\ 
A%JP°rnr;£obrm*}     Contributions  from  H.  M.  Gordin.  167 
COCA  LEAVES.  STANDARD  METHOD. 
Ten  grammes  in  No.  60  powder  were  moistened  in  a  small  mortar 
with  5N  c.c.  of  diluted  alcohol,  then  placed  in  a  small  percolator, 
washing  the  mortar  out  repeatedly  with  fresh  menstruum  and  pour- 
ing the  washings  on  the  top  of  the  drug.  Following  the  general 
rules  of  percolation,  i.  e.y  macerating  forty-eight  hours,  etc.,  the  per- 
colation was  continued  very  slowly  till  about  200  c.c.  of  percolate 
were  obtained.  The  first  10  c.c.  were  received  into  a  50  c.c.  meas- 
uring flask  and  set  aside ;  the  balance  was  concentrated  in  vacuo, 
first  at  about  45 0  C,  then  at  ordinary  temperature,  till  reduced  to 
about  25  c  c.  This  was  added  to  the  reserved  portion,  and  the 
whole,  after  washing  the  vessel  in  which  the  concentration  took 
place  with  acidulated  (2  per  cent.)  water,  was  made  up  with  acid 
water  to  50  c.c. 
The  dregs  were  first  deprived  of  moisture  as  much  as  possible  by 
forcing  dry  air  by  means  of  the  pump  through  the  percolator,  and 
then  thoroughly  dried  in  desiccator.  After  digesting  5  grammes  of 
the  dregs  a  few  hours  with  Prollius'  fluid,  filtering,  and  shaking  out 
with  acidulated  water,  no  alkaloid  could  be  detected  either  by 
Mayer's  or  Wagner's  reagents. 
The  exhaustion  being  complete  and  no  strong  reagents  or  high 
heat  having  been  used,  this  method  of  extraction  was  taken  as  a 
standard.  The  alkaloidal  assay  of  the  leaves  was  now  carried  out 
by  filtering  the  acid  liquid  (using  a  little  talcum),  shaking  out  25 
c.c.  (=  5  grammes  drug)  four  times  with  ether  and  ammonia,  using 
30  c.c.  ether  each  time.    After  distilling  off  the  ether  completely, 
a  few  drops  chloroform  and  then  20  c.c.  of  ^  acid  were  added,  and 
40 
the  chloroform  removed  by  blowing  air  into  the  flask.  The  estima- 
tion was  then  carried  out  by  my  general  alkalimetric  method,  using 
Mayer's  reagent  as  precipitant. 
N 
It  was  found  that  5  grammes  of  the  drug  consumed  6-6  c.c.  _ 
40 
acid  =  1  per  cent,  ether  soluble  alkaloids,  calculated  as  cocaine. 
The  same  leaves  in  the  same  state  of  fineness  were  then  assayed 
by  method  A.  The  liquid,  after  distilling  off  the  alcohol,  was 
made  up  to  50  c.c.  with  acidulated  water,  filtered  through  talcum, 
and  in  25  c.c.  of  the  filtrate  the  amount  of  alkaloid  estimated  exactly 
as  in  the  standard  method. 
