TINCTURE    OF  CHLORIDE  OF  IRON. 
103 
in  the  seeds,  but  like  oil  of  bitter  almonds  is  generated  by  the  re- 
action of  the  emulsin  on  some  principle  not  jet  isolated.  The 
question  at  once  suggests  itself,  whether  the  well  known  activity 
of  the  residue  after  the  expression  of  the  oil,  which  is  such  that 
the  amount  of  it  in  two  or  three  seeds  produces  cathartic  effects 
equivalent  to  an  ounce  of  castor  oil,  is  due  to  this  hypothetical 
substance,  developed  by  contact  of  moisture  ?  or  whether  it 
could  be  traced  to  a  pre-existent,  well  denned  principle,  of  ex- 
treme acrimony,  capable,  in  the  diluted  state  in  which  it  must 
exist  in  the  residue,  of  producing  the  effect  indicated  ?  And  fi- 
nally, if  such  a  principle  exists,  whether  it  is  soluble  to  any  ex- 
tent in  the  expressed  oil,  and  contributes  to  its  cathartic  power  ? 
The  statement  of  Dr.  Wood,  (U.  S.  Disp.,)  that  the  ebullition 
of  the  oil  with  water  removes  an  acrimony  at  first  possesses, 
seems  to  suggest  the  latter  view  as  correct.  These  inquiries  are 
worthy  of  the  attention  of  pharmaceutical  chemists. 
ON  THE  TINCTUKE  OF  CHLORIDE  OF  IRON. 
By  A.  P.  Sharp,  of  Baltimore. 
I  have  frequently  been  at  a  loss  to  know  how  to  make  the  above 
preparation  of  the  required  strength  of  the  U.  S.  Pharmacopoeia, 
from  the  fact  of  the  impossibility  (at  least  as  far  as  my  experience 
has  gone)  of  obtaining  the  acid  of  the  proper  specific  gravity, 
1160,  which  is  necessary  to  dissolve  all  the  iron. 
I  have  tried  different  plans,  and  have  gone  to  considerable 
expense  to  get  the  acid  of  1160,  and  even  after  obtaining  it  of  that 
specific  gravity,  have  found  it  would  not  answer  the  purpose,  and 
upon  investigating  the  cause  of  it,  have  always  found  that  the 
acid  was  brought  to  the  above  specific  gravity  by  the  adulteration 
of  sulphuric  acid,  either  intentionally  or  accidentally.  I  propose 
a  simple  plan  whereby  every  pharmaceutist  may  always  obtain 
the  tincture  of  the  proper  strength  and  with  very  little  trouble, 
which  plan  I  prefer  to  any  other  I  have  tried.  I  comply  with 
the  directions  of  the  U.  S.  Pharmacopoeia,  using  the  pure  muriatic 
acid,  until  I  am  satisfied  no  more  iron  will  be  taken  up.  'I  then 
fit  a  cork  and  bent  glass  tube  to  an  ordinary  Florence  fiask, 
partly  filled  with  commercial  muriatic  acid,  and  after  properly 
