222  Pharmacopceial  Assays  of  Drugs  and  Ga/e?iicals.{Am-^Ll^-^vm- 
yet  in  view  of  the  nearness  of  the  pharmacopoeial  revision  should 
be  thoroughly  examined  and  carefully  weighed. 
The  unbiassed  observer  must  acknowledge  that  the  pharmacists, 
as  a  class,  have  honestly  endeavored  in  the  past  to  perfect  the  pro- 
cesses of  the  Pharmacopoeia,  and  to  render  the  galenical  prepara- 
tions as  uniform  in  composition  and  as  permanent  as  possible ;  the 
revisions  of  the  National  Pharmacopoeia  during  the  past  fifty  years 
bear  ample  testimony  to  this  fact.  Even  processes  of  assay  were 
introduced  at  the  request  of  pharmacists.  They  made  their  appear- 
ance for  the  first  time  in  a  modest  way  in  the  Pharmacopoeia  of 
i860,  which  required  that  "  Opium  (crude)  should  yield  at  least  seven 
per  cent,  of  morphia  by  the  officinal  (Staples')  process  ;"  and  the 
quality  of  scammony  was  defined  by  requiring  that  "  Ether  dissolves 
at  least  75  per  cent,  of  it ;  and  when  the  ether  has  been  evaporated, 
the  residue,  dissolved  in  a  hot  solution  of  caustic  potassa,  is  not 
precipitated  by  dilute  sulphuric  acid." 
Both  these  processes  are  in  consonance  with  the  character  of  the 
Pharmacopoeia  as  a  law  book ;  and  in  following  them,  the  product 
obtained  by  the  one  could  only  consist  of  morphine  contaminated 
with  some  narcotine ;  and  the  results  of  the  other  could  only  be 
due  to  scammony  resin — provided  that  well-characterized  opium 
and  scammony  had  been  subjected  to  the  assays.  In  other  words, 
the  processes  were  in  the  main  correct,  but  the  Pharmacopoeia  had 
omitted  to  describe  the  material  which  should  be  subjected  to  these 
tests. 
The  Pharmacopoeia  of  1880  supplied  this  deficiency,  and  it  has 
also  improved  the  morphiometric  test  for  opium.  According  to  our 
present  knowledge,  opium  as  described  by  the  Pharmacopoeia,  when 
examined  by  the  process  laid  down  by  the  same  authority,  yields  as 
a  final  product  the  alkaloid  morphine  in  a  reasonable  state  of  purity ; 
no  other  alkaloid — at  least  none  of  those,  ordinarily  occurring  in 
drugs — can  be  present ;  the  process  is  adapted  for  morphine,  but 
for  no  other  alkaloid. 
The  old  process  for  the  assay  of  scammony  has  been  retained, 
and  coupled  with  the  pharmacopceial  description  of  the  drug, 
excludes  other  ether-soluble  convolvulaceous  resins,  even  orizabin 
(jalapin  of  authors)  which  has  been  shown  to  be  chemically  identical 
with  scammonin.  For  the  resin  of  the  orizaba  root  cannot  be 
manipulated  so  as  to  have  the  physical  characteristics  of  the  scam- 
