12  Tests  for  Gurjun  Balsam  in  Copaiba.  \^JS^mlm' 
the  present  day,  as  the  adulterators  have  rested  secure  in  the 
knowledge  that  the  methods  used  for  the  detection  of  Gurjun  bal- 
sam in  copaiba  have  not  been  satisfactory  and  could  not  be  depended 
upon  to  give  accurate  results.  Attempts  to  solve  the  difficulty  of 
providing  suitable  tests  for  the  detection  of  Gurjun  balsam  go  back  a 
great  many  years — one  test  after  another  has  been  proposed,  used  for 
a  time,  and  then  been  abandoned — and  so  to-day  we  have  two  or 
three  tests,  or  modifications  of  old  tests,  that  have  been  proposed 
during  the  past  year,  and  which  are  now  undergoing  a  period  of 
probation.  It  remains  to  be  seen  whether  or  not  they  will  stand  or 
fall. 
My  coming  before  you  to-day  is  therefore  more  in  the  nature  of 
a  discussion  of  what  has  already  been  done,  than  of  an  offer  of  any- 
thing new  on  the  subject.  I  wish  simply  to  make  for  you  a  few 
of  the  most  recently  proposed  tests  as  compared  with  similar  tests 
which  preceded  them,  in  order  that  all  chemists  reached  by  this 
meeting,  who  are  working  with  copaiba,  may  be  induced  to  try  the 
tests,  so  that  when  the  Pharmacopoeia  is  next  revised  we  may  have 
an  accumulation  of  evidence  and  data  to  submit  to  the  revision 
committee  to  help  them  in  their  work. 
The  earliest  official  test  for  Gurjun  balsam  in  copaiba  is  found  in 
the  U.S.P.  of  1880,  which  test  was  continued  unchanged  in  the 
U.S.P.  of  1890. 
This  test  consisted  in  adding  to  20  drops  of  a  5  per  cent,  solution 
of  copaiba  in  carbon  disulphide,  one  drop  of  a  mixture  of  nitric  and 
sulphuric  acids,  when  a  purplish  red  or  violet  color,  due  to  the 
oxidizing  action  of  the  nitric  acid  on  the  resins  indicated  Gurjun 
balsam.  This  test,  as  pointed  out  by  Kebler  in  the  American  Jour- 
nal of  Pharmacy  about  ten  years  ago  (see  proceedings  A.  Ph.  A., 
1896,  page  629),  was  not  sufficiently  delicate,  although  if  applied 
as  originally  intended  (see  E.  Schmidt's  Pharmacentische  Chemie,  4th 
edition,  page  1261)  to  a  drop  of  distillate  of  highest  boiling  point 
from  the  balsam  to  be  tested,  its  delicacy  is  increased.  A  test 
involving  fractional  distillation  of  the  sample,  however,  is  an 
impractical  one  for  constant  use,  and  so  about  this  time  (ten  or 
twelve  years  ago)  there  appeared  the  first  of  the  acetic-nitric  acid 
tests  — one  modification  of  which  is  at  present  official  in  the  U.S.P. 
So  far  as  I  am  able  to  trace  its  history,  this  test  first  appeared  in  the 
American  Druggist  and  Pharmaceutical  Record  of  July  10,  1895,  as  a 
