\ 
ON  THE  REVISION  OF  THE  U.  S.  PHARMACOPOEIA.  55 
Then  put  the  iodine  and  iron  into  a  bottle  with  three  fluid- 
ounces  of  distilled  water,  and  after  the  active  reaction  has  sub- 
sided, shake  the  bottle  vigorously  until  a  bright  clear  green  so- 
lution, free  from  brown  tint,  is  obtained.  By  this  time  the  solu- 
tion of  the  sugar  will  nearly  all  have  passed  through  the  filter. 
Perforate  the  syrup  filter  over  the  bottle  containing  the  solution  of 
iodide  of  iron,  and  allow  the  remaining  unfiltered  portion  of  the 
syrup  to  run  into  the  solution  of  the  iodide,  and  shake  the  mix- 
ture well.  Arrange  a  funnel,  containing  a  small  moistened  paper 
filter,  over  the  flask  of  filtered  syrup,  so  that  the  point  of  the 
funnel  enters  the  syrup,  and  then  filter  the  solution  of  the  iodide 
into  the  syrup,  keeping  but  a  small  portion  of  the  solution  in 
the  filter,  and  maintaining  a  constant  level  till  all  has  been 
poured  in.  Allow  the  filter  to  drain,  without  rinsing  it,  and  finally 
add  distilled  water  to  the  preparation  till  it  measures,  if  cool, 
twenty  fluid-ounces,  or  till  it  weighs  twenty-five  and  a  quarter 
ounces,  shake  it  well,  and  keep  it  in  small  bottles  well  filled  and 
well  stopped.  The  process  requires  three  hours,  and  yields  a 
bright  pale  green  solution  of  a  s.  g.  of  1.348  containing  a  little 
over  seven  grains  of  iodide  of  iron  in  each  fluid-drachm. 
This  preparation,  in  the  few  instances  in  which  the  writer  has 
seen  it  in  the  wholesale  market,  has  been  colorless  or  very  near- 
ly so,  or  of  a  brown  tint,  and  of  the  consistence  of  syrup.  He 
therefore  judges  that  in  the  wholesale  market  it  is  commonly 
made  by  the  cheaper  formula  of  the  foreign  Pharmacopoeia,  and 
contains  only  about  five  grains  of  the  iodide  in  each  fluid-drachm, 
with  a  larger  proportion  of  sugar.  This  larger  proportion  of 
sugar  is  inconvenient  and  unnecessary,  since  with  proper  ordi- 
nary precautions  the  product  of  our  officinal  formula  is  not  liable 
to  deterioration.  The  writer  deprecates  the  too  common  prac- 
tice of  making  this  preparation  rather  carelessly,  and  then  set- 
ting it  in  the  sun  light  to  improve  the  color  and  appearance, 
since  Mr.  Maisch  has  shown  that  this  treatment  probably  pro- 
duces an  iodate  of  the  sesquioxide  of  iron. 
From  the  facility  with  which  chemical  reactions  take  place  in 
spongy  or  porous  textures,  whose  pores  contain  air  or  gases 
often  in  a  condensed  state,  the  writer  was  easily  led  to  a  theoret- 
.cal  objection  to  filtering  the  hot  solution  of  iodide  of  iron  into 
he  sugar,  as  in  the  officinal  process ;  and  he  has  since  regarded 
