l62 
The  Opium  Assay  Question. 
J  Am.  Jour.  Pharm. 
X      April,  1891. 
other  methods,  this  is  due  most  probably  to  the  fact  that  in  this 
particular  method  the  sources  of  -error  are  more  nearly  counter- 
balanced than  in  the  others.  It  was,  hence,  from  a  purely  impartial 
and  critical  standpoint  that  I  undertook  to  compare  several  of  the 
most  prominent  methods  for  assaying  opium. 
Those  decided  upon  were  the  methods  of  Fliickiger,  Squibb  and 
of  the  U.  S.  Pharmacopoeia — being  virtually  the  ammonia  versus 
the  lime  method.  The  drugs  examined  were  Smyrna  opiums  from 
the  houses  of  Merck  and  of  Gehe  &  Co.,  the  former  having  been 
ordered  and  received  by  myself  while  still  at  the  laboratory  of  Geh. 
Rath  Fresenius  at  Wiesbaden  during  the  past  summer,  and  the 
latter  kindly  given  me  by  my  instructor,  Professor  Fliickiger,  here 
at  the  laboratory.  Both  samples  were  finely  powdered  and  dried 
at  8o°  C.  for  five  hours.  All  three  methods  were  begun  at  the 
same  time  and  the  directions  for  each  closely  followed  throughout. 
In  both  cases  the  determination  by  the  U.  S.  P.  method  was  com- 
pleted long  ere  the  others  were,  while  Squibb's  method,  due  to  its 
more  frequent  washing  and  slower  filtering,  took  up  the  most  time. 
Just  at  this  point  I  should  like  to  protest  against  the  impracticabil- 
ity and  uselessness  of  weighing  liquids,  which  so  often  is  found  in 
methods  of  plant  analysis  and  nowhere  else.  As  I  see  the  matter 
there  is  not  one  point  in  its  favor,  unless  perhaps,  that  it  is  an 
inherited  custom,  while  there  are  certainly  many  points  against  it. 
Firstly — it  occupies  more  time ;  secondly — accurate  balances  are 
not  arranged  for  weighing  liquids,  and  inaccurate  balances  (or 
moderately  accurate  balances,  as  their  owners  would  probably  pre- 
fer to  term  them)  certainly  make  the  weighing  less  accurate  than 
measuring ;  and  thirdly— weighing,  even  on  accurate  balances,  is 
seldom,  if  ever,  more  accurate  than  measuring  with  graduated 
glassware  which  every  druggist  does,  or  at  any  rate,  should  possess. 
The  U.  S.  P.  method,  besides  being  the  shorter,  required  less 
attention  and  care  than  the  other  methods  and,  as  the  figures  will 
show,  gave  the  most  satisfactory  results.  As  this  is  all  that  is 
required  of  a  method  of  analysis  I  can  see  no  reason  why  the  present 
officinal  process  should  be  altered,  for  no  other  now  in  use  is  more 
exact  and  at  the  same  time  as  practical.  The  morphine  obtained  in 
every  experiment  with  the  U.  S.  P.  method  was  undoubtedly  the 
whitest  and  purest  of  all  the  crystals  obtained  by  any  method. 
There  was  less  washing  necessary  than   in  either  Squibb's  or 
