ON  LIQUOR  FERRI  IODIDI. 
205 
turate  for  15  minutes  very  thoroughly,  then  wash  with  warm 
water,  and  dry  in  the  dark. 
In  view  of  the  conflicting  opinions  of  chemists  in  regard  to  the 
equivalent  number  of  mercury,  it  is  much  to  be  regretted  that  the 
example  of  the  Dublin  College  has  not  been  followed,  in  giving 
names  to  the  two  iodides,  which  are  founded  upon  their  constant 
and  distinctive  peculiar  colors,  thus  obviating  the  perplexing 
confusion  to  students,  which  the  frequent  use  of  different  names 
for  the  same  article  occasions. 
ON  LIQUOR  FERRI  IODIDI. 
By  Dr.  Robert  Battey. 
Complaints  are  often  made  of  the  difficulty  encountered  in 
keeping  and  dispensing  the  officinal  Liquor  Ferri  Iodidi  in  good 
condition.  Various  suggestions  have  been  made,  by  way  of 
remedy  for  the  evil,  some  proposing  modifications  of  the  formula, 
others  the  use  of  small  ground  stoppered  vials  of  transparent 
or  opaque  glass. 
In  my  own  experience  this  trouble  was  early  encountered  and 
easily  overcome  by  the  use  of  clean  iron  wire  as  an  additional 
protecting  agent.  I  much  prefer  it  in  the  form  of  wire  to  iron 
filings,  or  iron  by  hydrogen,  which  I  have  heard  spoken  of. 
Immediately  upon  the  completion  of  the  preparation,  I  take  a 
piece  of  fine  iron  wire,  clean  it  well  with  sandpaper,  coil  it 
around  a  glass  rod  or  cedar  pencil,  draw  out  the  coil  to  nearly 
the  length  of  the  bottle  and  drop  it  in.  If  the  bottle  be  a 
large  one,  I  use  two  or  three  of  these  coils.  In  dispensing  small 
quantities,  I  have  found  it  convenient  to  use  a  straight  piece  of 
larger  wire  passing  through  the  center  of  the  corks  (I  never 
use  glass  stoppered  vials)  and  to  the  bottom  of  the  vial.  I  do 
not  deem  it  necessary  that  the  wire  pass  to  the  bottom  of  the 
vial,  as  the  charge  commences  at  the  surface,  but  have  thought 
that  it  gave  some  additional  security  if  long  kept  on  hand. 
With  this  expedient  I  have  encountered  no  difficulty  in  keep- 
iag  from  two  to  five  pounds  of  the  solution  in  one  shop  bottle, 
and  dispensing  it.  day  by  day,  in  small  parcels.  I  have  not 
found  the  presence  of  the  wire  in  the  vial  to  detract  from  its 
