Am.  Jour.  Pharm.  ) 
June,  i278.  / 
Resin  of  Gurjun  Balsam. 
305 
found  more  than  twenty  years  ago,  that  the  hydriodate  of  quinidia 
requires  more  than  twelve  hundred  parts  of  cold  water  to  dissolve  it. 
One  gram  of  sulphate  of  quinidia,  prepared  by  myself,  in  1856, 
chemically  pure,  from  a  specimen  of  quinidia  kindly  presented  to  me 
by  Mr.  J.  Eliot  Howard,  was  dissolved  in  50  grams  of  hot  water,  and 
to  this  solution  added  0*5  gram  of  potassium  iodide.  By  this  addition 
a  heavy  sandy  crystalline  powder  of  hydriodate  of  quinidia  was 
precipitated,  and  on  filtering  off  the  liquid  on  the  next  day,  the  clear 
liquid  was  not  altered  by  the  addition  of  a  few  drops  of  liquor  ammonia^ 
but  remained  perfectly  clear. 
Having  ascertained  by  this  experiment  the  behavior  of  the  chemically 
pure  sulphate  of  quinidia  under  the  circumstances  mentioned,  I  applied 
this  test  to  the  good  commercial  sulphate,  presented  to  me  a  few  years 
ago  by  Messrs.  Howard.  I  found  that  the  liquor  filtered  from  the 
precipitated  hydriodate  of  quinidia  became  slightly  turbid  bv  the  addition 
of  liquor  ammoniae,  but  without  separating  an  appreciable  precipitate. 
Therefore,  the  practical  test  for  the  purity  of  the  commercial  article 
is  to  dissolve  one  part  of  the  salt  in  fifty  parts  of  hot  water,  and  to  add 
to  this  solution  a  half  part  of  iodide  of  potassium.  If  the  precipitate 
is  not  sandy,  but  resinous,  no  further  trouble  need  to  be  taken,  for  this 
resinous  aspect  proves  that  the  salt  contains  either  cinchonia  or  cin- 
chonidia,  or  perhaps  both  of  them.  If,  however,  the  precipitate 
constitutes  a  heavy  sandy  crystalline  powder,  the  filtered  liquid  is,  after 
some  hours,  tested  by  liquor  ammoniae.  If  this  addition  makes  the 
liquor  only  slightly  turbid  without  formation  of  an  appreciable  precipitate 'y 
the  conclusion  is  that  the  salt  is  really  good  sulphate  of  quinidia,  and 
contains  only  traces  of  other  cinchona  alkaloids,  which  generally  is  a 
slight  trace  of  cinchonia. — Phar.  four,  and  Trans. ,  March  23,  1878. 
The  Hague. 
NOTE  on  a  CRYSTALLIZABLE  INDIFFERENT  RESIN 
of  GURJUN  BALSAM,  an  ADDITION  to  the  "PHAR- 
MACOGRAPHIA."1 
By  Professor  Fluckiger. 
In  the  "  Pharmacographia,"  p.  204,  it  is  stated  that  copaivic  acid  is 
by  no  means  an  abundant  and  common  constituent  of  copaiba.  The 
only  kind  of  that  balsam  I  have  ever  met  with,  which  readily  yields 
'Translated  from  the  Archi-v  der  Pharmacie,  February,  1878. 
*9 
