574  Coca  Leaf,  and  Fluid  Extract  of  Coca.  {A^/embe?S* 
can  Pharmaceutical  Association  on  the  same  subject.  While  we, 
ultimately,  arrive  at  the  same  conclusion,  the  writer  cannot  agree 
with  Mr.  Dohme  that  Keller's  process  is  so  vastly  superior  to  all 
other  processes  of  assay. 
The  next  step  was  to  percolate  a  portion  of  the  leaf  according  to 
the  official  process  for  preparing  a  fluid  extract.  This  fluid  extract 
yielded  0-43  per  cent,  (grav.)  of  alkaloids  by  Keller's  process.  The 
marc  was  then  dried  and  assayed  by  the  same  process,  and  yielded 
016  per  cent.,  or  a  total  of  0-59  per  cent.,  against  0-62  per  cent.,  the 
total  amount  of  alkaloid  contained  in  the  crude  drug  by  the  same 
process  (grav.). 
These  results  prove  (1),  that  the  above  process  extracts  the 
alkaloids  as  completely  from  the  fluid  extract  as  from  the  drug 
itself ;  and  (2),  that  diluted  alcohol  does  not  extract  the  drug  com- 
pletely, even  when  well  percolated. 
Experiments  were  next  undertaken  to  determine  the  conditions 
most  favorable  for  extracting  the  active  principle  of  coca  leaf  in 
preparing  the  fluid  extract.  In  each  experiment  100  grammes  were 
percolated  with  120  cubic  centimetres  of  the  menstruum. 
The  following  table  embodies  the  condition  under  which  the 
experiments  were  performed  and  the  results  obtained  : 
~.  r  -n     j  "> t  Per  cent,  of  Alkaloids  in 
Fineness  of  Powder.  •     Menstruum.  Fluid  Extract.  Grav. 
No.  12   65  per  cent,  alcohol  o  19 
No.  40  .  .   65  per  cent,  alcohol  6 '29 
No.  40   Diluted  alcohol1  0*21 
No.  40   Diluted  alcohol  C20 
No.  12   Diluted  alcohol  0-18 
1  Acidulated  with  one-tenth  of  a  per  cent,  of  tartaric  acid. 
The  drug  assayed  by  Keller's  process  :  No.  12  powder,  4  hours 
0-20  per  cent.;  24  hours,  0-32  per  cent.  No.  40  powder,  4  hours,  0-2 1 
per  cent.,  and  24  hours,  0-32  per  cent. 
These  results  show  that  a  65  per  cent,  alcoholic  menstruum 
extracts  the  alkaloids  better  than  diluted  alcohol,  and  a  moderately 
fine  powder  is  better  than  a  very  coarse  one.  These  facts  have 
been  demonstrated  on  a  large  scale  since  the  experiments  were 
made.  The  acidulation  does  not  facilitate  extraction.  It  is  unfortu- 
nate that  a  low  assaying  leaf  was  operated  on,  but  the.  facts  remain 
the  same. 
