496  Mayer's  Reagent  for  Alkaloids.        i^"^' oct^/im^^""' 
SANGUINARINE. 
Dragendorfif  on  the  results  of  some  experiments  of  Masing  hazards 
a  guess  that  the  titration  equivalent  of  sanguinarine  will  be  found  to 
be  '00743.  Calculation  shows  that  this  is  a  theoretical  equivalent 
based  on  Fliickiger's  formula  for  the  alkaloid  (Cj^  H^g  N04=297,  ^ 
of  297=-00743),  and  assuming  C,^  B,,  NO4  HI.  Hgl2  to  be  the  com- 
position of  the  precipitate.  My  own  results  are  widdy  at  variance 
with  this  figure.  A  number  of  titrations  have  been  performed,  of 
which  the  following  are  averages : 
]  in  200   -0183 
1  in  300   -0178 
1  in  400    0173 
1  in  500   -0165 
1  in  600   -0155 
Duplicates  show  some  differences  even  when  the  conditions  seem 
the  same.  The  end  reaction,  however,  is  sharp  and  well  defined,  and 
approaches  closely  to  berberine  and  strychnine  in  this  respect.  Like 
these  alkaloids,  also,  the  excess  of  reagent  required  to  precipitate  the 
alkaloid  is  small,  at  least  in  the  stronger  solutions,  and,  on  the  whole^ 
the  alkaloid  may  be  ranked  with  those  giving  good  results  in  titra- 
tions. Just  what  the  action  of  its  associated  alkaloid  chelidonine  is  I 
cannot  say,  though  it  would  be  very  interesting  to  know.  O'lOO 
grammes  of  alkaloid  yield  a  precipitate  weighing  from  0*180  to  0*206, 
with  an  average  of  0*194,  corresponding  to  51*5  per  cent,  average  of 
alkaloid  in  the  precipitate. 
Fluid  measures,  30  cc.  at  the  beginning  of  the  titration,  and  contains  3  cc  of 
1  per  cent,  by  vol.  sulphuric  acid. 
Cc  reagent. 
Dilution. 
Equivalent. 
3-64 
1  in  500 
•0165* 
3-94 
1  in  450 
•0169 
4-34 
1  in  400 
•0173* 
4-89 
1  in  350 
•0176 
5-62 
1  in  300 
•0178* 
6-63 
1  in  250 
•0181 
8-19 
1  in  200 
•0183* 
STRYCHNINE. 
My  own  experiments  agree  substantially  with  those  of  previous  ob- 
servers.   For  dilutions  running  from  1  in  200  to  1  in  400  but  little 
