Am.  Jour.  Pharm. ) 
August,  1882.  J 
Analysis  of  Mustard. 
405 
Teiuaining  nitrogen  into  myrosine.  But  as  myrosine  contains  about 
1*6  per  cent,  of  sulphur,  further  calculations  are  necessary.  Such  cal- 
"Culations  may  or  may  not  yield  correct  results,  for  one  has  as  much 
iright  to  calculate  all  the  remaining  sulphur  first  into  myrosine,  or  all 
the  nitrogen  into  either  myrosine  or  sulphocyanide  of  sinapine,  as  the 
: sulphur  into  the  last-named  compound.  The  results  cannot  be  calcu- 
lated algebraically  because  there  is  only  one  equation,  and  this  equa- 
ition  has  two  unknown  factors.  In  one  of  the  samples  of  mustard 
ranalyzed  by  Hassall  he  finds  myrosine  31  "686  per  cent.,  sulphocyanide 
of  sinapine  5*714  per  cent.  Taking  his  percentages  of  nitrogen  and 
sulphur,  and  calculating  the  total  nitrogen  first  into  myrosine,  one 
.finds  myrosine  31*43  per  cent.,  sulphocyanide  of  sinapine  3*95  per 
•  cent. 
For  the  reasons  above  detailed.,  the  following  attempt  was  made  to 
.w^ork  out  a  method  for  the  analysis  of  mustard,  which  should  be  direct 
throughout,  and  should  rest  on  an  actual  separation  and  estimation  of 
.the  several  constituents.  The  moisture  and  ash  are  determined  as 
usual.  .  The  mustard  oil  is  extracted  with  ether  in  the  following  man- 
ner :  A  weighed  portion  of  mustard,  after  drying  at  105°,  is  carefully 
brushed  into  a  plaited  filter.  The  filter  and  its  contents  are  placed  in 
a  funnel  with  straight  sides.  The  stem  of  the  funnel  is  connected  by 
means  of  a  well-fitting  cork,  with  a  small  tared  flask  partially  filled 
with  ether,  while  the  funnel  itself  is  connected  with  an  upright  con- 
denser. On  cautiously  boiling  the  ether,  its  vapor  is  constantly  con- 
densed, and,  falling  on  the  mustard,  extracts  the  oil  which  is  retained 
in  the  flask.  When  all  of  the  oil  is  removed,  the  ether  is  distilled 
off,  and  the  flask  and  contents,  after  drying  at  100°,  re  weighed.  The 
difference  between  the  weight  of  the  flask  alone,  and  that  of  the  flask 
and  oil,  gives  the  amount  of  oil.  After  the  ether  has  evaporated  from 
the  mustard  residue,  a  tared  flask,  containing  half  water  and  half  alco- 
hol, is  substituted  for  that  containing  ether,  and  the  contents  are  boiled 
and  condensed  as  before.  The  dilute  alcohol  dissolves  both  the  sul[)ho- 
cyanide  of  sinapine  and  the  myronate  of  potash,  while  it  coagulates 
t\w,  myrosine,  and  leaves  both  it  and  the  cellulose  undissolved.  After 
all  the  sulphocyanide  of  sinapine  and  myronate  of  potash  have  been 
extra(;te(l,  the  coptents  of  the  flask  are  rinsed  into  a  tared  2)latinuin 
dish,  evaporated  to  dryness,  dried  at  105°  and  weighed.  The  dish 
and  contents  are  then  ignited  and  weighed.  The  dlflcM'ence  of  w  eight 
before  and  after  ignition  gives  tlie  total  amount  of  sulphocyanide  of 
