CHEMICAL  COMPOSITION  OF  QUINIDINE. 
169 
by  the  aid  of  heat,  finely  powdered  quinidine  in  acetic  acid. 
When  cold,  the  acetate  of  quinidine  appears  in  the  form  of  thin, 
long  silky  needles,  which  do  not  easily  dissolve  in  cold  water. 
When  dried,  the  salt  easily  loses  part  of  its  acid.  On  removing 
the  first  crystals,  and  allowing  the  mother-liquor  to  evaporate 
spontaneously,  a  salt  crystallizes  from  it,  consisting  of  a  mass  of 
semi-globularly  grouped,  small  pointed  needles,  having  an  appear- 
ance of  porcelain.  This  salt  is  by  far  more  soluble  in  water  than 
that  above  mentioned. 
Oxalate  of  Quinidine. — If  an  alcoholic  solution  of  oxalic  acid 
be  added  to  an  alcoholic  solution  of  quinidine  with  the  application 
of  heat,  till  the  liquid  is  neutral  to  test-paper,  the  oxalate  of 
quinidine  crystallizes  from  the  solution  after  the  latter  has  become 
cold,  in  the  form  of  long,  white,  silky  needles,  which  dissolve  with 
great  difficulty  in  water.  From  the  spontaneously  evaporated 
mother-liquor  a  salt  in  the  shape  of  warty  crusts,  with  an  opaque 
white  appearance,  crystallizes,  which  dissolves  with  less  difficulty 
in  water. 
Tartrate  of  Quinidine. — With  tartaric  acid  quinidine  forms 
two  compounds,  which  appear  to  possess  great  resemblance  to  the 
oxalates.  On  saturating  tartaric  acid  with  quinidine,  at  a  boiling 
heat,  a  salt  separates,  when  the  solution  cools,  in  the  shape  of 
small  pearly  needles,  which  dissolve,  but  with  great  difficulty,  in 
water.  The  solution  of  neutral  tartrate  of  quinidine  having  been 
allowed  to  evaporate  spontaneously,  yielded  beautiful  vitreous 
needles,  and,  by  the  further  evaporation  of  the  mother-liquor, 
small,  semi-globular,  white,  opaque  shining  crusts  of  small  needles 
appeared. 
Citrate  of  Quinidine  was  obtained  by  saturating  pure  quini- 
dine with  pure  citric  acid  at  a  boiling  heat.  From  the  cold  neu- 
tral solution  of  the  citrate  of  quinidine,  small,  but  slightly 
glittering  needles  crystallized,  which  did  not  easily  dissolve  in 
water. 
Formate  of  Quinidine,  obtained  by  saturating  the  pure  aqueous 
formic  acid  with  quinidine.  The  salt  forms  long,  beautiful,  silky 
needles,  readily  dissolving  in  water. 
Butyrate  of  Quinidine. — Aqueous  butyric  acid  was  saturated 
with  an  alcoholic  solution  of  quinidine.  The  salt  crystallized 
from  the  neutral  solution  in  large  warty  crusts  resembling 
