328    SYRUP  PHOSPHATES  OF  IRON,  QUINIA  AND  STRYCHNIA. 
Protosulphate  of  Iron,       .       .       173749  gr. 
Metaphosphoric  Acid,        .       .         666-61  gr. 
Tribasic  Phosphate  of  Lime,       .         645*83  gr. 
Water,  sufficient. 
The  manipulations  here  are  in  all  respects  similar  to  those 
previously  described.  The  result  is  a  deep  green,  dense  but 
mobile  liquid,  which  remains  permanent  for  several  days,  but 
then  becomes  subject  to  the  same  changes,  which  take  place  im- 
mediately when  much  diluted.  Addition  of  excess  of  ammonia 
to  this  solution  occasions  a  bulky  greenish-white  precipitate, 
which  is  again  partially  dissolved  to  an  intensely  green  solution, 
but  wholly  upon  exposure,  and  only  after  some  time,  to  a  dark- 
brown  liquid.  If  the  solution,  previous  to  the  addition  of  am- 
monia, has  been  acidulated  with  citric  acid,  no  precipitate 
occurs,  but  a  magnificent  emerald  green  coloration  is  imparted 
to  the  liquid.  A  similar  result  is. obtained  by  the  addition  of 
citrate  of  ammonia  to  the  precipitate  produced  by  the  previous 
addition  of  ammonia  to  the  liquid,  but  this  is  again  considerably 
relieved  by  a  sufficient  excess  of  the  citrate.  If  a  strictly  neu- 
tral or  slightly  acid  solution  of  citrate  of  ammonia  is  added  to 
the  solution  of  superphosphate  of  iron,  the  transparency  of  the 
solution  remains  unaffected — an  immaterial  deepening  of  the 
color  is  the  only  apparent  result.  The  mixture  with  a  sufficiency 
of  citrate  of  ammonia  may  be  evaporated  to  a  syrupy  liquid,  from 
which  the  dry  double  salt  can  readily  be  obtained  in  permanent 
light-green  scales,  readily  and  completely  soluble  in  water,  and 
possessing  a  sweetish  pleasant  saline,  not  metallic,  taste.  The 
solution  of  this  citrophosphate  of  iron  and  ammonia,  either  with 
or  without  an  excess  of  ammonia,  will  not  bear  evaporation  in 
contact  with  sugar — the  mixture  speedily  becoming  intensely 
brown.  But  when  containing  no  free  ammonia  it  may  be 
mixed  with  syrup  in  any  proportion — an  elegant  light-green 
and  permanently  transparent  syrup  being  the  result.  Now,  if 
to  the  syrup  of  the  phosphates,  prepared  in  pursuance  of  the 
proposed  formula,  or  if  to  the  solution,  before  its  admixture  with 
syrup,  a  neutral  solution  of  citrate  of  ammonia  containing  1000 
gr.  be  added,  a  beautiful  light-green,  dense,  and  permanent 
syrup  will  be  obtained,  which  surmounts  all  those  exceedingly 
