lO 
Rhizoluc  of  Iris  V ersicolor. 
(Am.  Jour.  Phann. 
\    January,  1911. 
value,  appeared  to  consist  chiefly  of  ethyl  laurate(l).  p.  269°  ;  saponifi- 
cation value  246) .  In  order  to  confirm  the  presence  of  lauric  acid, 
the  entire  fraction  was  hydrolyzed  with  alcoholic  potassium  hydrox- 
ide, and  the  mixture  then  acidified  and  distilled  in  a  current  of 
steam.  A  quantity  of  volatile  fatty  acid  was  thus  obtained,  which 
melted  at  40°,  and  was  further  identified  as  lauric  acid  by  means  of 
its  neutralization  value. 
0.3150  required  for  neutralization  15.7  c.c.  Ba(OH)2. 
Neutralization  value  =  280. 
C12H04O0  requires  Neutralization  value  =  280. 
Fractions  2  and  3. — These  fractions,  which  were  small  in  amount, 
were  united  and  hydrolyzed  with  alcoholic  potassium  hydroxide,  in 
order  to  obtain  the  free  fatty  acids.  The  latter  were  then  dissolved 
in  hot  alcohol,  and  separated  into  four  dififerent  fractions  by  the 
successive  ad^dition  of  small  quantities  of  concentrated  aqueous 
barium  acetate.  These  fractions  of  barium  salt  yielded  acids  which 
melted  at  33-35°,  33-35°.  35-36°,  and  39°,  and  whose  neutralization 
values  were  260,  261,  268,  and  275  respectively.  It  was  evident 
from  these  results  that  fractions  2  and  3  consisted  of  a  mixture  of 
lauric  acid  (neutralization  value  =  280)  and  the  acids  of  higher 
carbon  content  contained  in  the  succeeding  fraction. 
Fraction  4. — This  fraction  contained  the  greater  portion  of  the 
total  fatty  acids,  and  amounted  to  120  grammes.  Its  iodine  value 
(51.7)  indicated  the  presence  of  a  considerable  quantity  of  unsat- 
urated acid.  For  its  further  examination  the  acids  were  regener- 
ated by  hydrolysis,  and  then  fractionally  precipitated  in  hot  alcoholic 
solution  with  small  portions  of  concentrated  aqueous  barium  acetate. 
In  this  manner  the  saturated  acids  were  precipitated  in  the  first  4 
fractions,  while  the  final  fraction,  which  was  oily,  contained  the 
unsaturated  acids,  and  was  therefore  put  aside  for  subsequent 
examination,  as  described  below.  The  barium  salts  of  the  saturated 
acids  thus  obtained  were  treated  separately  with  dilute  hydrochloric 
acid,  and  the  liberated  fatty  acids  recrystallized  from  alcohol.  The 
several  fractions  were  then  found  to  melt  at  54-56°,  54-56°,  54-55°. 
and  53-55°  respectively,  while  the  corresponding  neutralization 
values  were  209,  212.5,  216,  and  217.  It  was  evident  from  these 
results  that  the  saturated  acids  contained  in  fraction  4  consisted  of  a 
mixture  of  stearic  and  palmitic  acids,  whose  neutralization  values 
are  198  and  219  respectively. 
