Am.  Jour.  Pharm.  \ 
January,  1911.  j 
Rhizome  of  Iris  Versicolor. 
II 
The  unsaturated  acids,  which  were  regenerated  from  the  above- 
mentioned  oily  barium  salt,  still  contained  small  quantities  of  satur- 
ated acids.  The  mixture  was  therefore  converted  into  its  lead  salt, 
and  the  latter  treated  with  cold  ether.  The  portion  insoluble  in  ether 
was  found  upon  examination  to  consist  of  the  lead  salts  of  lauric 
and  palmitic  acids.  The  portion  soluble  in  ether,  when  treated  with 
dilute  hydrochloric  acid,  yielded  the  unsaturated  acids  as  a  pale 
yellow  oil,  which  possessed  the  following  constants :  neutralization 
value  =  208  ;  iodine  value  =  1 1 1. 
In  order  to  ascertain  the  constituents  of  the  unsaturated  acids, 
12  grammes  of  the  mixture  were  oxidized  with  dilute  alkaline  per- 
manganate, as  described  by  Lewkowitsch  (Chemical  Technology  and 
Analysis  of  Oils,  Fats,  and  Waxes,  1904,  vol.  i,  p.  360),  when  the 
chief  oxidation  product  was  dihydroxystearic  acid,  melting  at  128°. 
0.3412  required  for  neutralization  10.95  c.c.  KOH. 
Neutralization  value  =  180. 
CtsH.,,.0^  requires  Neutralization  value  =  178. 
A  small  quantity  of  tetrahydroxystearic  acid  (sativic  acid),  melt- 
ing at  156°,  was  also  isolated. 
0.3164  required  for  neutralization  9.1  c.c.  KOH. 
Neutralization  value  =  164. 
CisHggOf;  requires  Neutralization  value  =  164. 
No  linusic  or  /^clinusic  acid  was  present  in  the  product  of  oxida- 
tion, and  it  may  therefore  be  concluded  that  the  unsaturated  acids 
consisted  of  a  mixture  of  oleic  and  linolic  acids,  the  former  pre- 
dominating. 
Isolation  of  Cerotic  Acid,  CorH-^oOo. 
Fraction  5. — The  final  fraction  obtained  by  the  distillation  of  the 
esters  of  the  total  fatty  acids  solidified  in  the  receiver  as  a  colorless 
solid.  It  was  recrystallized  several  times  from  alcohol,  when  it 
separated  in  glistening  leaflets,  melting  at  55-56°.  This  ester  was 
then  hydrolyzed,  and  the  liberated  fatty  acid  recrystallized  from 
ethyl  acetate.  It  was  deposited  from  this  solvent  in  colorless  leaflets, 
melting  at  78°,  and  was  identified  as  cerotic  acid. 
o.Tiio  gave  0.3185  CO.  and  0.1295  H.O.  C  =  78.3  ;  H  =  13.0 
0.1822  required  for  neutralization  4.75  c.c.  KOH. 
Neutralization  value  =  146. 
CocHr.^.O^  requires  C  =  78.8;  H  =  13. i  per  cent.  Neutralization 
value  =  142. 
