Am.  Jour.  Pharm.") 
January,  1902.  ) 
Cinchona  Bark. 
27 
(3)  Cool  and  filter  into  a  separatory  funnel  of  the  required  size, 
through  a  small  plug  of  cotton,  previously  arranged  as  to  its  filter, 
ing  capacity,  into  the  stem  of  the  funnel.  Wash  funnel  and  cotton- 
plug  with  "  aether,"  as  long  as  a  control  proof  with  an  alkaloid 
group  reagent  (Mayers  or  Wagner's)  shows  the  necessity  for  it.  It 
is  economical  to  have  a  small-sized  "  Erlenmeyer "  arranged  as 
washbottle. 
(4)  Shake  the  ethereal  fluid  once  with  10  (ten)  c.c.  of  10  (ten) 
per  cent.  HC1.  Separate  this  into  another  separatory  funnel  and 
repeat  this  operation,  gradually  taking  smaller  quantities  and  less 
strong  acid,  as  long  as  is  necessary  to  exhaust  the  aethereal  fluid. 
Verify  this  as  usual. 
(5)  Save  the  ethylic  aether,  to  be  recovered  by  distillation. 
(6)  Add  about  50  (fifty)  c.c.  fresh  ethylic  aether  to  the  aqueous 
acid  solution  of  the  alkaloids  contained  in  the  second  sep- 
aratory funnel.  (This  quantity  will,  in  nine  cases  out  of  ten, 
redissolve  all  the  alkaloids  eventually  to  be  set  free.  But  it  is 
well  to  bear  in  mind  that  cinchonine  is  not  very  soluble  in  ethyl- 
aether.) 
Make  alkaline  with  the  required  amount  of  a  10  (ten)  per  cent. 
NaOH  solution.  Verify  alkalinity  by  a  (small)  piece  of  red  or 
neutral  litmus  paper.  Keep  this  small  piece  of  litmus  paper  in  the 
fluid.  Rotate  until  the  ethyl-aether  is  clear.  Don't  shake.  Allow 
the  different  fluids  to  separate.  Tap  off  the  aqueous  layer  into 
another  separatory  funnel  and  wash  the  aether  with  small  quanti- 
ties (2-5  c.c.)  distilled  water,  as  long  as  this  is  alkaline  to  (red) 
litmus  (paper).  Repeat  the  shaking  out  of  the  alkaline  fluid,  with 
25  c.c.  fresh  aether;  add  this  to  the  previously  collected. 
This  second  exhaustion  yielded  me  an  increase  of  0-022  gramme 
on  0-152  gramme  obtained  by  the  first  agitation — over  12-5  per 
cent,  of  the  total  amount  alkaloid. 
Tap  off  now  the  ethereal  fluids  into  a  tared  Erlenmeyer  (of  Jena 
glass  and  of  such  size  as  will  be  necessary  for  the  amount  of  ether 
used  in  S  6,  previously  fitted  with  a  good  cork  and  distilling  tube) 
distil  the  aether  from  a  safety  waterbath,  of  which  the  temperature 
must  not  exceed  500  C.  (the  author  lays  stress  upon  the  fact  that 
the  aether  will  "  bump  "  sometimes,  for  which  there  is  no  necessity) 
or  on  an  iron  plate,  warmed  by  an  electric  current,  or  submerge 
the  tared  Erlenmeyer  into  water  previously  heated  to  about  40  to 
