AmsSt.?Sarm'}    Dieter  iclis  Morphiometric  Method.  441 
From  these  facts  and  figures,  the  following  conclusions  may  be 
drawn:  That  the  method  of  the  U.  S.  Pharmacopoeia,  1 880,  gives 
results  that  do  at  any  rate  agree  with  one  another,  if  not  with  the 
truth  as  has  been  claimed,  so  that  reliance  can  be  placed  upon  them  ; 
while  Dieterich's  method  gives  results  that  vary  so  greatly  from  one 
another  that  hardly  any  reliance  can  be  put  in  them. 
That  using  the  entire  extracting  fluid  in  Dieterich's  method  instead 
of  an  aliquot  part  does  not  improve  the  yield  of  morphine  (see 
experiments  8,  9  and  10) — but : 
That — a  longer  and  hence  more  intimate  and  complete  contact 
of  the  water  with  the  opium  does  improve  the  yield  of  morphine 
(see  experiments  12,  13  and  14);  and  that  the  results  by  Dieterich's 
method  vary  so  very  greatly  among  one  another  that  it  is  hardly 
justifiable  to  draw  any  conclusions  from  them. 
ON  DIETERICH'S  MORPHIOMETRIC  METHOD. 
By  J.  B.  Nagelvoort. 
The  preface  of  the  "  Helfenberger  Annalen "  for  1890  is  not 
dated,  as  was  the  case  in  the  two  preceding  editions ;  but  since  the 
present  issue  contains  several  papers  which  were  read  in  Berlin,  Ger- 
many, April  2,  1 89 1,  it  is  evident,  that  the  volume  could  not  have 
reached  me  here  in  Detroit,  before  the  publication  of  my  paper  in 
Pharm.  Weekblad  (Holland),  May,  1 89 1.  In  this  paper  the  most 
important  objections  to  the  Helfenberg  method  of  morphine  deter- 
mination have  been  considered.  As  early  as  the  beginning  of 
summer,  1890,  I  communicated,  privately,  to  Prof.  Maisch  the  results 
of  a  number  of  assays  made  by  that  method,  which  had  led  me  to 
the  conclusion  that  the  method  could  not  be  implicitly  relied  upon 
in  all  cases. 
On  p.  76  of  the  "  Helfenberger  Annalen  "  for  1890  is  given  a 
modification  of  the  assay  process,  which  is  translated  as  follows : 
"  Based  upon  later  observations,  we  find  it  necessary  to  add  the 
following  :  Not  every  opium  powder  used  for  assaying  yields  after 
maceration  sufficient  filtrate  for  using,  therefrom,  42  gm.,  and  it 
may  happen  that  only  38  to  39  gm.  are  obtained  by  spontaneous 
dropping.  In  such  a  case,  the  residue  upon  the  filter  is  to  be  mod- 
erately pressed  with  a  thick  glass  rod,  whereby  the  deficient  amount 
of  liquid  will  be  caused  to  drop  off." 
As  the  Helfenberg  method  has  been  adopted  by  the  German 
