310  Acetic  Acid  in  Extracting  Drugs.  { 
ASSAYS  OF  CINCHONA  PERCOLATES. 
500  gm. 
Portions. 
500  c.c. 
Percolates. 
U.S.P.  Menstruum, 
800  c.c.  Alcohol,  91  p.  c. 
200  c.c.  Glycerin,  95  " 
Acetic  Acid 
Menstruum, 
10  p.  c.  Acetic  Acid. 
Weight 
Gm. 
Differ- 
Gm. 
Total 
Alkciloicls 
Gm. 
Weight 
Gm. 
Differ- 
Gm. 
Total 
Alkaloids 
Gm. 
1st  portion 
1st  500  c.c. 
487-9 
32-0 
I2T 
534'o 
268 
7*5 
2d 
1st   "  " 
495  8 
39'8 
12-7 
537'5 
30-3 
"*? 
3d  " 
1st   "  " 
499-8 
44'5 
I9-5 
537-8 
30-1 
14-9 
2d    «  '«■ 
475*1 
19-9 
9'4 
5I9'3 
n-6 
9*5 
3d    "  " 
468-2 
13-0 
4'3 
5H'9 
4*2 
6-9 
4th  "  " 
460-2 
5-o 
27 
5107 
3'o 
5'9 
459*8 
4*5 
2'5 
510*2 
2"5 
3-8 
6th  •«  " 
4577 
2*4 
.7 
509-6 
i'9 
3'5 
7th  "  " 
456-2 
i-o 
i-6 
509*1 
1  '4 
3'° 
8th  "  " 
i'i 
Vi 
9th  "  " 
07 
o-8 
68-3 
68-8 
1500  gm.  Cin- 
choua  of 
4'9  P-  c 
=  73'5 
73*5 
In  summarizing  the  results  of  this  work  the  following  con- 
clusions are  reached  and  adopted  : 
That  10  per  cent,  acetic  acid  is  a  good  menstruum  for  the 
exhaustion  of  cinchona. 
That  the  U.S.P.  menstruum  is  a  better  one  for  rapid  exhaustion, 
but  the  percolates  are  so  loaded  with  useless  and  objectionable 
organic  matters,  from  which  the  acetic  acid  percolates  are  compara- 
tively free,  that  this  difference  in  the  character  of  the  results  trans- 
fers the  advantages  to  the  acetic  acid  side.  The  stronger  percolates 
from  the  alcohol  and  glycerin  menstruum  are  almost  syrupy  in  con- 
sistence, are  so  black  as  to  be  almost  intransparent,  are  very  astrin- 
gent, and  throw  down  an  unmanageable  precipitate  of  nearly  insol- 
uble cincho-tannates  on  dilution  or  admixture  with  other  prepara- 
tions or  any  ordinary  diluents.  These  disadvantages  are  of  so 
serious  a  character  as  to  have  always  obstructed  the  use  of  the  offi- 
cinal fluid  extract  and  extract. 
The  acetic  acid  stronger  percolates  are  nearly  free  from  these  dis- 
advantages, and  are  far  more  manageable  pharmaceutical^  as  well 
as  therapeutically.    It  is  hardly  within  the  range  of  possibility  that 
