26  Assay  of  Belladonna  Root.  {A™klll^ml™ 
blowing  air  into  the  flask  to  remove  all  chloroform  and  to  carry  out 
any  free  ammonia  which  may  be  present.  Now  add  about  io  c.c. 
chloroform,  shake  up  and  evaporate  down  again  as  before,  to  assist 
in  driving  off  any  ammonia.  This  residue  is  then  titrated  as  directed 
later  on.  Ether  should  not  be  substituted  here  for  chloroform,  as 
the  writer  has  found  ether  to  be  almost  invariably  acid,  which  being 
the  case,  it  will  ruin  the  result. 
The  water-bath  should  be  heated  by  steam,  as  any  open  flame 
nearby  will  decompose  the  chloroform  vapors  to  hydrochloric  acid, 
filling  the  room  with  its  fumes  and  possibly  neutralizing  some  of 
the  alkaloid  in  the  flask.  The  operation  can,  however,  be  carried 
out  over  a  bath  heated  by  a  flame,  if  there  is  a  good  ventilation  to 
remove  the  vapors,  and  the  contents  of  the  flask  are  kept  boiling 
hard. 
In  the  shaking-out  process  the  writer  experienced  considerable 
trouble  with  the  spitting  of  the  solutions  from  the  mouth  of  the 
separator  when  the  stopper  was  removed  after  shaking.  The  U.S.P. 
advises  that  the  best  way  to  control  this  in  these  separators  is  to 
shake  the  contents  slightly  before  putting  in  the  stopper,  but  this 
scheme  was  not  at  all  successful  in  preventing  the  trouble,  due 
probably  to  the  warmth  of  the  hand  in  shaking  the  very  volatile 
contents  of  the  separator.  An  easy  solution  of  the  difficulty,  how- 
ever, was  found  in  putting  the  stopper  in  tightly,  shaking  up  as 
usual  and  allowing  to  separate  without  relieving  the  pressure,  and 
then,  when  ready  to  draw  off,  opening  the  outlet  cock  slightly  and 
allowing  the  pressure  to  exert  itself  in  gently  blowing  out  the  lower 
stratum  through  its  natural  outlet.  After  a  few  cubic  centimetres 
have  been  expelled  the  pressure  will  have  expended  itself,  the  cock 
can  be  closed  and  the  stopper  removed  without  harm,  after  which 
the  solution  can  be  run  off  as  usual. 
As  to  the  method  of  titrating  the  alkaloidal  residue  from  the 
three  mixed  chloroform  solutions,  the  writer  finds  that  the  best  way 
is  to  dissolve  the  brown  residue  in  about  5  c.c.  neutral  alcohol  in 
the  cold,  then  add  about  100  c.c.  distilled  water  and  three  drops  of 
1  per  cent,  alcoholic  haematoxylin  solution.    This  is  then  titrated 
at  once  with  twentieth  normal  hydrochloric  acid         HQ  J  to  a 
pure  yellow  color,  the  neutral  point  being  indicated  by  the  absence 
of  any  trace  of  red. 
