610  Examination  of  Balsam  of  Peru.  {^"''Bec^^ssl^"^ 
Purified  storax  behaves  similarly,  but  gives  up  somewhat  less  cin- 
namein  to  petroleum  spirit  and  about  as  mueh  more  styracin  to  ether. 
Colophony  and  benzoin  solutions,  when  maeerated  with  calcic  hydrate, 
combine  with  it  so  that  petroleum  spirit  extracts  scarcely  anything 
from  the  mass.  On  the  other  hand,  castor  oil  can  be  completely 
removed  with  petroleum  spirit  as  long  as  there  has  been  no  addition  of 
water ;  but  if  castor  oil  be  digested  in  a  water  bath  for  several  hours 
with  calcic  hydrate  and  successive  additions  of  water,  saponification 
takes  place,  and  })etroleum  spirit  no  longer  dissolves  out  oil  from  the 
mass.  Copaiba  balsam  behaves  similarly,  its  resin  eventually  com- 
bining with  the  lime,  after  which  petroleum  spirit  only  dissolves  out 
the  essential  oil  of  the  balsam. 
After  several  hours'  digestion  with  caustic  lime  and  water  petroleum 
spirit  removes  from — 
Peru  balsam,  .  .  .41  per  cent. 
Purified  storax,     .  .  .         35  per  cent. 
Copaiba  balsam,  .  .  .    Its  essential  oil. 
Castor  oil,  .  .  .    ,     Almost  nothing. 
Benzoin  solution,  .  .  .    Almost  nothing. 
Colophony  solution,  .  .         Almost  nothing. 
This  method  is  not  very  suitable  for  the  recognition  of  the  sub- 
stances used  for  sophistication,  but  it  is  of  great  value  in  their  quanti- 
tative determination. 
C.  Behavior  of  Peru  Balsam  toivards  Caustic  Ammonia. — When  an 
ethereal  solution  of  Peru  balsam  is  shaken  with  ammonia  solution,  sp. 
gr.  0*960,  two  yellowish-brown  layers  are  formed,  between  which 
brownish  flocks  swim.  The  upper  layer  is  the  ethereal  solution  of  the 
balsam,  and  leaves,  when  separated  and  evaporated,  about  80  per  cent, 
of  the  quantity  used  as  a  brown  balsam.  The  inconsiderable  resinous 
mass  swimming  between  the  two  layers  adheres  partially  to  the  side  of 
the  vessel.  The  lower  ammoniacal  layer,  when  separated  and  ren- 
dered acid  with  acetic  acid,  shows  a  whitish  turbidity,  but  becomes 
almost  clear  on  boiling  and  again  turbid  on  cooling  through  separation 
of  cinnamic  acid,  without,  however,  forming  a  solid  deposit  at  the 
bottom.  The  ammonia  solution  withdraws  the  free  cinnamic  acid  from 
the  balsam,  without  affecting  its  other  constituents. 
Benzoin  solution  behaves  similarly.  It  gives  up  to  the  ethereal 
layer  the  greater  part  of  its  resin,  whilst  the  watery  layer  takes  up  the 
benzoic  acid,  and  upon  supersaturation  with  acetic  acid  and  boiling 
becomes  only  slightly  turbid. 
