NEW  PROCESS  FOR  DOVER'S  POWDER. 
515 
ON  A  NEW  PROCESS  FOR  DOVER'S  POWDER. 
Louisville,  August  26$,  1856. 
Mr.  Wm.  Procter,  Jr.  : — Dear  Sir, — I  have  taken  the  liberty 
of  enclosing  to  you  a  sample  of  Dover's  powder,  made  in  a 
different  way  from  any  process  I  have  ever  seen.  It  may  not 
be  new  to  you,  but  I  always  make  it  in  the  way  I  propose,  and 
the  result  has  always  been  satisfactory.  The  greatest  difficulty 
I  met  with  in  making  this  compound  before  I  adopted  the  pre- 
sent, was  in  reducing  the  sulphate  of  potash  to  a  fine  powder. 
This  I  obviated  at  once  by  dissolving  the  salt  in  boiling  water 
to  perfect  saturation,  and  by  the  addition  of  alcohol  I  precipi- 
tate the  salt  in  a  highly  divided  state,  which  is  readily  mixed 
with,  the  opium  and  ipecac.  I  enclose  you  a  sample  for  your 
examination.  This  is  not  meant  as  a  communication,  but  act  as 
you  think  proper.* 
Very  respectfully,  your  obed'nt  serv'nt, 
T.  H.  Tannehill. 
ON  PILLS  OF  IODIDE  OF  IRON. 
Memphis,  Tenn.,  Sept.  IWi,  1856. 
To  the  Editor  of  the  American  Journal  of  Pharmacy  : — 
Dear  Sir, — In  the  last  (July)  number  of  the  Medico-Chi- 
rurgical  Review,  I  observed  the  following  paragraph  : — - 
"  M.  Perrens  proposes  the  preparation  of  pills  of  the  iodide  of  iron  ac- 
*[Note. — The  U.  S.  Pharmacopoeia,  in  directing  the  sulphate  of  potassa 
to  be  in  crystals,  designs  it  to  act  as  a  more  eifectuul  means  of  thoroughly 
dividing  the  opium  and  ipecacuanha,  which  are  thus  reduced  to  the  finest 
condition  by  the  amount  of  attrition  necessary  to  reduce  the  sulphate  to  a 
powder  of  sufficient  fineness,  and  thus  insures  the  requisite  trituration. 
This  is  the  more  important  as  it  is  too  much  the  custom  to  have  the  sul- 
phate ground  to  a  powder,  and  simply  mix  the  three  ingredients.  This  is 
a  pharmacopoeial  precaution,  analogous  to  that  of  directing  powdered  opium 
to  make  laudanum,  it  being  presumed  that  dry  opium  is  thus  insured  if 
the  directions  are  followed.  But  dry  opium  will  answer  equally  well  if 
properly  broken  up  ;  and  so  also  powdered  sulphate  of  potash  may  be  used 
with  equal  propriety,  if  the  requisite  amount  of  trituration  is  subsequently 
bestowed  to  reduce  the  whole  to  a  homogeneous  powder.  A  specimen  of 
the  Dover's  powder  received  from  the  author,  made  by  the  above  process, 
is  quite  unexceptionable,  and  equal  to  any  we  have  seen. — Editor  Amer. 
Jour.  Pharm.] 
