270    Chemical  Examination  of  Ipomcea  Purpurea. 
Am.  Jour.  Pharm. 
June,  1908. 
reddish-brown  liquid.  By  the  fractional  distillation  of  this  product 
they  established  the  presence  of  acetic,  tiglic,  and  palmitic  acids. 
As,  however,  there  is  no  indication  that  the  resin  employed  by  them 
had  been  freed  from  substances  soluble  in  petroleum,  it  is  probable 
that  the  palmitic  acid  pre-existed,  and  was  not  produced  by  the 
destructive  distillation. 
Fusion  with  Potassium  Hydroxide. — Twenty  grammes  of  the  resin 
were  fused  with  120  grammes  of  potassium  hydroxide  in  the 
manner  described  in  connection  with  the  ether  extract  of  the  resin. 
The  reaction  was  particularly  vigorous  between  220  and  2300  C, 
the  temperature  of  the  mass  having  been  finally  raised  to  2500  C. 
After  allowing  the  mass  to  cool,  it  was  dissolved  in  water,  the  solu- 
tion acidified  with  sulphuric  acid,  and  then  subjected  to  distillation 
with  steam.  The  distillate,  which  contained  some  oily  drops,  was 
extracted  with  ether,  the  ethereal  solution  being  washed  with  water, 
dried  with  calcium  chloride,  and  the  ether  removed,  when  about 
2  grammes  of  oily  acid  were  obtained.  This  was  distilled  under 
30  mm.  pressure,  and  the  distillate  collected  in  the  following  three 
fractions:  (1)  below  no°;  (2)  no-1200;  (3)  above  1200  C./30 
mm.    The  fractions  (1)  and  (2)  were  analzyed. 
Fraction  below  no0  C./30  mm. 
00996  gave  0-2074  CO,  and  0.0874  H20.    C  =  56-8;  H  ==  97 
Fraction  uo-1200  C. / 30  mm. 
0-1290  gave  0-2746  C02  and  o-i  120  H20.     C  =  58-1  ;  H  =  9  6 
C4H802  requires  C  =  54-5  ;  H  =  9-1  per  cent. 
C5Hie02     «      C  =  58  8  ;  H  =  9-8   "  « 
From  these  results  it  may  be  concluded  that  the  above  two  frac- 
tions consisted  chiefly  of  mixtures  of  butyric  and  valeric  acids. 
Fraction  above  1200  C./jo  mm. 
From  this  fraction  a  silver  salt  was  prepared,  which,  after  being 
well  washed  with  water  and  dried  in  a  vacuum,  was  analyzed. 
0-1834  of  salt  gave  on  ignition  0-0790  Ag.     Ag.  =  43-1 
01874    "  "  "     0-0806  Ag.     Ag.  =  43-0 
C8H1502  Ag  requires  Ag  =  43-0  per  cent. 
Although  the  results  of  these  analyses  are  in  agreement  with  the 
figures  required  for  silver  octoate,  it  is  not  probable  that  the  frac- 
tion consisted  of  a  pure  substance. 
