240  Cocaine  Salts  and  Potassium  Permanganate.  {Am,Ma^'iSarnu 
The  tannin  was  estimated  by  boiling  15  gm.  of  the  powdered  bark 
with  water,  precipitating  the  filtrate  with  gelatin  and  washing  and 
drying  the  precipitate;  it  weighed  3"929  gm.,  showing  the  presence  in 
the  bark  of  26*2  per  cent,  of  tannin. 
NOTE  ON  THE  REACTIONS  OF  COCAINE  SALTS  WITH 
POTASSIUM  PERMANGANATE. 
By  A.  B.  Lyons,  M.  D. 
Potassium  permanganate  has  been  recently  proposed  as  a  test  for  the 
purity  of  commercial  cocaine  salts.  [F.  Giesel,  in  Pharm.  Zeitung,  No. 
16,  1886].  If  to  a  strong  solution  of  pure  cocaine  hydrochlorate  there  is 
added  decinormal  solution  of  potassium  permanganate,  there  is  produced 
a  precipitate  of  a  deep,  violet-purple  color,  consisting  of  a  permanganate 
of  the  alkaloid.  The  salt  is  very  unstable,  and  if  left  to  itself  decom- 
poses spontaneously  in  a  few  hours,  leaving  behind  a  deposit  of  the 
dark  brown  hydrated  peroxide  of  manganese. 
If  examined  with  a  microscope  when  first  thrown  down,  the  pre- 
cipitate will  be  found  to  consist,  wholly  or  in  part,  according  to  the 
strength  of  the  cocaine  solution,  of  translucent  violet-red  crystals,  of 
great  baauty.  These  assume  the  form  of  rhombic  (nearly  rectangular) 
plates,  of  which  several  are  frequently  grouped  in  a  rosette-like  ar- 
rangement. A  solution  containing  5  per  cent,  of  cocaine  hydrochlo- 
rate yields  at  once  a  copious  deposit  of  crystals.  Solutions  containing 
2  per  cent,  of  the  salt  gave  crystals  after  a  short  time.  When  the 
proportion  of  cocaine  was  reduced  to  1  per  cent.,  crystals  formed  only 
as  evaporation  took  place,  and  a  solution  of  one-half  this  strength 
yielded  only  a  few  crystals.  In  all  cases  there  appeared  simultaneously 
with  the  crystals  amorphous  floccules  of  the  manganic  hydrate,  and  the 
crystals  would  shortly  disappear,  leaving  behind  the  same  unsightly 
residue. 
If  the  solution  containing  the  deposit  is  heated  to  boiling,  the  same 
change  takes  place  at  once,  but  the  decomposition  of  the  salt  is  not 
attended  with  the  evolution  of  any  peculiar  odor. 
The  behavior  of  impure  products  will  vary,  naturally,  with  the 
nature  of  the  impurity.  The  amorphous  cocaine  hydrochlorate,  which 
is  now,  however,  not  often  met  with,  generally  manifests  its  impurity 
by  an  immediate  reduction,  in  the  cold,  of  the  permanganate  solution. 
The  first  drop  or  two  of  the  reagent  produces  a  brown  discoloration 
