^'"■jmie'^'iQii*™'}  Permanganate  Test  for  Cocaine.  265 
A  fine  white  powder,  without  odor,  and  having  a  cooHng,  saline, 
bitter  taste.  It  is  ahiiost  completely  soluble  in  water.  When 
exposed  to  air  it  absorbs  moisture. 
An  aqueous  solution  of  the  salt  (i  in  40)  should  be  neutral  to 
litmus  paper. 
When  mixed  with  ammonium  chloride  test  solution  and  ammonia 
water,  the  aqueous  solution  of  the  salt  (i  in  40)  yields  with  sodium 
phosphate  test  solution,  a  white,  crystalline  precipitate.  With 
barium  chloride  test  solution  the  aqueous  solution  of  the  salt  yields 
a  white  precipitate  insoluble  in  hydrochloric  acid. 
Ten  c.c.  of  the  aqueous  solution  of  the  salt  (i  in  200)  should 
not  respond  to  the  time  limit  test  for  heavy  metals  prescribed  in 
the  United  States  Pharmacopoeia,  8th  Revision.  Five  c.c.  of  the 
aqueous  solution  of  the  salt  (i  in  40)  should  not  respond  to  the 
modified  Gutzeit's  test  for  arsenic.  United  States  Pharmacopoeia, 
8th  Revision. 
If  from  0.200  gm.  to  0.300  gm.  of  dried  magnesium  sulphate 
be  dissolved  in  50  c.c.  of  water,  the  solution  filtered  if  necessary, 
and  if  10  c.c.  of  ammonium  chloride  test  solution,  10  c.c.  of  sodium 
phosphate  test  solution  and  sufficient  ammonia  water  to  render  the 
mixture  alkaline,  be  added  in  the  order  named,  shaking  after  the 
addition  of  each  reagent,  the  mixture  allowed  to  stand  for  12  hours, 
the  precipitate  collected  in  a  tarred  Gooch  crucible,  washed  with  i 
per  cent,  ammonia  water  until  free  from  chlorides,  dried,  heated 
to  low  redness  for  15  minutes,  cooled  and  weighed,  the  weight  of 
the  resultant  magnesium  pyrophosphate  should  correspond  to  at 
least  77.5  per  cent,  of  pure  anhydrous  magnesium  sulphate 
(MgSOJ. 
From  the  Laboratory  of  the 
American  Medical  Association. 
THE  PERMANGANATE  TEST  FOR  COCAINE. 
By  Francis  J.  Seiter. 
The  behavior  of  cocaine  with  potassium  permanganate  was  first 
described  by  F.  Giesel.^  He  found  that  the  crystalline  precipitate 
of  cocaine  permanganate  is  very  stable  compared  with  the  corre- 
^  Giescl — Pliarm.  Zeit.  1886  p.  132;  also,  Chcm.  Ccntralbl.  1887,  p.  1448. 
