268 
CITRATE  OF  IRON  AND  QUINIA. 
Carbonate  of  Quinia, 
Take  of  Sulphate  of  quinia,  3J  ounces,  troy. 
Carbonate  of  soda,  a  sufficient  quantity. 
Water,  a  sufficient  quantity. 
Diluted  sulphuric  acid,  4J  fluid  ounces. 
Dissolve  the  sulphate  of  quinia  in  five  pints  of  water,  with 
the  aid  of  the  diluted  sulphuric  acid.  Dissolve  twenty  ounces 
of  carbonate  of  soda  in  five  pints  of  water  and  add  as  much  of 
the  solution  to  the  solution  of  sulphate  of  quinia,  as  may  be  ne- 
cessary to  precipitate  the  whole  of  the  quinia  ;  a  considerable 
excess  of  carbonate  of  soda  is  not  objectionable.  Transfer  the 
precipitated  carbonate  of  quinia  to  a  muslin  filter  and  allow  it 
to  drain  so  as  to  free  it  as  much  as  possible  from  sulphate  and 
the  excess  of  carbonate  of  soda  ;  the  remainder  may  be  removed 
by  displacement  with  a  small  quantity  of  water,  so  as  to  avoid 
any  loss  of  the  carbonate  of  quinia,  which  seems  to  be  slightly 
soluble  after  it  is  freed  from  sulphate  and  carbonate  of  soda. 
Ammomo- Citrate  of  Iron  and  Quinia. 
Upon  adding  the  washed  magma  of  carbonate  of  quinia  to 
the  previously  prepared  and  cooled  solution  of  ammonio  per-ci- 
trate  of  iron,  it  dissolves  readily,  with  effervescence.  The  solu- 
tion should  now  be  filtered  and  evaporated  in  a  water-bath  to 
about  the  consistence  of  thin  syrup,  and  spread  thinly  and 
evenly  on  plates  of  glass  to  dry.  The  concluding  part  of  the 
process  requires  some  management  to  produce  an  elegant  re- 
sult :  it  should  be  performed  in  a  warm  and  dry  atmosphere  at 
*  a  temperature  of  from  70^  to  SO''  F.  If  the  salt  is  allowed  to 
dry  on  the  plate  of  glass  at  the  temperature  of  the  room  until 
the  whole  surface  has  separated  into  small  fissures,  and  then 
suspended  over  a  furnace  or  stove,  at  some  distance  above  it, — 
say  at  the  temperature  of  90^  F., — it  immediately  loosens  from 
the  plate  in  the  form  of  brilliant  scales,  and  may  be  removed 
without  difficulty  with  a  palet  knife  or  a  plane  iron. 
Ammonio-citrate  of  iron  and  quinia  cannot  be  regarded  as  a 
chemical  compound  of  definite  proportions,  but  merely  as  a  mix- 
ture of  the  citrates  of  iron,  quinia  and  ammonia :  its  component 
parts  may  be  stated  as  follows,  in  100  parts : 
