A^uaryf£m"}       Substitute  for  Ethyl  Alcohol.  5 
make  up  the  following  table,  which  shows  approximately  the  rate 
of  exhaustion  as  each  fraction  was  received. 
The  first  portion  of  500  grammes  of  U.S. P.  fine  powder  was  moist- 
ened with  the  U.S.P.  proportion,  or  500  c.c.  of  64-5  per  cent,  alcohol, 
to  which  25  c.c.  of  36  per  cent,  acetic  acid  had  been  previously 
added,  and  macerated  for  48  hours  in  a  closely  covered  vessel.  It 
was  then  packed  in  a  syphon  percolator  and  600  c.c.  of  the  64-5  per 
cent,  alcohol,  without  acetic  acid,  was  poured  on  top  in  successive 
portions  of  about  100  c.c.  each  until  a  stratum  remained  permanent 
on  top,  and  the  percolate  in  the  central  well-tube  stood  nearly  up 
to  the  level  of  the  stratum  of  menstruum  on  top.  In  this  condition 
it  was  closely  covered  and  allowed  to  digest  for  24  hours.  Then  the 
syphon  was  put  in  place,  started  and  adjusted  so  high  as  to  control 
the  rate  of  dropping  to  an  average  of  about  three  or  four  drops  per 
minute  during  the  day,  and  very  much  slower,  or  at  rest,  during  the 
night,  when  the  columns  in  the  syphon  legs  reached  a  balance,  as 
no  more  menstruum  was  poured  on  top  during  the  night. 
The  first  five  fractions  after  having  been  separately  weighed  were 
added  together  in  a  500  c.c.  flask  remarked  for  230  C,  and  the  few 
drops  needed  to  make  up  the  measure  were  added  from  the  sixth 
fraction. 
Then  10  c.c.  of  this  500  was  carefully  measured  off  into  a  1 2  centi- 
metre flat-bottom,  tared  capsule,  and  evaporated  on  a  water-bath 
until  it  nearly  ceased  to  lose  weight.  The  weight  of  this  extract 
multiplied  by  50  was  accepted  as  the  total  extract  contained  in  the 
500  c.c.  of  percolate. 
The  second  five  fractions  of  percolate  were  weighed,  the  differences 
taken,  and  they  were  then  added  together  and  made  up  to  500  c.c, 
as  before,  and  then  25  c.c.  of  36  per  cent,  acetic  acid  having  been 
added,  the  525  c.c.  was  used  to  moisten  the  second  portion  of  500 
grammes  of  fine  U.S.P.  powder.  This  was  then  digested,  packed 
and  percolated  as  the  first  portion,  and  the  fractions  of  weak  perco- 
late from  the  first  portion  first,  and  fresh  menstruum  afterwards, 
were  poured  on  top  until  the  exhaustion  was  complete,  as  judged 
by  the  weight  and  taste  of  the  fractions.  The  fractions  of  this 
second  portion  were  managed  exactly  as  those  from  the  first  portion, 
and  10  c.c.  of  the  500  evaporated  to  dryness  for  proportion  of  extract 
in  the  same  way,  and  the  capsule  and  extract  were  reserved  for  assay. 
The  second  five  fractions  of  the  second  portion  were  put  together, 
