480 
Datura  Stramonium. 
Am.  Jour.  Pharm. 
Oct.,  1893. 
These  results  approximate  the  results  of  to-day  much  nearer  than 
those  of  Guenther  and  are  probably  nearer  the  truth.  TrommsdorfT 
could  obtain  only  0-002-0  02  per  cent,  of  alkaloids  from  Stramon- 
ium Seed  and  E.  Schmidt  only  0  05-0  06  per  cent. 
Dragendorff  by  the  application  of  his  volumetric  method1  (using 
a  vigintinormal  solution  of  mercurio-potassium  iodide2),  obtained 
the  following  results : 
Per  Cent. 
Alkaloids. 
Belladonna  Leaves  yielded,  •  •  •  .   o*66 
"         Roots       "    0*40 
Stramonium  Leaves    "    0*612 
Seed       "    0-380 
The  writer's  experience  in  assaying  narcotic  herbs  has  been  that 
Dragendorff's  method  or  any  other  method  that  employs  a  solution 
of  mercurio-potassium  iodide  is  unreliable.  Some  assays  given 
below  and  made  at  various  times  during  the  course  of  two  years  by 
various  gravimetric  methods3  and  Dragendorff's  method  show  this 
quite  plainly.  In  case  of  those  results  opposite  one  another,  marked 
with  an  asterisk,  the  same  drug  was  used  in  both  methods  so  as  to 
enable  direct  comparisons  to  be  made : 
Belladonna  Leaves. 
Belladonna  Root. 
Gravimetric  method 
without  titration. 
Dragendorff's 
volumetric 
method. 
Gravimetric 
method  without 
titration. 
Dragendorff's 
volumetric 
method. 
Per  cent, 
alkaloids. 
0-40* 
0-38 
0-42 
o'34* 
Per  cent, 
alkaloids. 
075* 
0*64 
0-56 
0-51* 
o-8i 
o'45 
Per  cent. 
alkaloids. 
0-26* 
0-54* 
0-49* 
Per  cent. 
alkaloids. 
0*46* 
074* 
0-83* 
1  Dragendorff's  method — Manual  Pharmaceutical  Assaying  (Lyons),  \  91, 
p.  48. 
2  Mayer's  solution. 
3  Lyons  method — Manual  Pharmaceutical  Assaying,  \  29,  p.  20,  and  Dunstan 
and  Ransom's  method — Manual  Pharmaceutical  Assaying,  \  112,  p.  56. 
