ON  SOME  PEEPARATIONS  OP  THE  U.  S.  PHARMACOPOEIA.  301 
Committee  of  Revision  to  arrange  preparations  under  their  sev- 
eral generic  heads. 
Aqua  Chlorinii. — This  formula  is  nearly  that  of  the  late 
Dublin  Pharmacopoeia,  both  in  proportions  and  manipulation, 
as  found  in  the  Dispensatory. 
Aqua  Cinnamomi.— -It  should  be  remembered  that  the  only 
oil  of  cinnamon  recognized  by  the  U.  S.  Pharmacopoeia  is  the 
Ceylon  oil,  and  that  this  is  directed  in  cinnamon  water. 
Argenti  nitras. — This  formula  is  an  improvement.  The 
former  recipe  inferred  the  use  of  chemically  pure  silver.  The 
present  formula  is  so  constructed  as  to  rid  the  salt  of  all  free 
nitric  acid,  and  in  case  cupreous  silver  is  used  to  reject  the 
impurity  almost  wholly  as  oxide  of  copper,  if  the  heat  is  man- 
aged carefully,  the  cupreous  nitrate  being  decomposed  by  a 
temperature  at  which  the  nitrate  of  silver  is  intact.  Neverthe- 
less, the  Pharmacopoeia  process  is  intended  for  pure  silver,  as 
seen  by  consulting  the  test  in  the  list  of  the  Materia  Medica. 
Atropia  This  is  a  new  officinal,  although  in  general  use 
before  the  publication  of  the  Pharmacopoeia.  The  process  is 
nearly  that  recommended  by  the  author  of  this  paper,  in  the 
proceedings  of  the  Amer.  Pharra.  Assoc.  for  1860.  The  re- 
commendation in  that  paper  to  wash  the  sulphated  liquor  with 
chloroform  to  insure  the  entire  removal  of  fixed  oil  and  resin 
before  adding  the  potassa,  was  not  adopted  in  the  Pharmaco- 
poeia process.  This,  in  the  absence  of  any  subsequent  purifi- 
cation, is  liable  to  render  the  product  less  pure.  The  product 
of  the  Pharmacopoeia  process  is,  therefore,  not  pure  atropia, 
but  that  alkaloid  with  some  coloring  matter,  the  removal  of  which 
the  Committee  deemed  not  of  sufficient  importance  to  justify  the 
loss  of  product  which  would  follow  it.  The  loss  of  at  least  the 
greater  part  of  the  chloroform  may  be  avoided  by  placing  the 
chloroformic  solution  of  atropia  in  a  beaker  glass  suspended  in 
water,  in  a  small  still,  and  applying  a  heat  sufficient  to  vapor- 
ize the  chloroform,  which  will  be  recovered  by  proper  refrigera- 
tion. The  propriety  of  not  further  purifying  the  crystals  of 
atropia  may  be  doubted,  as  from  the  direction  to  evaporate  to 
dryness  the  exterior  portion  of  the  residual  crystalline  mass  is 
