4 
Practical  Notes. 
J  Am  Jour.  Pharm. 
(      Jan.,  1877. 
will  remain  sufficiently  pure  for  pharmaceutical  purposes,  giving  clear 
and  permanent  solutions  with  the  red  and  yellow  mercurial  oxides,  as 
high  as  thirty  per  cent,  if  necessary. 
As  crude  commercial  oleic  acid  can  be  bought  at  very  low  figures, 
it  may  be  purified  by  combining  it  with  litharge,  deriving  from  it  the 
oleate  of  lead,  from  which  again,  by  the  aid  of  benzin,  the  purified 
oleate  can  be  separated,  and  as  before  stated,  purified  oleic  acid  pre- 
pared at  but  a  small  expense. 
To  gain  the  same  end,  the  simplest  way  perhaps  is  to  utilize  the 
ready-made  oleo-palmitate  of  lead,  the  officinal  leadplaster,  dissolve 
it  in  benzin  and  extract  from  it  the  oleic  acid  by  precipitating  the  lead 
by  aid  of  hydrochloric  acid. 
Oleic  acid  thus  prepared  has  been  used  for  some  time,  and  found  to 
answer  better  for  the  preparation  of  the  oleates  than  the  article  sold 
by  some  of  the  manufacturing  chemists. 
The  above  results  by  no  means  limit  the  utility  of  petroleum  benzin 
as  a  solvent  and  important  pharmaceutical  factor,  but  they  will  show 
that  this  refuse  article,  of  comparative  little  commercial  value,  which 
has  been  applied  to  but  little  more  than  the  removal  of  oil,  grease  or 
paint  stains,  may  be  turned  to  good  account  by  its  very  deficiency  to 
act  like  ether  or  similar  substances  as  a  general  solvent  for  both  fats 
and  resins. 
Philadelphia,  Dec.  1st,  1876. 
PRACTICAL  NOTES. 
(Extracted  from  theses  presented  to  the  Philadelphia  College  of  Pharmacy  in  1876.) 
Aquae  Medicatae. — Wm.  Wesley  Trout  has  examined  the  various 
methods  proposed  for  the  preparation  of  medicated  waters,  and  gives 
the  preference  to  those  prepared  by  distillation.  When  this  process 
is  not  practicable,  the  "  hot  water  process  "  is  considered  the  best,  as 
yielding  a  pure  and  strong  water.  Very  acceptable  waters  may  be 
obtained  by  the  use  of  the  elaeosacchara  of  the  European  pharmaco- 
poeias, which,  for  this  purpose,  the  author  proposes  to  prepare  by  using 
15  ^minims  of  the  oil  to  three  drachms  of  sugar,  triturating  them 
together  and  then  adding  one  pint  of  distilled  water  gradually,  with 
constant  trituration.  Using  paper  pulp  for  dividing  the  valatile  oils, 
the  author  obtained  the  weakest  waters  [probably  because  too  much 
