^Novy'i'.mr'}  Tincture  Opii,  V.  S.  R— Water,  etc.  ^  489 
tract  or  other  substance  used  is,  by  this  process,  first  uniformly  dis- 
seminated through  the  butter  of  cacao  whilst  cold,  that  substance 
being  reduced  to  powder  by  trituration  ;  that  the  cacao  butter,  &c., 
are  kept  constantly  stirred  when  being  heated,  and  that  the  mixture 
is  only  reduced  to  the  consistence  of  cream  by  carefully  regulating 
the  amount  of  heat  applied,  so  as  to  avoid  the  danger  of  deposition  of 
extract,  which  always  occurs  when  it  becomes  too  thin  from  the  use  of 
too  much  heat. 
TINCTURA  OPTI  (U.S. P.) 
By  H,  Treverton  Bond,  M.  D. 
The  following  is  a  quick  method  of  preparing  tinctura  opii,  thor- 
oughly exhausting  the  opium  ;  the  resulting  product  is  of  oflScinal 
strength. 
^i.    Powdered  opium  ;  two  and  one-half  troyounces. 
Triturate  in  a  mortar  with  one  pint  of  boiling  water  gradually 
added,  then  add  one  pint  of  alcohol,  shake  thoroughly  and  filter ; 
the  opium  left  on  the  filter  will  be  properly  packed  for  percolation 
with  the  filtered  liquid,  which  is  the  next  step,  adding  sufficient  water 
to  the  dregs  to  displace  any  remaining  portion,  until  two  pints  of 
tincture  are  obtained. 
Fhilada.,  Oct  llth,  1871. 
WATER— MUDDY,  CLEAR,  DISTILLED. 
By  H.  M.  Wilder. 
Editor  of  the  American  Journal  of  Pharmacy  : 
Dear  Sir, — I  think  that  the  following  will  be  of  use  to  some  of 
your  readers,  particularly  to  those  who  have  to  depend  on  more  or 
less  muddy  streams  for  their  water  supply,  and  who  are  not  provided 
with  a  filtering  apparatus,  which,  of  course,  is  less  expensive  and  ob- 
noxious. 
To  clear  muddy  water  I  boil  it  with  magnes.  carbon.  (1  tablespoon- 
ful  to  one  or  two  gallons,  according  to  its  turbidity),  and  filter  hot, 
magn.  carbon,  being  much  less  soluble  in  boiling  water  (1:9000)  than 
in  cold  (1:2500). 
The  only  objection  to  the  above  is,  a  little  dissolved  carbon,  of 
magnes.  is  not  valid  so  long  as  the  U.  S.  P.  permits  medicated  waters 
to  be  prepared  by  means  of  it.  As  several  salts  and  alkaloids  are  precipi- 
