AmjJu0]y"'il>99arm-}    Acetic  Acid  in  Extracting  Drugs.  309 
The  fractions  of  the  above  table  were  put  together  in  successive 
groups  of  five  fractions  each,  the  exact  measure  of  500  c.c.  being 
made  up  from  the  next  percolate  in  succession.  In  this  way  the  100 
c.c.  fractions  were  concentrated  into  500  c.c.  fractions,  which  were 
weighed  as  well  as  measured  and  the  differences  taken,  these  larger 
fractions  being  carried  through  in  pairs,  each  being  assayed  for  the 
total  alkaloids  contained.  For  these  assays  10  c.c.  of  the  stronger 
liquids  was  taken  and  the  results  multiplied  by  50.  For  the  weaker 
liquids  20  c.c.  was  taken  and  the  results  multiplied  by  25.  Each  of 
the  three  portions  consisted  of  500  grammes  of  cinchona  and  each 
large  fraction  consisted  of  500  c.c.  of  percolate. 
Of  the  first  and  second  portions  only  the  first  500  c.c.  of  perco- 
late was  reserved,  the  succeeding  fractions  from  the  first  portion 
being  used  as  menstruum  for  the  second  and  those  from  the  second 
portion  being  carried  to  the  third  portion.  But  all  the  fractions 
from  the  third  portion  to  practical  exhaustion  were  reserved  and  as- 
sayed, and  if  the  repercolation  had  been  carried  farther  these  fractions 
would  have  been  successively  used  as  menstruum  on  a  fourth  por- 
tion of  cinchona. 
The  single  separate  percolation,  "  Fourth  Portion  "  of  the  table 
above,  made  for  the  purpose  of  comparing  the  results  from  the  use 
of  fine  powder  against  coarse,  does  not  enter  the  following  table,  as 
these  were  only  comparable  assays.  The  first  500  c.c.  from  coarse 
powder  had  7-5  grammes  of  alkaloids,  while  the  similar  fraction 
from  fine  powder  gave  8-2  grammes  of  alkaloid.  This  leads  directly 
to  the  conclusion  that  if  fine  powder  had  been  used  for  the  principal 
series  of  comparisons  the  results  given  in  the  following  table  would 
have  been  more  favorable  to  the  acetic  acid  menstruum  by  about  9 
per  cent. 
