454  Alkaloidal  Assays  of  the  U.S.P.  {AnoS^\mT' 
In  some  assay  methods  of  the  U.S.P.  care  has  been  taken  to  avoid 
the  use  of  aliquot  parts  of  the  real  liquids,  while  in  others  no  such 
care  is  taken. 
In  some  assays  solid  substances  are  dissolved  in  ether  or  a  mix- 
ture of  ether  and  chloroform  and  the  solutions  transferred  to  a 
separating  funnel.  Thus  in  the  assay  of  extract  of  nux  vomica  we 
are  told  to  dissolve  the  extract  in  an  open  beaker  by  means  of  a 
mixture  of  ether,  chloroform  and  ammonia  water,  and  when  the 
extract  is  dissolved  to  transfer  the  solution  to  a  separating  funnel. 
As  the  extract  goes  only  very  slowly  in  solution,  requiring  continu- 
ous stirring  with  a  glass  rod,  and  the  liquid  has  a  great  tendency  to 
i(  creep  "  on  the  outside  of  the  beaker  when  poured  into  the  sepa- 
rating funnel,  it  is  easy  to  see  that  much  greater  accuracy  would  be 
obtained  by  weighing  the  extract  directly  into  the  separating  funnel, 
adding  the  solvent  mixture  to  the  powder  and  shaking  the  stoppered 
funnel  till  the  extract  is  dissolved. 
Some  of  the  assay  methods  of  the  pharmacopoeia  are  completely 
unworkable.  Such,  for  example,  are  the  assays  of  aconite  root,  its 
fluid  extract  and  fluid  extract  of  ipecac  root,  in  all  of  which  we  are 
directed  to  filter  the  first  acid  liquids  obtained  in  these  assays,  but 
as  these  liquids  are  very  thick  and  contain  sticky  resinous  sub- 
stances, the  filters  are  very  soon  completely  clogged  and  the 
assays  cannot  be  finished.  This  is  in  accord  with  my  own  experience 
and  the  experience  of  several  teachers  and  students  in  our  school. 
As  hydrastis  and  its  galenical  preparations  are  standardized  in 
the  new  pharmacopoeia  an  assay  method  ought  also  to  be  adopted 
for  the  glycerite  of  hydrastis. 
1  shall  now  take  up  the  individual  assays  in  the  order  they  occur 
in  the  U.S.P. 
Aconitum. — As  said  before,  the  assay  method  is  unworkable. 
Even  if  it  worked  it  is  unnecessarily  complicated.1 
Belladonnae  Folia  et  Radix. — This  assay  method  requires 
only  a  few  modifications  in  order  to  make  it  simple  and  exact. 
(1)  The  percolation  ought  to  be  continued  to  exhaustion,  as  indi- 
cated by  Wagner's  reagent. 
(2)  The  cause  of  error  liable  to  result  from  transferring  of  the 
"  creeping  "  ethereal  mixture  from  one  vessel  to  another  and  the 
1  See  paper  read  by  the  author  at  the  meeting  of  the  A.Ph.A.,  1906,  entitled 
1"  Some  Alkaloidal  Assays."    (This  Journal,  p.  4580 
