520     DETECTION  OF  ADULTERATIONS  IN  COPAIVA  BALSAM. 
DETECTION  OF  ADULTERATIONS  IN  COPAIYA  BALSAM. 
By  Dr.  H.  Hager. 
The  author  has  met  with  copaiva  balsam  adulterated  with  oil 
of  sassafras.  The  adulteration  is  detected  in  the  following 
manner  :  1  c.c.  balsam  and  2  c.c.  concentrated  sulphuric  acid 
are  mixed ;  after  the  mixture  has  cooled,  20  c.c.  alcohol  are 
added,  the  mixture  is  heated  to  boiling,  and  then  set  aside.  If 
the  balsam  be  pure,  after  the  addition  of  the  alcohol,  a  milky 
grey  yellowish  or  pale  reddish  yellow  liquid  is  obtained,  which 
on  boiling,  becomes  yellow,  clear  and  transparent,  a  resinous 
compound  settling  to  the  bottom.  If  adulterated  with  oil  of 
sassafras,  the  addition  of  alcohol  produces  a  dark  brown-red 
color,  becoming  after  boiling  much  darker,  with  a  tint  of  violet, 
similar  to  the  juice  of  black  cherries. 
Oil  of  turpentine,  which  is  probably  rarely  used  as  an  adulte- 
rant, is  readily  detected  by  heating  slightly  two  to  four  drops 
of  the  balsam,  dropped  upon  bibulous  paper,  in  such  a  manner 
that  no  visible  vapors  are  evolved.  Oil  of  turpentine  evaporates 
first  and  is  recognized  by  its  odor. 
This  test  is  unreliable  if  Venice  turpentine  is  used  for  adulte- 
ration. The  author  invites  experiments  with  the  following  test, 
which  has  given  him  reliable  results :  5  or  6  drops  of  water  and 
5  to  7  c.c.  balsam  are  mixed  in  an  evaporating  dish  with  suffi- 
cient levigated  litharge  to  form  a  thick  semi-liquid  mass.  At 
a  temperature  of  20  to  25'^  C.  (68  to  77°  F.,)  a  well  marked 
turpentine  odor  is  given  off,  if  the  balsam  contains  but  10  per 
cent.  Venice  turpentine,  and  even  5  per  cent,  may  be  still 
recognized. 
An  approximate  quantitative  estimation  of  the  adulterant  may 
be  made  as  follows :  5  grm.  balsam,  8  to  10  drops  vrater,  and  15 
grm.  litharge  are  heated  for  a  quarter  hour  in  a  sand-bath,  then 
for  several  hours  in  a  water-bath.  After  cooling,  the  hard  mass 
is  rubbed  to  powder  and  boiled  with  benzin,  the  liquid  evapora- 
ted and  the  residue  macerated  with  90  per  cent,  alcohol  for  several 
hours.  The  alcoholic  filtrate  evaporated  to  dryness,  leaves 
about  0*2  to  0*3  resin,  which,  when  boiled  with  solution  of  po- 
tassa,  yields  a  filtrate  which  is  not  or  scarcely  tinged  by  sulphide 
