Am.  Jour.  Pharm.  j 
March,  19 19.  J 
Correspondence. 
187 
I  note  that  you  refer  to  the  10  per  cent,  foreign  material  as 
"  inert."  It  occurs  to  me,  therefore,  that  possibly  primary  stems 
instead  of  secondary  stems  as  stated  was  the  material  used,  as  this 
is  relatively  inert,  while  the  secondary  stems,  as  you  have  shown, 
could  not  be  considered  "  inert "  in  comparison  with  the  leaves. 
It  is  possible  that  other  readers  may  have  found  the  same  diffi- 
culty that  I  have  found  and  possibly  publication  of  the  explanation 
would  be  found  useful  by  others  as  well  as  myself. 
Respectfully, 
A.  G.  Murray, 
Assistant  Chemist. 
February  24,  191 9. 
Dr.  A.  G.  Murray, 
Room  1034,  U.  S.  Appraiser's  Stores, 
Christopher  and  Washington  Sts., 
New  York  City,  N.  Y. 
Dear  Sir:  I  have  your  letter  of  the  18th  instant,  relative  to  my 
paper  on  stramonium,  which  appeared  in  the  January  issue  of  the 
American  Journal  of  Pharmacy. 
Samples  were  made  by  adding  to  the  dry  unground  secondary 
stems,  nos.  214,  215  and  216  to  samples  of  dry  leaves,  nos.  211,  212 
and  213,  respectively,  so  that  the  former  furnished  10  per  cent,  and 
the  latter,  9c  per  cent,  of  the  whole.  These  samples  were  made 
when  the  materials  were  in  the  whole  condition,  that  is,  before  being 
ground  for  analysis.  It  is  true,  if  10  per  cent,  of  the  ground 
samples  of  nos.  214,  215  and  216  was  added  to  nos.  211,  212  and 
213,  respectively,  the  resulting  mixtures  should  certainly  have 
assayed  approximately,  0.55,  0.56  and  0.40  per  cent.,  respectively, 
as  you  suggest.  However,  in  making  samples  using  the  pieces  of 
stems  in  the  unground  condition  as  before  mentioned,  due  to  the 
natural  variation  of  the  individual  parts  of  the  plants,  it  would  be 
quite  impossible  to  expect  the  analytical  results  to  be  as  mathe- 
matically calculated.  I  must  attribute  the  variation  of  these  results 
to  this  fact  of  the  variation  of  the  individual  parts  of  the  plants, 
since  the  whole  (unground  parts)  of  these  samples  were  mixed,  then 
ground  and  mixed  well  for  analysis. 
In  carrying  out  this  experiment,  it  was  not  my  intention  to  test 
the  analytical  method,  but  make  mixtures  of  unground  parts  of  the 
plants  as  nearly  as  possible  as  they  would  occur  under  practical 
