A juJeUriV^7 arm'  }    Pharmacy  of  Calcium  Glycerophosphate.  245 
The  discovery  that  the  official  elixir  actually  contains  only  75  per 
cent,  of  the  calcium  glycerophosphate  directed  was  disconcerting  but 
not  entirely  unexpected,  for  after  several  years'  experience  with 
glycerophosphate  mixtures  I  did  not  believe  that  the  N.  F.  IV  for- 
mula was  so  adjusted  that  it  would  dissolve  16  Gm.  of  the  salt. 
An  experimental  batch  of  elixir  calcium  and  sodium  gylcero- 
phosphates  N.  F.  IV  was  now  made  to  determine  the  satisfactory 
character  of  this  formula.  The  ingredients  were  manipulated  ac- 
cording to  the  N.  F.  directions ;  the  calcium  salt  completely  dissolved 
in  the  diluted  phosphoric  acid :  upon  the  addition  of  the  sodium 
glycerophosphate  solution  a  white  precipitate  appeared  at  first  but 
redissolved  when  all  the  solution  had  been  added.  A  faint  cloudi- 
ness was  produced  when  the  glycerin  was  mixed  in  and  this  became 
pronounced  when  the  aromatic  elixir  was  added.  The  mixture  was 
made  up  to  volume  with  water  which  did  not  redissolve  the  pre- 
cipitate;  one  half  of  the  mixture  was  filtered,  the  other  half  was 
bottled  without  filtration. 
The  filtered  portion  precipitated  within  twelve  hours :  it  was 
refiltered  and  allowed  to  stand.  Another  precipitate  formed  in  four 
hours.  Lactic  acid  was  nowT  added  to  this  in  the  proportion  of  15 
mils  per  liter;  the  precipitate  was  redissolved  and  after  standing 
three  months  the  amount  of  precipitation  was  inappreciable.  The 
unfiltered  portion  continued  to  precipitate  until  a  large  deposit 
covered  the  bottom  of  the  container. 
From  these  experiments  it  appears  that  neither  of  these  formulas 
is  wholly  satisfactory.  In  order  to  compete  with  proprietary  prepa- 
rations now  in  commerce  the  compound  elixir  must  contain  ap- 
proximately 8  grains  and  the  dual  elixir  4  grains  of  calcium  salt  per 
fluidounce. 
One  of  the  best  known  proprietary  brands  of  the  compound 
elixir  was  submitted  to  analysis.  One  fluidounce  yielded  0.1186  Gm. 
calcium  oxide,  equivalent  to  6.854  grains  of  calcium  glycerophos- 
phate. This  preparation  had  apparently  been  filtered  after  precipita- 
tion: it  was  labelled  8  grains.  Tests  showed  the  presence  of  free 
phosphoric  and  lactic  acids. 
It  was  then  decided  that  the  solubility  of  calcium  glycerophos- 
phate should  be  determined  under  various  conditions  and,  if  possible, 
a  combination  was  to  be  found  which  would  retard  the  hydrolysis  of 
the  salt. 
All  work  with  the  U.  S.  P.  substance  is  complicated  by  the  fact 
