Am.  Jour.  Pharm. 
June,  1880. 
Citric  Acid  in  the  Cranberry. 
one-half  and  filtered  while  boiling  hot.  On  adding  half  its  volume  of 
alcohol  to  the  filtrate  a  precipitate  formed  which  was  removed  by  fil- 
tration ;  twice  its  volume  of  alcohol  was  added  to  the  filtrate,  the 
resulting  precipitate  dissolved  in  acetic  acid,  alcohol  added,  and  filtered. 
To  this  filtrate  lead  acetate  was  added,  then  ammonium  hydrate  to 
neutralization,  and  the  precipitate,  after  repeated  washings,  was  suspended 
in  water,  hydrogen  sulphide  passed  through  it,  filtered,  evaporated  to 
half  and  treated  as  follows  :  (a)  With  solution  of  calcium  hydrate  na 
precipitate  ;  (/?)  with  lead  acetate  a  barely  perceptible  precipitate  that 
fell  to  bottom  of  the  tube  when  boiled  ;  boiled  with  nitric  acid,  evap>- 
orated  to  dryness,  dissolved  residue  in  water,  added  excess  of  sodiumj 
carbonate,  filtered  ;  treated  filtrate  with  calcium  chloride  which  pro- 
duced a  precipitate  that  was  entirely  dissolved  in  acetic  acid.  The 
above  reactions  having  demonstrated  the  absence  of  malic  acid,  succinic 
acid  was  now  sought  for,  but  the  failure  of  neutral  ferric  chloride  to 
produce  any  change  in  the  clear  concentrated  liquid  filtered  from  the. 
lead  sulphide  denoted  the  absence  of  this  acid. 
The  original  precipitate  obtained  by  treating  the  juice  with  calcium 
caibonate  and  solution  calcium  hydrate  was  now  examined.  After 
being  again  well  washed  with  cold  water  a  portion  thereof  was  placed 
in  a  tube,  mixed  with  solution  of  potassium  hydrate,  triturated  and 
allowed  to  stand  for  several  hours,  when  the  clear  liquid  was  poured 
off  and  boiled.  The  failure  of  a  precipitate  to  appear  with  this  treat- 
ment is  a  sufiicient  proof  of  the  absence  of  tartaric  acid. 
Another  portion  of  the  precipitate  was  now  taken,  an  excess  of 
sodium  carbonate  in  solution  added,  boiled  and  filtered.  The  absence 
of  oxalic  acid  in  the  filtrate  was  shown  by  the  precipitate  produced  on- 
the  addition  of  calcium  chloride,  being  wholly  dissolved  by  acetic  acid.. 
An  examination  for  citric  acid  was  made  as  follows  :  The  juice  of 
the  berries  was  taken,  boiled  and  while  hot  saturated  with  calcium  car- 
bonate and  solution  of  calcium  hydrate.  This  was  placed  on  a  filter,, 
and  the  precipitate,  after  being  thoroughly  washed  with  boiling  water, 
was  collected  and  dried.  It  was  then  treated  with  cold  water,  filtered 
and  to  a  portion  («)  of  the  filtrate  calcium  chloride  added,  which  upon 
boiling  produced  a  white  precipitate  ;  (/?)  adding  silver  nitrate  to  another 
part  of  the  filtrate  produced  a  white  precipitate  which  turned  black 
only  after  long  boiling  ;  {'f)  another  portion  of  the  solution  being  mixed 
with  a  few  drops  of  solution  of  potassium  permanganate  and  heated 
showed  no  reduction  of  the  potassium  permanganate,     o  To  the  last 
