SOLUTION  OP  PYROPHOSPHATE  OF  SODA  AND  IRON. 
395 
preparation  explains  itself  from  the  above,  particularly  if  a  so- 
called  " elixir"  is  desired,  which  term  now-a-days  applies  to 
pleasant  forms  of  alcoholic  beverages.  The  necessity  of  stich  a 
preparation  is  moreover  very  questionable,  since  the  ordinary 
perphosphate  of  iron  is  readily  kept  in  solution  by  Gitrate  of 
ammonia,  since  we  have  an  officinal  soluble  pyrophosphate  of 
iron  containing  about  half  its  weight  of  the  pure  ferric  salt,  and 
since  solution  of  pyrophosphate  of  iron  in  pyrophosphate  of  soda 
may  be  made  extemporaneously  without  difficulty.  We  append 
the  following  two  formulas,  as  indicating  the  mode  in  which  it 
may  be  prescribed : 
R.  Liquor,  ferri  tersulph.,  Ix. 
Sodas  pyrophosphatis,  gr.  C. 
Ammoniac  carbonatis,  gr.  xxx. 
Aquae  destillatas,  f§  vij. 
Syrupi  simplicis,  f^  vi. 
M. 
In  this  formula  the  addition  of  some  carbonate  of  ammonia  is 
necessary  to  at  least  neutralize  the  acid  liberated.  The  next 
one  does  not  require  this  addition,  unless  kept  on  hand  for  a 
long  time  : 
R.  Liquor,  ferri  subsulphat.,        ttl  Ix. 
Sodae  pyrophosphatis,  gr.  CC. 
Aquas  destillatae,  fs  xiv. 
Syrupi  simplicis,  fg  iss. 
M. 
The  mode  of  manipulation  is  to  dissolve  the  pyrophosphate  of 
soda  in  about  one-half  of  the  water,  add  the  syrup,  then  the 
iron  solution  and,  without  the  application  of  heat,  agitate  for  a 
few  minutes  until  the  precipitate  is  redissolved ;  finally  add  the 
remainder  of  the  water,  holding,  in  the  former  case,  the  carbonate 
of  ammonia  in  solution.  Acids  and  tinctures  must  be  avoided ; 
if  some  flavor  is  desired,  a  distilled  medicated  water  may  be 
substituted  for  the  whole  or  a  portion  of  the  water. 
If  the  iron  solutions  had  been  properly  prepared,  these  prepa- 
rations will  be  permanent,  and  each  fluidrachm  will  contain 
II  grains  of  dry  pyrophosphate  of  iron,  equivalent  to  about  2  J 
grains  of  the  officinal  salt  of  that  name. 
/  ^ 
