4  Analysis  of  Bitter  Wine  of  Iron.  {'^"'•/an.^im'''"' 
cinchona  alkaloid  reactions,  were  applied  to  an  aqueous  solution  of 
this  residue,  but  with  negative  results.  This  solution  was  neither 
precipitated  by  tannic  or  picric  acid,  nor  potassio-mercuric  iodide, 
indicating  the  absence  of  most  alkaloids.  It  is  believed  that  sample 
No.  6  does  not  contain  any  trace  of  the  cinchona  alkaloids,  nor  any 
other  active  organic  ingredient.  Several  tests  for  morphine  were 
applied  to  the  alkaloidal  residues  obtained  from  the  samples,  but  all 
with  negative  results. 
Determination  of  citric  and  tartaric  acids. — The  presence  or  ab- 
sence of  citric  acid  in  the  samples  was  also  ascertained  by  recognized 
methods.  The  officinal  article  contains  citric  acid  alone,  as  used  in 
preparing  the  solution  of  citrate  of  iron,  and  also  again  in  the  solu- 
tion of  citrate  of  iron  and  quinine.  Nos.  3  and  4  showed  the  presence 
of  citric  acid  alone.  No.  2  gave,  with  the  tartaric  acid  tests,  very 
decided  results ;  this  also  showed  a  very  small  trace  of  citric  acid 
present.  Nos.  5  and  6  could  be  made  to  respond  to  tartaric  acid  tests 
alone,  and  proved  the  total  absence  of  citric  acid.  It  was  suggested 
that  the  tartaric  acid  tests  were  responded  to,  due  to  the  probable 
existence  of  traces  of  this  acid  present  in  the  wine,  which  was  used  in 
preparing  the  bitter  wine  of  iron.  But  this  seemed  impossible  accord- 
ing to  the  results  gotten.  The  amount  of  liquid  used  was  small,  and 
the  results  obtained  were  so  decided  to  suggest  more  than  such  traces. 
The  following  test  for  citric  acid  was  used  : 
To  a  portion  of  the  liquid  KOH  solution  was  added  and  boiled  ;  the 
precipitate,  consisting  of  the  hydrated  iron,  was  filtered  out.  To  the 
cooled  filtrate  was  added  test-solution  of  calcium  chloride  and  allowed 
to  stand  some  time,  then  filtered.  The  new  filtrate,  when  heated  to 
boiling,  afforded  a  white  precipitate,  due  to  citrates. 
The  following  tests  for  tartaric  acid  were  used : 
(1.)  To  a  portion  of  the  liquid  was  added  test-solution  of  nitrate  of 
silver,  and  then  a  few  drops  of  NH^OH ;  on  boiling,  a  mirror  of 
metallic  silver  was  formed  on  the  test  tube. 
(2.)  Another  portion  of  the  liquid  was  deprived  of  its  iron  by  boil- 
ing with  KOH  solution ;  the  cooled  filtrate  was  then  supersaturated 
with  acetic  acid,  and  yielded  a  white  crystalline  precipitate  due  to 
tartrates. 
The  percentage  of  sugar  in  each  sample  was  not  estimated. 
Below  will  be  found  a  table  showing  the  results  gotten  from  each 
sample  as  described  above  : 
