24 
Assay  of  Belladonna  Root. 
/  Am.  Jour.  Pharm. 
\    January,  1901. 
Now  set  up  the  reflux  condenser,  add  the  rest  of  the  60  c.c.  or  70 
c.c.  alcohol-chloroform  and  heat  on  a  water- bath,  extracting  for  seven 
hours.  Presuming  the  rate  of  percolation  to  be  60  or  70  drops  per 
minute,  there  will  pass  through  the  20  grammes  root  about  1,500  c.c. 
of  the  hot  menstruum  or  about  seventy-five  times  its  weight,  a  much 
larger  proportion  than  is  ever  used  in  a  slow  cold  extraction. 
The  above-described  method  of  moistening  and  packing  (the  granu- 
lated root)  is  sufficiently  accurate  if  reasonable  care  is  exercised  in 
carrying  it  out. 
The  percolate  containing  the  alkaloid  is  now  transferred  to  a  sep- 
aratory  funnel  and  the  alkaloid  dissolved  out  by  shaking  with  20  c.c. 
dilute  H2S04  (j£  per  cent.). 
Sometimes  the  fluids  seem  to  mix  and  there  is  no  separation  or 
line  of  demarcation.  If  this  is  the  case,  add  10  c.c.  or  15  c.c.  water, 
shake  again  and  the  chloroform  layer  will  be  precipitated  on  stand- 
ing about  a  minute,  leaving  eventually  a  clean-cut  line  between  the 
liquids. 
Since  the  chloroform  solution  separates  as  a  bottom  stratum,  it 
must  be  drawn  off  first  into  a  clean  beaker,  after  which  the  acid  solu- 
tion is  run  out,  well  drained  and  put  aside  and  the  chloroform  solu- 
tion returned  to  the  separator. 
The  chloroform  solution  is  then  shaken  again  with  15  c.c.  dilute 
acid,  separated  in  the  same  way  and  shaken  again  with  10  c.c.  of  the 
dilute  acid.  Quite  frequently  it  will  be  found  that  the  third  shaking 
out  will  cause  emulsification  of  the  two  liquids.  If  this  happens  it 
can  be  instantly  remedied  by  adding  10  c.c.  or  15  c.c.  more  of  the 
original  mixture  of  alcohol  and  chloroform  in  equal  volumes  and 
shaking  up  again  after  adding  it. 
There  is  no  use  in  carefully  washing  out  the  stem  of  the  funnel, 
etc.,  between  each  of  these  operations,  as  the  minute  quantity  of 
solution  adhering  to  it  is  simply  carried  over  and  is  again  separated 
in  a  much  diluted  condition  next  time. 
There  is  usually  a  small  quantity  of  flocculent  precipitate  and  dirt 
collected  at  the  line  of  separation  in  these  acid  extractions,  and 
wherever  such  occurs  to  any  appreciable  extent,  the  dirt  should  be 
run  out  with  the  chloroform  stratum,  bringing  the  clean  edge  of  the 
acid  layer  down  to  the  bottom  of  the  opening  in  the  stop-cock. 
Sometimes  a  minute  amount  of  the  acid  solution  has  to  be  allowed 
to  go  through  with  the  dirt,  but  this  again  will  be  diluted  and 
