46 
ON  SOLUTION  OF  ACETATE  OF  AMMONIA. 
which  lie  has  thrown  together  may  prove  of  some  interest,  and 
will  be  accepted  instead. 
The  subject,  then,  may  be  considered  both  in  a  chemical  and 
pharmaceutical  point  of  view,  and  first  we  will  briefly  allude 
to  the  pure  salt  in  solution  before  entering  on  the  main  in- 
quiry. 
Solution  of  acetate  of  ammonia  was  first  described  by  Boer- 
have,  in  1732.  It  was  also  introduced  into  medical  use  by  him. 
He  prepared  it  in  a  similar  manner  to  that  followed  now,  by 
saturating  the  purest  vinegar  with  carbonate  of  ammonia. 
Subsequently,  Minderer,  a  Scotch  physician,  by  bringing  it 
further  into  notice,  claimed  the  honor  of  its  discovery,  and  the 
solution  was  hence  known  as  "  Spiritus  Mindereri." 
The  difficulty  of  preparing  a  neutral  solution,  as  well  as  the 
uncertainty  of  its  strength,  was  early  observed ;  and  in  1773 
Baume  endeavored  to  obtain  the  solid  salt  by  concentrating  the 
solution.  In  this  he  failed,  having  to  encounter  the  difficulty 
of  the  salt  being  readily  decomposed  by  heat  while  in  a  moist 
state, — the  ammonia  being  first  given  off,  and  subsequently  the 
acetic  acid.  Berzelius,  by  uniting  equal  weights  of  dry  sal 
ammoniac  and  acetate  of  lime,  and  subliming  by  a  carefully 
regulated  temperature,  obtained  the  dry  salt  by  double  decom- 
position. 
In  a  pure  state,  acetate  of  ammonia  is  a  white  crystalline 
salt,  easily  deliquescing  in  a  damp  atmosphere.  If  this  dry 
salt  be  dissolved  in  hot  water  to  full  saturation,  and  enclosed 
in  flasks,  upon  cooling  slowly  the  pure  salt  crystallizes  in  long 
acicular  crystals.  In  this  state  it  appears  to  have  an  acid  re- 
action. 
To  prepare  the  solution  of  the  salt,  however,  more  directly, 
its  constituents  may  be  immediately  combined : — solution  of 
acetic  acid  and  solution  of  ammonia.  If  these  are  pure  and  the 
mixture  rendered  perfectly  neutral,  the  solution  may  be  con- 
sidered pure.  In  this  state  it  is  not  a  permanent  salt,  except 
in  perfectly  full  bottles,  hermetically  closed.  In  partially  full 
vessels  at  ordinary  temperatures  it  gradually  changes,  the 
acetic  acid  becoming  decomposed,  vinegar  animalcules  appear- 
ing, and  the  solution  becomes  alkaline,  carbonate  of  ammonia 
being  thus  generated. 
