Am.  Jonr.  Pharm. ) 
March,  1899.  J 
Assay  of  Belladonna  Leaves. 
1 1 1 
tions  made  I  c.c.  sulphuric  acid,  U.S.P.,is  a  little  more  than  needed 
to  decompose  10  grammes  of  the  official  plaster. 
Ten  grammes  of  the  belladonna  plaster  were  weighed  into  a 
beaker  and  covered  with  a  mixture  of  I  c.c.  sulphuric  acid  and  15 
c.c.  of  water  ;  the  plaster  is  disintegrated  by  stirring  and  pressing 
against  the  side  of  the  beaker,  but  is  slow,  as  no  heating  is  allowable 
saving  the  heat  of  the  hand  ;  if  heating  over  a  burner  is  resorted  to 
the  lead  sulphate  and  fat  acids  separate  in  pulverulent  form,  and  are 
then  more  difficult  to  manipulate.  The  end  of  the  operation  is  as- 
sured when  the  stirring  rod  np  longer  discloses  any  hard  lumps  in 
the  putty-like  mass  produced,  if  manipulated  as  described.  The 
acid  solution  is  filtered  through  a  small  filter  into  a  separatory  fun- 
nel and  the  mass  worked  with  the  glass  rod  so  that  as  much  of  the 
solution  as  possible  is  separated  and  removed  to  the  filter.  The 
mass  in  the  beaker  is  then  thoroughly  mixed  up  with  two  portions 
of  10  c.c.  each  of  the  acidulated  water  (2  c.c.  H2S04  to  make  500 
c.c),  followed  afterwards  by  three  portions  of  5  c.c.  each,  allowing 
to  settle  and  working  up  the  mass  so  as  to  get  as  much  as  possible 
of  each  portion  upon  the  filter  before  adding  the  next  portion. 
After  all  these  portions  have  run  through  the  filter,  wash  the  latter 
with  a  few  c.c.  of  the  acidulated  water,  then  add  to  the  contents  of 
the  separatory  funnel  25  c.c.  of  the  ether-chloroform  mixture,  10  c.c. 
of  ammonia  water  (10  percent.)  and  proceed  as  under  the  assay  of 
the  leaves, 
EMULSIFICATION  IN  ALKALOIDAL  EXTRACTIONS. 
While  emulsification  in  assays  of  belladonna  leaves  and  extracts 
by  the  described  processes  were  occasionally  met  with,  the  assay  of 
belladonna  plaster  as  just  described  was  effectually  blocked  by  the 
formation  of  a  persistent  emulsion.  In  the  case  of  the  leaves  and 
extracts  the  relatively  large  proportion  of  the  clear  mixed-solvent 
with  the  smaller  emulsified  portion  was  run  into  the  smaller  sepa- 
rator and  then  generally  separated  on  standing  a  short  time;  the 
aqueous  solution  thus  transferred  to  the  smaller  separator  was  freed 
from  alkaloid  by  agitation  with  the  portions  of  solvent  used  to  rinse 
the  separator;  in  the  subsequent  filtration  care  was  taken  to  pre- 
vent the  aqueous  solution  passing  on  to  the  filter.  This  manipu- 
lation did  not  avail  in  the  assay  of  the  plaster,  and  it  therefore 
became  necessary  to  find  some  expedient  which  would  bring  about 
the  separation  of  the  solvent. 
