360  Syrup  of  Hypophosphites  with  Iron.  {Km-^\^.rm' 
necessary.  The  sulphate  process  may  well  be  passed  by  on  account  of 
the  impurity  of  the  product,  consequent  on  the  solubility  of  calcium 
sulphate.  The  carbonates  of  sodium  and  potassium,  because  of  their 
indefiniteness,  the  impurities  they  always  contain  and  the  bulkiness  of 
the  resulting  calcium  carbonate  may  well  be  replaced  by  the  correspond- 
ing bicarbonates  which  are  definite  and  far  less  liable  to  contamina- 
tion.  By  employing  the  bicarbonates  calcium  bicarbonate  is  mo- 
mentarily formed,  and  on  being  decomposed  the  resulting  carbonate  is 
dense  and  crystalline,  thereby  lessening  the  liability  to  loss  of  the 
liquid  by  absorption  as  well  as  facilitating  filtration.  When  a 
moderately  dilute  solution  of  calcium  hypophosphite  is  mixed  with  a 
solution  of  sodium  bicarbonate  no  decomposition  takes  place.  Even 
after  standing  several  hours  the  liquid  remains  clear  and  retains  its 
alkalinity ;  but  when  heated  a  few  minutes  the  calcium  carbonate  is 
precipitated.  It  is  a  noticeable  fact  that  under  similar  conditions 
potassium  bicarbonate  parts  with  its  carbonic  acid  much  more  readily 
than  the  sodium  salt  does  ;  the  solution  is  at  first  clear,  but  soon  de- 
posits the  calcium  carbonate.  It  is  therefore  necessary  in  order  to  in- 
sure the  complete  decomposition  of  the  sodium  bicarbonate  to  employ 
a  saturated  solution  of  calcium  hypophosphite.  It  is  also  necessary  to 
heat  the  solution  until  action  has  entirely  ceased  before  adding  the 
potassium  bicarbonate,  which  readily  and  rapidly  decomposes. 
The  composition  of  the  preparation  made  by  the  following  formula 
is  almost  identical  with  that  made  by  the  process  ordered  in  the 
pharmacopoeia,  each  fluid  drachm  containing  three  grains  of  calcium 
hypophosphite  and  one  grain  each  of  the  hypophosphites  of  sodium 
and  potassium,  and  is  sufficiently  palatable  without  the  aid  of  flavor- 
ing. The  preparation  contains  the  same  amount  of  metallic  iron  as  the 
pharmacopoeia  orders. 
Calcium  hypophosphite   554  parts  (or  591  grains). 
Sodium  bicarbonate   95     "     (or  101  " 
Potassium  bicarbonate   115    "     (or  123  " 
Ferric  citrate   85    "     (or  91  " 
Sugar,  powdered  4,050    "     (or    9  troy  ounces. 
Water,  a  sufficient  quantity  to  make  10,000  parts  (or  16  fluid  ounces). 
Dissolve  the  calcium  hypophosphite  previously  reduced  to  a  fine 
powder  in  3,500  parts  (or  8  fluid  ounces)  of  water  with  the  aid  of  heat, 
and  add  to  the  solution  the  sodium  bicarbonate,  continuing  the  heat 
until  action  has  entirely  ceased.    After  removing  the  solution  from  the 
