PREPARATION  OF  CITRATE  OF  IRON  AND  QUINIA.  295 
based  upon  480  grains  of  crystallized  sulphate  of  iron  ;  yet  no 
particular  modification  of  proceeding,  or  of  time  required  in 
heating,  digesting,  &c,  is  necessary,  if  the  proportions  be  not 
multiplied  beyond  five  times. 
The  sulphate  of  protoxide  of  iron  used  was  well  crystallized 
and  free  from  efflorescence,  was  in  masses  near  the  size  of  a  filbert, 
dry  externally,  but  affording  a  moist  granular  powder,  adhering 
round  the  pestle  and  mortar  when  rubbed  up.  When  rubbed  up 
and  dried  for  half  an  hour  at  85°,  efflorescence  being  avoided  as 
far  as  practicable,  480  grains  lost  16  ;  and  this  was  probably  near 
the  index  of  the  accidental  water.  The  salt  was  of  a  good 
greenish  blue  color,  with  but  slight  stains  from  peroxidation,  and 
was  made  from  the  turnings  of  wrought  iron,  and  the  residue  of 
the  ether  process. 
The  sulphuric  acid  used  was  the  commercial  acid,  s.  g.  1.855, 
but  contained  a  larger  proportion  of  sulphate  of  lead  than  usual. 
The  nitric  acid  used  was  pure,  as  obtained  by  redistilling  the 
commercial  acid  and  rejecting  the  first  portions.  It  had  the  usual 
density  of  acid  so  obtained,  viz.,  s.  g.  1.41. 
The  solution  of  ammonia  was  of  the  officinal,  ^U.  S.  P.]  and 
not  the  commercial  strength. 
The  citric  acid  was  the  ordinary  crystalline  masses ;  and  the 
sulphate  of  quinia  that  of  Powers  &  Weightman,  of  Philadelphia. 
Hydrated  Peroxide  of  Iron. 
Take  of  Sulphate  of  iron,  gl. 
Sulphuric  acid,  grs.  86,  or  rr^  47. 
Nitric  acid,  grs.  90,  or  f.  gl. 
Solution  of  ammonia  f.  g2,  f.  $1. 
Distilled  water,  q.  s. 
Water,  q.  s. 
To  f.  34  of  distilled  water  in  a  six  ounce  beaker,  add  the  sul- 
phuric acid  and  heat  the  mixture  in  a  water  bath.  Then  add 
successively  the  nitric  acid  and  sulphate  of  iron  in  crystals,  and 
heat  the  whole  with  occasional  stirring  for  an  hour  and  a  half, 
supplying  the  loss  by  evaporation  with  distilled  water.  Dilute 
the  solution  with  two  parts  of  distilled  water  and  filter  it  into  a 
half  gallon  beaker,  and  wash  the  filter  through  with  f.  ^10  of  dis- 
tilled water.  Then  add  the  solution  of  ammonia  and  stir  till  a 
smooth  equable  mixture  is  formed,  when  the  vessel  is  to  be  filled 
