220  ELIXIR  OP  CALISATA,  IRON  AND  BISMUTH. 
Rub  the  citrate  bismuth  with  one  ounce  water,  and  carefully 
add  sufficient  water  of  ammonia  to  effect  the  solution.  Mix 
with  the  other  ingredients. 
Add  water  of  ammonia  until  neutral  to  litmus  paper  (avoiding 
excess),  and  finally  as  much  water  as  will  bring  the  whole  to  the 
measure  of  sixty  fluidounces,  and  filter.  To  be  kept  and  dis- 
pensed in  dark  bottles. 
One  fluidounce  contains  about  eight  grains  ammonio-citrate 
bismuth,  eight  grains  pyrophosphate  iron,  and  the  equivalent  in 
quinine  of  sixteen  grains  of  calisaya  bark. 
The  following  is  the  process  I  have  employed  for  making 
citrate  bismuth :  First, 
Take  of  pure  sub-Nitrate  Bismuth,  two  troyounces, 
Nitric  Acid  (sp.  gr.  1*44),  1450  grains, 
Water,  sufficient. 
Put  the  bismuth  in  a  porcelain  dish ;  add  the  acid,  and  heat 
over  a  spirit  lamp  until  the  bismuth  is  dissolved ;  then  add  one 
fluidounce  water,  and  let  stand  until  cold ;  then  gradually  add 
water,  constantly  stirring  with  a  glass  rod,  until  a  further  addi- 
tion produces  milkiness,  or  until  the  whole  measures  one  and  a- 
half  pints.    Filter  and  set  aside.  Next, 
Take  of  Carbonate  Soda  crystals,  sufficient  quantity, 
Citric  Acid,  three  troyounces, 
Water,  one  and  a-half  pints. 
Dissolve  the  citric  acid  in  the  water  and  add  sufficient  carbon- 
ate of  soda  (previously  dissolved  in  water)  to  exactly  neutralize 
the  acid.  It  is  important  that  there  shall  be  no  excess  of  soda, 
as  the  resulting  citrate  bismuth  would  be  contaminated  with  the 
oxide  after  decomposition. 
Put  the  bismuth  solution  in  a  suitable  vessel,  and  add,  stirring 
constantly  with  a  glass  rod,  sufficient  of  the  solution  citrate  soda 
exactly  to  decompose  ;  the  precise  quantity  is  known  to  have  been 
added,  when,  after  placing  the  whole  upon  a  cloth  filter,  the  wash- 
ings, after  having  been  suffered  to  run  awhile  until  clear,  first 
fail  to  precipitate  bismuth  when  dropped  into  water,  and  second 
show  no  precipitate  upon  the  addition  of  a  few  drops  of  ter- 
nitrate  bismuth,  a  small  quantity  of  which  should  be  reserved  for 
this  purpose.    When  the  liquid  portion  has  mostly  passed,  pour 
