Am.  Jour.  Pharm. 
Nov.,  1880. 
Testing  of  Mustard  Oil. 
SSS 
water  bath,  in  order  to  obtain  the  sulphcyanide  of  ammonium.  It 
follows  herefrom  that  the  sulphocyanide  of  iron  reaction  cannot  be 
employed  for  the  purpose  of  detecting  bisulphide  of  carbon  in  mustard 
oil. 
In  order  to  obtain  from  pure  mustard  oil  a  metallic  sulphide,  proba- 
bly always  accompanied  by  sulphocyanide,  it  is  not  necessary  to  apply 
potassa,  soda  or  ammonia  ;  baryta  water  or  lime  water,  even  without 
alcohol,  when  warmed  with  mustard  oil,  accomplish  the  formation  of 
the  metallic  sulphide,  which  may  be  detected  by  means  of  the  nitro- 
prusside  of  sodium.  Even  saturated  solutions  of  carbonate  of  sodium 
are  capable  of  extracting  sulphur  from  mustard  oil,  forming  therewith 
traces  of  sodium  sulphide. 
Mustard  oil  and  ammonia  combine  to  form  thiosinammin,  SCNH 
(C3H5)NH2;  I  molecule  of  mustard  oil  =  99  gives  1 16  thiosinam- 
min. 100  parts  of  mustard  oil  must  therefore  yield  1177  parts  of 
thiosinammin.  I  warmed  5  grams  of  the  pure  mustard  oil,  distilled 
by  Schimmel  &  Co.,  with  2*5  grams  of  absolute  alcohol,  and  8*6  grams 
of  ammonia  water,  sp.  gr.  0*960,  to  about  60°,  in  a  loosely  stopped 
flask.  After  a  quarter  of  an  hour  the  mixture  became  clear,  of  a 
yellow  color,  and,  at  the  expiration  of  an  hour,  the  odor  of  the  mustard 
oil  had  disappeared.  Evaporated  on  a  watch  glass  upon  the  water  bath 
until  no  further  considerable  reduction  in  weight  took  place,  the  resi- 
due furnished  upon  cooling  a  white  crystalline  mass  of  thiosinammin, 
which,  after  drying  completely  over  sulphuric  acid,  weighed  5*634 
grams,  or  11 -2  per  cent,  of  the  applied  mustard  oil. 
Other  experiments,  with  slight  deviation  from  this  procedure,  gave 
ii'i,  11*23        ^^'57  P^^  cent,  of  thiosinammin. 
Four  grams  of  mustard  oil,  adulterated  with  bisulphide  of  carbon,, 
furnished  on  the  contrary  only  3-6  per  cent.,  f.,  90  per  cent,  of 
residue. 
It  is  thus  seen  that  the  weighing  of  the  thiosinammin,  which  can 
be  obtained  from  a  given  specimen  of  mustard  oil,  is  very  well  adapted 
for  the  determination  of  its  value. 
This  very  neat  reaction  is,  however,  accompanied  by  an  unavoidable 
error.  The  action  of  the  ammonia  is,  as  one  might  expect,  not  con- 
fined to  the  formation  of  the  thiosinammin,  but  the  latter  is  always 
accompanied  by  some  ammonium  sulphocyanide.  The  amount  of  the 
latter  is  indeed  very  small,  when  a  moderate  heat  and  not  much  more 
ammonia  is  applied  than  is  necessary  according  to  the  above  formula. 
