AmNoT;iP87trm'}  Miscible  Copaiba.  527 
with  it  a  white  emulsion.  It  therefore  differs  essentially  from  that 
which  is  known  as  soluble  copaiba. 
Since  that  time  the  preparation  has  occasionally  been  employed  here, 
but  as  its  applications  were  limited  it  did  not,  until  the  recent  papers  on 
copaiba  by  Mr.  Siebold  and  others  appeared,  occur  to  me  to  examine 
the  reaction. 
As  it  is  I  have  but  made  a  superficial  examination  of  the  question, 
which,  in  order  to  do  it  justice,  would  require  the  expenditure  upon  it 
of  far  more  time  than  I  have  at  my  disposal. 
A  sample  some  six  or  eight  years  old  of  this  miscible  copaiba  (Bals. 
Copabiae,  Oi,;  Ol.  Tartari,       fl.)  presented  the  following  characters  : 
It  was,  as  I  have  already  said,  similar  in  appearance  and  consistence 
to  ordinary  copaiba,  but  instead  of  having  an  acid  it  had  an  alkaline  re- 
action, and  when  shaken  with  water  instead  of  floating  on  its  surface  as 
ordinarily  it  readily  formed  with  it  a  white  emulsion,  more  or  less  stable 
according  to  the  degree  of  dilution.  This  emulsion  was  of  course 
readily  destroyed  by  acids.  As  regards  its  behavior  towards  solvents  it 
differed  little  from  ordinary  balsam  of  copaiba.  The  only  point  worth 
remarking  on  in  this  connection  was  the  fact  that  alcohol  did  not  affect 
a  perfectly  clear  solution,  and  caused  after  a  few  days  a  minute  whitish 
deposit  to  collect  at  the  bottom  of  the  bottle.  The  removal  of  this 
substance  (probably  a  resin-salt  of  potassium)  did  not,  however,  affect 
the  emulsibility  of  the  balsam. 
So  much  for  the  fluid  balsam  which  had  been  carefully  drained  off 
from  the  underlying  white  saline  deposit.  This  was  found  to  be  im- 
bedded in  a  pasty  resinous  substance  on  the  surface  of  which  were 
planted  numerous  crystals,  slender  needles  of  from  one  quarter  to  half 
an  inch  long.  The  mass  having  been  well  washed  with  benzol  these 
crystals  disappeared,  and  up  to  now  they  have  refused  on  the  evapora- 
tion of  the  solvent  to  put  in  a  second  appearance.  The  white  substance 
left  after  the  washing  above  referred  to  proved  to  be  entirely  composed 
of  minute  crystals  of  bicarbonate  of  potassium. 
The  action,  therefore,  of  the  acid  resins  of  the  copaiba  had  been 
this,  to  deprive  two  molecules  of  the  carbonate  of  half  their  potassium, 
leaving  the  second  atom  to  combine  with  both  atoms  of  carbonic  acid 
and  one  atom  of  water  to  form  the  acid  carbonate  of  potassium  and 
water  known  as  bicarbonate  of  potassium.  No  evolution  of  gas,  there- 
fore, attends  the  operation.     It  seems,  moreover,  that  balsam  of  copaiba 
