THE  AMERICAN 
JOURNAL  OF  PHARMACY. 
APRIL,  i8gi. 
THE  OPIUM  ASSAY  QUESTION. 
By  Alfred  Dohme,  Ph.D. 
Perhaps  no  chapter  of  Pharmaceutical  Chemistry  has  received 
more  attention  and  been  more  discussed  than  that  of  opium  and  its 
analysis.  Scarcely  a  journal  appears  nowadays  that  does  not  con- 
tain an  article  or  two  upon  how  opium  can  "  best  "  be  assayed  and 
just  how  the  method  of  Prof.  X —  or  Mr.  Y —  is  inaccurate  and 
unreliable.  There  is  a  certain  sameness  about  articles  written  about 
opium  assaying — a  sameness  that  becomes  monotonous  in  course  of 
time  and  causes  the  reader  to  become  perplexed,  if  not  disgusted, 
as  the  result  of  a  perusal  of  them.  Invariably  the  author  picks  all 
other  methods  to  pieces  and  then  proposes  an  "  original  new  " 
method  which  gives  better  agreeing  results  and  is  much  more 
easily  manipulated  than  any  yet  proposed.  As  a  matter  of  fact,  we 
possess  not  a  single  accurate  and  exact  method  of  analysis  of  any 
plant  or  of  any  of  its  organic  constituents.  Plant  analysis,  as 
Dragendorff  aptly  remarks,  has  not  yet  reached  the  stage  which 
enables  us  to  say,  without  an  interrogation  point  at  the  end  of  our 
sentence,  that  this  plant  contains  just  so  much  of  that  constituent  and 
no  more.  Plant  analysis  is  as  yet  synonymous  with  approximate 
analysis,  and  until  our  knowledge  of  the  chemistry  and  physiology 
of  plant  life  and  growth  has  advanced  considerably  beyond  its 
present  status,  it  is  doomed  to  continue  to  be  approximate  analysis. 
Hence,  no  method  is  accurate  as,  for  instance,  is  the  determination 
of  sulphuric  acid  as  barium  sulphate,  or  of  hydrochloric  acid  as 
chloride  of  silver,  and  if  one  of  them  does  give  better  agreeing 
results  and  such  as  are  nearer  the  mean  of  those  obtained  by  all 
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