482 
Acid  Phosphates, 
Km.  Jour.  Pharm. 
Oct  ,  1880. 
parts  carbonate  of  calcium.  The  phosphate  of  magnesium  consists  of 
72  parts  acid  and  60  parts  of  magnesia  in  every  132  parts  of  the  phos- 
phate. In  175*4  parts  of  phosphate  of  potassium  are  72  parts  acid 
and  94*4  parts  caustic  potash=i38'4  of  carbonate.  The  officinal  phos- 
phate of  iron,  which  is  always  kept  on  hand,  is  freely  soluble  in  diluted 
phosphoric  acid,  and  may  be  added  direct.  From  these  proportions  the 
following  formula  for  a  pint  of  each  solution  is  deduced: 
Liquor  Acidi  Phosphorici. 
Carbonate  of  calcium,  369  grains  (i  56  : 150: :  384:  369) 
Magnesia  (calc),  116     "      (13^:  6o::256:ii6) 
Carbonate  of  potassium,  151      "      (i75-4:  i38'4::  192: 151-4) 
o  ,  , ,         ^  ^  ct       {  665  in  combination 
Syrupyphos.acid(6opr.ct.)i72i  |  , ^6=640  TT],  free. 
Water,  sufficient  to  make  i  pint. 
Liquor  Acidi  Phosph.  Comp. 
Carbonate  of  calcium,  369  grains  (156  :  150  ::  384  :  369) 
Magnesia  (calcined),  29     "     (132:  60::  64:  29) 
Carbonate  of  potassium,       25     "     ( 1 75-4  :  1 38-4  : :  32:  25-2) 
Phosphate  of  iron,  64  " 
Syrupy  phos.  acid(6o  pr.ct.)  1 705  " 
Water,  sufficient  to  make  i  pint. 
Mix  the  acid  with  half  a  pint  of  water,  add  the  phosphate  of  iron  and 
stir  until  dissolved  (for  liq.  ac.  phos.  comp.),  then  add  gradually  the 
carbonates  of  calcium,  stirring  until  effervescence  ceases  and  the  freshly- 
formed  phosphate  is  dissolved,  and  finally  add  the  magnesia  and  car- 
bonate of  potassium ;  stir  until  dissolved,  and  make  up  the  measure  to 
one  pint  with  water.  On  standing  for  several  days  a  slight  precipitate 
occurs,  which  may  be  prevented  by  slightly  increasing  the  amount  of 
acid. 
The  whole  can  be  prepared  in  half  an  hour,  less  time  than  required 
to  send  to  another  druggist  for  it,  and  at  a  cost  of  less  than  40  cents  a 
pint,  while  Horsford's  Acid  Phosphate,  at  $4.00  a  dozen,  will  cost 
about  90  cents  per  pint.  Besides  securing  a  larger  profit,  the  phar- 
macist will  have  the  satisfaction  of  dispensing  a  preparation  of  whose 
composition  he  is  sure  and  of  his  own  production,  and  the  physician 
will  get  what  he  prescribes. 
These  preparations  taste  about  as  acid  as  Horsford's,  and  do  not  vary 
much  in  specific  gravity,  liq.  acid.  phos.  being  1*170,  liq.  acid  phos. 
comp.,  1  125  and  Horsford's  1*121. 
In  Dr.  Pepper's  calculation  as  to  the  comparative  acidity  between 
