208 
ON  CORYDALIS  FORMOSA. 
They  yield  with  bi-chloride  of  mercury  an  insoluble  double 
salt.  The  soluble  salts  are  precipitated  by  alkaline  iodides, 
bromides  and  ferrocyanides,  as  insoluble  compounds. 
From  the  above  statements  it  will  appear  that  the  alkaloid  is 
identical  with  that  described  by  European  chemists,  obtained  from 
the  Corydalis  bulbosa  and  Corydalis  fabacea,  plants  analogous  in 
their  botanical  characters  to  our  own  indigenous  plant,  the 
Corydalis  formosa. 
VI.  The  filtrate  left  in  the  preceding  article  after  the  first 
precipitation  with  ammonia,  was  heated  to  expel  the  ammonia, 
and  mixed  with  a  solution  of  acetate  of  lead.  The  precipitate 
washed  and  decomposed  with  dilute  sulphuric  acid  and  filtered, 
the  filtrate  again  precipitated  by  acetate  of  lead  and  decomposed 
by  a  current  of  hydro-sulphuric  acid  gas,  heated  to  expel  the 
latter,  and  finally  decolorized  by  passing  through  prepared  animal 
charcoal.  The  acid  solution  thus  obtained  reddened  litmus  paper 
very  strongly,  and  possessed  an  agreeable  acid  taste.  On  testing 
with  solutions  of  chloride  of  barium  and  calcium,  barytie  and 
lime  waters,  no  precipitates  were  obtained. 
A  portion  of  the  acid  solution  evaporated  to  dryness,  sublimed 
with  residue,  and  when  boiled  with  concentrated  nitric  acid  no 
decomposited  ensued.  On  neutralizing  with  ammonia  and  adding 
chloride  of  calcium,  no  precipitate  occurred  until  heating  to 
ebullition.  Acetate  of  lead  gave  a  white  voluminous  precipitate 
insoluble  in  acetic  acid  and  ammonia,  but  soluble  in  dilute 
nitric  acid ;  on  heating  in  water  it  did  not  perceptibly  change. 
Nitrate  of  silver  produced  a  white  precipitate,  which  did  not 
undergo  any  alteration  in  cold  or  boiling  water,  even  after  stand- 
ing some  time. 
Sulphate  of  copper  added  and  heated,  a  greenish  blue  crystal- 
line precipitate  subsided.  Tincture  of  sesquichloride  of  iron 
added  and  gently  heated,  a  dirty  yellow  voluminous  precipitate 
immediately  subsided.  Proto-chloride  of  manganese  reacted 
similarly  to  the  preceding ;  a  dirty  white  flocculent  precipitate 
appeared.  The  acid  under  examination  was,  therefore,  fumaric 
acid,  a  peculiar  acid  found  likewise  to  be  a  constituent  of  the 
Fumaria  officinalis,  a  plant  belonging  to  the  same  natural  order 
of  plants.  In  the  present  course  of  analysis,  I  have  only  stated 
those  reactions  of  a  positive  character,  neglecting  to  take  note  of 
