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ON  THE  MEDICINAL  HYPOPHOSPHITES. 
stirring  till  the  salt  granulates,  when  it  should  be  introduced 
into  bottles. 
Hypophosphite  of  lime  is  a  white  salt  with  a  pearly  margarin- 
like  lustre,  and  crystallizes  in  flattened  prisms.  Its  composition, 
according  to  Wurtz,  is  CaO,-{-2HO,PO,  the  water  being  essential 
to  the  salt.  It  is  soluble  in  six  parts  of  cold  water,  and  in  not 
much  less  of  boiling  water ;  it  is  soluble  slightly  in  diluted 
alcohol,  but  insoluble  in  alcohol  sp.  gr.  .835.- 
Hypophosphite  of  Soda  is  prepared  by  double  decomposition 
between  hypophosphite  of  lime  and  crystallized  carbonate  of  soda. 
Take  of  Hypophosphite  of  lime       .       .       .       6  oz. 
Crystallized  carbonate  of  soda  .       .       10  oz. 
Water,  a  sufficient  quantity. 
Dissolve  the  hypophosphite  in  four  pints  of  water,  and  the 
carbonate  in  a  pint  and  a  half,  mix  the  solutions,  pour  the  mix- 
ture on  a  filter,  and  lixiviate  the  precipitate  of  carbonate  of  lime, 
after  draining,  with  water,  till  the  filtrate  measures  six  pints. 
Evaporate  this  liquid  carefully  till  a  pellicle  forms,  and  then  stir 
constantly,  continuing  the  heat  till  it  granulates.  In  this  state 
the  salt  is  pure  enough  for  medical  use  ;  but  if  desired  in  crys- 
tals, treat  the  granulated  salt  with  alcohol  sp.  gr.  .835,  evaporate 
the  solution  till  syrupy,  and  set  it  by  in  a  warm  place  to  crystal- 
lize. 
Hypophosphite  of  soda  crystallizes  in  rectangular  tables  with 
a  pearly  lustre,  is  quite  soluble  in  water  and  in  ordinary  alcohol, 
and  deliquesces  when  exposed  to  the  air.  Its  composition  is 
NO+2HO,PO. 
Hypophosphite  of  Potassa  is  prepared  by  the  same  process  as 
that  given  above  for  the  soda  salt,  substituting  5|  ounces  of 
granulated  carbonate  of  potassa,  in  place  of  10  ounces  of  crys- 
tallized carbonate  of  soda,  and  using  half  a  pint  instead  of  a  pint 
and  a  half  of  water  to  dissolve  it. 
Hypophosphite  of  potassa  is  a  white,  opaque,  deliquescent  salt, 
very  soluble  in  water  and  alcohol.  Its  greater  tendency  to 
absorb  moisture  renders  it  less  eligible  for  prescription  than  the 
soda  salt.    Its  composition  is  KO+2HO,PO. 
Hypophosphite  of  Ammonia  is  prepared  from  hypophosphite 
of  lime  and  sulphate  or  carbonate  of  ammonia. 
