524  Assay  Processes  of  the  U.  S.  P.      { ^NovfXr^^mT 
quantity  prescribed  for  the  assay  to  dryness,  take  up  residue  in 
dilute  alcohol,  and  proceed  as  just  given. 
Opium. — In  regard  to  this  drug,  we  wish  to  refer  to  an  article 
submitted  to  the  A. Ph. A.  (Proc.  A. Ph. A.,  1910,  page  829)  a  year 
ago.  There  is  no  doubt  that  by  the  present  official  process  almost 
the  entire  morphine  contained  in  the  drug  is  obtained,  although 
Debourdeaux,  Journ.  dc  Pharm.  ct  Chem.,  vii,  iv,  68,  claims  that  by 
further  exhaustion  with  water,  still  more  morphine  can  be  exhausted. 
He  also  claims  that  if  the  crude  morphine,  as  obtained  by  the  U.S. P. 
process,  is  not  washed  thoroughly,  lime-water  soluble  substances  are 
determined  as  morphine,  rendering  the  percentage  of  the  latter  too 
high.  We  have  obtained  very  good  results  with  the  present  method  ; 
we  think,  however,  that  a  shortening  of  the  process  would  be 
desirable. 
Extract  Opiitm  and  Tincture  Opium. — The  assay  methods  work 
satisfactorily. 
Pancreatin. — For  the  assay  process  the  use  of  potato  starch 
should  be  recommended.  The  milk  test  is  unreliable  and  should  be 
deleted. 
Pepsin. — We  have  at  times  experienced  considerable  trouble 
with  the  assay  process,  which  apparently  was  due  to  the  age  of  the 
eggs.  Recently  we  have  only  used  eggs  from  5  to  10  days  old,  and 
have  obtained  with  such  material  rather  concordant  results.  At  the 
Indianapolis  meeting  of  the  Am.  Chem.  Soc.  a  paper  will  be  read 
dealing  with  the  use  of  dry  egg  albumin  in  the  assay  process  of 
pepsin.  If  the  results  obtained  by  using  dry  albumin  are  encour- 
aging, this  modification  should  certainly  be  tried  by  the  Revision 
Committee.  Dry  albumin  can  more  easily  be  obtained  in  a  uniform 
quality  than  fresh  albumin,  which  contains  a  varying  amount  of 
water,  according  to  the  age  of  the  eggs. 
Physostigma  and  Its  Preparations. — Slight  modifications  as  to 
the  quantities  of  immiscible  solvent  and  acidulated  water  should  be 
made. 
Extr actum  Physostigmatis. — The  use  of  sand  and  evaporation 
to  dryness  are  to  be  avoided.  We  prefer  to  use  powdered  glass  and 
to  evaporate  the  liquid  until  the  alcohol  is  expelled.  Such  a  moist 
mass  can  be  transferred  to  a  bottle  much  easier  than  the  hard  mass 
obtained  by  the  official  process.  Results  just  as  accurate  can  be 
obtained  by  converting  the  solid  extract  into  a  fluidextract  by  dis- 
