652  United  States  Pharmacopoeial  Revision.  { ^Spt?mb2r!'Y92o; 
usually  needed  to  extract  all  of  the  alkaloid.  A  faint  cloudiness 
may  be  obtained  after  each  of  a  number  of  extractions,  due  probably 
to  the  difficult  solubility  of  the  alkaloid.  In  the  aggregate,  the 
alkaloid  extracted  by  each  of  these  shake-outs  represents  a  sub- 
stantial quantity,  particularly  if  the  lot  being  assayed  is  a  large 
one.  In  view  of  these  facts,  we  recommend  that  the  words,  "not 
more  than  a  very  faint,"  as  found  on  lines  twenty-six  and  thirty- 
nine  (page  594)  be  omitted  and  the  word  "no"  substituted  so  that 
the  phrase  shall  read:    "Shows  no  cloudiness  on  the  addition  of." 
Determination  of  Alcohol-Soluble  Constituents. — standard  method 
for  the  determination  of  the  alcohol-soluble  constituents  of  asa- 
foetida,  benzoin,  gambir,  gamboge,  kino,  and  myrrh  is  needed. 
A  continuous  extraction  method  is  recommended  because  of  its 
ease  of  operation  and  the  saving  of  time  and  solvent.  As  some  of  the 
constituents  dissolve  rather  slowly  a  test  should  be  included  to 
determine  if  the  extraction  is  complete. 
Menstrum  for  Assay  of  Crude  Drugs  and  Extracts. — Considerable 
trouble  has  been  experienced  with  the  menstrum  composed  of  ether, 
two  parts,  and  chloroform,  one  part,  which  is  directed  to  be  used  as 
the  macerating  medium,  in  various  assay  processes,  as  given  under 
belladonna  root.  An  ether  chloroform  mixture  in  these  proportions 
is  not  satisfactory  on  account  of  a  strong  tendency  to  form  emulsions. 
Complete  contact  of  all  portions  of  the  two  layers  of  liquid  is  quite 
difficult  and  much  more  time  is  required  on  account  of  the  necessity 
of  using  much  care  during  the  agitation.  The  disintegration  of 
emulsions  is  also  time  consuming,  so  that  this  factor,  together  with 
the  other  factors,  previously  stated,  renders  it  necessary  to  change 
the  proportions  of  ether  and  chloroform  used  as  menstrum  or  solvent. 
The  menstrum  of  three  parts  of  ether  and  one  of  chloroform,  as 
used  in  the  U.  S.  P.  VIII,  is  much  more  satisfactory  as  it  permits  a 
more  vigorous  agitation  and  a  complete  contact  of  the  two  layers. 
A  menstrum  composed  of  these  proportions  of  ether  and  chloro- 
form is  much  less  likely  to  form  emulsions  and  gives  a  cleaner  sep- 
aration of  the  two  layers.  We  therefore  earnestly  recommend  the 
re-adoption  of  the  menstrum  of  ether,  three  parts,  and  chloroform, 
one  part,  as  formerly  used  in  the  U.  S.  P.  VIII. 
Assay  of  Fluid  and  Solid  Extracts  and  Tinctures. — The  assay  of 
solid  extracts  of  belladonna,  hyoscyamus,  and  stramonium  could  be 
simplified  and  shortened  if  a  maceration  method,  such  as  that  used 
for  powdered  extracts  were  adopted.    The  present  method  of  dis- 
