Am.  Jour.  Pharm.  \ 
March,  1899.  / 
Assay  of  Belladonna  Leaves. 
115 
diluted  alcohol  was  percolated  with  100  c.c.  distilled  water  and 
treated  as  above.    The  results  were  as  follows  : 
95  p.c.  Alcohol.     Dil.  Alcohol.         Water.  Total. 
Extract  13-40  p.c.       14-45  p.c.       8*95  p.c.       36-80  p.c. 
Alkaloid  0-391  "  0-064  "        none  0-455  " 
The  total  yield  of  alkaloid  obtained  in  this  experiment  was  ex- 
ceeded only  by  {B)  of  the  preceding  series ;  this  experiment  also 
gives  an  idea  of  the  difficulty  of  extracting  belladonna  leaves  with 
95  per  cent,  alcohol. 
To  determine  to  what  extent  the  20  c.c.  of  diluted  ammonia  used 
in  the  assay  of  the  extract  retained  alkaloid,  two  portions  of  20 
grammes  each  were  percolated,  as  described  on  page  116,  with  300 
c.c.  of  a  menstruum,  consisting  of  2  volumes  alcohol  and  1  volume 
water  and  the  entire  quantity  of  extract  taken  for  the  assay  (method 
page  116). 
Extract.  Alkaloid. 
A  26-3  per  cent.  0-4839  per  cent. 
B.  27.7  "     "  0-4891  "  " 
The  results  indicate  that  the  assays  of  the  extracts  as  previously 
made  are  a  little  low,  and  corroborate  the  statements  made  as  to 
the  results  attending  the  taking  of  an  aliquot  portion. 
Another  possible  source  of  error,  due  to  the  solubility  of  the 
ether-chloroform  in  the  aqueous  solution  and  of  water  in  the  ether- 
chloroform,  causing  alteration  in  weight  and  volume  of  the  alkaloidal 
solution,  has  not  been  separately  considered.  It  therefore  became 
necessary  to  again  assay  the  three  varieties  of  leaves  and  also  the 
extracts  prepared  from  them  ;  moisture  determinations  were  also 
made  in  the  leaves,  but  not  in  the  case  of  the  extracts,  as  these  had 
been  placed  in  well-closed  containers  as  soon  as  possible  after  their 
manufacture,  and  for  these  assays  portions  were  taken  from  the 
center  of  the  mass. 
ASSAY  PROCESS  FOR  BELLADONNA  LEAVES  AND  EXTRACT. 
Moisture. — Determined  in  about  2  grammes  at  100°  C. 
Assay  proper. — A  small,  slightly  conical  percolator  about  8  inches 
long  and  1^-1^  inches  wide,  such  as  are  used  in  certain  continu- 
ous extraction  apparatus,  is  connected  with  a  piece  of  rubber  tubing 
(about  12  inches  long)  having  a  small  piece  of  glass  tubing  (about  2 
inches  long)  attached,  for  the  purpose  of  regulating  the  dropping  of 
the  percolate  ;  this  can  also  be  regulated  by  use  of  a  brass  spring. 
