120 
Assay  of  Belladonna  Leaves. 
/  Am,  Jour.  Pharin 
\      March,  1899. 
Leaves.  Extract. 
Moisture. 
Per  Cent. 
English,  cultivated  (Allen's)  .   8*40 1 
German,  cultivated  7'6o| 
German,  wild  ,  6*8o| 
In  Table  No.  II  we  have  these  results  substituted  for  the  corre- 
sponding ones  of  Table  No.  I.  A  comparison  of  these  two  tables 
shows  a  most  notable  increase  in  the  assay  of  the  leaves  by  the 
finally  adopted  method  which  removes  the  discrepancy  shown  in  (7) 
and  (8)  of  Table  No.  I. 
In  the  assay  of  the  extracts  the  final  method  shows  slightly  higher 
results,  averaging  about  o-i  per  cent,  alkaloid  ;  this  makes  the  calcu- 
lated percentage  of  alkaloids  in  the  plaster  a  little  higher  than  that 
found,  a  result  naturally  to  be  expected. 
The  yield  of  extract  obtained  from  the  leaves,  26  5  to  32-2  per 
cent.,  is  much  higher  than  the  yield  usually  published,  20  to  24  per 
cent.;  this  is  no  doubt  due  to  the  use  of  more  menstruum,  about  6 
volumes  having  been  used  for  1  part  by  weight  of  the  drug ;  in  those 
cases  in  which  the  extract  obtained  in  the  assay  of  leaves  was  weighed, 
there  was  used  about  15  volumes  menstruum  for  1  part  by  weight 
of  the  drug,  and  it  will  be  noted  that  the  percentage  of  extract  was  in- 
creased (see  top  of  page  ).  By  comparing  the  percentage  of  alkaloid 
calculated  for  the  extract  from  the  assay  ot  the  leaves  and  that  found 
in  the  extract  the  possibility  of  incomplete  extraction  of  the  alkaloid 
is  indicated  in  the  cases  of  the  English  cultivated  and  the  German 
wild  leaves. 
A  study  of  the  results  of  Table  I  indicates  that  it  is  possible,  in 
assaying  leaves  by  a  process  giving  low  results  and  assaying  an  ex- 
tract by  a  process  which  very  closely  indicates  the  true  alkaloidal 
percentage  of  the  same,  to  obtain  figures  which  apparently  confirm 
total  extraction  of  the  leaves  with  a  yield  of  say  about  20  per  cent, 
extract. 
An  investigation  is  now  wanted  having  for  its  object  the  determi- 
nation of  the  quantity  of  menstruum  needed  for  the  extraction  of 
belladonna  leaves  with  assays  of  the  preparations,  so  that  the  rela- 
tion between  yield  of  extract  and  alkaloidal  percentage  can  be 
ascertained. 
Extract. 
Alkaloid. 
Alkaloid 
Per  Cent. 
Per  Cent. 
Per  Cent, 
a. 
33*55 
a. 
o-5996 
a. 
1-8510 
b. 
32-55 
b. 
0.6054 
b. 
1-8280 
a. 
36-55 
a. 
o-5i55 
a. 
1-5980 
b. 
36-30 
b. 
0-5050 
b. 
1  "5850 
a. 
27*00 
a. 
0-4997 
a. 
1*6998 
b. 
2y45 
b. 
0-4997 
b. 
1 7 133 
