♦ 
PREPARATIONS  OP  THE  U.  S.  PHARMACOPOEIA,  1860.  329 
tunate  that  this  preparation  was  originally  introduced  through 
the  journals  under  the  name  "persulphate  of  iron,"  which  was 
much  used  to  indicate  the  tersulphate.  The  late  Dr.  Bache  sug- 
gested and  strongly  advocated  the  name  "Liquor  Ferri  Sulphatis 
Astringens"  for  Monsel's  Solution,  but  gave  up  his  preference  in 
favor  of  the  present  name,  which  is  strictly  correct,  the  salt  being 
a  subsulphate  of  the  sesquioxide  of  iron  2Fe2  O3 ,  5S03 .  It  is 
quite  important  in  this  preparation  to  use  sufficient  nitric  acid  to 
peroxidize  the  iron,  but  it  is  of  far  greater  importance  that  too 
much  should  not  be  used,  as  its  presence  gives  an  irritating 
quality  to  the  liquid,  not  intended ;  hence  the  direction  to  boil 
until  nitrous  vapors  cease  to  be  perceptible.  The  commercial 
solution  when  opened  often  evolves  the  odor  of  nitrous  acid, 
which  shows  it  to  be  faulty. 
It  would  have  been  well  had  the  dry  salt  of  Monsel  been  intro- 
duced, as  many  surgeons,  especially  those  in  California,  use  it 
in  the  solid  form  for  hemorrhages.  The  salt  is  obtained  easily 
from  the  solution  by  evaporation  to  a  thicker  syrup,  spreading 
on  glass  and  drying  in  a  warm  place,  and,  while  yet  warm, 
scaling  it  off  with  a  spatula  sharpened  on  one  side.  It  should 
be  bottled  immediately  and  kept  closed.  In  this  state  it  is  hy- 
drated  and  soluble  quickly  in  water ;  but  when  too  much  heated, 
the  anhydrous  salt  is  obtained,  which  dissolves  more  slowly,  and 
is  less  efficient  in  dangerous  cases  of  haemorrhage  where  instant 
action  is  needed.  Some  physicians  are  in  the  habit  of  prescribing 
a  given  weight  of  the  solid  salt,  to  be  dissolved  in  water,  in  a 
mixture,  for  internal  use,  or  as  a  lotion.  It  would  save  much 
trouble  if  the  prescriber  would  recollect  that  a  fluid  drachm  of 
the  U.  S.  P.  solution  contains  very  nearly  forty  grains  of  the 
anhydrous  subsulphate,  and  that  he  will  be  better  and  more 
quickly  served  by  diluting  this  than  by  dissolving  the  solid  salt, 
which  varies  much  in  character.  -The  apothecary,  by  recollecting 
that  each  minim  represents  two-thirds  of  a  grain  of  the  dry  salt, 
may  easily  use  the  officinal  solution  in  such  cases. 
Liquor  Ferri  Citratis. — This  is  one  of  the  useful  preparations 
of  the  Pharmacopoeia,  being  used  as  the  ferric  basis  of  the 
formulae  for  the  citrate,  ammonia  citrate  and  quinia  citrate  of 
