AmAiiuTsiSm-}    Balsam  Copaiba  vs.  Gurjun  Balsam.  395 
French,  of  Smith,  Kline  &  French  Company,  I  have  investigated 
the  questionable  possibility  of  detecting  gurjun  balsam  in  balsam 
copaiba  by  the  present  methods. 
Owing  to  the  natural  variable  composition  of  balsam  copaiba,  its 
purity  cannot  always  be  ascertained  with  absolute  certainty.  If  the 
variable  composition  of  balsam  copaiba  was  the  only  obstacle  to 
surmount,  our  task  would  not  be  so  difficult,  but  when  we  remem- 
ber that  it  is  practically  impossible  to  secure  this  article  from  first 
hands  (in  this  country  only  from  third  hands)  we  see  how  uncertain 
the  genuineness  of  even  a  sample  becomes  from  which  reliable  data 
can  be  secured.  The  tests,  until  recently,  at  our  command,  for 
detecting  gurjun  balsam  in  balsam  copaiba,  frequently  made  it 
impossible  for  the  analyst  to  render  an  absolute  decision  as  to  its 
presence  or  absence  when  less  than  25  per  cent,  was  present. 
Balsam  copaiba  is  described  as  varying  in  color  from  a  pale  yellow 
to  a  brownish-yellow,  is  usually  quite  transparent,  but  there  are 
varieties  that  always  remain  opalescent.  Some  kinds  are  occasion- 
ally slightly  fluorescent.  Samples  have  come  into  my  hand,  guar- 
anteed genuine,  and  an  examination  proved  them  so,  that  were  of  a 
dark  amber  color  and  highly  fluorescent.  Balsam  copaiba  is  insol- 
uble in  water,  but  soluble  in  absolute  alcohol,  ether,  chloroform, 
benzine,  carbon  disulphide  and  fixed  and  volatile  oils.  It  varies  in 
specific  gravity  from  0-940  to  0  993  at  150  C. 
In  order  to  obtain  the  most  reliable  material  possible,  samples 
were  obtained  from  several  well-known  dealers  of  this  article  ;  some 
were  guaranteed  pure,  while  others  were  represented  to  be  of  ques- 
tionable purity. 
Several  samples  of  gurjun  balsam  were  also  secured.  The  dealers 
appeared  somewhat  reluctant  to  furnish  this  article,  either  because 
they  were  not  in  possession  of  it,  or  did  not  desire  it  to  become 
known  that  they  handled  it. 
The  samples  were  all  examined  by  the  most  approved  methods, 
which  are  briefly  reviewed  below  : 
Turpentine. — When  a  sample  of  balsam  is  heated  the  odor  of 
turpentine  should  not  be  emitted. 
Fixed  Oils — The  residue  left  after  driving  off  the  volatile  oil 
should  be  transparent,  friable  and  amorphous. 
Paraffin  Oil  can  be  detected  by  introducing  1  c.c.  of  the 
balsam  into  a  test  tube  containing  4  c.c.  of  95  per  cent,  alcohol, 
