Am.  Jour.  Pharm.  \ 
March,  1901.  J 
The  Assay  of  Coca. 
127 
The  ideal  menstruum  to  be  employed  in  extracting  any  drug  un- 
der assay  is  the  one  which,  while  completely  removing  in  a  reason- 
able length  of  time  the  alkaloids  or  other  active  principles  contained 
therein,  at  the  same  time  brings  into  solution  the  least  possible 
amount  of  the  objectionable,  so-called  extractive  matter,  which  not 
infrequently  occasions  so  much  trouble  in  the  subsequent  steps  of 
the  process. 
Such  a  menstruum  is  confidently  believed  to  exist  in  the  em- 
ployment of  kerosene  oil  for  the  exhaustion  of  coca. 
The  process  about  to  be  described  is  a  modification  of  the  well- 
known  one  of  the  late  Dr.  E.  R.  Squibb,1  in  which  a  dilute  solution 
of  ammonium  hydrate  is  substituted  for  the  solution  of  sodium  car- 
bonate employed  to  liberate  the  alkaloids  from  their  natural  com- 
binations. 
The  ammonium  hydrate  appears  to  be  more  penetrating,  prob- 
ably due  to  its  volatility,  and  for  this  reason  it  is  favored. 
The  quantities  employed  and  the  method  of  procedure  are  as  fol- 
lows: 
Coca  in  No.  40  powder   25  grammes. 
Ammonic  hydrate  (2  per  cent.  NH3)   25  c.c. 
N 
—  hydrochloric  acid   75  c.c. 
Ether  ^  #  each  a  sufficient  quantity. 
Kerosene  oil  j 
Place  the  powdered  leaf  into  an  open  vessel  of  suitable  capacity 
(about  450  c.c);  a  beaker,  except  for  its  fragility,  answers  very  well. 
However,  a  covered  jar,  such  as  is  commonly  used  for  holding  solid 
extracts,  has  been  used  to  advantage,  and  in  fact  is  rather  to  be 
preferred. 
Now  add  to  it  25  c.c.  of  an  approximately  2  per  cent,  solution  of 
ammonia  and  mix  well  together  by  means  of  a  stout  glass  rod  of 
such  a  length  that,  while  in  the  jar,  will  just  allow  the  cover  to  rest 
in  its  normal  position;  permit  this  to  macerate  for  half  an  hour, 
stirring  from  time  to  time,  the  whole  being  well  covered. 
At  the  expiration  of  this  time  remove  the  cover  and  note  whether 
or  not  the  odor  of  ammonia  is  perceptible  after  stirring;  if  so, 
1  Ephemeris,  Vol.  Ill,  p.  1104. 
