
In  the  first  place  it  is  of  course  necessary  to  ascertain  the  presence 
of  cocoanut  oil,  and  this  can  be  done  by  heating  the  sample  under 
examination  in  a  small  porcelain  dish,  when  the  distinctive  odor  of 
cocoanut  oil  can  be  readily  ascertained.  By  this  plan  the  presence  of 
even  1  percent,  can  be  detected,  and  5  per  cent,  is  quite  distinctive  to 
anyone  possesring  an  ordinary  sense  of  smell. 
I  have  heard  within  the  last  few  days  that  some  castor  oil  has 
