Am.  Jowr.  Pharm.  ( 
July,  1882.  I 
Separation  of  Ether, 
355 
SEPAKATION  OF  ETHER. 
By  C.  J.  H.  Warden. 
In  separating  quinine  and  amorphous  alkaloids  from  the  mixed  cin- 
•chona  alkaloids  by  agitation  with  ether,  the  subsequent  removal  of  the 
-ethereal  layer  from  undissolved  alkaloid  and  from  the  aqueous  stratum 
is  an  operation  of  some  little  difficulty.  If  the  ether  be  decanted  oflP, 
or  taken  up  by  a  pipette,  small  quantities  of  solid  matter,  as  well  as 
watery  fluid,  are  also  likely  to  be  removed,  while  the  ordinary  sepa- 
rating funnels  do  not  facilitate  the  operation.  To  obviate  these  diffi- 
'Culties  the  following  apparatus  was  devised.  The  apparatus  is  essen- 
tially a  filtering  syphon,  and  consists  of  a  syphon-shaped  tube  of  thick 
glass,  of  small  bore,  on  the  shorter  limb  of  which  a  small  funnel  has 
iDeen  blown,  which  is  provided  with  a  narrow  projecting  lip,  and  with 
a  ground  flat  rim,  while  the  other  end  of  the  larger  limb  is  drawn  out. 
The  shorter  limb  is  mounted  on  a  cork,  in  which  there  is  a  second  ap- 
erture, which  carries  a  small  bent  tube.  The  cork  fits  the  bottle  in 
which  the  operation  of  agitation  with  ether  has  been  conducted,  and 
which  should  be  long  and  narrow.  To  use  the  apparatus  the  funnel  is 
lightly  stuffed  with  a  few  fragments  of  cotton  wool,  and  a  piece  of  fil- 
ter paper  tied  over  the  mouth,  the  flange  preventing  it  from  slipping, 
aad  the  superfluous  paper  is  cut  off  short.  The  funnel  is  then  intro- 
duced a  short  distance  below  the  surface  of  the  ether,  and  the  cork 
fixed.  The  apparatus  has  now  somewhat  the  appearance  of  a  wash- 
bottle,  save  that  the  tube  from  which  the  liquid  escapes  is  three  or  four 
times  the  length  of  the  tube  which  is  immersed  in  the  liquid.  On 
gently  blowing  through  the  open  end  of  the  small  tube — which  may 
conveniently  have  a  piece  of  india  rubber  tubing  attached — the  ether 
is  forced  through  the  filter  and  fills  both  limbs  of  the  syphon,  and  then 
continues  to  flow  automatically  into  a  reservoir  placed  for  its  reception. 
As  the  ethereal  stratum  diminishes,  thej  tube  carrying  the  funnel  is 
•depressed  until  its  flat  surface  is  within  a^  line  or  so  from  the  surface  of 
the  aqueous  layer,  and  is  engaged  in  the  precipitate.  When  this 
■occurs,  air  has  again  to  be  blown  through  the  small  tube,  and  this  is  con- 
tinued until  drops  of  ether  escape  only  at  long  intervals.  The  cork 
carrying  the  tubes  is  then  removed,  fresh  ether  poured  into  the  bottle, 
agitated,  and  the  series  of  operations  described  above  again  performed  ; 
and  this  may  have  to  be  re[)eated  a  third  time.  When  it  is  judged 
the  precipitate  has  been  exhausted  of  principles  soluble  in  ether,  the 
syphon  is  removed,  and  any  particles  adherent  to  the  base  or  sides  of 
