306  Acetic  Acid  in  Extracting  Drugs.  {A^'!^;xm^m' 
given  to  it  for  many  years  past  in  papers  published  from  time  to 
time  in  the  Proceedings  of  The  American  Pharmacetitical  Association} 
A  fair  grade  of  yellow  cinchona  was  taken  which,  when  carefully 
assayed  by  the  process  to  be  given  in  detail  farther  on,  yielded  4-9 
per  cent,  of  total  alkaloids,  of  which  2-7  per  cent,  belonged  to  the 
quinine  group.  This  was  carefully  ground,  one  portion  into  a  No. 
9  powder  and  another  portion  to  a  No.  60  powder.  Repercolation 
was  used  in  exactly  the  same  way  as  with  nux  vomica  in  the  first 
paper. 
For  the  U.S.P.  No.  60  powder  the  U.S.P.  menstruum  of  a 
mixture  of  eight  volumes  of  alcohol  (91  percent.)  and  two  volumes 
of  glycerin  (95  per  cent.)  was  used.  For  the  No.  9  powder  a  10  per 
cent,  acetic  acid  was  used.  A  third  single  percolation  was  made  of 
the  No.  60  powder  with  10  per  cent,  acetic  acid  to  determine  the 
difference  in  rate  and  degree  of  exhaustion  between  fine  and  coarse 
powder  with  a  10  per  cent,  acetic  acid  menstruum.  The  U.S.P. 
menstruum  was  adopted,  first  because  it  is  the  officinal  menstruum, 
and  next  because  it  is  pharmaceutical^  the  best  menstruum  for 
extracting  and  holding  the  active  principles  in  concentrated  prepa- 
rations. But  therapeutically  these  preparations  are  objectionable 
because  they  are  overloaded  with  inert  extractive  matter,  and  on 
dilution  either  before  or  after  administration  deposit  copious  insolu- 
ble precipitates.  The  percolations  were  managed  exactly  as  were 
those  with  nux  vomica.  Each  100  c.c.  fraction  as  it  came  off  was 
weighed,  and  the  weight  of  the  same  measure  of  menstruum  being 
subtracted,  the  difference  was  noted  to  indicate  the  rate  and  degree 
of  exhaustion  and  these  differences  are  shown  in  the  following 
table: 
Each  portion  consisted  of  500  grammes  of  cinchona.  The  first 
and  fourth  portions  are  single  percolations  with  acetic  acid,  the 
only  difference  being  in  the  fineness  of  powder,  and  these  are  com- 
pared in  the  fourth  pair  of  columns.  After  the  fifth  fraction  of  the 
first  portion  the  successive  fractions  were  used  to  moisten  and  perco- 
late the  second  portion  of  500  grammes,  and  after  the  fifth  fraction 
of  the  second  portion  the  successive  fractions  of  weak  percolate  were 
'See  Proceedings  for  1865,  p.  214. — 1867,  p.  391. — 1870,  p.  161.— 1878,  p. 
715. — Amer.  Journ.  Pharm.,  Vol.  XXXIX,  pp.  398,  408. — Ephemeris,  Vol.  I„ 
pp.  76,  105,  146,  174.— Vol.  Ill,  p.  993. 
