Am.  Jour.  Pharm.  1 
May,  1911.  J 
Identification  of  Cocaine. 
199 
when  the  solution  is  undisturbed.  A  buff  colored  precipitate  is 
formed  which,  under  the  microscope,  appears  as  large  feathers  or 
plumes,  sometimes  arranged  in  stellate  pattern.  In  higher  dilutions 
(1:600)  crystals  slowly  form  which  ''resemble  carpet  tacks."  ^ 
Alpha-eucaine,  with  the  above  test,  gives  bundles  of  fine  needles ; 
beta-eucaine,  after  30  minutes^  gives  a  few  very  large,  broad  leaves, 
rosettes  and  cubes ;  holocaine  gives  small  stars ;  acoine  gives  an 
amorphous  precipitate,  while  stovaine  and  euphthalmine  give  no 
precipitates.  None  of  the  precipitates  yielded,  by  the  cocaine  sub- 
stitutes resemble  the  cocaine  chloroplatinate  in  any  way. 
GOLD  CHLORIDE  TEST."^ 
To  one  c.c.  of  a  dilute  solution  ( i :  300)  of  cocaine  are  added 
three  drops  of  gold  chloride  test  solution,  avoiding  shaking  as  in 
the  case  of  the  platinum  chloride  test.  A  precipitate  immediately 
forms  and  slowly  changes  from  the  amorphous  into  the  crystalline 
state.  Under  the  microscope,  the  crystals  resemble  fern-fronds, 
generally  with  a  stellate  arrangement.  In  dilutions  of  i  :  12,000, 
similar  crystals  form,  after  long  standing. 
With  the  gold  test,  alpha-eucaine  gives  branching,  twig-like 
crystals ;  stovaine  gives  large  crystals  resembling  those  of  cocaine 
chloroplatinate  in  general  structure,  but  differ  in  that  the  branches 
possess  smaller  branches,  which  is  not  the  case  with  the  cocaine 
chloroplatinate.  Amorphous  precipitates  are  given  with  beta- 
eucaine,  acoine  and  holocaine.    Euphthalmine  gives  no  precipitate. 
CHROMIC  ACID  TEST.* 
To  y2  c.c.  of  a  one  per  cent,  solution  of  cocaine  are  added  two 
drops  of  chromic  acid  test  solution  and  then  concentrated  hydro- 
chloric acid,  drop  by  drop  with  shaking,  until  the  precipitate 
dissolves.  After  a  short  time,  clusters  of  fine  needles  separate  out 
and  the  solution  remains  yellow  for  several  days. 
Alpha-eucaine  gives  a  precipitate  which  requires  a  large  volume 
of  hydrochloric  acid  for  complete  solution.  The  liquid  remains 
yellow  for  several  days  but  no  crystals  form.  Beta-eucaine  and 
stovaine  behave  like  cocaine  but  no  crystals  separate  out  in  either 
"Allen,  loc.  cit.,  p.  275. 
^  A.  B.  Lyons,  loc.  cit. 
"  K.  Metzger,  Pharm.  Zeit.,  xxxiv,  697,  also  Allen,  loc.  cit.,  p.  276. 
