572  Coca  Leaf,  and  Fluid  Extract  of  Coca.  {^oVembefK' 
The  drawings  were  made  by  the  aid  of  the  camera  lucida  and  the 
magnification  determined  by  means  of  the  stage  micrometer. 
In  conclusion,  I  take  pleasure  in  acknowledging  the  kindness  of 
Messrs.  Parke,  Davis  &  Co.,  of  New  York,  and  Prof.  E.  L.  Greene, 
of  the  University  of  California,  in  providing  me  with  the  excellent 
specimens  from  which  these  studies  have  been  made. 
ON   THE  ASSAYING  OF  COCA   LEAF,  AND  EXPERI- 
MENTS WITH  THE  FLUID  EXTRACT  OF  COCA. 
By  Lyman  F.  Kebi/er. 
Presented,  in  part,  at  the  American  Pharmaceutical  Association,  Denver,  1895. 
Since  this  communication  is,  primarily,  an  investigation  of  the 
so-called  Keller  process,  it  will  not  be  inappropriate  here  to  call 
attention  to  an  error  that  has  crept  into  literature.  The  writer 
believes  in  giving  credit  to  whom  credit  is  due. 
O.  Schweissinger1  and  G.  Sarnow  were  the  first  to  apply  and  call 
attention  to  the  advantages  possessed  by  a  mixture  of  chloroform 
and  ether  in  assaying  galenical  preparations.  They  applied  the 
method,  practically  as  we  now  have  it,  to  various  fluid  extracts,  two 
years  before  Keller's  contributions  appeared.  Mr.  Keller2  duly  gives 
the  above  authors  credit,  and,  furthermore,  says  :  "  Es  eignet  sich 
fiir  alle  alkaloidhaltigen  Praparate,  ja  es  lasst  sich  sogar  (selbstver- 
standlich  mit  gewissen  Modificationen)  fiir  Rohstoffe  anwenden." 
Mr.  Keller  has  simply  applied  the  process  to  the  drug  itself,  with  a 
slight  modification.  Mr.  Keller  certainly  deserves  credit  for  his 
modification,  but  it  should  not  be  forgotten  that  Schweissinger  and 
Sarnow  are  the  authors  of  this  process. 
Keller's  method  having  for  some  time  yielded  unsatisfactory 
results  in  standardizing  the  fluid  extract  of  coca  leaf,  the  writer 
determined  to  investigate  the  reliability  of  the  method  when  applied 
to  coca  leaves  and  its  preparations.  A  sample  of  coca  leaves  was 
reduced  to  a  No.  40  powder,  and  assayed  by  all  the  well-known 
methods.  The  following  gravimetric  and  volumetric  results  were 
secured  by  these  processes  : 
1 1890,  Pharm.  Centralhalle,  31,  771. 
-1892,  Schweiz.  Wochenschr.  f.  Chem.  u.  Pharm.,  30,  501. 
