Am.  Jour.  Pharm.  ) 
July,  =878.  / 
Fluid  Extracts, 
33 1 
Determination  of  the  Dry  Extract. — The  amount  of  dry  extract  was 
determined  by  the  following  method  :  From  the  first  to  the  tenth  per- 
colate 1  gram  was  weighed  on  a  carefully  tared  watch-glass  and  evap- 
orated on  a  steam  bath  until  it  no  longer  lost  weight.  After  subtract- 
ing the  weight  of  the  watch-glass  the  residue  multiplied  by  25  gave  the 
total  amount  of  dry  extract  in  the  25  grams  of  percolate.  From  the 
eleventh  to  the  twentieth  percolate  5  grams  was  taken  and  the  residue 
multiplied  by  five  ;  of  the  500  grams  dilute  percolate  10  grams  was 
taken  and  the  residue  multiplied  by  fifty.  By  slow  percolation  it 
appears  to  be  possible  to  get  about  75  per  cent,  of  the  dry  extract  in 
the  first  75  parts  of  percolate,  whether  previously  macerated  or  not, 
and  practical  exhaustion  is  arrived  at  when  the  total  percolates  amount 
to  times  the  weight  of  the  drug,  these  containing  nearly  98  per 
cent,  of  the  total  dry  extract  yielded.  The  percolation  might  even  be 
stopped  when  percolate  equaling  i\  times  the  weight  of  the  drug  is 
obtained,  as  that  would  contain  nearly  95  per  cent,  of  the  total  extract. 
The  third  experiment,  particularly,  with  seneca  was  quite  a  disap- 
pointment. By  a  preformed  opinion,  I  expected  to  get  such  results 
from  remaceration  in  facility  of  exhaustion  and  economy  of  menstruum 
as  would  quite  overbalance  the  value  of  the  greater  length  of  time 
required  for  the  process. 
Weight  of  Dry  Extract  in  each  25  grams  of  Percolate. 
100  grams 
of  drug 
used  in 
each  ex- 
periment. 
No. 
Name. 
ISt. 
2d. 
3d. 
4th. 
5th. 
6th. 
7th. 
8th. 
9th. 
10th. 
nth. 
I2th. 
Senna 
7-25 
6*50 
6*50 
6*25 
3*75 
2'00 
'75 
•40 
•25 
•15 
•14 
•IO 
2 
tt 
1075 
9*00 
5^5 
3"25 
2  18 
I'lO 
•70 
"55 
•44 
•38 
•30 
'22 
3 
4 
it 
a 
1075 
9-54 
5  92 
3  00 
1*29 
I  'OO 
'75 
•50 
'44 
•38 
"*5 
•37 
Seneka 
10*50 
825 
7'oo 
3**5 
1  50 
1  -oo 
•63 
50 
•38 
•40 
•30 
2 
<< 
10  50 
925 
6*00 
4-25 
3-25 
2*25 
1  50 
I  25 
I'OO 
'5° 
•46 
•50 
3 
4 
it 
tt 
9*oo 
8-50 
yoo 
5'75 
3'oo 
2-50 
I-75 
•88 
'So 
"5° 
•38 
'44 
