22  Assay  of  Belladonna  Root,         {A  January St1^ 
THE  ASSAY  OF  BELLADONNA  ROOT  AND  ITS  SOLID 
EXTRACT. 
By  Arthur  Wayne  Clark,  B.S. 
Having  occasion  constantly  to  handle  samples  of  large  quantities 
of  the  root  of  Atropa  Belladonna  used  in  preparing  solid  extract  for 
use  in  belladonna  plasters,  the  writer  has  had  some  experience  with 
about  all  the  standard  methods  of  assay,  and  while  little  that  is  new 
is  herein  described,  yet  the  method  of  procedure  is  given  in  detail, 
believing  this  attention  to  minutia  to  be  a  necessity  to  success  and 
lack  of  such  information  the  chief  difficulty  in  working  out  a 
rational  method  for  one's  own  constant  use. 
In  favor  of  the  method  here  described,  it  can  be  said  that  it  is 
quite  accurate,  and  yet  can  be  carried  out  with  a  relatively  short 
amount  of  time  actually  given  to  the  work. 
The  method  of  extraction  used  is  hot  extraction  with  a  reflux 
condenser,  and  while  this  and  the  other  parts  of  the  process  require 
about  twelve  consecutive  hours  for  the  completion  of  one  assay,  still 
the  total  time  given  to  the  work  need  not  exceed  three  or  four  hours, 
and  during  the  shaking-out  process  the  work  can  be  left  for  any 
length  of  time  necessary;  in  fact  the  longer  the  better.  Besides 
this,  duplicate  assays  can  readily  be  managed  at  the  same  time, 
thus  effecting  a  considerable  saving  of  labor. 
The  objection  is  sometimes  made  to  hot  extraction  of  belladonna 
root,  that  there  is  a  possibility  of  loss  of  alkaloid  from  the  heat 
applied,  but  the  writer  could  never  see  the  force  of  this  argument, 
for  practically  all  the  methods  ever  proposed  finish  by  evaporating 
down  the  alkaloidal  solution  in  chloroform  or  ether,  thus  applying 
the  very  heating  process  objected  to  above. 
The  fact  that  the  mixed  menstruum  boils  at  65 0  C.  would  seem 
also  to  make  it  impossible  that  there  should  be  any  loss  from  this 
source. 
The  advantages  of  hot  reflux  extraction  are  that  it  can  be  carried 
out  much  more  quickly  than  a  cold  percolation,  is  more  economical 
of  menstruum,  an  important  factor  where  a  large  number  of  assays 
is  constantly  being  performed  for  commercial  purposes,  and  it  re- 
quires no  attention  whatever  after  the  heat  is  once  regulated,  pro- 
vided, of  course,  there  is  sufficient  water-bath  capacity  to  run  for 
the  required  time. 
