5a8 
'    Miscihle  Copaiba, 
Am.  Jour.  Pharm. 
Nov.,  1878. 
in  the  cold  exerts  no  action  on  bicarbonate  of  potassium.  The  balsam 
of  copaiba  used  in  making  the  preparation  above  referred  to  was  pre- 
sumably the  Maranham  variety  ;  it  was  obvious,  however,  that  as  the 
copaiba  balsams  of  commerce  differ  as  widely  in  their  characters  as  in 
their  botanical  sources  it  would  be  desirable  to  experiment  on  well 
defined  samples  of  known  origin.  I  accordingly  obtained  from  Messrs, 
Barron  &  Co.,  of  Giltspur  street,  London,  authentic  samples  of  Maran- 
ham and  Para  balsams  of  copaiba  and  of  Gurgun  balsam,  and  treated 
them  as  follows  : 
In  bottle  No.  1  were  placed  i\  fluidounces  of  Maranham  balsam  of 
copaiba  and  \  fluidounce  of  oil  of  tartar.  A  fluid  drachm  of  this 
yielded  on  evaporation  34  grains  of  solid  saline  residue. 
Bottle  No.  2  contained  Para  balsam  of  copaiba  and  oil  of  tartar  in 
the  same  proportions. 
Bottle  No.  3  contained  Gurgun  balsam  and  oil  of  tartar  in  the  same 
proportions. 
Bottles  No.  4  and  5  contained  Maranham  balsam  of  copaiba,  adultera- 
ted to  the  extent  of  10  per  cent.,  in  one  case  with  linseed  oil,  in  the 
other  with  Gurgun  balsam.  It  was  thought  probable  that  these  ad- 
mixtures would  be  at  once  detected  when  the  oil  of  tartar  should  be 
added  ;  but  as  such  was  not  the  case  and  an  opinion  on  the  subject  could 
not  be  certainly  formed  before  the  lapse  of  several  days,  I  will  not 
further  refer  to  them. 
Each  of  the  mixtures  well  shaken  over  night  showed  signs  the  next 
morning  of  depositing.  It  was  not,  however,  until  five  days  had  elapsed 
that  the  operation  seemed  complete. 
No.  1  had  by  that  time  deposited  a  whitish  layer  of  bicarbonate  ; 
over  that  lay  a  thin  stratum  of  viscid  resin,  on  the  surface  of  which 
floated  numerous  small  needle-shaped  crystals  ;  above  that  came  the 
clear  balsam,  through  which  could  be  seen  numerous  crystals  attached 
to  the  sides  of  the  bottle.  Neither  layer  was  emulsible,  although  the 
lower  one  showed  some  tendency  that  way. 
No.  2  differed  altogether  from  the  preceding.  There  was  indeed  the 
stratum  of  bicarbonate,  but  it  was  less  in  volume  ;  the  viscid  resin  was 
absent ;  the  space  occupied  in  the  other  case  by  clear  balsam  was  here 
cleanly^divided  into  two  equal  parts,  the  upper  portion  containing  a  pale 
colored  essential  oil  not  miscible  with  water,  the  lower  portion  a  sapon- 
