Amjfmer'i908.arm'}     Chemical  Examination  of  Ipomcea  Purpurea.  259 
remaining  undissolved.  The  petroleum  solution  was  warmed  with 
a  little  animal  charcoal,  filtered,  and  the  solvent  removed,  when  a 
green  colored  mass  was  obtained.  This  was  distilled  under  15  mm. 
pressure,  when  it  passed  over  for  the  most  part  at  230°  C.  as  a  pale 
yellow  oil,  which  solidified  on  cooling  to  a  nearly  white,  crystalline 
mass,  and  amounted  to  4  5  grammes.  The  solid  was  dissolved  in 
hot  alcohol,  from  which,  on  cooling,  the  greater  portion  separated, 
and,  after  drying,  melted  at  60-620  C.  This  portion  was  converted 
into  a  lithium  salt,  and  the  acid  regenerated  from  the  latter  obtained 
in  two  fractions.  The  first  of  these  melted  at  66-68°  C,  and  was 
analyzed  with  the  following  result: 
0-0730  gave  0-2036  C02  and  0  0826  H20.    C  =  76-1 ;  H  ==  126. 
ClsH3602  requires  C  =  76-1  ;  H  =  127  per  cent. 
This  substance  was  evidently  stearic  acid. 
The  second  fraction  of  acid  melted  at  60-62°  C,  and  was  also 
analyzed. 
0  0600  gave  0-1660  C02  and  0-0696  H20.    C  —  75-4;  H  '=  12-9 
C16H3202  requires  C  =  75  0  ;  H  =  12-5  per  cent, 
C18H3602       «     C  =76-1  ;  ¥L  =  12 7    «  « 
The  characters  of  this  second  fraction  indicated  it  to  consist  of  a 
mixture  of  palmitic  and  stearic  acid. 
The  alcoholic  mother-liquor  from  the  crystallization  of  the  above 
mentioned  acids  was  tested  for  the  presence  of  unsaturated  acids  by 
treatment  with  an  alcoholic  solution  of  lead  acetate,  and  digesting 
the  precipitated  lead  salt  with  ether.  The  portion  of  salt  dissolved 
by  the  ether  was  decomposed  with  hydrochloric  acid,  when  a  very 
small  amount  of  an  oily  acid  was  obtained.  The  latter,  when  dis- 
solved in  chloroform,  decolorized  a  solution  of  bromine  in  the  same 
solvent,  thus  indicating  the  presence  of  some  unsaturated  acid. 
II.  Ether  Extract  of  the  Resin. 
This  extract  was  a  hard,  dark  green,  brittle  resin. 
Fusion  with  Potassium  Hydroxide. — Forty  grammes  of  the  resin 
were  fused  with  240  grammes  of  potassium  hydroxide  in  a  nickel 
basin,  the  temperature  of  the  mixture  being  kept  for  some  time  at 
200°  C,  and  finally  increased  to  260°  C,  when  the  mass  became 
thick  and  pasty.    After  being  allowed  to  cool,  it  was  dissolved  in 
