386 
Ipomcea  Pandurata. 
f  Am.  Jour.  Pl)arm, 
\      Aug.,  1881. 
ing  a  reddish-brown  mass  having  the  taste  of  burnt  sugar.  A  por- 
tion of  it  was  dissolved  in  water  and  solution  of  subacetate  of 
lead  added,  which  produced  a  yellowish  precipitate.  This  was  col- 
lected on  a  filter,  washed,  suspended  in  water  and  treated  with 
sulphuretted  hydrogen,  by  which  the  lead  was  eliminated.  The 
liquid  was  boiled  to  free  it  from  sulphuretted  hydrogen.  Uj^on 
adding  ferric  chloride  to  this  solution,  it  gave  a  greenish-blue  colora- 
tion which  did  not  disappear  on  boiling ;  solution  of  gelatin  added  to 
another  portion  produced  no  precipitate.  The  coloration  produced 
with  iron  is  probably  due  to  some  coloring  matter  acting  similar  to 
tannin.  The  filtrate  was  freed  from  lead  and,  with  Trommer's  test, 
deposited  red  cuprous  oxide,  indicating  the  presence  of  sugar. 
The  resin  is  of  a  yellowish-brown  color,  fusible,  breaking  with  a 
glossy,  resinous  fracture  and  translucent  on  the  edges.  It  becomes 
much  lighter  in  color  on  repeated  solution  in  alcohol  and  precipitation 
with  water.  The  powder  is  yellowish-gray  to  yellowish-white  in 
color,  has  a  slight  odor  at  ordinary  temperature,  which  becomes  more 
perceptible  on  heating.  It  is  soluble  in  chloroform  and  in  ether. 
Its  solution  in  alcohol  has  an  acid  reaction  to  litmus  paper.  It  dis- 
solves in  aqueous  alkalies,  from  which  solution  it  is  precipitated  by 
hydrochloric  acid.  Methylic  alcohol  dissolves  it  to  some  extent.  It 
is  insoluble  in  benzol,  benzin  and  acetic  acid.  Its  cathartic  properties 
were  shown  by  experiments ;  given  to  adults  in  three-grain  doses,  it 
operated  within  two  hours  of  the  time  it  was  taken,  causing  consider- 
able griping  and  producing  watery  stools.  The  resin  was  boiled  with 
successive  portions  of  water  until  the  last  gave  no  reaction  for  sugar. 
It  was  then  boiled  with  very  dilute  sulphuric  acid,  filtered,  and  tlie 
iiltrate  freed  from  sulphuric  acid  by  adding  carbonate  of  barium. 
This  filtrate,  when  treated  with  Trommer's  test,  caused  a  precipitate  of 
red  cuprous  oxide,  showing  the  resin  to  be  a  glucoside. 
To  an  alcoholic  solution  of  the  resin,  acetate  of  lead  was  added, 
which  produced  a  precipitate.  The  filtrate  was  treated  with  an  alco- 
holic solution  of  ammonia  until  completely  precipitated.  This  pre- 
cipitate was  collected,  mixed  with  the  first  precipitate,  washed  with 
alcohol,  then  suspended  in  alcohol,  freed  from  lead,  filtered  and  evap- 
orated to  dryness.  This  resin  is  of  a  light-brown  color,  transparent 
in  thin  layers,  has  the  odor  and  taste  of  pop-corn  and  is  soluble  in  alco- 
hol, ether,  chloroform,  methylic  alcohol  and  in  hydrate  of  potassium, 
from  which  it  is  precipitated  by  hydrochloric  acid.    It  is  insoluble  in 
