Am.  Jour.  Pharm. 
November,  1911. 
I     Assay  Processes  of  the  U.  S.  P.  521 
off  by  treating-  the  residue  twice  or  three  times  with  ether.  In  our 
laboratory,  we  invariably  control  the  gravimetric  results  by  titration, 
because  the  alkaloidal  residue  very  frequently  includes  waxy  and 
other  substances,  which  naturally  increase  the  weight.  The  titration 
when  carried  out  strictly  according  to  Panchaud's  direction,  is  not 
at  all  difficult. 
Coca. — Here  also  the  percolation  process  should  be  abandoned 
in  the  assay  method.  Keller's  method,  using  plain  ether,  gives  very 
satisfactory  results.  In  case  emulsions  occur,  which  frequently 
takes  place  on  account  of  the  large  amount  of  mucilaginous  matter 
in  the  drug,  tragacanth  should  be  used  for  breaking  up  the  emulsions. 
Cochineal. — It  is  advisable  to  include  in  the  U.S. P.  a  deter- 
mination of  the  color  strength  of  the  drug,  also  an  estimation  of 
the  moisture. 
Colchicmn  Seed  and  Conn. — We  have  pointed  out  on  various 
occasions  that  the  results  obtained  by  the  present  assay  methods 
are  absolutely  wrong,  that  the  residue  calculated  as  colchicine  con- 
tains only  about  50  per  cent,  of  the  alkaloid.  The  assay  processes 
should  be  thoroug-hly  revised.  Dr.  A.  B.  Lyons  has  given  valuable 
information  in  what  way  these  processes  could  be  improved.  For 
the  estimation  of  pure  colchicine  in  the  alkaloidal  residue,  several 
methods  are  available  also.  We  do  not  care  to  go  into  details  about 
these  improvements,  since  we  have  given  a  compilation  of  them 
some  time  ago. 
Conium  Seed. — The  assay  method  for  this  drug"  also  should  be 
revised.  It  is  very  cumbersome  and  could  easily  be  replaced  by  a 
more  expeditious  process. 
Conium  Leaves. — This  drug,  although  not  official,  should  never 
be  used.  All  the  samples  submitted  to  this  laboratory  for  examina- 
tion were  almost  void  of  coniine. 
Cuhehs. — An  estimation  of  and  requirements  for  the  percentage 
of  oleoresin  should  be  given.  Cubebs  vary  considerably  in  the 
amount  of  oleoresin. 
Emplastrnni  Belladonncc. — A  few  slight  modifications  of  this 
assay  process  have  recently  been  recommended.  The  process,  how- 
ever, we  find  works  very  well. 
Ergot, — On  various  occasions  we  have  mentioned  a  simple 
process  to  estimate  the  approximate  amount  of  cornutine  present  in 
the  drug.  If  it  can  be  proven  beyond  doubt  that  the  percentage  of 
cornutine  is  in  proportion  to  the  physiological  activity,  this  test 
should  be  adopted  for  the  U.S. P. 
