Am  Jour. Pharm.  1 
February,  1896  / 
The  Assay  of  Cinchona  Bark, 
81 
The  time  required  for  the  execution  of  the  several  processes  varied 
from  six  to  twenty-four  hours,  unless  stubborn  emulsions  were  en- 
countered, as  is  not  infrequently  the  case  with  several  of  the  above 
processes. 
The  introduction  of  Prollius'  method  marks  a  new  era  in  drug 
assaying.  This  method  contains  the  germ  from  which  have  sprung 
nearly  all  of  the  most  valuable  methods  of  recent  date.  Prollius 
proposed  to  employ  an  ethereal  solvent  for  estimating  the  ether- 
soluble  alkaloids,  and  a  chloroformic  mixture  for  extracting  the  total 
cinchona  alkaloids.  It  was  originally  designed  for  determining  the 
alkaloidal  value  of  cinchona  bark,  but  the  various  modifications  pro- 
posed now  make  it  possible  to  apply  the  process  to  a  large  number 
of  narcotic  drugs  and  their  preparations.  At  first,  it  was  deemed 
essential  to  macerate  the  drug  twenty-four  hours,  but  experiments 
have  proven  that  four  hours,  with  a  fine  powder,  is  ample  time.  In 
this  work,  maceration  for  all  methods,  with  the  bark,  was  continued 
about  four  hours,  with  repeated  agitation. 
The  fluid  extracts  were  prepared  as  follows :  Fluid  extract  No.  I: 
ioo  grammes  of  the  drug  were  macerated  three  days  with  a  men. 
struum  composed  of  alcohol  two  parts,  glycerin  and  water  each  one 
part ;  the  percolation  was  then  allowed  to  proceed,  gradually 
adding  of  the  above  mixture,  until  150  c.c.  of  the  percolate 
were  obtained.  Fluid  extract  No.  II  was  prepared  in  the  same  way 
as  the  above,  except  that  the  U.  S.  P.  menstruum  was  employed. 
Fluid  extract  cinchona  calisaya  was  prepared  on  a  large  scale.  The 
fluid  extracts  were  prepared  from  the  respective  barks  assayed 
below. 
With  the  processes  involving  the  extraction  of  the  alkaloids  by 
means  of  immiscible  solvents,  the  fluid  extracts  were  diluted  with 
an  equal  weight  oi  water,  then  treated  directly  with  the  solvents  for 
one  hour,  with  frequent  agitation,  and  an  aliquot  part  taken  for 
analysis.  Fluid  extracts  Nos.  land  II  were  only  two-thirds  normal 
strength,  but  the  percent,  of  the  alkaloids  is  based  on  a  normal 
extract.  Under  these  conditions  the  following  results  were  ob- 
tained : 
The  results  on  the  following  page  indicate  that  the  methods  which 
evaporate  an  aliquot  part  of  the  extractive  solvent,  then  extract  the 
partly  dried  residue  with  dilute  sulphuric  acid,  and  subsequently  shake 
out  the  alkaloids,  do  not  yield  the  full  amount  of  the  active  constitu- 
