370 
Assay  of  Belladonna  Root. 
{ 
A.m.  Jour.  Pharcu. 
August,  1908. 
hydrochloric  acid  used  by  0  0287,  and  this  by  10,  and  the  result  will 
be  the  per  cent,  of  total  mydriatic  alkaloids." 
For  accurate  measuring  of  the  tenth  normal  acid,  an  apparatus 
shown  in  Fig.  1  was  devised.  A  is  a  small  reservoir  for  water  which 
is  connected  with  a  three-way  stop-cock  of  a  burette  B,  which  is  in 
turn  connected  at  the  top  by  means  of  a  curved  glass  tube  with  a 
5  c.c.  pipette  C.  By  turning  the  stop-cock  in  the  burette,  the 
pipette  may  be  filled  with  tenth  normal  acid  and  accurately  added 
to  the  flask  containing  the  alkaloids  in  small  drops.  To  facilitate 
accurate  reading,  a  clothes-pin,  D,  carrying  a  strip  of  white  paper, 
and  on  this  half  of  a  small  round  red  label,  is  clamped  at  any  de- 
sired point  on  the  pipette  and  the  readings  very  accurately  made. 
The  idea  of  this  device  was  obtained  from  Dr.  John  Anderson,  of 
the  Marine  Hospital  Service.  If  properly  made,  the  semi-circular 
red  label  will  show  a  straight  red  line  through  the  pipette  or  burette 
with  which  the  lowest  point  of  the  meniscus  can  be  made  to 
coincide. 
For  our  regular  work  we  use  the  U.S.P.  method  with  slight  modi- 
fications, which  simplifies  the  operation  and  increases  the  accuracy. 
The  first  deviation  from  the  U.S.P.  process  is  in  the  use  of  a  Gordin 
combination  maceration  flask  and  percolator,  which  is  shown  in 
Fig.  2,  A.    Instead  of  macerating  the  belladonna  root  in  an  Erlen- 
Figs.  1  and  2. — Alkaloidal  Assay  of  Belladonna  Root. 
