Am.  Jour.  Pharm.  > 
August,  1910.  | 
Ipomcea  Horsfallice. 
357 
The  root  was  sliced,  and  then  dried  in  a  water-oven,  when  it 
weighed  408  grammes,  the  loss  of  weight  in  drying  having  thus 
been  1987  grammes,  or  nearly  83  per  cent.  The  dried  material 
was  ground  to  a  fine  powder,  when  it  amounted  to  385  grammes. 
It  was  then  brought  into  a  large  Soxhlet  apparatus,  and  thoroughly 
extracted  with  hot  alcohol,  the  greater  portion  of  the  alcohol  being 
subsequently  removed,  and  the  resulting  extract  distilled  in  a  cur- 
rent of  steam.  The  distillate  was  found  to  contain  only  traces  of 
formic  and  butyric  acids. 
After  the  above-described  treatment,  the  contents  of  the  distil- 
lation flask  consisted  of  a  dark  red,  aqueous  liquid,  together  with  a 
small  amount  of  resinous  material.  The  liquid  was  filtered,  and 
the  resin  repeatedly  washed  with  hot  water,  after  which  the  resin 
was  dissolved  in  a  little  alcohol,  the  solution  evaporated  to  dryness, 
and  the  residue  dried  at  ioo°  C.  The  amount  of  resin  obtained 
was  9.6  grammes,  thus  corresponding  to  2.5  per  cent,  of  the 
weight  of  dried,  or  0.4  per  cent,  of  the  weight  of  the  entire  fresh 
root. 
The  resin  formed  a  dark  brown,  spongy  mass,  which  became 
somewhat  sticky  on  exposure  to  the  air.  It  was  found  to  be  almost 
completely  soluble  in  ether. 
Optical  Rotation  of  the  Crude  Resin. 
The  optical  rotatory  power  of  the  convolvulaceous  resins  has  been 
considered  to  afford  some  indication  of  their  identity  or  purity.3 
As  this  factor  has  previously  been  determined  for  several  such 
resins,  including  those  of  Ipomcea  purpurea,  Roth,  and  jalap  by  the 
present  authors,2  it  was  deemed  of  interest  to  make  this  determina- 
tion with  the  resin  under  examination.  For  this  purpose  1.0  gramme 
of  the  crude  resin  was  dissolved  in  absolute  alcohol,  and  the  solution 
treated  with  successive  small  quantities  of  animal  charcoal  until  it 
was  nearly  deprived  of  color.  The  rotation  of  this  liquid  in  a  2  dcm. 
tube  was  —  o°54',  and  the  amount  of  substance  contained  in  10 
c.c.  of  the  liquid,  after  drying  at  105-100  C,  was  0.1584  gramme, 
whence  [a]n — 28.40.    It  may  be  noted  that  this  degree  of  optical 
1  Compare  Guigues,  Journ.  de  Pharm.  et  de  Chim.,  [6],  22,  241,  and 
CJicm.  Centralblatt,  1907,  Bd.  I,  p.  309.  Also  Bull  soc.  chim.  [4],  3,  872,  (1908). 
2  This  Journal,  1908,  80,  p.  253,  and  Journ.  Amer.  Chem.  Soc,  1910, 
32,  P-  85. 
