Am.  Jour.  Pharm.  \ 
Oot.,  1877.  ) 
Laboratory  Notes, 
485 
1*8  per  cent,  of  the  preparations.  A  sample  of  citrate  of  iron  and 
ammonium,  from  the  same  manufacturer  who  furnished  the  sample  of 
quinia  iron  citrate  which  had  the  6*5  per  cent,  of  sulphuric  anhydride 
(above  given)  was  found  to  contain  4*9  per  cent,  of  sulphuric  anhydride. 
A  few  ounces  of  solution  of  tersulphate  of  iron  were  precipitated  by 
ammonia  water,  and  the  precipitate  washed  "  with  water  until  the 
washings  are  nearly  tasteless,"  as  the  Pharmacopoeia  directs  in  the  pre- 
paration of  solution  of  citrate  of  iron,  from  which  the  three  scale  iron 
citrates  are  made.  In  this  washed  ferric  hydrate,  sulphate  was  found 
present,  amounting,  as  sulphuric  anhydride,  to  I4'8  per  cent,  of  the 
drained  moist  precipitate.  A  sample  of  citrate  of  iron  and  quinia  was 
made  by  the  pharmacopoeial  process,  except  that  the  quinia  sulphate 
was  added,  as  such,  without  precipitating  the  alkaloid,  and  the  scales 
were  found  to  contain  4*3  per  cent,  of  sulphuric  anhydride.  By  cal- 
culation (if  I  am  correct)  all  the  sulphuric  anhydride  of  the  quinia 
sulphate  cannot  form  over  1*8  per  cent,  of  the  scales  of  quinia  iron 
citrate.  If  10  per  cent,  of  water  be  assumed  in  the  scales,  their  per 
cent,  of  sulphuric  anhydride  would  be  about  i*6.  It  will  be  remem- 
bered that  the  British  Pharmacopoeia,  for  preparation  of  the  iron  citrates, 
directs  to  "  wash  the  precipitate  (ferric  hydrate)  with  distilled  water 
until  that  which  passes  through  the  filter  ceases  to  give  a  precipitate 
with  chloride  of  barium."  Such  is  the  well-known  adhesion  of  ferric 
hydrate  for  alkali  salts,  that  to  wholly  remove  them  requires  persistence, 
and  wash-water,  in  a  sufficient  quantity  of  each  ;  but  it  is  farcical  to 
wash  away  the  sulphate  from  the  quinia,  wasting  from  2  to  1 1  per  cent, 
of  the  alkaloid  and  making  the  preparation  uncertain  in  strength  within 
the  same  limits,  while  taking  a  greater  quantity  of  sulphate  in  the 
hydrated  oxide  of  iron.  Of  course,  after  the  solution  takes  place,  any 
quantity  of  combined  sulphuric  acid  present,  if  derived  from  the  iron 
precipitate,  will  be  just  as  much  in  combination  with  the  quinia  as  though 
it  had  been  introduced  in  quinia  salt. 
VII.   The  Proportion  of  Quinia  in  the  Citrate  of  Iron  and 
Quinia  of  the  U.  S.  P. 
Our  Pharmacopoeia  has  no  statement  of  the  percentage  of  quinia  in 
the  scales,  nor  any  quantitative  test.  By  calculation  from  the  materials, 
assuming  that  normal  ferric  citrate  is  formed,  the  preparation,  if  made 
strictly  anhydrous,  would  contain  15*0  per  cent,  of  absolute  quinia, 
