A%i0rchSfm-}        Notes  on  Practical  Pharmacy.  121 
present  edition  makes  it  1*8  grs.;  a  reduction  of  55  per  cent.  The 
writer  has  furnished  a  satisfactory  preparation  by  averaging  the  two 
extremes  and  making  it  3  grains  to  the  fluidounce. 
Ammonia  Water  Containers. — The  best  method  for  preservation 
of  ammonia  water  in  containers  that  the  writer  has  found  is  a  com- 
mon cork,  covered  with  a  piece  of  cheese  cloth,  and  this  covered  with 
a  piece  of  paraffin  paper.  An  ordinary  glass  stopper  is  totally  insuf- 
ficient to  prevent  some  of  the  vapor  from  escaping,  while  the  dark 
coloration,  produced  by  contact  of  the  ammonia  with  cork  tissue 
alone  renders  the  use  of  corks  objectionable. 
Spirit  of  Camphor. — The  officinal  dilution  in  alcoholic  strength 
of  20  per  cent.,  with  water,  is  inadmissible  for  the  reason  that  when 
it  is  prescribed  with  volatile  oils,  turpentine,  soap  liniment,  etc.,  as 
is  often  done  in  making  stimulating  liniments,  there  is  precipitation 
of  camphor,  or  rather,  a  deficiency  in  the  amount  dissolved  that 
would  have  remained  in  solution  had  the  spirits  of  camphor  been 
made  with  strong  alcohol,  as  in  the  U.  S.  P.  '70  formula. 
Spirits  of  Peppermint  and  Spearmint. — The  officinal  formulae  of 
these  two  preparations  can  be  improved  by  macerating  the  herbs 
with  alcohol,  filtering  and  dissolving  the  oils  in  the  filtrate.  It  is 
needless  to  say  that  filtration  without  the  presence  of  dissolved  oils 
is  much  more  rapid  than  with  their  presence.  Turbidity  in  these 
spirits,  arising  from  undissolved  oils  or  more  probably  from  traces 
of  resinified  oil,  can  be  removed  by  agitating  the  liquid  with  long 
narrow  strips  of  a  sheet  of  filtering  paper  and  filtering.  Sometimes 
the  addition  of  a  small  quantity  of  precipitated  phosphate  of 
calcium  is  also  necessary. 
Compound  Tincture  of  Lavender. — This  preparation  which  has 
been  very  largely  replaced  by  the  increasing  popularity  of  compound 
tincture  of  cardamom,  can  have  its  officinal  formula  improved  by 
exhausting  the  drugs  with  the  menstruum  first,  and  then  dissolving 
the  volatile  oils  in  the  percolate.  By  this  means  the  drugs  are 
more  readily  exhausted  and  the  preparation  more  quickly  made. 
Solution  of  Magnesium  Citrate. — For  causing  effervescence,  a  very 
elegant  substitute  for  the  acrid  potassium  bicarbonate  is  Merck's 
sodium  bicarbonate  "  in  crusts."  It  gives  a  pleasant  saline  taste  to 
the  preparation,  instead  of  the  usual  bitter,  acrid  one. 
Compound  Syrup  of  Hypophosphites. — Glycerin  in  the  proportion 
