ON  SOLUTION  OF  ACETATE  OF  AMMONIA. 
49 
The  German  and  British  Pharmacopoeias  order  the  liquor 
ammonias  acetatis  to  be  made  by  the  union  of  strong  acetic  acid 
and  concentrated  aqua  ammonias  ;  the  former  adding  water  to 
the  neutral  solution  until  its  density  becomes  1*035.  The 
British  Pharmacopoeia  employs  it  undiluted,  of  specific  gravity 
r060 ;  made  in  this  way,  the  solution  is  nearly  four  times  the 
strength  of  our  own.  It  is  also  much  less  liable  to  decompo- 
sition, and  no  difficulty  occurs  in  preparing  it  neutral,  there 
being  no  carbonic  acid  in  the  solution.  In  commenting  upon 
this  process,  Prof.  Bache,  alluding  to  the  absence  of  the  car- 
bonic acid  in  the  solution,  says,  that  "  a  great  benefit  remedi- 
ally  is  gained  by  its  presence,  which  reconciles  the  stomach  to 
the  medicine,  and  sometimes  even  allays  vomiting  in  febrile 
diseases."  With  this  view  of  the  subject,  and  believing  that 
the  remedial  efficacy  of  a  medicine  should  always  be  esteemed 
of  the  highest  importance,  and,  in  fact,  as  constituting  its  only 
value,  I  suggest  the  following  method  of  preparing  the  liquor 
ammoniae  acetatis  ;  a  modification  of  the  officinal  directions,  yet 
following  strictly  its  spirit. 
A  solution  of  the  translucent  internal  portion  of  sesqui-car- 
bonate  of  ammonia  is  to  be  made  according  to  the  following 
data : 
The  pharmacopoeia  gives  7*6  grains  bi-carbonate  of  potassa 
as  the  quantity  necessary  to  saturate  100  grains  of  dilute  acetic 
acid,  or  nearly  34"9  grains  per  fluidounce.  As  the  equivalent 
saturating  powers  of  bi-carbonate  of  potassa  and  sesqui-carbon- 
ate  of  ammonia  are  respectively  100*2  and  59,  it  would  there- 
fore require  20  grains  of  this  latter  to  saturate  one  fluidounce 
of  dilute  acetic  acid.  The  solution  of  ammonia  I  make  of 
double  this  strength,  or  20  grains  to  half  an  ounce  of  distilled 
water, — the  other  half-ounce  requiring  to  be  made  up  of  a  dilute 
acetic  acid  of  double  the  officinal  strength.  It  is  in  preparing 
this  acid  solution  of  pro/per  strength,  that  the  only  practical 
difficulty  lies.  The  method  I  have  taken  is  the  following : 
from  a  pipette  graduated  into  100  parts  and  filled  with  No.  & 
acetic  acid,  I  drop  sufficient  of  the  acid  to  neutralize  100  similar 
parts  of  the  prepared  ammoniacal  solution.  The  quantity 
requisite  is  noted,  and  that  amount  of  acid  must  consequently 
4 
