342  White  and  Black  Mustard  Seed.         { Am  /^'SK™ 
principles  from  the  white  and  black  mustard  were  obtained  by  the 
action  of  the  ferment  upon  the  glucosides.  In  the  subjoined  para- 
graphs a  statement  is  made  as  clearly  as  possible  as  to  the  best 
methods  of  procedure  in  obtaining  the  principles  named. 
To  obtain  sinigrin  from  black  mustard  seed ;  reduce  them  to  a 
fine  powder,  and  express  the  fixed  oil  as  completely  as  possible, 
then  extract  with  benzene  (C6HC)  to  remove  the  remainder.  Expose 
the  seed  thus  treated  to  the  air,  and  allow  the  benzene  to  evaporate 
completely.  Then  re-powder  and  place  them  in  three  or  four  times 
their  bulk  of  boiling  alcohol.  Boil  for  about  thirty  minutes  on  a 
water  bath  and  evaporate  to  dryness ;  re-powder,  and  extract  with 
Sinigrin.    From  an  Alcoholic  Solution. 
cold  water.  Treat  this  with  barium  carbonate  and  evaporate  on  a 
water  bath  to  dryness.  Extract  the  residue  with  strong  boiling 
alcohol  and  filter  while  hot.  Set  the  solution  away  in  a  cool  place 
for  several  days,  and  sinigrin,  or  potassium  myronate  will  crystallize 
out  in  long,  fine,  silky  needles.  From  aqueous  solution  it  crystallizes 
in  four-sided  prisms.  It  may  be  purified  by  recrystallization  from 
boiling  alcohol. 
Free  myronic  acid  may  be  obtained  from  sinigrin  by  decomposing 
it  with  a  concentrated  solution  of  tartaric  acid,  and  adding  alcohol. 
To  obtain  sinalbin  from  white  mustard  seed,  powder  finely,  and 
extract  the  fixed  oil  completely  with  benzene  (C6H6).    Spread  the 
