Am.  Jour.  Pharm.  ) 
January,  1910.  j 
Standards  and  Changes. 
21 
SOME  SUGGESTED  STANDARDS  AND  CHANGES  FOR 
THE  U.S.P. 
By  Charles  H.  LaWall. 
The  following  notes  have  been  collected  during  a  period  of 
several  years  and  embody  observations  made  from  a  practical  appli- 
cation of  the  various  tests  and  requirements  of  the  U.  S.  Pharmaco- 
poeia in  examining  a  large  number  of  substances.  Some  of  them 
are  not  entirely  new,  but  a  number  of  the  suggestions  have  not 
appeared  in  pharmaceutical  literature,  to  the  author's  knowledge. 
They  are  submitted  as  being  along  the  lines  of  constructive  criticism. 
Acidum  Sulphur o sum. — As  this  preparation  is  very  prone  to 
deteriorate  rapidly,  there  should  be  a  statement  to  the  effect  that 
the  concentrated  product  should  be  assayed  and  diluted  at  the  time 
of  dispensing.  This  is  preferable  to  the  present  official  method  of 
assay  and  immediate  dilution  and  would  eliminate  the  necessity 
of  advising  its  frequent  assay  as  given  in  the  text. 
Alcohol. — The  present  official  method  of  testing  for  wood  alcohol 
has  been  alleged  to  be  unreliable.  It  would  be  advantageous,  there- 
fore, to  substitute  some  authoritative  method  like  the  Riche-Bardy 
process  of  the  A.A.O.A.C.,  as  given  in  U.  S.  Department  of  Agri- 
culture Bulletin  No.  107. 
Alumen  Exsiccatum.—As  recently  stated  by  other  investigators 
the  rubric  should  be  brought  into  complete  accordance  with  practical 
requirements.  If  strictly  interpreted  it  does  not  allow  even  a  trace 
of  moisture.  This  is  impracticable.  A  limit  of  moisture  should  be 
given  (not  more  than  2  or  3  per  cent.)  and  a  method  for  its  esti- 
mation should  be  included. 
Amylum. — Some  commercial  varieties  of  corn-starch  contain 
appreciable  amounts  of  nitrous  acid  or  nitrites,  which  mi°-ht  occasion 
difficulty  in  its  use  as  an  indicator.  A  test  for  the  presence  of 
nitrous  acid  or  nitrites  by  the  Griess-Ilosvay  method  should  be 
given. 
A  method  for  the  estimation  of  the  95  per  cent,  of  hydroliz^ble 
carbohydrates  should  also  be  included  if  this  requirement  is  retained. 
Aqua  Hamamelidis. — A  test  for  the  presence  of  methyl  alcohol 
should  be  given  among  the  requirements  for  this  article,  as  it  is 
frequently  reported  as  containing  this  substance  instead  of  ethyl 
alcohol. 
