ON  THE  SOLUBILITY  OF  PHOSPHATE  OF  IRON. 
413 
the  phosphate,  which  would  indicate  the  formation  of  a  double 
salt. 
As  suggested  by  Mr.  Maisch,  these  facts  render  the  prescrib- 
ing of  phosphate  of  iron  in  solution  extremely  simple,  and  phy- 
sicians can  extemporaneously  vary  the  proportion  of  the  phos- 
phate to  suit  their  views  of  particular  cases,  as  a  few  examples 
will  explain,  viz : 
Take  of  Phosphate  of  soda,       .       .  giij. 
Sulphate  of  iron,  .       .  giiss. 
Citric  acid  in  powder,    .       .  3J*. 
Lemon  syrup, 
Water,  of  each,     .        .       .  fgiij. 
Mix  the  syrup  with  the  water,  dissolve  the  phosphate  in  one 
half,  the  sulphate  in  the  other  half,  mix  them  and  add  the  citric 
acid. 
The  resulting  mixture  is  a  transparent  thin  syrupy  liquid, 
not  very  unpleasant  to  the  taste.  Each  fluid  ounce  contains 
about  12  grains  of  protophosphate  of  iron  and  a  little  sulphate 
of  soda.  The  dose  may  be  either  a  dessertspoonful  or  a  table- 
spoonful,  (3  or  6  grains),  as  the  case  may  require. 
Or  the  sulphate  of  soda  may  be  avoided  thus  : 
Take  of  (Vallet's)  protocarbonate  of  iron,  siiss. 
Citric  acid,        ....  ^iss. 
Phosphate  of  soda,     .       .       .  ^iij\ 
Lemon  (or  other  syrup) 
Water,  of  each,         .       .       .  fgiij. 
Triturate  the  carbonate  of  iron  with  half  the  water  and  the 
citric  acid,  till  dissolved,  add  the  syrup  and  lastly  the  remainder 
of  the  water  in  which  the  phosphate  of  soda  has  been  dissolved. 
The  resulting  liquid  is  a  solution  of  phosphate  of  iron  and  ci- 
trate of  soda,  containing  about  three  grains  of  the  iron  salt  to 
the  dessertspoonful. 
A  syrup  of  proto-phosphate  of  iron  may  be  made  by  dissolv- 
ing five  drachms  of  sulphate  of  iron,  and  six  drachms  of  phos- 
phate of  soda,  severally  in  hot  sweetened  water,  mixing  the  solu- 
tions, washing  the  precipitate  with  warm  sweetened  water  on  a 
cloth  filter,  expressing  carefully  and  forcibly,  and  dissolving 
the  moist  mass  with  two  drachms  of  citric  acid,  and  sufficient 
water  to  make  the  whole  measure  two  fluid  ounces.    To  this  add 
