56 
ON  EFFERVESCING  POWDERS. 
a  bottle  filled  with  water,  a  clear  solution  is  obtained,  from  which 
on  exposure  to  the  air  sesquioxide  of  iron  is  separated.  If  a 
brisker  effervescence  is  desired,  the  acid  and  soda  may  be  in- 
creased in  due  proportion,  or  instead  of  the  latter,  5k  scruples 
of  bicarbonate  of  soda  substituted,  when  the  mixture  will  con- 
tain double  the  amount  of  carbonic  acid.  A  little  sulphate  of 
soda,  corresponding  with  the  quantity  of  iron  will  be  formed, 
and  the  neutral  tartrate  of  soda  which  does  not  decompose  the 
dissolved  carbonate  of  protoxide  of  iron.  The  quantity  of  these 
salts  formed  is  but  small,  only  large  enough  as  is  necessary  for 
obtaining  a  sufficiency  of  carbonic  acid ;  thus  an  opportunity  is 
offered  to  combine  with  the  powder  such  substances  as  may  be 
thought  necessary  to  increase  its  effect  or  direct  it  to  a  certain 
point ;  such  substances  of  course  must  not  interfere  with  the  car- 
bonate of  iron.  The  teaspoonful  of  the  above  chalybeate  effer- 
vescing powder  contains  about  18  grs.  of  sulphate,  equal  to  7| 
grs.  of  carbonate  of  protoxide  of  iron.  With  regard  to  the  sul- 
phate of  iron  I  would  here  yet  remark,  that  even  not  the  finest 
crystals  ought  to  be  used  for  such  a  preparation  if  stability  is 
desired.  Without  entering  into  details  at  present  it  may  suffice 
to  say,  that  this  salt  keeps  best,  by  itself  and  mixed  with  other 
powders,  if  it  has  been  precipitated  from  a  concentrated  solution 
by  strong  alcohol,  well  washed  with  the  same,  and  afterwards 
well  dried  in  the  open  air,  spread  out  in  thin  layers  on  bibulous 
paper. 
My  investigation  with  reference  to  the  administration  of 
quinine  has  not  been  completed  yet,  but  the  few  experiments 
made  convince  me  that  it  is  a  very  good  mode  to  administer 
quinine  and  cinchonine  in  an  effervescing  powder,  made .  with 
citric  acid  and  sweetened  with  sugar,  previously  rubbed  up  with 
the  yellow  skin  of  fresh  orange  peel.  This  corrects  the  taste 
better  than  lemon,  cloves,  or  any  other  aromatic  that  I  have  tried. 
The  bitterness  seems  to  be  less  perceptible,  when  the  efferves- 
cing powder  affords  a  nearly  neutral  mixture,  and  a  sufficiency  of 
the  orange  skin  has  been  added  to  impart  a  high  and  agreeable 
flavor  to  the  draught. 
Administration  of  Ammonia. — Bicarbonate  of  ammonia  is  de- 
void of  the  ammoniacal  smell,  and,  although,  having  still  a  some- 
what pungent  taste,  may  be  given  in  almost  any  form,  even  the 
